ma ine d ugs
Re iew
Halophiles and Thei Biomolecules: Recen Ad ances
and Fu u e Applica ions in Biomedicine
Paulina Co al 1,2 , Mohammad A. Amoozega 3and An onio Ven osa 2,*
1Depa men o Biology, Uni e si y o Naples Fede ico II, 80126 Naples, I aly; [email p o ec ed]
2Depa men o Mic obiology and Pa asi ology, Facul y o Pha macy, Uni e si y o Se illa,
41012 Se illa, Spain
3Depa men o Mic obiology, School o Biology, College o Science, Uni e si y o Teh an,
Teh an 14155-6955, I an; [email p o ec ed]
*Co espondence: [email p o ec ed]; Tel.: +34-954556765
Recei ed: 30 No embe 2019; Accep ed: 28 Decembe 2019; Published: 30 Decembe 2019


Abs ac :
The o ganisms h i ing unde ex eme condi ions be e han any o he o ganism li ing on
Ea h, ascina e by hei hos ile g owing pa ame e s, physiological ea u es, and hei p oduc ion o
aluable bioac i e me aboli es. This is he case o mic oo ganisms (bac e ia, a chaea, and ungi) ha
g ow op imally a high salini ies and a e able o p oduce biomolecules o pha maceu ical in e es o
he apeu ic applica ions. As along as he mic obio a is being app oached by massi e sequencing,
no el insigh s a e e ealing he en i onmen al condi ions on which he compounds a e p oduced in
he mic obial communi y wi hou mo e s ess han sha ing he same subs a um wi h hei pee s, he
sal . In his e iew a e epo ed he molecules desc ibed and p oduced by halophilic mic oo ganisms
wi h a spec um o ac ion
in i o
: an imic obial and an icance . The ac ion mechanisms o hese
molecules, he u gen need o in oduce al e na i e lead compounds and he cu en aspec s on he
exploi a ion and i s limi a ions a e discussed.
Keywo ds:
halophilic bac e ia; a chaea and ungi; biomolecules; biomedicine; an imic obial
compounds; an icance compounds
1. Halophilic Mic oo ganisms
Halophiles a e o ganisms ep esen ed by a chaea, bac e ia, and euka ya o which he main
cha ac e is ic is hei salini y equi emen , halophilic “sal -lo ing”. Halophilic mic oo ganisms
cons i u e he na u al mic obial communi ies o hype saline ecosys ems, which a e widely dis ibu ed
a ound he wo ld [
1
]. They equi e sodium ions o hei g ow h and me abolism. Thus, based on
he NaCl op imal equi emen o g ow h he halophiles a e classi ied in h ee di e en ca ego ies:
sligh (1–3%); mode a e (3–15%); and ex eme (15–30%) [
2
,
3
]. In con as o halo ole an o ganisms,
obliga e halophiles equi e NaCl concen a ions highe han 3% NaCl o abo e o seawa e , wi h abou
3.5% NaCl [
4
]. The ole ance pa ame e s and sal equi emen s a e dependen on empe a u e, pH,
and g ow h medium. In his way, he halophiles a e adap ed and limi ed by speci ic en i onmen al
ac o s. Those mic oo ganisms able o su i e and op imally h i e unde a wide spec um o ex eme
en i onmen al ac o s a e designed polyex emophiles [
5
,
6
]. In ac , a halophilic mic oo ganism can
also be alkaliphile, designa ed as haloalkaliphile, g owing op imally o e y well a pH alues abo e
9.0, bu canno g ow a he nea neu al pH alue o 6.5 [7].
The gene al ea u es o halophilic mic oo ganisms a e he low nu i ional equi emen s and esis ance
o high concen a ions o sal wi h he capaci y o balance he osmo ic p essu e o he en i onmen [
8
].
Thei mechanisms o haloadap a ion a e based on he in acellula s o age o KCl o e 37% (5 M) (sal -in
s a egy) o he accumula ion o compa ible solu es (sal -ou s a egy) o keep he balance o sodium in o he
Ma . D ugs 2020,18, 33; doi:10.3390/md18010033 www.mdpi.com/jou nal/ma ined ugs
Ma . D ugs 2020,18, 33 2 o 33
cy oplasm and coun e ac he osmo ic p essu e o he ex e nal en i onmen gi en by he high salini y [
9
].
They a e physiologically di e se; mos ly ae obic and as well anae obic, he e o ophic, pho o ophic,
and chemoau o ophic [
10
,
11
]. Ecologically, he halophilic mic oo ganisms inhabi di e en ecosys ems
cha ac e ized by a salini y highe han seawa e , i.e., 3.5% NaCl, hese niches go om hype saline soils,
sp ings, sal lakes, sabkhas, and o he na u ally-occu ing coas al saline habi a s, ma shes, ma ine abyssal
sedimen s o endophy es [
12
]. O he known habi a s a e he esul o human in e en ion like sal ed oods,
b ines, oil ields, sal e n ponds and anne ies [
13
]. The high salini y educes he numbe o o ganisms
whe e jus halophilic o halo ole an ones can su i e in such hype saline ecosys em, wi h a chaea
ypically domina ing he highe salini y en i onmen s. The p edominan na u al habi a s be e s udied
a e he hype saline lakes o oceanic ( halassohaline) o non-oceanic (a halassohaline) o igin and sola
sal e ns [
14
–
16
]. The be e known hype saline en i onmen s a e he G ea Sal Lake and he Dead Sea,
wi h pH alues a ound 7, and soda lakes wi h highly alkaline alues o pH 9–11, among hem a e he
Lake Magadi in Kenya, he Wadi Na un lakes in Egyp , Mono Lake, Big Soda Lake, Soap Lake in Wes e n
USA, and Kulunda S eppe soda lakes in Russia [
17
]. Many new species o bac e ia and a chaea ha e
been epo ed om a ious hype saline egions loca ed in di e en coun ies, mainly China, Spain, USA,
Aus ia, Aus alia, Egyp , Ko ea, Japan, I an, Thailand, Indonesia, Russia, A gen ina, Kenya, Mexico,
F ance, Poland, Philippines, Taiwan, Romania, and India [
10
,
18
,
19
]. The as majo i y o halophilic
bac e ia and a chaea p oduce ca o enoid pigmen s, p esen in high amoun in hei memb anes. The
dense communi y o halophiles and he algae Dunaliella, also p oduce o ca o enoids, a e he esponsible
o he ypical pink, ed, and pu ple colo a ion o he hype saline en i onmen s [20].
2. Bio echnological Impo ance/In e es o Haloa chaea and Halophilic Bac e ia
The exploi a ion o ex emophiles is ha ing special impo ance in he de elopmen o new molecules
wi h po en ial applica ions in biomedicine. Cu en e o s a e ocused p ima ily o co e he u gen
heal h needs, especially hose ha ep esen he main global h ea s, cance and an ibio ic esis ance. The
g ea me abolic e sa ili y o halophilic mic oo ganisms, hei low nu i ional equi emen s and hei
gene ic machine ies o adap a ion o ha sh condi ions, like nu ien s a a ion, desicca ion, high sun
adia ion, and high ionic s eng h, make hem p omising candida es and a hope o d ug disco e y [
21
].
Con inuous ad ances in “omics” and bioin o ma ic ools a e e ealing uncoun able encoding genes o
he p oduc ion o se e al ac i e compound in esponse o he ex eme condi ions [
22
,
23
]. The concomi an
applica ion o cu ing-edge echnologies is helping o deciphe ing he molecula , physiological, and
me abolic mechanisms o he p oduc ion o new bioac i e compounds [24].
Halophilic mic oo ganisms a e ecognized p oduce s o ca o enoid pigmen s, e inal p o eins,
hyd oly ic enzymes, and compa ible solu es as mac omolecules s abilize s, biopolyme s, and
bio e ilize s [
19
,
25
]. Halophilic bac e ia and ex emely halophilic ae obic a chaea, also known as
haloa chaea, play a signi ican ole in he indus y wi h a la ge numbe o applica ions like e men ed
ood p oduc s, cosme ics, p ese a i es, manu ac u ing o bioplas ics, pho oelec ic de ices, a i icial
e inas, holog ams, biosenso s, e c. [26–31].
In his e iew, we ocus on he biomolecules desc ibed as an imic obial o an icance compounds
p oduced by halophilic bac e ia, a chaea, o ungi and discuss cu en and u u e pe spec i es in his ield.
3. An imic obial Compounds
The cu en si ua ion o an ibio ic esis ance p opaga ion poses a global h ea o public heal h.
O e he pas decades, an ibio ics ha e sa ed millions o li es, bu hei misuse has led o he
eme gence o mul i-d ug esis an bac e ia (MDR), educing o nulli ying hei e ec i eness. Recen ly,
he con inuous inc ease in an ibio ic esis ance is eaching c i ical le els, which implies an inc ease in
mo bidi y in he heal hy popula ion and an imminen isk o hospi alized pa ien s [
32
,
33
]. In ac ,
he main cause o dea h o inpa ien s a e a ibu able o complica ions due o MDR in ec ions [
34
].
P e en ing he e u n o he p e-an ibio ic e a is one o he main challenges o science. The u gen
need o in oduce new e ec i e an imic obial he apies is leading o he exploi a ion o all possible
Ma . D ugs 2020,18, 33 3 o 33
na u al and sus ainable esou ces, including ex eme en i onmen s as a p omising esou ce o new
an ibio ic disco e y.
The i s an imic obial compounds om halophilic mic oo ganisms we e epo ed in 1982 by
Rod iguez-Vale a e al. Halocin was he e m coined o subs ances sec e ed by se e al membe s o he
genus Halobac e ium capable o causing dea h and lysis o he su ounding mic obio a. Halocins a e he
p o eins and an imic obial pep ides (AMPs) p oduced by haloa chaea [
35
,
36
]. Despi e he ecological
and en i onmen al ole o se e al halocins, hei ac ion agains human pa hogens has been less s udied.
In he igh agains ime, he clinical signi icance o halophilic mic oo ganisms is mino ly
epo ed and he an imic obial ac ion agains he mos impo an isk g oup o human pa hogens
ESKAPE: En e ococcus aecium,S aphylococcus au eus,Klebsiella pneumoniae,Acine obac e baumannii, and
Pseudomonas ae uginosa, s ill emains as a po en ial.
Acco ding o he da a in e ed, he an agonis ic ac ion iden i ied and he p oduc ion o bioac i e
compounds by halophilic mic oo ganisms a e de i ed om bac e ia, a chaea, and ungi. In he
ch onology o AMPS disco e y, se e al au ho s ha e gone beyond he p ima y sc eenings deciphe ing
he chemical s uc u e o he molecules in bac e ia (Table 1), while he as majo i y o inhibi o y
s udies a e solely limi ed o he ac i i y (Table 2).
