Differential retention and utilization of dissolved organic carbon by bacteria in river sediments

• DOI: 10.4319/lo.2002.47.6.1702
• Publication Date: 2010-06-30T20:25:29Z
• Authors: Helmut Fischer; Anke Sachse; Christian E. W. S...; Martin Pusch
• Keywords: Biogeochemistry; Bacterial growth; Carbon fibers

The differential ability of natural sediment biofilms to store and metabolize specific dissolved organic carbon (DOC) fractions was studied with a set perfusion experiments that combined chromatographic method for the analysis several DOC measurement bacterial abundance activity. High proportions low‐molecular‐weight substances polysaccharides low but significant humic were retained in cores after perfusion. Bacterial production these high (1.7—3.0 × 10 9 cells cm −3 0.7—12.0 µg C h −1 , respectively). abundance, production, turnover times correlated retention various fractions, especially polysaccharides, indicating microbial utilization DOC. Temperature as well quantity quality matter major factors influenced production. However, particulate represented main energy source bacteria. It is concluded certain may be readily utilized growth, irrespective molecular size. Instead, presence chemical groups might decisive. Hence, processing substrates by biofilm largely influence biogeochemistry river waters.