Work

Bacterioplankton growth in seawater: II. Organic matter utilization during steady-state growth in seawater cultures

Year: 1984

Type: article

Abstract: The objective of this study was to examine the coupling between production of dissolved organic matter in the sea and its utilization by bacteria.We found that growth of natural assemblages of marine bacteria could be sustained in continuous cultures supplied with particle-free (0.22 wm filtered), unsupplemented seawater.Bacteria grew at generation times of 6 to 39 h, showing the ability of the mixed population to use the dissolved organic matter pool at both low and high growth rates.Control experiments with submerged glass coverslips suggest that wall growth was not significant.Bacteria removed 63 % of the total d~ssolved carbohydrates and 34 % of the total dissolved amino acids from the inflow.At a dilution rate of 0.11 h-' (6 h doubling time) this carbon consumption was suff~cient to account for the entire biomass production even if no other substrates were utilized.High turnover rates of L-leucine and L-glutamic acid (8 times h-') could maintain these amino acids at subnanomolar concentrations, in spite of rapid protein hydrolysis.These results suggest that at least some bacteria in the sea can grow rapidly at the expense of ambient levels of dissolved organic matter.Such bacteria may be responsible for the exceedingly low dissolved organic matter concentration found in seawater.

Source: Marine Ecology Progress Series

DOI: 10.3354/meps018041

Authors: Å Hagström, JW Ammerman, S Henrichs, F Azam

Institutions: Scripps Institution of Oceanography, University of California San Diego

Language: English

Topic: Microbial Community Ecology and Physiology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDG: Life below water

Open Access status: bronze

Funders: National Science Foundation, U.S. Department of Energy