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Adaptation to a quaternary ammonium surfactant by suspended microbial communities in a model stream
Author(s) -
Shimp Robert J.,
Schwab Burney S.,
Larson Robert J.
Publication year - 1989
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620080810
Subject(s) - microbial population biology , pulmonary surfactant , ammonium , biodegradation , environmental chemistry , chemistry , ammonium chloride , bacteria , ecology , biology , biochemistry , organic chemistry , genetics
Abstract The adaptation of suspended microbial communities to a quaternary ammonium surfactant, dodecyltrimethylammonium chloride (C‐12TMAC), was studied in a model stream dosed with the surfactant. Water collected at several sites downstream of the introduction of C‐12TMAC was tested for the ability of the suspended microbial community to biodegrade the surfactant and several naturally occurring chemicals. At the concentrations tested, C‐12TMAC had no significant impact on the total size of the microbial community or its ability to degrade natural materials (glucose or amino acids). However, the ability of the community to degrade C‐12TMAC increased by 10‐ to 1,000‐fold during exposure at all locations downstream from the dose site. After prolonged exposure, the C‐12TMAC‐degrading microbial community also developed a resistance to “shock loads” of the surfactant (i.e., adaptation was maintained even when input concentrations were increased to levels that previously decreased biodegradation activity). Adaptation was a stable process as long as some quantity of C‐12TMAC entered the stream. However, when input of surfactant was halted, the microbial community lost its ability to rapidly degrade the material. Upon redosing the stream with a low concentration of the chemical, the microbial community rapidly regained its enhanced biodegradative activity toward C‐12TMAC. These results illustrate the importance of adaptation in determining the fate of synthetic chemicals in aquatic environments.