3.1. Bac e ia
Membe s o he phylum Ac inobac e ia a e mainly esponsible o he inhibi o y ac i i y agains
human pa hogens wi h clinical signi icance. As in non-ex eme en i onmen s, in saline and hype saline
en i onmen s he e o ophic bac e ia a e also p esen in soils, being Ac inobac e ia equen ly isola ed om
sola sal e ns, mang o es, and sea loo sedimen s [
37
,
38
]. The mos equen p oduce s o me aboli es
epo ed come om species o he genus Noca diopsis and S ep omyces, hence cons i u ing he main
p oduce s o bioac i e compounds. In ac , membe s o he genus S ep omyces a e widely ecognized as
ui ulp oduce so na u alcompounds[
39
]. Thechemicalelucida iono moleculesknown omhalophilic
membe s o Noca diopsis a e: (i) py olo (1,2-A (py azine-1,4-dione, hexahyd o-3-[2-me hylp opyl]-)
and Ac inomycin C2, wo compounds p oduced by he haloalkaliphilic s ain Noca diopsis sp. AJ1,
isola ed om saline soil o Ko alam sola sal e ns in India [
40
]; (ii) Angucyclines and Angucyclinones
a e p oduced by Noca diopsis sp. HR-4, isola ed om a sal lake soil in Alge ian Saha a, he new
na u al compound was es ablished as 7-deoxy-8-O-me hyl e angomycin, which is also e ec i e agains
Me hicillin-Resis an S aphylococcus au eus (MRSA) ATCC 43300 [
41
]; (iii) Bo elidin C and D a e p oduced
by Noca diopsis sp. HYJ128, isola ed om opsoil sal e n in Jeungdo, Jeollanamdo, Republic o Ko ea,
exhibi ed an imic obial ac ion agains Salmonella en e ica ATCC 14028 [
42
]; (i ) Quinoline alkaloid
(4-oxo-1,4-dihyd oquinoline-3-ca boxamide) was iden i ied as a new na u al p oduc om Noca diopsis
e ae YIM 90022 isola ed om saline soils in China. The an ibac e ial ac i i y o he quinolone was
epo ed in S. au eus,B. sub ilis and E. coli; he quinolone has also an i ungal ac i i y agains he pa hogenic
ungi, as i was obse ed agains Py icula ia o yzae. Ano he i e known compounds we e also p oduced
by N. e ae YIM 90022 [
43
]; ( ) new p- e phenyls: p- e phenyl 1 and a no el p- e phenyl de i a i e
bea ing a benzo hiazole moie y a e p oduced by halophilic ac inomyce e Noca diopsis gil a YIM 90087,
isola ed om a hype saline soil Xinjiang, China. Fu he mo e, o he an imic obial ac i i y agains clinical
s ains, hese compounds exhibi an i ungal ac i i y agains species o Fusa ium, T ichophy on, Aspe gillus,
Candida, and Py icula ia. Known molecules like p- e phenyl 2, no obiocin, cyclodipep ides, and a oma ic
acids a e also p oduced by N. gil a YIM 90087, which is conside ed as a new sou ce o no obiocin [44].
Rega ding he me aboli es p oduced by membe s o he genus S ep omyces, only a low numbe o
s ains has been isola ed om hype saline en i onmen s; howe e , membe s o his genus a e equen ly
isola ed om ma ine deep o coas al sedimen s whe e he salini y is highe han ha o seawa e .
Among he molecules iden i ied a e: (i) 1-hyd oxy-1-no esis omycin, his quinone- ela ed an ibio ic
was ex ac ed om S ep omyces chibaensis AUBN1/7, isola ed om ma ine sedimen samples o he
Bay o Bengal, India. This compound exhibi ed an ibac e ial ac i i ies agains G am-posi i e and
G am-nega i e bac e ia, besides o a po en
in i o
cy o oxic ac i i y agains cell lines HMO2 (gas ic
Ma . D ugs 2020,18, 33 4 o 33
adenoca cinoma) and HePG2 (hepa ic ca cinoma) [
45
]; (ii) Himalomycin A and Himalomycin B, wo
new an h acycline an ibio ics p oduced by S ep omyces sp. s ain B692, isola ed om sandy sedimen o
a coas al si e o Mau i ius (Indian Ocean). In addi ion, known me aboli es like abelomycin, idamycin
D, N benzylace amide, and N-(2
0
-phenyle hyl) ace amide we e also p oduced by S ep omyces sp. s ain
B692 [
46
]; (iii) 7-deme hoxy apamycin was p oduced by a mode a ely halophilic s ain S ep omyces
hyg oscopicus BDUS 49, isola ed om seasho e o Bigeum Island, Sou h Wes coas o Sou h Ko ea; he
molecule displayed a b oad spec um an imic obial ac i i y agains G am-posi i e and G am-nega i e
bac e ia. An i ungal and cy o oxic ac ion was also iden i ied on his s ain [
47
]; (i ) S ep omonomicin
(STM) is an an ibio ic lasso pep ide om S ep omonospo a alba YIM 90003, isola ed om a soil sample in
Xinjiang p o ince, China. STM is ac i e agains se e al G am-posi i e bac e ia, in pa icula species o
Bacillus, Lis e ia, En e ococcus, Mycobac e ium and S aphylococcus. Despi e ha STM has an inhibi o y
ac ion agains a wide panel o G am-posi i e pa hogens, he ac i i y agains ungi and G am-nega i e
bac e ia was no e idenced [48].
In addi ion o he men ioned gene a o Ac inobac e ia (Noca diopsis and S ep omyces), ecognized as
he mo e p oli ic p oduce s o na u al subs ances, o he halophilic species belonging o di e en gene a
ha e also been desc ibed as p oduce s o molecules like: (i) cyclic an imic obial lipopep ides: G amicidin S
and ou cyclic dipep ides (CDPs), named cyclo(l-4-OH-P o-l-Leu), cyclo(l-Ty -l-P o), cyclo(l-Phe-l-P o),
and cyclo(l-Leu-l-P o), we e ex ac ed om Paludi ilum halophilum s ain SMBg3, which cons i u e a
new genus o he amily The moac inomyce aceae, isola ed om supe icial sedimen collec ed om S ax
ma ine sola sal e n in Tunisia. These CDPs possess an inhibi o y e ec agains he plan pa hogen
Ag obac e ium ume aciens and he human pa hogens S aphylococcus au eus, Salmonella en e ica, Esche ichia coli,
and Pseudomonas ae uginosa [
49
]; (ii) A semi syn he ic de i a i e N-(4-aminocyclooc yl)-3,5-dini obenzamide,
ob ained om he p ecu so o he no el na u al p oduc cyclooc ane-1,4-diamine and a known compound
3-([1H-indol-6-yl] me hyl) hexahyd opy olo [1,2-a] py azine-1,4-dione we e ob ained om Pseudonoca dia
endophy ica VUK-10, isola ed om sedimen o Nizampa nam mang o e ecosys em in Bay o Bengal, India.
The new compound, semi syn he ic de i a i e N-(4-aminocyclooc yl)-3,5-dini obenzamide showed a s ong
an imic obial and an i ungal ac i i y agains S ep ococcus mu ans,Pseudomonas ae uginosa, Candida albicans,
and Aspe gillus nige . Signi ican an icance ac i i ies a nanomola concen a ions we e also obse ed in
ca cinoma cell lines MDA-MB-231 (b eas ), HeLa (ce ical), OAW-42 (o a ian), and MCF-7 (b eas ) epo ed
as esis an o cance d ugs [
50
]. In mino g ade, o he halophilic bac e ia no belonging o he phylum
Ac inobac e ia p oduce an imic obial compounds, as o example halophilic s ains o he genus Vib io,
like Vib io sp. A1SM3-36-8, isola ed om Colombian sola sal e ns, which p oduces 13-cis-docosenamide
wi h special an imic obial ac ion agains Me hicillin- esis an S aphylococcus au eus (MRSA) and cy o oxic
ac i i y agains ce ical adenoca cinoma (SiHa) and lung ca cinoma (A-549) [
51
]. Wi hin his genus,
Vib io pa ahaemoly icus s ain B2 is ecognized by p oducing Vib indole A, and was also e ec i e agains
S aphylococcus au eus [52].
Finally, Bacillus sp. BS3 [
53
] and Halomonas sali odinae MPM-TC [
54
] showed an imic obial ac ion
agains Pseudomonas ae uginosa. Bo h s ains we e isola ed om sola sal e ns in Thama aikulam, Tamil
Nadu, India. In he case o Halomonas sali odinae MPM-TC, besides o he inhibi ion o bac e ial g ow h
also exhibi s an an i i al ac ion agains he Whi e Spo Synd ome Vi us (WSSV) in he whi e sh imp
Fenne openaeus indicus. The e ec supp esso o he i us and he boos ing o immune sys em o he
sh imps make o he ex ac ed compound a easible al e na i e o comme cially banned an ibio ics and
excellen candida e o de elop new an i i al d ugs agains sh imp i uses such as WSSV.
A genome-mining s udy conduc ed on 2699 genomes ac oss he h ee domains o li e demons a ed
he widesp ead dis ibu ion o non- ibosomal pep ide syn he ase (NRPSs) and modula polyke ide
syn hase (PKSs) biosyn he ic pa hways. Among 31 phyla o bac e ia in e ed, Ac inobac e ia is he mos
ep esen a i e exhibi ing he p esence o 1225 gene clus e s be ween NRPS, PKS and hyb ids om a
o al o he 271 genomes s udied. I was obse ed ha Salinispo a a enicola CNS-205 and Salinispo a
opica CNB-440 ha bo PKS and NRPS gene clus e s, espec i ely. The halophilic bac e ium Halomonas
elonga a DSM 2581 also con ains NPRS [55].
Ma . D ugs 2020,18, 33 5 o 33
Table 1. Ch onological epo o halophilic bac e ia and hei molecules wi h an imic obial ac i i y in i o agains human pa hogens.
Isola ion Sou ce Genus An imic obial Ac i i y Molecule Fo mula Re e ence
Saline soil o Ko alam sola
sal e ns India Noca diopsis sp. AJ1
E. coli,
S. au eus,
P. ae uginosa,
V. pa ahaemoly icus,
A. hyd ophila
Py olo (1,2-A (py azine-1,4-dione,
hexahyd o-3-(2-me hylp opyl)-) C11H18N2O2
[40]
Ac inomycin C2 C63H88N12O16
S ax sola sal e n, Tunisia Paludi ilum halophilum
SMBg3
E. coli BW25113,
S. henoxaz ATCC43972,
P. ae uginosa ATCC 49189
G am-posi i e M. lu eus LB 14110,
S. au eus ATCC6538, and
L. i ano ii BUG 496)
Cyclic lipopep ide:
[49]
G amicidin S C60H92N12O10
Cyclic dipep ides (CDPs):
Cyclo(l-4-OH-P o-l-Leu) C11H18N2O3
Cyclo(l-Ty -l-P o) C14H16N2O3
Cyclo(l-Phe-l-P o) C14H16N2O2
Cyclo(l-Leu-l-P o) C11H18N2O2
B ine and sedimen s om
Manau e sola sal e n. La
Guaji a, Colombia
Vib io sp. A1SM3–36-8
Me hicillin- esis an
S. au eus (MRSA) ATCC BAA-44,
B. sub ilis ATCC 21556
13-cis-docosenamide C22H43NO [51]
Sal lake soil, Alge ian Saha a.
