caa a22 4500 397552408 CHVBK 20180308164753.0 cr unu---uuuuu 161202e199607 xx s 000 0 eng 10.1111/j.1574-6941.1996.tb00312.x doi (NATIONALLICENCE)oxford-10.1111/j.1574-6941.1996.tb00312.x Bacterivory by the ciliate Euplotes in different states of hunger [Elektronische Daten] [Mikhail V. Zubkov, Michael A. Sleigh] The feeding of the marine ciliate Euplotes mutabilis was studied using bacteria (Vibrio natriegens) doubly labelled with 3H-thymidine and 14C-leucine. In the presence of abundant bacteria (30 × 106 bacteria ml−1), an average Euplotes cell (initially without food vacuoles) with a protein content of 12 ng consumed 16 × 103 bacteria in the first hour and 27 × 103 bacteria over four hours, accumulating about 60% of the bacterial protein into ciliate macromolecules. Euplotes which had been starved or under-fed to reduce cell protein biomass to 7 or 9 ng consumed significantly fewer bacteria, but the gross growth efficiency for protein did not change. The rate of consumption of bacteria by large Euplotes of protein content 15 ng was initially less than that of 12 ng cells, and it decreased markedly before the end of a 4-hour experiment. Recently divided cells ingested bacteria rapidly, but showed a reduced gross growth efficiency of about 40%. At low bacterial concentrations (6 × 106 bacteria ml−1) the rates of ingestion were markedly reduced to between and of maximal levels; the smallest cells could not sustain feeding activity at the low prey concentration and gross growth efficiency fell from 43 to 20% during a 4-hour experiment. The strategy adopted by Euplotes in response to local fluctuations in food supply involves rapid consumption with high growth efficiency in times of plenty, but slow shrinkage without cell division to survive in times of shortage. © 1996 Federation of European Microbiological Societies. Published by Elsevier Science B.V. Protozoan grazing nationallicence Bacteria consumption nationallicence Gross growth efficiency nationallicence Starvation nationallicence Microbial loop nationallicence Dual radioactive-labelled bacteria nationallicence Zubkov Mikhail V. Department of Biology, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK aut Sleigh Michael A. Department of Biology, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK aut FEMS Microbiology Ecology Blackwell Publishing Ltd 20/3(1996-07), 137-147 20:3<137 1996 20 femsec https://doi.org/10.1111/j.1574-6941.1996.tb00312.x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1111/j.1574-6941.1996.tb00312.x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zubkov Mikhail V. Department of Biology, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK aut NATIONALLICENCE 700 1- Sleigh Michael A. Department of Biology, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK aut NATIONALLICENCE 773 0- FEMS Microbiology Ecology Blackwell Publishing Ltd 20/3(1996-07), 137-147 20:3<137 1996 20 femsec Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford