From bacteria to zooplankton, the impact of food-limitation on their physiology and biochemistry

From bacteria to zooplankton, the impact of food-limitation on their physiology and biochemistry 2015 Aquatic Sciences Meeting Aquatic Sciences: Global And Regional Perspectives — North Meets South M. Gómez, T.T. Packard, F. Maldonado, A. Herrera, I. Martínez, N. Osma, I. FernándezUrruzola, V. Romero-Kutzner, M.T. Tamés-Espinosa & M.A. Viera-Rodríguez. Marine Ecophysiology Group EOMAR Universidad de Las Palmas de Gran Canaria The impact of food-limitation Starvation Let’s have a look into a key metabolic pathway, The Krebs Cycle Substrates ETS controls the ATP production. o o o o o o o matrtx • • What happens to respiration when organisms pass from well-fed to starvation conditions? From bacteria to zooplankton Phisiological experimentation Marine enzymology Respiratory metabolism and pyridine nucleotides levels in the marine dinoflagellate Oxyrrhis marina during starvation. N. Osma, I. Fernández-Urruzola, M. Aristizabal T.T. Packard, M. Gómez Respiratory metabolism and pyridine nucleotides levels in the marine dinoflagellate Oxyrrhis marina during starvation. N. Osma, I. Fernández-Urruzola, M. Aristizabal T.T. Packard, M. Gómez First time Pyridine nucleotides have been measured in plankton Respiration decreases during food-limitation by a third and displays a circadian rhythm. ETS activity is constant during food-limitation. Starvation causes NH4+ excretion to decrease however GDH activity remains constant. A ,-.. 0,25 ...... !,..... o ..... o.. • O) E 0,20 • ...... .'..e • + O, 15 '<!" I z • o • E O, 10 :::t - e o :¡::¡ Q) L.. 0,05 (.) X Q) + '<!" I z 0,00 o Cont ents l ists available at ScienceDir ect journal of Experimental Marine Biology and Ecology l )l 1 1 journa l homepage : www .e l se v ier . com / locate /j embe GDH activity and ammonium excretion in the marine mysid, Leptomysis lingvura: Effects of age and starvation l. Fernández-Urruzola *, T.T. Packard, M. Gómez • • 20 y= 0.17 X+ e-00 2x (r2 = 0.56, n = 19) • • • 40 60 Time (hours) o o o o o • o 8 80 B ...... !,..... o L.. a. O) E ...... .'..e + "<t I z o E :t - :>. - · :; u ro I o <.9 3 y= 0. 001x + 1.43 (r 2 = 0.002, n = 19) • • 2 • • 1 1 • • • • • • • • • o o 20 40 60 Time (hours) o o • o o o o o o o 80 What happen to the R/Q during starvation? Romero-Kutzner et al., 2015 ETS Other Uses: RQ understanding Romero-Kutzner et al., 2015 Conclusion: 1.- Starvation decreases respiration and ammonia excretion, but not their enzyme-based potentials. 2.-Metabolic Theory of Ecology can not predict respiration under conditions of starvation. 3.- Starvation decreases the energy currency molecule needed for carbón synthesis. 4.- Starvation can cause R/Q to increase 10-fold. Marine Ecophysiology Group: EOMAR Thank you! Acknowledgements EXZOME Project CTM 2008-01616/MAR BIOMBA Project CTM 2012-32729/MAR RETAMAR Project CEI 10/00018