Alge ia Noca diopsis sp. HR-4
S. au eus ATCC 25923,
Me hicillin-Resis an
S. au eus (MRSA) ATCC 43300,
M. lu eus ATCC 4698,
E. aecalis ATCC 29212
Angucyclines and angucyclinones:
[41]
Compound 1:
(−)-8-O-me hyl e angomycin C20H16O5
Compound 2:
(−)-7-deoxy-8-Ome hyl e angomycin C20H18 O5
Topsoil sal e n in Jeungdo,
Jeollanam-do, Republic o
Ko ea
Noca diopsis sp. HYJ128 Salmonella en e ica ATCC 14028 Bo elidin C C28H43NO7[42]
Bo elidin D C28H43NO7
Sedimen s o mang o e
Nizampa nam, Bay o Bengal,
Andh a P adesh, India
Pseudonoca dia endophy ica
VUK-10
B. ce eus (MTCC 430),
S. mu ans (MTCC 497),
S. au eus (MTCC 3160),
S. epide mis (MTCC 120),
B. sub ilis (ATCC 6633),
B. mega e ium (NCIM 2187),
E. coli (ATCC 35218),
P. ae uginosa (ATCC 9027),
P. ulga is (MTCC 7299),
S. ma cescens (MTCC 118),
X. campes is (MTCC 2286),
X. mal acea um (NCIM 2954)
and S. yphi (ATCC 14028)
N-(4-aminocyclooc yl)-3,5-dini obenzamide
C15H20N4O5
[50]
3-((1H-indol-6-yl) me hyl)
hexahyd opy olo [1,2-a] py azine-1,4-dione C16H17N3O2

Ma . D ugs 2020,18, 33 6 o 33
Table 1. Con .
Isola ion Sou ce Genus An imic obial Ac i i y Molecule Fo mula Re e ence
Soil sample, Xinjiang P o ince,
China
S ep omonospo a alba YIM
90003
B. an h acis,
B. halodu ans,
B. ce eus ATCC 4342, ATCC 13472,
B. sub ilis,
L. monocy ogenes,
E. aecalis,
S. au eus
and M. smegma is
S ep omonomicin (STM) C107H160N22O30 [48]
G ea Ba ie Ree (GBR)
sponges, Queensland,
Aus alia
Salinispo aa enicola
M. a ium,
M. lep ae,
M. lep oma osis,
M. ube culosis
Ri amycin B C39H49NO14
[56]
Ri amycin S C37H45NO12
Ri amycin W C35H45NO11
Saline soil, Qaidam Basin,
no h-wes China
Noca diopsis e ae YIM
90022
S. au eus,
E. coli
and B. sub ilis
Quinoloid alkaloid
4-oxo-1,4-dihyd oquinoline-3-ca boxamide C10H7N2O2
[43]
p-hyd oxybenzoic acid C7H6O3
N-ace yl-an h anilic acid C9H9NO
Indole-3-ca boxylic acid C9H7NO2
Cyclo (T p-Gly) C13H13N3O2
Cyclo (Leu-Ala) C9H16N2O2
Condense wa e , sola sal
wo ks in Thama aikulam,
Kanyakuma i dis ic , Tamil
Nadu, India
Bacillus sp. BS3
E. coli,
S. au eus,
P. ae uginosa
and S. yphi
Lipopep ide biosu ac an s
[53]
13-Docosenamide, (Z)
CH
3
(CH
2
)
7
CH=CH(CH
2
)
11
CONH
2
Mannosamine C6H13NO5.HCl
9-Oc adecenamide, (Z) C18H35NO
2-Oc anol, 2-me hyl-6-me hylene C12H22O2
Cylohex-1,4,5- iol-3-one-1-ca bo C5H8FN3
2-Bu anamine, 2-me hyl- C5H13N
1,2-E hanediamine, N,N,N0,N0- e ame hyl- C6H16N2
Hype saline soil, Xinjiang,
China
Noca diopsis gil a YIM
90087
B. sub ilis,
S. au eus
p-Te phenyl:
6
0
-Hyd oxy-4,2
0
,3
0
,4
00
- e ame hoxy-p- e phenyl
C22H22O5
[44]
p-Te phenyl de i a i e:
4,7-bis(4-me hoxyphenyl)-6-hyd oxy-
5-me hoxybenzo[d] hiazole
C22H19NO4S
Ma . D ugs 2020,18, 33 7 o 33
Table 1. Con .
Isola ion Sou ce Genus An imic obial Ac i i y Molecule Fo mula Re e ence
Sola sal condense ,
Thama aikulam sola sal e n,
Kanyakuma i dis ic , Tamil
Nadu, India
Halomonas sali odinae
MPM-TC
V. ha eyi,
V. pa ahaemoly icus,
P. ae uginosa
and A. hyd ophila
Pe luo o ibu ylamine C12F27N
[54]
Cyclopen ane, 1-bu yl-2-e hyl- C11H22
1,10-Biphenyl]-3-amine C12H11N
Py idine, 4-(phenylme hyl)- C12H11N
Hexadecane, 2-me hyl- C17H36
Nonadecane C19H40
Phy ol C20H40O
Seasho e soil, Bigeum Island,
Sou h Wes coas o Sou h
Ko ea
S ep omyces hyg oscopicus
BDUS 49
B. sub ilis,
S. au eus,
E. coli,
S. yphi
7-Deme hoxy apamycin C50H75NO12 [47]
Ma ine sedimen o Mission
Bay, San Diego, Sou h
Cali o nia
Ma inispo a sp. NPS12745
S. au eus ATCC 29213-MSSA,
S. au eus ATCC 43300-MRSA,
S. epide midis ATCC 700578,
S. epide midis ATCC 700582,
S. pneumoniae ATCC 49619-Penicillin
sensi i e,
S. pneumoniae ATCC 51915-Penicillin
esis an ,
E. aecalis ATCC 29212-Vancomycin sensi i e,
E. aecium ATCC 700221-Vancomycin
esis an ,
Haemophilus in luenzae ATCC 49247,
Haemophilus in luenzae ATCC 49766
E. coli pe meable mu an
Chlo ina ed bisindole pi oles:
[57]
Lynamicin A C22H16N3O2Cl2
Lynamicin B C22H14N3O2Cl3Na
Lynamicin C C20H12N3Cl4
Lynamicin D C24H18N3O4Cl2
Lynamicin E C24H19N3O4Cl
Pla inum Coas on he
Medi e anean Sea, no h o
Egyp
S ep omyces sp. Me 8102
E. coli ATCC 10536,
P. ae uginosa ATCC 10145),
B. sub ilis ATCC 6051,
S. au eus ATCC 6538
and M. lu eus ATCC 9341
Ess amycin
T iazolopy imidine
[1,2,4] T iazolo[1,5-a]py imidin-7(4H)-one,
5-me hyl-2-(2-oxo-2-phenyle hyl)-
C14H12N4O2[58]
Ma ine sedimen , La Jolla,
Cali o nia S ep omyces sp. CNQ-418 Me hicillin- esis an S. au eus (MRSA) Ma inopy oles A C22H12Cl4N2O4[59]
Ma inopy oles B C22H11B Cl4N2O4
Ma . D ugs 2020,18, 33 8 o 33
Table 1. Con .
Isola ion Sou ce Genus An imic obial Ac i i y Molecule Fo mula Re e ence
Sedimen o Bay o Bengal,
India
S ep omyces chibaensis sp.
AUBN1/7
B. sub ilis ATCC 6633,
B. pumilus ATCC 19164,
S. au eus ATCC 29213,
E. coli ATCC 25922,
P. ae uginosa ATCC 27853
P. ulga is ATCC 6897
1-Hyd oxy-1-no esis omycin C21H14O7[45]
Sedimen o he Lagoon de
Te minos a he Gul o Mexico
S ep omyces
B8005S ep omyces B4842
E. coli,
S. au eus,
S. i idoch omogenes
Resis omycin
1-Hyd oxy-1-no esis omycin C21H14O7
[60]
Resis o la in
Resis o la in me hyl e he C23H18O7
Ma ine sedimen om Sc ipps
Canyon. La Jolla, Cali o nia,
Paci ic Coas , Uni ed S a es
S ep omyces nodosus
NPS007994
D ug-sensi i e and d ug- esis an
G am-posi i e eac ion bac e ia
Lajollamycin
Ni o- e aene Spi o-β-lac one-γ-lac am C36H53N3O10 [61]
Sedimen o Jiaozhou Bay,
China Ac inomadu a sp. M048
S. au eus,
B. sub ilis,
and S. i idoch omogenes
Chand ananimycin A
Ace amide,
N-(9-hyd oxy-3-oxo-3H-phenoxazin-2-yl)-
C14H10N2O4
[62]
Chand ananimycin B
Ace amide,
2-hyd oxy-N-(3-oxo-3H-phenoxazin-2-yl)-
C14H10N2O4
Chand ananimycin C
1-Me hoxy-3-me hyl-1,2,3,4- e ahyd o-5H-py ido[3,2
a]phenoxazin-5-one
C17H16N2O3
Sandy sedimen , coas al si e o
Mau i ius, Indian Ocean S ep omyces sp. B6921
S. au eus,
E. coli,
B. sub ilis,
and S. i idoch omogenes
F idamycin D C31H32O12
[46]
Himalomycin A C43H52O16
Himalomycin B C43H56O16
Mucus sec e ed by he box-
ish Os acion cubicus, Is ael Vib io pa ahaemoly icus B2
S. au eus,
S. albus
and B. sub ilis
Vib indole A C18H16N2[52]
Ma . D ugs 2020,18, 33 9 o 33
Table 2. Ch onological epo o bac e ia wi h an imic obial ac i i y in i o agains human pa hogens which molecules ha e no been chemically iden i ied.
