Benthic bacterial biomass supported by streamwater dissolved organic matter
Bacterial biomass in surface sediments of a headwater stream was measured as a function of dissolved organic carbon (DOC) flux and temperature. Bacterial biomass was estimated using epifluorescence microscopic counts (EMC) and ATP determinations during exposure to streamwater containing 1,788μg DOC/...
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Published in | Microbial ecology Vol. 10; no. 4; p. 335 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
01.12.1984
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Online Access | Get more information |
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Summary: | Bacterial biomass in surface sediments of a headwater stream was measured as a function of dissolved organic carbon (DOC) flux and temperature. Bacterial biomass was estimated using epifluorescence microscopic counts (EMC) and ATP determinations during exposure to streamwater containing 1,788μg DOC/liter and after transfer to groundwater containing 693μg DOC/liter. Numbers of bacteria and ATP concentrations averaged 1.36×10(9) cells and 1,064 ng per gram dry sediment, respectively, under initial DOC exposure. After transfer to low DOC water, biomass estimates dropped by 53 and 55% from EMC and ATP, respectively. The decline to a new steady state occurred within 4 days from ATP assays and within 11 days from EMC measures. A 4°C difference during these exposures had little effect on generation times. The experiment indicated that 27.59 mg/hour of natural DOC supported a steady state bacterial biomass of approximately 10μg C/g dry weight of sediment (from EMC determinations). Steady state bacterial biomass estimates on sediments that were previously muffled to remove organic matter were approximately 20-fold lower. The ratio of GTP∶ATP indicated differences in physiological condition or community composition between natural and muffled sediments. |
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ISSN: | 0095-3628 |
DOI: | 10.1007/BF02015558 |