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INFLUENCE OF PROTOZOAN GRAZING ON CONTAMINANT BIODEGRADATION. (R825418)
Citation:
Kota, S., R. C. Borden, AND M. A. Barlaz. INFLUENCE OF PROTOZOAN GRAZING ON CONTAMINANT BIODEGRADATION. (R825418). FEMS Microbiology Ecology. FEMS - The Federation of European Microbiological Societies, 29(2):179-189, (1999).
Description:
The influence of protozoan grazing on biodegradation rates in samples from contaminated aquifer sediment was evaluated under aerobic and anaerobic conditions. Predator¯prey biomass ratios suggested that protozoan grazing might be influencing bacterial populations. Experiments under aerobic conditions were conducted with a sediment extract fed with BTEX and treated with protozoan inhibitors (cycloheximide, neutral red, amphotericin-B). After 10 days, BTEX losses were enhanced in the presence of protozoan inhibitors, suggesting that reduced protozoan grazing enhanced the rate of BTEX biodegradation. In tests conducted in macrocosms under anaerobic conditions, treatments included benzaldehyde (carbon substrate), benzaldehyde+cycloheximide, a live control (no carbon), and an abiotic control. In both the benzaldehyde-only and benzaldehyde+cycloheximide treatments, repeated benzaldehyde additions resulted in an increase in the total fermenter population from 103 to 105 cells (g sediment)-1 and in the Fe-reducing population from 101 to 105 cells g-1. However, the protozoan population remained at about 20 cells g-1 in the sediment with no cycloheximide, and there was no difference in benzaldehyde biodegradation in the presence and absence of cycloheximide, suggesting that predation was not a significant control on anaerobic benzaldehyde biotransformation.
Author Keywords: Protozoan grazing; Bioremediation