Isola ion Sou ce Genus An imic obial Ac i i y Re e ence
Khew a Sal Range, Punjab, Pakis an
Aquisalibacillus elonga us MB592,
Salinicoccus sesu ii MB597,
and Halomonas aquama ina MB598
B. sub ilis,
B. pumilus,
E. aecalis,
B. ce eus,
K. pneumoniae,
Alcaligenes aecalis,
P. genicula a,
E. aecium
[63]
Hype saline soils (solonchaks, solone z and aky ) om
Kos anay, Auliekol and Mendyka a. Alma y egion, Balkhash,
Kazakhs an
Ac inomyce es spp. S. au eus MRSA,
E. coli (pMG223) [64]
Ma ine wa e , Guja a , Wes e n India Kocu ia sp. s ain sk4 An ibio ic- esis an S. au eus [65]
C ys allize pond sedimen s o Ribanda sal e n, Goa, India
S ep omyces adiopugnans
S. yphimu ium,
P. ulga is,
E. coli
[66]
S ep omyces spo ocine eus S. yphimu ium,P. ulga is,E. coli
Kocu ia palus is S. au eus
Mic omonospo a sp. V. chole ae
Noca diopsis sp. S. ci eus
Coas al Sola Sal e n, India Nonomu aea sp. JAJ18
Me hicillin-Resis an S. au eus (MRSA),
B. sub ilis MTCC 441,
K. pneumonia MTCC 109,
S. yphi MTCC 733,
and P. ulga is MTCC 426
[67]
Sedimen o es ua ine coas al b ackish, Chilika Lake, Khu dha
Odisha, India S ep omyces chilikensis RC 1830
E. coli,
S. au eus,
B. ce eus
and S. yphi
[67]
Mang o e sedimen o Visakhapa nam, Andh a P adesh, India S ep omyces sp.
S. au eus,
B. sub ilis,
B. ce eus,
E. coli,
P. ae uginosa,
P. ulga is
[68]
Mang o e sedimen , Nizampa nam, Andh a P adesh, India Pseudonoca dia VUK-10
S. au eus,
S. mu ans,
B. sub ilis,
E. coli,
E. aecalis,
P. ae uginosa
[69]
Ma . D ugs 2020,18, 33 16 o 33
4. An icance Compounds
Na u al p oduc s a e ele an an icance d ugs, which a e also called bioac i e molecules,
p oduced by o ganisms. Al hough, ea lie and he well-es ablished an icance na u al p oduc s ha e
been ob ained om plan cells o iginally, mic oo ganisms a e an excellen al e na i e, due o he
di e si y o he mic obial wo ld, hei easy manipula ion, and hey can be sc eened physiologically
o disco e new na u al p oduc s wi h an i umo ac i i y. Al hough bac e ial cells ha e di e en
communica ion me hods wi h umo cells o he han me aboli es expe imen ally, bac e ial me aboli es
ha e been conside ed he mos con en ional way agains cance cells iabili y. Today, mo e a en ion is
ocused on ex emophiles as a new sou ce o no el biomolecules [
104
,
105
]. Among ex emophiles,
halophilic and halo ole an mic oo ganisms, which inhabi hype saline en i onmen s, a e conside ed
as eliable sou ces o an i umo me aboli es wi h ewe side e ec s. In ecen yea s, se e al s udies ha e
been ocused on he impo ance o me aboli es om halophilic mic oo ganisms on cance ea men .
The halophilic bac e ia, a chaea, and ungi in ol ed on he p oduc ion o an i-cance biomolecules a e
summa ized in Table 4.
4.1. Bac e ia
Since he las wo decades, halophilic bac e ia ha e a ac ed he in e es s o esea che s due o
hei adap abili y o a wide ange o salini ies. Some s udies ha e been ca ied ou o de e mine he ole
o halophilic bac e ia in cance ea men . In one o hese s udies, Chen e al. (2010) assayed ou een
c ude ex ac s om 45 halophilic bac e ial s ains and showed cy o oxic ac i i y agains human li e
cance cell line Bel 7402 wi h a hal maximal inhibi o y concen a ion (IC
50
) o 500
µ
g/mL and i e o
hem showed ema kable ac i i ies wi h IC50 lowe han 40
µ
g/mL [
106
]. The an ineoplas ic an ibio ic
known as ube cidin, was isola ed om he halophilic ac inobac e ium Ac inopolyspo a e y h aea YIM
90600, his compound exhibi ed he capabili y o s abilize he umo supp esso P og ammed Cell Dea h
P o ein 4 (Pdcd4), which is known o an agonize c i ical e en s in oncogenic pa hways. Tube cidin,
signi ican ly inhibi ed p o easomal deg ada ion o a model Pdcd4-luci e ase usion p o ein, wi h an
IC
50
o 0.88
±
0.09
µ
M, un eiling a no el biological ac i i y o his well-s udied na u al p oduc [
107
].
In wo s udies on di e en ex ac s o halophilic and halo ole an bac e ia isola ed om
b ine-seawa e in e ace o he Red Sea, Saga e al. (2013) es ed he cy o oxic and apop o ic
ac i i y o hei ex ac s agains h ee human cance cell lines, including HeLa (ce ical ca cinoma),
MCF-7 (b eas adenoca cinoma) and DU145 (p os a e ca cinoma). In one o hei s udies, a o al o
20 lipophilic (chlo o o m) and hyd ophilic (70% e hanol) ex ac s om wel e di e en s ains we e
assessed. Among hese, wel e ex ac s we e ound o be e y ac i e a e 24 h o ea men , which
we e u he e alua ed o hei cy o oxic and apop o ic e ec s a 48 h. The ex ac s om he isola es
Halomonas sp. P1-37B, Halomonas sp. P3-37A, and Sul i obac e sp. P1-17B we e ound o be he mos
po en agains es ed cance cell lines [
108
]. In he o he s udy, e hyl ace a e ex ac s o 24 s ains we e
assayed and he esul s showed ha mos ex ac s we e cy o oxic agains one o mo e cance cell lines.
Ou o he hi een mos ac i e mic obial ex ac s, six ex ac s induced signi ican ly highe apop osis
(>70%) in cance cells. Molecula s udies e ealed ha ex ac s om Ch omohalobac e salexigens
s ains P3-86A and P3-86B ollowed he sequence o e en s o apop o ic pa hway in ol ing ma ix
me allop o einases (MMP) dis up ion, Caspase-3/7 ac i i y, Caspase-8 clea age, polyme ic adenosine
diphospha e ibose polyme ase 1 (PARP-1) clea age, and phospha idylse ine exposu e, whe eas he
ex ac s om ano he Ch omohalobac e salexigens s ain K30 induced Caspase-9 media ed apop osis.
The ex ac s om Halomonas me idiana s ain P3-37B and Idioma ina loihiensis s ain P3-37C we e unable
o induce any change in MMP in HeLa cance cells and hus sugges ed a mi ochond ia-independen
apop osis induc ion. Howe e , u he de ec ion o a PARP-1 clea age p oduc and he obse ed
changes in Caspase-8 and Caspase-9 sugges ed he in ol emen o caspase-media ed apop o ic
pa hways [
109
]. An e hyl ace a e ex ac om S ep omyces sp. WH26 showed signi ican cellula
oxici y. Two new compounds, 8-O-me hyl e angulol and naph homycin A, we e isola ed om his
ex ac ia silica gel column ch oma og aphy and high-p essu e liquid ch oma og aphy (HPLC). These

Ma . D ugs 2020,18, 33 17 o 33
wo compounds showed po en cy o oxic ac i i y agains se e al human cance cell lines including
A549, HeLa, BEL-7402, and HT-29 [
110
]. No el an icance molecules, Sal e namide A–D, we e isola ed
om a halophilic S ep omyces sp. isola ed om a sal e n on Shinui Island, in he Republic o Ko ea,
and exhibi ed an ex ensi e iabili y educ ion in se e al cance cell lines [
111
]. Among hese molecules,
Sal e namide A inhibi ed he hypoxia-induced accumula ion o HIF-1
α
in se e al cance cell lines and
supp essed he HIF-1
α
by down egula ion o i s ups eam signaling pa hways such as PI3K/Ak /mTOR,
p42/p44 MAPK, and STAT3. Mo eo e , in human colo ec al cance cell lines, sal e namide A caused
cell dea h by a es ing he cells in he G2/M phase and lead o apop osis [
112
]. A halophilic bac e ium,
Vib io sp. s ain A1SM3-36-8, isola ed om Manau e sola sal e n in Colombia, showed a high
po en ial o inhibi me hicillin- esis an S aphylococcus au eus and causing a sligh inhibi ion o lung
cance cell lines [
51
]. In ano he s udy, among nine mode a ely halophilic bac e ia isola ed om
saline en i onmen s o I an, he supe na an o ou s ains showed abili y o educe he iabili y o
HUVEC cance cell line while one o hese supe na an s induced he p oli e a ion o adipose-de i ed
mesenchymal s em cells [
113
]. The ac inobac e ium Noca diopsis lucen ensis DSM 44048 isola ed om
Sal ma sh soil in Alican e, Spain p oduces a new benzoxazole de i a i es, Noca benzoxazole G.
The compound showed cy o oxic ac i i y agains li e ca cinoma cells (HepG2) and HeLa cance
cells wi h IC50 alues o 3 and 1
µ
M, espec i ely [
114
]. A halo ole an Bacillus sp. KCB14S006,
which was isola ed om a sal e n, p oduced h ee new lipopep ides wi h cy o oxic ac i i y. These
new lipopep ides lead o a ~30% dec ease in he iabili y o HeLa and s c( s)-NRK cells [
115
]. In
ano he s udy, he me hanolic ex ac s o Bacillus sp. VITPS14 and Bacillus sp. VITPS16 showed
cy o oxici y agains HeLa cance cell line bu no agains A549 cells. These halophilic s ains we e
isola ed om soil samples o Ma akkanam sal e n and Picha a am mang o e o es , India, espec i ely.
Ano he halophilic s ain, Bacillus sp. VITPS7, isola ed om his a ea showed signi ican an ioxidan
ac i i y. The p esence o
β
-ca o ene and la onoids was con i med in hese ex ac s [
116
]. In ano he
s udy, wen y- ou no el halophilic bac e ia isola ed om he su ounding o ac i e olcanic Ba en
Island Andaman and he Nicoba Islands in India we e examined o hei cy o oxic ac i i y agains
MDA-MB-231 b eas cance cell line. Abou 65% o hese bac e ial s ains dec eased he iabili y o his
cell line o 50% o lowe [
117
]. Me aboli es om Piscibacillus sp. C12A1 isola ed om Sambha Lake,
India, dec eased he iabili y o MDA-MB-231 b eas cance cell line wi h down egula ion o Bcl-xL
and CDK-2 exp ession. Fu he mo e, cell mig a ion and colony o ma ion o he cells we e inhibi ed in
he p esence o hese me aboli es [118].
Biosu ac an s p oduced by mic oo ganisms a e ac i e molecules ha c ea e an amphipa hic
su ace con aining hyd ophilic and hyd ophobic moie ies. In ecen yea s, hese biomolecules we e also
ound o possess se e al in e es ing p ope ies o he apeu ic and biomedical impo ance. Biosu ac an s
om he halophilic bac e ia Bacillus sp. BS3 and Halomonas sp. BS4 had he abili y o educe he
iabili y o mamma y epi helial ca cinoma cells o 24.8% and o 46.8 signi ican ly (p<0.05) a 0.25
µg/mL and 2.5 µg/mL concen a ions, espec i ely [53,119].
