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Linking autotrophic activity in environmental samples with specific bacterial taxa by detection of 13 C‐labelled fatty acids
Author(s) -
Knief Claudia,
Altendorf Karlheinz,
Lipski André
Publication year - 2003
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.2003.00510.x
Subject(s) - autotroph , biology , fatty acid , bacteria , thiobacillus , labelling , oxidizing agent , nitrospira , biochemistry , environmental chemistry , food science , chromatography , microorganism , chemistry , organic chemistry , genetics
Summary A method for the detection of physiologically active autotrophic bacteria in complex microbial communities was developed based on labelling with the stable isotope 13 C. Labelling of autotrophic nitrifying, sulphur‐oxidizing and iron‐oxidizing populations was performed in situ by incubation with NaH[ 13 C]O 3 . Incorporated label into fatty acid methyl esters (FAMEs) was detected and quantified using gas chromatography‐mass spectrometry in single ion monitoring mode. Before the analyses of different environmental samples, the protocol was evaluated in pure culture experiments. In different environmental samples a selective labelling of fatty acids demonstrated which microbial taxa were responsible for the respective chemolithoautotrophic activity. The most strongly labelled fatty acids of a sample from a sulphide treating biofilter from an animal rendering plant were cis ‐7‐hexadecenoic acid (16:1 cis7) and 11‐methyl hexadecanoic acid (16:0 11methyl), which are as‐yet not known for any sulphide‐oxidizing autotroph. The fatty acid labelling pattern of an experimental biotrickling filter sample supplied with dimethyl disulphide clearly indicated the presence and activity of sulphide‐oxidizing bacteria of the genus Thiobacillus . For a third environmental sample from an acid mining lake sediment, the assignment of autotrophic activity to bacteria of the genus Leptospirillum but not to Acidithiobacillus could be made by this method, as the fatty acid patterns of these bacteria show clear differences.