PROTEIN FROM OIL : THE BP ALKANE PROCESS

PROTEIN FROM OIL : THE BP ALKANE PROCESS K. ALLISON BP PROTEINS LIMITED, GRANGEMOUTH, STIRLINGSHIRE, SCOTLAND 1. INTRODUCTION The ac ha yeas s will g ow on hyd oca bons has been known om he ea ly pa ı o his cen u y when some o he i s academic pape s we e published. The use o yeas s as animal eed is well es ablished and now la ge amoun s o odde yeas g own on ca bohyd a e a e p oduced in he wo ld based on wood pulp liquo . The no el de elopmen desc ibed in his pape is he con inuous g ow h o yeas s on pu e hyd oca bons on a comme cial scale. Wo k in his ield by BP s a ed in ca 1957 wi h he s udies by A. Champagna o Socie e F ancaise des Pe oles BP (SFBP) in o he mic obial oxida ion o pe oleum ac ions. Ini ially he objec i e was desulphu isa ion, bu in he cou se o his wo k he disco e ed, su p isingly, ha he n-pa a ins in he pe oleum ac ion we eu ilised selec i ely by he mic o-o ganism. This and he ealisa ion ha he e exis ed in his ield he basis o a comme cial p ocess o he p oduc ion o p o ein concen a e led, in 1959, o he e-o ien a ion o he wo k a La e a o he complemen a y objec i es o p o ein p oduc ion and oil de-waxing. P og ess was apid. 74 K. Allison By 1962 Champagna and his co-wo ke s had published pape s on he p oduc ion o p o ein concen a e om oil ac ions and i was in 1963 ha he de elopmen phase go unde way wi h he commissioning a La e a, nea Ma seilles o a ca k e/d pilo plan p oducing yeas on a con inuous basis om a e ine y gas oil s eam. A yea la e , a s udy on he g ow h o yeas s using pu e n-pa a ins as he ca bon subs a e was commenced by BP a G angemou h, Sco land. Al hough he ini ial aim o his wo k was o suppo he gas oil p ocess unde de elopmen a La e a and o ob ain a mo e undamen al knowledge o hyd oca bon e men a ion, his pe iod in he mid 1960's coincided wi h he in oduc ion o la ge scale comme e alplan s ' o ' he 'ex ac ion o 'highly’pü e n-pa a ins using molecula sie e echnology and, i soon became appa en ha he e was he basis o a second p ocess o he p oduc ion o p o ein concen a e. O he wo p ocesses de eloped by BP o he p oduc ion o p o ein concen a e he "Gas Oil' P ocess and he ‘No mal Pa a in' P ocess, he p esen pape is p incipally conce ned wi h he la e ou esince his is he p ocess wi h which he au ho has mos i s hand knowledge and i is he basis o he 4000 /a Demons a ion Uni a G angemou h. s Re BP Alkane P ocess 19 The p oduc o he BP 'No mal Pa a in' P ocess is ma ke ed in a ious o ms unde he egis e ed ade ma k TOPRINA. 2.0 THEY BP na>=PARAPRINS (PROTEIN: PROCESS 221 °P ocess The p oduc ion o yeas can con enien ly be di ided in o: ( i) eed ma e ials ( ii) e men a ion and(iii) ha es ing A simpli ied low diag am is shown in Figu e l. EPICURE IL. BP n-Pa a in P o ein P ocess. RAW FERMENTATIO MATERIALS N HARVESTING AND DESPATCH VENT VENT SEPARATED HOT WATER AIR INOCULUM MINERALS ——o— e WATER. D D- PARAFFINS m AIR u | FINISHED BP PROTEIN S SEPARATOR F FERMENTER CONCENTRATE. S STERILIZER € COOLER OR CONDENSER Bb DRYER V STORAGE VESSEL 76 K. Allison The e men a ion s ep is he co e o he p ocess and an essen ial ea u e o he n-pa a ins based ou e is ha he e men a ion is ope a ed unde applied asep ic condi ions. This means ha all yeas s o he han he speci ically de eloped cul u e yeas s ain a e excluded om he e men e , and o ensu e he s e ili y o he e men e a s a -up, i is s e ilised by s eam p io o being cha ged. I is impo an o no e ha no pa hogenic bac e ia ha e e e occu ed in ou hyd oca bon e men e s. (i) Feed Ma e ials: The liquid eeds o he e men e comp ise n-pa a in, wa e , nu ien mine al sal s and essen ial g ow h ac o s, The pa a in eeds ock, he ca bon sou ce, isa highly pu e ma e ial o Pha macopoeia s anda d and passes FDA es 121/1146. I is a colou less, odou less ma e ial o high no mal pa a in con en , 99%, on which s ic limi s a e imposed on he a oma ics con en . The quali y o he eeds ock is an impo an ac o in he quali y con ol o he inal p oduc Since, unlike he 'Gas Oil' P ocess, he p o ein p oduc om he n-pa a in p ocess is no subjec ed o a inal sol en ex ac ion s age. BP Alkane P ocess a7 The mine al sal s which a e hose essen ial o he op imum g ow h o he o ganism include e.g. sulpha es o Zn, Mn, Mg e c. and hey a e p epa ed as a concen a ed acidi ied solu ion which is hen con inuously dilu ed wi h wa e o he equi ed medium concen a ion. Tigh speci ica ions .a e se on he quali y o hese sal s as an essen ial pa o he quali y con ol o he inal p oduc . To ensu e he applied asep ic na u e o he e men a ion, hese liquid s eams