Ex acellula polyme ic subs ances (EPS) ha e ecen ly been a ac ing conside able a en ion
because o hei po en ial applica ions in many ields, including biomedicine. EPSs a e he e ogeneous
polyme s ha con ain a wide ange o homo- o he e o-ca bohyd a es as well as o ganic and ino ganic
subs i uen s. EPSs p oduced by bo h halophilic bac e ia and a chaea showed ema kable an icance
ac i i y. Also, hese polysaccha ide polyme s ha e been in oduced as impo an agen s o de eloping
nanoca ie sys ems o an i-cance d ugs. Fo example, in 2011, Ruiz-Ruiz e al. showed ha a a
concen a ion o 500
µ
g/mL, he o e sul a ed exopolysaccha ide o he halophilic bac e ium Halomonas
s enophila s ain B100 comple ely blocked he p oli e a ion o he human T leukemia cells (Ju ka cells) in
a dose- esponse manne . Also, hey e ealed he posi i e e ec o sul a e g oups in iabili y educ ion
o Ju ka cells [
120
]. Mo eo e , in ano he s udy, he an i-cance ac i i y o he polysaccha ide le an
and i s aldehyde-ac i a ed de i a i es was epo ed. This polysaccha ide was isola ed om Halomonas
smy nensis AAD6 and i s an icance ac i i y agains human cance cell lines such as lung (A549), li e
(HepG2/C3A), gas ic (AGS), and b eas (MCF-7) cance cells (Table 4) has been in es iga ed. In his
Ma . D ugs 2020,18, 33 18 o 33
s udy, all e alua ed cells we e ea ed wi h le an samples a a b oad concen a ion anging om 10
o 1000
µ
g/mL. All samples we e ound o display g ow h inhibi ion agains cance cell lines a he
highes dose (1000
µ
g/mL). Unmodi ied le an showed highe an i-cance e ec agains AGS cells
agains o he cance cell lines. Aldehyde-ac i a ed le an showed highe an i- umo ac i i y han
unmodi ied le an agains all cance cell lines. Oxidized le an samples showed highe an icance
ac i i y agains A549 and HepG2/C3A cells. By inc easing he oxida ion deg ee, he an i-cance ac i i y
also inc eased. The e o e, i was clea ly demons a ed ha he in oduc ion o he chemically modi ied
g oup, aldehydes, in o he linea le an molecule could signi ican ly enhance he an i umo ac i i y o
le an polysaccha ide [121].
Recen p eclinical and medicinal s udies ha e shown an in e se ela ionship be ween die a y
up ake o ca o enoids and cance occu ence. I was epo ed ha he ex ac ed ca o enoid om he
halo ole an bac e ium Kocu ia sp. QWT-12, isola ed om indus ial anne y was ewa e in Qom, in
I an, had he abili y o educe he iabili y o human b eas cance cell lines MCF-7, MDA-MB-468, and
MDA-MB-231 wi h an IC50 o 1, 4, and 8 mg/mL, espec i ely. Also, his ca o enoid dec eased he
iabili y o human lung cance cell line A549, wi h IC50 o 4 mg/mL. This ca o enoid did no educe
he iabili y o no mal ib oblas cell line a hese concen a ions [122].
Among all an icance enzymes, l-aspa aginase and l-glu aminase a e enzymes wi h he abili y o
inhibi acu e lymphoblas ic leukemia and o he cance cells. Halophilic and halo ole an bac e ia a e
no el sou ces o hese an icance enzymes. Fo example, a sc eening om 85 halophilic s ains om he
hype saline U mia Lake in I an e ealed ha 16 (19%) and h ee s ains (3.5%) showed l-aspa aginase
and l-glu aminase ac i i y, espec i ely. I was shown ha l-aspa aginase was p oduced mainly
by s ains belonging o he genus Bacillus, while l-glu aminase was p oduced mainly by s ains o
he genus Salicola [
27
]. In ano he s udy, i was epo ed ha om 110 halophilic s ains isola ed
om di e en saline en i onmen s o I an, a o al o 29, ou , and wo s ains p oduced an icance
enzymes including l-aspa aginase, l-glu aminase, and l-a ginase, espec i ely. These s ains belonged
o he gene a Bacillus,Die zia,Halobacillus,Rhodococcus,Paenibacillus, and Planococcus, as G am-posi i e
bac e ia, and Pseudomonas,Ma inobac e ,Halomonas,Idioma ina,Vib io, and S appia as G am-nega i e
bac e ia [
123
]. F om hese s ains, he an i-cance ac i i y o a no el ecombinan l-aspa aginase
enzyme p oduced by Halomonas elonga a s ain IBRC M10216 was assayed agains human lymphoblas ic
and myeloid leukemia cell lines, Ju ka and U937 (Table 4). This enzyme enhanced he iabili y o
hese cance cell lines wi h IC50 alues o 2 and 1 U/mL, espec i ely, bu a hese concen a ions had
no e ec on he iabili y o no mal HUVEC cell line [124].
Ma . D ugs 2020,18, 33 19 o 33
Table 4. Halophilic bac e ia, a chaea, and ungi and hei ela ion o cance ea men .
An icance Ac i i y
o : Isola ion Sou ce Halophilic S ain Cance Cell Lines Molecule Fo mula Re e ence
Bac e ia
Me aboli e
Ma akkanam sal e n and Picha a am
mang o eFo es in India Bacillus sp. VITPS16 Ce ical ca cinoma
Squalene C30H50
[116]
3-Me hyl-2-(2-oxop opyl) u an C8H10O2
Me hyl hexadecona e C17H34O2
Topsoil sal e n in Jeungdo,
Jeollanam-do, Republic o Ko ea
Noca diopsis sp.
HYJ128 S omach and Leukemia ca cinoma Bo elidin C C28H43NO7[42]
Bo elidin D C28H43NO7
Sal e n in Incheon in Ko ea Bacillus sp.
KCB14S006
Ce ical ca cinoma
Myeloid leukemia
I u in F1C51H80N12O15Na
[115]
I u in F2C51H80N12O15Na
I u in A8C51H80N12O14Na
I u in A9C51H80N12O14Na
A sal e n on Shinui Island in Ko ea S ep omyces sp. Colo ec al cance
Gas ic cance Sal e namide A C23H32ClNO5[111]
Sal ma sh soil, Alican e, Spain Noca diopsis
lucen ensis DSM 44048
Li e cance
Ce ical cance cells Noca benzoxazole G C15H13NO4[114]
- B ine-seawa e in e ace o he Red Sea 12 halophilic ma ine
s ains
B eas adenoca cinoma
Ce ical ca cinoma
P os a e ca cinoma
C ude ex ac NR [108]
- Deep-sea b ine pools o he Red Sea 24 halophilic ma ine
s ains
B eas adenoca cinoma
Ce ical ca cinoma
P os a e ca cinoma
C ude ex ac NR [109]
-Weihai Sola
Sal e n in China
S ep omyces sp.
WH26 Lung adenoca cinoma
Li e hepa ocellula adenoca cinoma
Ce ical ca cinoma
Colo ec al cance
8-O-Me hyl e angulol C20H14O4[110]
- Naph homycin A C40H46ClNO9
-Baicheng sal ield, Xingjiang P o ince,
China
Ac inopolyspo a
e y h aea YIM 90600
Tumo supp esso P og ammed Cell Dea h P o ein 4
(Pdcd4)
Ac inopolyspo ins A C15H28O4
[107]
Ac inopolyspo ins B C16H30O4
Ac inopolyspo ins C C16H30O2
Weihai Sola
Sal e n in China
45 mode a ely
halophilic s ains Li e hepa ocellula adenoca cinoma C ude ex ac s NR [106]
Ma . D ugs 2020,18, 33 20 o 33
Table 4. Con .
An icance Ac i i y
o : Isola ion Sou ce Halophilic S ain Cance Cell Lines Molecule Fo mula Re e ence
Supe na an
me aboli e
Sambha Lake in India Piscibacillus sp.
C12A1 B eas adenoca cinoma C ude ex ac NR [118]
B ine and sedimen o he Manau e
sola sal e n in Colombia
Vib io sp. A1SM3-36-8
Lung adenoca cinoma 13-cis-docosenamide C22H43NO [51]
Di e en hype saline lakes in I an 9 mode a ely
halophilic s ains Umbilical ein endo helial cance cell C ude ex ac NR [113]
Biosu ac an
Thama aikulam sola sal wo ks in
India Halomonas sp. BS4 Mamma y epi helial ca cinoma
1,2-E hanediamine, N,N,N’,N’- e a C6H16N2
[119]
8-Me hyl-6-nonenamide C10H19NO
9-Oc adecenamide, (Z) C18H35NO
Sola sal wo ks in India Bacillus sp. BS3 Mamma y epi helial ca cinoma
13-Docosenamide, (Z)
CH
3
(CH
2
)
7
CH=CH(CH
2
)
11
CONH
2
[53]
Mannosamine C6H13NO5·HCl
9-Oc adecenamide, (Z) C18H35NO
2-Oc anol,2-me hyl-6-me hylene C12H22O2
Cylohex-1,4,5- iol-3-one-1-ca bo C5H8FN3
2-Bu anamine, 2-me hyl- C5H13N
1,2-E hanediamine,
N,N,N0,N0- e ame hyl- C6H16N2
Exopolysaccha ide Çamal i sal e n a ea in Tu key Halomonas smy nensis
s ain AAD6
B eas adenoca cinoma
Lung adenoca cinoma
Li e hepa ocellula adenoca cinoma
Gas ic adenoca cinoma
Le an C18H32O16 [121]
Sabina saline we land in Spain Halomonas s enophila
s ain B100 Lymphoblas ic leukemia
Single acidic exopolysaccha ide
wi h glucose, mannose
and galac ose
NR [120]
Ca o enoid Indus ial anne y was ewa e in I an Kocu ia sp. MA-2 P os a e ca cinoma Neu ospo ene C40H58 [122]
Enzyme Hype saline soil in I an Halomonas elonga a
IBRC-M 10216
Lymphoblas ic leukemia
Myeloid leukemia l-aspa aginase C1377H2208N382O442S17 [124]
Ma . D ugs 2020,18, 33 21 o 33
Table 4. Con .
An icance Ac i i y
o : Isola ion Sou ce Halophilic S ain Cance Cell Lines Molecule Fo mula Re e ence
A chaea
Supe na an
me aboli e A an Bidgol hype saline lake in I an
Halobac e ium
salina um IBRC-M
10715
P os a e ca cinoma C ude ex ac NR [105]
Exopolysaccha ide U mia Lake in I an Halo ub um sp.
TBZ112 Gas ic adenoca cinoma
Monosaccha ide composi ion
mainly composed o mannose,
glucosamine, galac u onic acid,
a abinose, and glucu onic acid
NR [125]
Ca o enoid Ma ine sola sal e n in eas e n China
Halogeome icum limi
s ain RO1-6
Haloplanus escus
s ain RO5-8
Li e hepa ocellula adenoca cinoma Bac e io ube in C50H76O4[127]
Tunisian sola sal e n Halobac e ium
halobium Li e hepa ocellula adenoca cinoma Bac e io ube in C50H76O4[126]
Fungi
Me aboli e Weihai Sola
Sal e n in China Aspe gillus sp. F1
Lung adenoca cinoma
Li e hepa ocellula adenoca cinoma
Ce ical ca cinoma
Colo ec al cance
Cy ochalasin E C28H33NO7
[128]
E gos e ol C28H44O
Rosellichalasin C28H33NO5
Abb e ia ions: No epo ed (NR).

