Protein content and protein synthesis rates of planktonic marine bacteria

作者：Meinhard Simon, Farooq I. Azam · 发表于：Marine Ecology Progress Series · 年份：1989 · DOI：10.3354/meps051201 · 被引用次数：1837 · 研究领域：Microbial Community Ecology and Physiology、Methane Hydrates and Related Phenomena、Marine and coastal ecosystems

Bacterial carbon production is an important parameter in understanding the flows of carbon and energy in aquatic ecosystems, but has been difficult to measure.Present methods are based on measuring the rate of cell production, and thus require a knowledge of cellular carbon content of the growing bacteria to convert cell production into carbon production.We have examined the possibility that protein synthesis rate of pelagic bacteria might serve as the basis for directly estimating bacterial carbon production.We measured bacterial protein content and protein production of pelagic bacteria.Bacterial protein content was measured as amino acids by high performance liquid chromatography of cell hydrolysates of bacterial assemblages of mean diameters from 0.026 to 0.4 km.Cellular protein:volume (w/v) in the largest bacteria was 15.2 '10 (similar to cultured Escherichia coli] but increased with decreasing cell size to 46.5 % in 0.026 pm bacteria.Protein per bacterium was correlated with cell volume by the power function y = 8 8 .~2 ~'(r2 = 0.67; p C 0.01; n = 25).An inventory of major bacterial macromolecular pools revealed that cell protein:dry weight and cell protein:carbon were essentially constant (63 % and 54 %. respectively) for the entire cell size range although cell protein:volume increased with decreasing cell size.Thus, the smaller cells in the size range were rich in carbon and dry weight and poor in water compared with larger cells.We established the experimental condi...