a e combined and passed o he medium s e ilisa ion sys em whe e hey a e hea ed and held a a high empe a u e su icien ly long o ensu e comple e "kill" o all mic o-o ganisns. Hea economy is achie ed by exchange be ween he incoming cold eed and he ho s e ilised eed. The cooled s e ilised medium passes di ec ly o he e men e . Oxygen necessa y o cell g ow h is p o ided by a con inuous s eam o ai blown in o he e men e h ough a spa ge ing and he excess ai and ca bon dioxide pass o a mosphe e. 78 K. Allison Ni ogen, essen ial o he g ow h o he o ganisn, is injec ed in he o m o ammonia wi h heai s eam. The ammonia se es also o main ain he e men e con en s a he equi ed pH, he addi ion a e being au oma ically con olled by he pH in he e men e . The combined ai and ammonia s eam is s e ilised. (ii) Fe men a ion A he s a o he ope a ion, a small ba ch e men a ion is se up o p o ide an inoculum o he p oduc ion e men e , and i s comple ion synch onised wi h he cha ging o a s e ilised ba ch o medium (wa e , n-pa a in, sal s e c.) which has been pH adjus ed by he addi ion o ammonia. The inoculum is injec ed in o he p oduc ion e men e , s e ilised ai admi ed and agi a ion commenced. The ba ch g ow h in he p oduc ion e men e is allowed o p oceed un il he d y cell weigh eaches he equi ed le el a e which he p ocess is un as a uely con inuous ope a ion wi h he e men e unde s eady s a e condi ions. F esh s e ilised liquid eeds a e passed in o he e men e and he b o h ( he aqueous phase con aining he yeas , excess sal s and a e y small amoun o excess pa a in) is, e aken o in o he ha es ing sec ion unde liquid le el con ol. BP Alkane P ocess 19 The hea e ol ed in he e men a ion oge he wi h he op imum g ow h empe a u e o ca 90°C, necessi a es cooling which is p o ided by ci cula ing he e men e con en s h ough an ex e nal hea exchange . The in ima e mixing o he ou phase sys em o e ec he e icien ans e o hyd oca bon, essen ial mine als and oxygen o he cells is achie ed by a combina ion o ai spa ging and mechanical agi a ion. The e men e a iables, no ably dilu ion a e, empe a u e, pH, agi a ion andai supply a es a e op imised so as o lea e as li le hyd oca bon unconsumed as possible. (iii) Ha es ing Ha es ing is essen ially a wo s age wa e emo al ope a ion comp ising cen i uga ion and sp ay d ying. The con inuous p oduc s eam (b o h) om he e men e is p ocessed in a yeas /wa e con inuous cen i ugal sepa a o which sepa a es a clea aqueous phase and a yeas c eam con aining abou 15% solids. The aqueous phase can hen ei he by ecycled o passed o an e luen plan o ea men . 80 K. Allison The yeas c eam is hen passed o he inal sp ay d ying s age. The sp ay d ied powde con aining 5-6% weigh mois u e is discha ged om he d ie chambe and cyclone sepa a o s in o a pneuma ic con eying sys em and anspo ed o s o age hoppe s om which i can be bagged-o o loaded di ec ly in bulk o despa ch. Al hough cen i uga ion and sp ay d ying a e well es ablished echniques, hei use in he p esen p ocess p esen ed new p oblems and conside able know- how has had o be de eloped o ensu e a high on-s eam e iciency o he equipmen and ep oducible mic obiological quali y o he p oduc . in ( ac he plan is i ually buil o human ood s anda ds. S ainless s eel is used h oughou mos o he plan , de ailed a en ion has o be paid o enginee ing p ac ice h oughou he plan and igo ous cleaning p ocedu es a e adop ed. 2.2 P oduc and P oduc Clea ance The basic p oduc is a bu ee lowing powde which can be made a ailable in di e en o ms depending on he ma ke ou le . To ob ain p oduc o he desi ed pa icle size, s anda d p ocesses o agglome a ion o a i ion can be applied dependen on he ma ke equi emen . BP Alkane P ocess 81 P io o despa ch, he ma e ial has o be clea ed bo h chemically and mic obiologically. The chemical analyses co e , e.g. c ude p o ein con en , ash, phospho us and esidual hyd oca bon. Checks a e also made on ace elemen s such as a senic, an imony, lead, e c. hough con ol o hese a he equi ed le els is exe cised by quali y con ol o he p ocess inpu s eans. The ypical analysis o n-pa a ins - g own yeas s is shown in Table 1. TABLE 1 | | Cha ac e is ics o Alkane-G own Yeas s | Yeas : ¢ ı Mois u e % w <7 30 | C ude P o ein (N x 6.25) % w on 60 d y ma e Lipids a e acid hyd olysis % w 8.-,.10 Ash % w 6.0 Ca % w 0.01 P S w 1.6 Pepsin diges ibili y % 7 80 The c ude p o ein con en compa es wi h ish meal and is conside ably highe han ha o soya a 45%. Because o he na u e o he p ocess, a ia ions in p oduc composi ion a e e y small so ha he p oduc quali y is e y consis en .