Ma . D ugs 2020,18, 33 22 o 33
4.2. A chaea
Al hough mos s udies in his ield ha e been ocused on halophilic bac e ia, some s udies
in es iga ed he po en ials o haloa chaea. In one o hese s udies, among nine haloa chaeal s ains
isola ed om A an-Bidgol Sal Lake, in I an, supe na an me aboli es om Halobac e ium salina um
IBRC M10715 had he mos po en cy o oxic e ec on p os a e cance cell lines (DU145 and PC3,
IC50 =0.5 mg/mL) wi hou any e ec s on no mal ib oblas cells (HFF-5). Mo eo e , he selec i e
me aboli e signi ican ly inc eased bo h ea ly and la e apop osis (abou 11% and 9%, espec i ely) in he
and ogen-dependen PC3 cell line and educed sphe e o ma ion abili y o bo h cance cell lines wi h
down- egula ion o SOX2 gene exp ession. Fu he mo e, p os a e cance cell umo s de eloped in
nude mice signi ican ly sh ank pos in a umo injec ion o he me aboli e om Halobac e ium salina um
IBRC M10715 [
105
]. Halo ub um sp. TBZ112 is a haloa chaeal species isola ed om he U mia Lake,
I an. I was epo ed ha his s ain could p oduce EPSs. The isola ed EPSs possess a ela i ely low
molecula weigh in compa ison wi h hose EPSs isola ed om o he ex eme en i onmen s (5 s.
≥
100 kDa, espec i ely) and he absence o sul a e unc ional g oups in hei s uc u e was epo ed.
The an icance ac i i y o he EPSs om Halo ub um sp. TBZ112 was examined and he esul s did
no show any signi ican changes in he iabili y o gas ic cance cells (MKN-45) and no mal human
de mal ib oblas cells (HDF) a concen a ions o 100, 250, 500, and 1000
µ
g/mL a e 24 and 48 h o
ea men . As he exis ence o sul a e unc ional g oups and he EPSs bioac i i ies a e di ec ly ela ed,
he low cy o oxici y po en ial o he EPSs om Halo ub um sp. TBZ112 was no unexpec ed [125].
Bo h
in i o
and
in i o
s udies con i m chemop e en ion e ec s o some ca o enoids an icance
ac i i y. Halophilic mic oo ganisms showed g ea po en ial owa d he p oduc ion o a ious
ca o enoids such as
β
-ca o ene, bac e io ube in, and xan hophylls. In ecen yea s, some in es iga ions
we e ca ied ou o de e mine he ole o ca o enoids o o he bioac i e molecules p oduced by
halophiles on cance ea men . The e ec s o Halobac e ium halobium ca o enoid ex ac on he iabili y
o human hepa oma, HepG2, ha e been analyzed. This haloa chaeal s ain was isola ed om a Tunisian
sola sal e n and he esul s emphasized ha inc easing concen a ions o he ca o enoid ex ac o his
halophilic a chaeon dec eased signi ican ly he iabili y o he HepG2 cance cell line [
126
]. Ca o enoids
om he haloa chaea Halogeome icum limi s ain RO1-6 and Haloplanus escus s ain RO5-8 showed
a po en an ioxidan ac i i y in compa ison wi h
β
-ca o ene. In addi ion, hese ca o enoid ex ac s
inhibi ed HepG2 cells
in i o
, in a dose-dependen manne . Bac e io ube in was he p edominan
ca o enoid ex ac ed om hese haloa chaea [127].
4.3. Fungi
The bio echnological applica ions o halophilic ungi a e ema kedly less s udied in compa ison
wi h halophilic bac e ia. The e is only one s udy ocused on he cy o oxic e ec o me aboli es
om a mode a ely halophilic ungal s ain, Aspe gillus sp. F1 [
128
]. Based on his publica ion, his
s ain p oduced h ee compounds wi h an icance ac i i y including cy ochalasin E, e gos e ol, and
osellichalasin, and highe sal concen a ions inc eased he p oduc ion o hese compounds. All
isola ed compounds dec eased he iabili y o A549, Hela, BEL-7402, and RKO human cance cell
lines and he inhibi ion e ec o e gos e ol on human colon cance cell line, RKO, was he mos po en
cy o oxic epo in his s udy.
Table 4summa ize all he men ioned epo s in Sec ion 4, which a e ela ed o he an icance e ec
o halophilic bac e ia, a chaea, and ungi isola ed om di e en saline and hype saline en i onmen s
in he wo ld.
The ollowing able (Table 5) ga he s he mos p omising new compounds de i ed om halophilic
mic oo ganisms. The minimum inhibi o y concen a ion (MIC) and he hal maximal inhibi o y
concen a ion (IC
50
) a e shown, based on hei
in i o
bioac i i y. The esul s sugges ha hese
compounds could be candida es o p eclinical ials.
Ma . D ugs 2020,18, 33 23 o 33
Table 5. P omising new compounds de i ed om halophilic mic oo ganisms candida es o p eclinical ials.
Compound S uc u e An ibio ic Ac i i y An icance Ac i i y Re e ence
Mic oo ganism MIC (µM) Cell Lines IC50 (µM)
Bo elidin C, D
Ma . D ugs 2019, 17, x FOR PEER REVIEW 20 o 30
Table 5. P omising new compounds de i ed om halophilic mic oo ganisms candida es o p eclinical ials.
Compound S uc u e
An ibio ic Ac i i y An icance Ac i i y Re e ence
Mic oo ganism MIC (μM) Cell Lines IC
50
(μM)
Bo elidin C, D
S. en e ica 16–63
S omach 5.5
[42]
Leukemia 5.7
Leukemia 6.7
Angucyclinone:
N-(4-aminocyclooc yl)-3,5-dini obenzamide
S. au eus,
S. epide mis,
B. sub ilis,
B. mega e ium,
P. ae uginosa
16
B eas , ce ical,
o a ian cys ,
adenoca cinoma
10 nM [50]
S. mu ans 4
X. mal acea um,
S. yphi,
E. coli
32
B. ce eus 8
C. albicans 16
S ep omonomicin STM
B. an h acis 2–4
NR NR [48]
B. halodu ans 4
B. ce eus 4–7
Bacillus sp. 7
B. sub ilis 29
L. monocy ogenes 14
E. aecalis 29
S. au eus 57
4-oxo-1,4-dihyd oquinoline-3-ca boxamide
S. au eus 64 NR NR [43]
B. sub ilis 64
S. en e ica 16–63
S omach 5.5
[42]
Leukemia 5.7
Leukemia 6.7
Angucyclinone:
N-(4-aminocyclooc yl)-3,5-dini obenzamide
Ma . D ugs 2019, 17, x FOR PEER REVIEW 21 o 31
Angucyclinone:
N-(4-aminocyclooc yl)-3,5-dini obenzamide
S. au eus,
S. epide mis,
B. sub ilis,
B. mega e ium,
P. ae uginosa
16
B eas , ce ical,
o a ian cys ,
adenoca cinoma
10 nM [50]
S. mu ans 4
X. mal acea um,
S. yphi,
E. coli
32
B. ce eus 8
C. albicans 16
S ep omonomicin STM
B. an h acis 2–4
NR NR [48]
B. halodu ans 4
B. ce eus 4–7
Bacillus sp. 7
B. sub ilis 29
L. monocy ogenes 14
E. aecalis 29
S. au eus 57
4-oxo-1,4-dihyd oquinoline-3-ca boxamide S. au eus 64 NR NR [43]
S. au eus,
S. epide mis,
B. sub ilis,
B. mega e ium,
P. ae uginosa
16
B eas , ce ical,
o a ian cys ,
adenoca cinoma
10 nM [50]
S. mu ans 4
X. mal acea um,
S. yphi,
E. coli
32
B. ce eus 8
C. albicans 16
S ep omonomicin STM
Ma . D ugs 2019, 17, x FOR PEER REVIEW 21 o 31
Angucyclinone:
N-(4-aminocyclooc yl)-3,5-dini obenzamide
S. au eus,
S. epide mis,
B. sub ilis,
B. mega e ium,
P. ae uginosa
16
B eas , ce ical,
o a ian cys ,
adenoca cinoma
10 nM [50]
S. mu ans 4
X. mal acea um,
S. yphi,
E. coli
32
B. ce eus 8
C. albicans 16
S ep omonomicin STM
B. an h acis 2–4
NR NR [48]
B. halodu ans 4
B. ce eus 4–7
Bacillus sp. 7
B. sub ilis 29
L. monocy ogenes 14
E. aecalis 29
S. au eus 57
4-oxo-1,4-dihyd oquinoline-3-ca boxamide S. au eus 64 NR NR [43]
B. an h acis 2–4
NR NR [48]
B. halodu ans 4
B. ce eus 4–7
Bacillus sp. 7
B. sub ilis 29
L. monocy ogenes 14
E. aecalis 29
S. au eus 57
4-oxo-1,4-dihyd oquinoline-3-ca boxamide
Ma . D ugs 2019, 17, x FOR PEER REVIEW 22 o 31
B. sub ilis 64
6′-Hyd oxy-4,2′,3′,4″- e ame hoxy-p- e phenyl
B. sub ilis 64
NR NR [44]
C. albicans 32
Lynamicin A, B, C, and D
S. au eus 1.8–6.2
NR NR [57]
S. epide midis 2.2–9.5
S. pneumoniae 18–57
E. aecalis 3.3–19
E. aecium 4.4–19
H. in luenzae 4.4–38
E. coli 13–16
Ess amycin
E. coli 8
NR NR [58]
P. ae uginosa 3.5
B. sub ilis,
S. au eus 1
M. lu eus 1.5
Resis omycin E. coli 40 NR NR [60]
S. au eus 64 NR NR [43]
B. sub ilis 64
60-Hyd oxy-4,20,30,4”- e ame hoxy-p- e phenyl
Ma . D ugs 2019, 17, x FOR PEER REVIEW 22 o 31
B. sub ilis 64
6′-Hyd oxy-4,2′,3′,4″- e ame hoxy-p- e phenyl
B. sub ilis 64
NR NR [44]
C. albicans 32
Lynamicin A, B, C, and D
S. au eus 1.8–6.2
NR NR [57]
S. epide midis 2.2–9.5
S. pneumoniae 18–57
E. aecalis 3.3–19
E. aecium 4.4–19
H. in luenzae 4.4–38
E. coli 13–16
Ess amycin
E. coli 8
NR NR [58]
P. ae uginosa 3.5
B. sub ilis,
S. au eus 1
M. lu eus 1.5
Resis omycin E. coli 40 NR NR [60]
B. sub ilis 64 NR NR [44]
C. albicans 32
Lynamicin A, B, C, and D
Ma . D ugs 2019, 17, x FOR PEER REVIEW 21 o 30
6′-Hyd oxy-4,2′,3′,4″- e ame hoxy-p- e phenyl
B. sub ilis 64
NR NR [44]
C. albicans 32
Lynamicin A, B, C, and D
S. au eus 1.8–6.2
NR NR [57]
S. epide midis 2.2–9.5
S. pneumoniae 18–57
E. aecalis 3.3–19
E. aecium 4.4–19
H. in luenzae 4.4–38
E. coli 13–16
Ess amycin
E. coli 8
NR NR [58]
P. ae uginosa 3.5
B. sub ilis,
S. au eus 1
M. lu eus 1.5
Resis omycin
1-hyd oxy-1-No esis omycin
E. coli
40 NR NR
[60]
S. au eus
S. i idoch omogenes
Resis o la in me hyl e he B. sub ilis 3.1 NR NR
S. au eus 1.8–6.2
NR NR [57]
S. epide midis 2.2–9.5
S. pneumoniae 18–57
E. aecalis 3.3–19
E. aecium 4.4–19
H. in luenzae 4.4–38
E. coli 13–16
Ma . D ugs 2020,18, 33 24 o 33
Table 5. Con .
Compound S uc u e An ibio ic Ac i i y An icance Ac i i y Re e ence
Mic oo ganism MIC (µM) Cell Lines IC50 (µM)
Ess amycin
Ma . D ugs 2019, 17, x FOR PEER REVIEW 22 o 31
B. sub ilis 64
6′-Hyd oxy-4,2′,3′,4″- e ame hoxy-p- e phenyl
B. sub ilis 64
NR NR [44]
C. albicans 32
Lynamicin A, B, C, and D
S. au eus 1.8–6.2
NR NR [57]
S. epide midis 2.2–9.5
S. pneumoniae 18–57
E. aecalis 3.3–19
E. aecium 4.4–19
H. in luenzae 4.4–38
E. coli 13–16
Ess amycin
E. coli 8
NR NR [58]
P. ae uginosa 3.5
B. sub ilis,
S. au eus 1
M. lu eus 1.5
Resis omycin E. coli 40 NR NR [60]
E. coli 8
NR NR [58]
P. ae uginosa 3.5
B. sub ilis,
S. au eus 1
M. lu eus 1.5
Resis omycin
1-hyd oxy-1-No esis omycin
Ma . D ugs 2019, 17, x FOR PEER REVIEW 23 o 31
1-hyd oxy-1-No esis omycin
S. au eus
S.
i idoch omogenes
Resis o la in me hyl e he
R=Me
B. sub ilis 3.1
NR NR
E. coli,
S. au eus,
C. albicans
10
Lajollamycin
MSSA 4
Mu ine
melanoma
cell line B16-
F10
9.6 [61]
MRSA 5
SPPS 2
PRSP 1.5
VSEF 14
VREF 20
E. coli 12
No e: No epo ed (NR). Mic oo ganisms: Bacillus (B.): B. ce eus, B. halodu ans, B. mega e ium, B. sub ilis, B. an h acis. Candida (C.): C. albicans. En e ococcus (E.): E. aecalis, E. aecium,
Vancomycin esis an En e ococcus aecium (VREF), Vancomycin sensi i e En e ococcus aecalis (VSEF), Vancomycin esis an en e ococci (VRE). Esche ichia (E.): E. coli. Haemophilus (H.): H.
in luenzae. Lis e ia (L.): L. monocy ogenes. Mic ococcus (M.): M. lu eus. Pseudomonas (P.): P. ae uginosa. Salmonella (S.): S. yphi, S. en e ica. S aphylococcus (S.): S. au eus, S. epide midis, S.
mu ans, Me hicillin Sensi i e S aphylococcus au eus (MSSA), Me hicillin- esis an S aphylococcus au eus (MRSA). S ep ococcus (S.): S. pneumoniae, Penicillin esis an S ep ococcus pneumoniae
(PRSP), Penicillin sensi i e S ep ococcus pneumoniae (SPPS). S ep omyces (S.): S. i idoch omogenes. Xan homonas (X.): X. mal acea um.
E. coli
40 NR NR
[60]
S. au eus
S. i idoch omogenes
Resis o la in me hyl e he
Ma . D ugs 2019, 17, x FOR PEER REVIEW 23 o 31
1-hyd oxy-1-No esis omycin
S. au eus
S.
i idoch omogenes
Resis o la in me hyl e he
R=Me
B. sub ilis 3.1
NR NR
E. coli,
S. au eus,
C. albicans
10
Lajollamycin
MSSA 4
Mu ine
melanoma
cell line B16-
F10
9.6 [61]
MRSA 5
SPPS 2
PRSP 1.5
VSEF 14
VREF 20
E. coli 12
No e: No epo ed (NR). Mic oo ganisms: Bacillus (B.): B. ce eus, B. halodu ans, B. mega e ium, B. sub ilis, B. an h acis. Candida (C.): C. albicans. En e ococcus (E.): E. aecalis, E. aecium,
Vancomycin esis an En e ococcus aecium (VREF), Vancomycin sensi i e En e ococcus aecalis (VSEF), Vancomycin esis an en e ococci (VRE). Esche ichia (E.): E. coli. Haemophilus (H.): H.
in luenzae. Lis e ia (L.): L. monocy ogenes. Mic ococcus (M.): M. lu eus. Pseudomonas (P.): P. ae uginosa. Salmonella (S.): S. yphi, S. en e ica. S aphylococcus (S.): S. au eus, S. epide midis, S.
mu ans, Me hicillin Sensi i e S aphylococcus au eus (MSSA), Me hicillin- esis an S aphylococcus au eus (MRSA). S ep ococcus (S.): S. pneumoniae, Penicillin esis an S ep ococcus pneumoniae
(PRSP), Penicillin sensi i e S ep ococcus pneumoniae (SPPS). S ep omyces (S.): S. i idoch omogenes. Xan homonas (X.): X. mal acea um.
R=Me
B. sub ilis 3.1
NR NR
E. coli,
S. au eus,
C. albicans
10
Lajollamycin
Ma . D ugs 2019, 17, x FOR PEER REVIEW 23 o 31
1-hyd oxy-1-No esis omycin
S. au eus
S.
i idoch omogenes
Resis o la in me hyl e he
R=Me
B. sub ilis 3.1
NR NR
E. coli,
S. au eus,
C. albicans
10
Lajollamycin
MSSA 4
Mu ine
melanoma
cell line B16-
F10
9.6 [61]
MRSA 5
SPPS 2
PRSP 1.5
VSEF 14
VREF 20
E. coli 12
No e: No epo ed (NR). Mic oo ganisms: Bacillus (B.): B. ce eus, B. halodu ans, B. mega e ium, B. sub ilis, B. an h acis. Candida (C.): C. albicans. En e ococcus (E.): E. aecalis, E. aecium,
Vancomycin esis an En e ococcus aecium (VREF), Vancomycin sensi i e En e ococcus aecalis (VSEF), Vancomycin esis an en e ococci (VRE). Esche ichia (E.): E. coli. Haemophilus (H.): H.
in luenzae. Lis e ia (L.): L. monocy ogenes. Mic ococcus (M.): M. lu eus. Pseudomonas (P.): P. ae uginosa. Salmonella (S.): S. yphi, S. en e ica. S aphylococcus (S.): S. au eus, S. epide midis, S.
mu ans, Me hicillin Sensi i e S aphylococcus au eus (MSSA), Me hicillin- esis an S aphylococcus au eus (MRSA). S ep ococcus (S.): S. pneumoniae, Penicillin esis an S ep ococcus pneumoniae
(PRSP), Penicillin sensi i e S ep ococcus pneumoniae (SPPS). S ep omyces (S.): S. i idoch omogenes. Xan homonas (X.): X. mal acea um.
MSSA 4
Mu ine
melanoma cell
line B16-F10
9.6 [61]
MRSA 5
SPPS 2
PRSP 1.5
VSEF 14
VREF 20
E. coli 12
No e: No epo ed (NR). Mic oo ganisms: Bacillus (B.): B. ce eus, B. halodu ans, B. mega e ium, B. sub ilis, B. an h acis. Candida (C.): C. albicans. En e ococcus (E.): E. aecalis, E. aecium,
Vancomycin esis an En e ococcus aecium (VREF), Vancomycin sensi i e En e ococcus aecalis (VSEF), Vancomycin esis an en e ococci (VRE). Esche ichia (E.): E. coli. Haemophilus (H.): H.
in luenzae. Lis e ia (L.): L. monocy ogenes. Mic ococcus (M.): M. lu eus. Pseudomonas (P.): P. ae uginosa. Salmonella (S.): S. yphi, S. en e ica. S aphylococcus (S.): S. au eus, S. epide midis, S. mu ans,
Me hicillin Sensi i e S aphylococcus au eus (MSSA), Me hicillin- esis an S aphylococcus au eus (MRSA). S ep ococcus (S.): S. pneumoniae, Penicillin esis an S ep ococcus pneumoniae (PRSP),
Penicillin sensi i e S ep ococcus pneumoniae (SPPS). S ep omyces (S.): S. i idoch omogenes. Xan homonas (X.): X. mal acea um.
Ma . D ugs 2020,18, 33 25 o 33
5. Fu u e Pe spec i es
As he p e alence o an imic obial esis ance inc eases, esea che s a e de eloping new
echnologies and s a egies o ind al e na i es ha educe he mo bidi y and mo ali y caused by he
MDR bac e ia. Ca ego izing he need o ob aining new molecules, he mos eques ed by he public
heal h a e an imic obial and an icance compounds acco ding o he da a annually epo ed by he Wo ld
Heal h O ganiza ion (WHO). The cu en and u u e o na u al p oduc disco e y is he applica ion o a
combina ion o mul i-omics app oaches. Depending on he phase o he s udy, i is o eseen genomics,
me agenomics, ansc ip omics, p o eomics, and me abolomics o e eal he biosyn he ic capabili ies
o a single mic oo ganism o mic obial communi ies in hype saline en i onmen s.
The disco e y o no el lead compounds equi es mo e ha in silico p edic ed genes and la ge
p omising da a. The cu en p oblem wi h massi e app oaches is p ecisely he lack o conc e e esul s
aduced in no el lead compound de i ed o “me a-omics” s udies. The he e ologous exp ession o
biosyn he ic genes is he bo leneck since in se e al cases he ecombinan p oduc and i s exp ession is
o ally di e en om wha was expec ed. Howe e , i is impo an o emphasize ha he cul i a ion o
hidden and uncul i able mic obio a is imp o ing wi h he assessmen o me agenomic s udies [
129
,
130
].
Genome mining has been implemen ed as a manda o y ool widely used o cha ac e ize he
gene ic basis o seconda y me aboli e biosyn hesis based on he ea u es o seconda y me aboli es
o ganized as biosyn he ic gene clus e s (BGCs), especially he p o ile o gene encoding key signa u e
enzymes [
131
–
133
]. The applica ion o Nex Gene a ion Sequencing (NGS) allows he s udy o mic obial
di e si y e e y day mo e accessible and a o dable ha allows he p edic ion o c yp ic me abolic
pa hways and genes in ol ed in he ac i i y. The genome-guided disco e y elies on sophis ica ed
me hods o iden i ica ion o knew gene amilies ela ed clus e s. The accu a e p edic ion and analysis
o ele an genes o seconda y me aboli e biosyn he ic pa hways in mic obes is pe o med h ough
he ool based on he An ibio ics and Seconda y Me aboli es Analysis Shell (an iSMASH) [134].
Due o he high a e o edisco e y o known compounds, he de eplica ion is an essen ial app oach
ha allows he iden i ica ion o duplica e molecules. De eplica ion is elying on inding a ma ching o
mass spec a wi h hose p esen in he mass spec ome y da a eposi o y. The de elopmen o new
compu a ional ools like he algo i hm sea ching spec al, DEREPLICATOR+is helping o iden i ying
in one o de o magni ude pep idic na u al p oduc s (PNPs) ha include non ibosomal pep ides
(NRPs), and ibosomally syn hesized and pos - ansla ionally modi ied pep ides (RiPPs). The ma ching
is ex ended o he iden i ica ion o polyke ides, e penes, benzenoids, alkaloids, la onoids, and o he
classes o na u al p oduc s. One o he u ili ies o DEREPLICATOR+is he enabling o c oss- alida ion
o genome-mining and pep idogenomics/glycogenomics esul s [135].
Se e al labo a o ies wo king in mic obial biop ospec ing keep hei p i a e collec ion once he
an imic obial, an icance , an i ungal, e c. ac i i y is de ec ed. In many cases, hese posi i e isola es
de i ed om p ima y sc eenings a e no u he s udied by genome sequencing and de eplica ion.
A common issue is he ob aining o he pu i ied ac i e compound unde labo a o y condi ions
wi h limi ed acili ies and handling la ge da a wi h a p ope analysis. Mo eo e , i is impo an o
conside he de eplica ion cos s and ime-consuming in e p e ing. The men ioned ac s delay he
biodisco e y a emp s and cons i u e he easonable causing o keeping a s o ed lib a y o po en ial
compounds. The p ojec ion o d ug disco e y p oduc esea ch is he simpli ica ion and accessibili y
o all hese ools as e and wi h less e o . The powe o genome mining in s udying na u al p oduc
biosyn hesis by showing he widesp ead dis ibu ion o NRPS/PKS gene clus e s and by he elici a ion
o p e iously uniden i ied pa hways has been demons a ed. I is clea ha coupling genome mining
and de eplica ion will accele a e he biodisco e y a ini ial s eps. The in eg a ion and linking o
compu a ional app oaches a e ce ainly he u u e o na u al p oduc esea ch.
In his e iew, we ha e ocused in all an icance molecules epo ed om halophilic
mic oo ganisms. Acco ding o he cellula lines used, he ocus o p ima y sc eenings is add essed
o he leading cance ypes ha a ec he global popula ion. Howe e , i is impo an ha u he
sc eenings should include cellula lines wi h in insic chemo esis ance, like sa coma and glioblas oma,
Ma . D ugs 2020,18, 33 32 o 33
117.
Law ance, A.; Balak ishnan, M.; Gunaseka an, R.; S ini asan, R.; Valsalan, V.N.; Gopal, D.; Ramalingam, K.
Unexplo ed deep sea habi a s in ac i e olcanic Ba en Island, Andaman and Nicoba Islands a e sou ces o
no el halophilic eubac e ia. In ec . Gene . E ol. 2018,65, 1–5. [C ossRe ]
118.
Neelam, D.K.; Ag awal, A.; Tome , A.K.; Bandyopadhayaya, S.; Sha ma, A.; Jagannadham, M.V.; Mandal, C.C.;
Dadheech, P.K. A Piscibacillus sp. isola ed om a soda lake exhibi s an icance ac i i y agains b eas cance
MDA-MB-231 cells. Mic oo ganisms 2019,7, 34. [C ossRe ]
119.
Donio, M.B.S.; Ronica, F.A.; Viji, V.T.; Velmu ugan, S.; Jeni e , J.S.C.A.; Michaelbabu, M.; Dha , P.; Ci a asu, T.
Halomonas sp. BS4, a biosu ac an p oducing halophilic bac e ium isola ed om sola sal wo ks in India
and hei biomedical impo ance. Sp inge Plus 2013,2, 149. [C ossRe ]
120.
Ruiz-Ruiz, C.; S i as a a, G.K.; Ca anza, D.; Ma a, J.A.; Llamas, I.; San ama
í
a, M.; Quesada, E.; Molina, I.J.
An exopolysaccha ide p oduced by he no el halophilic bac e ium Halomonas s enophila s ain B100 selec i ely
induces apop osis in human T leukaemia cells. Appl. Mic obiol. Bio echnol. 2011,89, 345–355. [C ossRe ]
121.
Sa ilmise , H.K.; Ozlem, A.; Gonca, O.; A ga, K.Y.; Toksoy One , E. E ec i e s imula ing ac o s o mic obial
le an p oduc ion by Halomonas smy nensis AAD6T. J. Biosci. Bioeng. 2015,119, 455–463. [C ossRe ]
122.
Rezaeeyan, Z.; Sa a pou , A.; Amoozega , M.A.; Baba alian, H.; Tebyanian, H.; Shake i, F. High ca o enoid
p oduc ion by a halo ole an bac e ium, Kocu ia sp. s ain QWT-12 and an icance ac i i y o i s ca o enoid.
EXCLI J. 2017,16, 840–851.
123.
Zol agha , M.; Amoozega , M.A.; Khajeh, K.; Baba alian, H.; Tebyanian, H. Isola ion and sc eening o
ex acellula an icance enzymes om halophilic and halo ole an bac e ia om di e en saline en i onmen s
in I an. Mol. Biol. Rep. 2019,46, 3275–3286. [C ossRe ]
124.
Ghasemi, A.; Asad, S.; Kabi i, M.; Dabi manesh, B. Cloning and cha ac e iza ion o Halomonas elonga a
L-aspa aginase, a p omising chemo he apeu ic agen . Appl. Mic obiol. Bio echnol.
2017
,101, 7227–7238.
[C ossRe ] [PubMed]
125.
Hamidi, M.; Mi zaei, R.; Dela e, C.; Khanaki, K.; Pie e, G.; Ga da in, C.; Pe i , E.; Ka imi aba , F.; Faezi, S.
Cha ac e iza ion o a new exopolysaccha ide p oduced by Halo ub um sp. TBZ112 and e alua ion o i s
an i-p oli e a i e e ec on gas ic cance cells. 3 Bio ech 2019,9, 1. [C ossRe ] [PubMed]
126.
Abbes, M.; Baa i, H.; Gue mazi, S.; Messina, C.; San ulli, A.; Gha sallah, N.; Amma , E. Biological p ope ies
o ca o enoids ex ac ed om Halobac e ium halobium isola ed om a Tunisian sola sal e n. BMC Complemen .
Al e n. Med. 2013,13, 255. [C ossRe ] [PubMed]
127.
Hou, J.; Cui, H.-L.
In i o
an ioxidan , an ihemoly ic, and an icance ac i i y o he ca o enoids om
halophilic a chaea. Cu . Mic obiol. 2018,75, 266–271. [C ossRe ]
128.
Xiao, L.; Liu, H.; Wu, N.; Liu, M.; Wei, J.; Zhang, Y.; Lin, X. Cha ac e iza ion o he high cy ochalasin E
and osellichalasin p oducing Aspe gillus sp. no . F1 isola ed om ma ine sola sal e n in China. Wo ld J.
Mic obiol. Bio echnol. 2013,29, 11–17. [C ossRe ]
129.
Le
ó
n, M.J.; Fe n
á
ndez, A.B.; Ghai, R.; S
á
nchez-Po o, C.; Rod iguez-Vale a, F.; Ven osa, A. F om me agenomics
o pu e cul u e: Isola ion and cha ac e iza ion o he mode a ely halophilic bac e ium Spi ibac e salinus gen.
no ., sp. no . Appl. En i on. Mic obiol. 2014,80, 3850–3857. [C ossRe ]
130.
Hamm, J.N.; E dmann, S.; Eloe-Fad osh, E.A.; Angeloni, A.; Zhong, L.; B ownlee, C.; Williams, T.J.; Ba on, K.;
Ca swell, S.; Smi h, M.A.; e al. Unexpec ed hos dependency o An a c ic nanohaloa chaeo a.P oc. Na l. Acad.
Sci. USA 2019,116, 14661–14670. [C ossRe ]
131.
Blin, K.; Kim, H.U.; Medema, M.H.; Webe , T. Recen de elopmen o an iSMASH and o he compu a ional
app oaches o mine seconda y me aboli e biosyn he ic gene clus e s. B ie . Bioin o m.
2019
,20, 1103–1113.
[C ossRe ]
132.
Wang, S.; Zheng, Z.; Zou, H.; Li, N.; Wu, M. Cha ac e iza ion o he seconda y me aboli e biosyn he ic gene
clus e s in a chaea. Compu . Biol. Chem. 2019,78, 165–169. [C ossRe ]
133.
Zheng, Y.; Sai ou, A.; Wang, C.-M.; Toyoda, A.; Minakuchi, Y.; Sekiguchi, Y.; Ueda, K.; Takano, H.; Sakai, Y.;
Abe, K.; e al. Genome ea u es and seconda y me aboli es biosyn he ic po en ial o he class K edonobac e ia.
F on . Mic obiol. 2019,10, 893. [C ossRe ]

Ma . D ugs 2020,18, 33 33 o 33
134.
Webe , T.; Blin, K.; Duddela, S.; K ug, D.; Kim, H.U.; B uccole i, R.; Lee, S.Y.; Fischbach, M.A.; Mülle , R.;
Wohlleben, W.; e al. an iSMASH 3.0—A comp ehensi e esou ce o he genome mining o biosyn he ic
gene clus e s. Nucleic Acids Res. 2015,43, W237–W243. [C ossRe ] [PubMed]
135.
Mohimani, H.; Gu e ich, A.; Shlemo , A.; Mikheenko, A.; Ko obeyniko , A.; Cao, L.; Shche bin, E.;
No hias, L.-F.; Do es ein, P.C.; Pe zne , P.A. De eplica ion o mic obial me aboli es h ough da abase sea ch
o mass spec a. Na . Commun. 2018,9, 4035. [C ossRe ] [PubMed]
©
2019 by he au ho s. Licensee MDPI, Basel, Swi ze land. This a icle is an open access
a icle dis ibu ed unde he e ms and condi ions o he C ea i e Commons A ibu ion
(CC BY) license (h p://c ea i ecommons.o g/licenses/by/4.0/).