Open AccessEnrichment and characterization of a sulfate‐reducing toluene‐degrading microbial consortium by combining in situ microcosms and stable isotope probing techniques
Author(s) -
Bombach Petra,
Chatzinotas Antonis,
Neu Thomas R.,
Kästner Matthias,
Lueders Tillmann,
Vogt Carsten
Publication year - 2010
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2009.00809.x
Subject(s) - toluene , stable isotope probing , microcosm , biology , microbial consortium , environmental chemistry , terminal restriction fragment length polymorphism , chromatography , microbiology and biotechnology , chemistry , biochemistry , bacteria , organic chemistry , microorganism , gene , restriction fragment length polymorphism , polymerase chain reaction , genetics
A toluene‐degrading microbial consortium was enriched directly in a BTEX‐contaminated aquifer under sulfate‐reducing conditions using in situ microcosms consisting of toluene‐loaded activated carbon pellets. Degradation of toluene and concomitant sulfide production by the consortium was subsequently demonstrated in laboratory microcosms. The consortium was physiologically and phylogenetically characterized by isotope tracer experiments using nonlabeled toluene, [ 13 C]‐α‐toluene or [ 13 C 7 ]‐toluene as growth substrates. Cells incubated with [ 13 C]‐α‐toluene or [ 13 C 7 ]‐toluene incorporated 8–15 at.% 13 C and 51–57 at.% 13 C into total lipid fatty acids, respectively, indicating a lower specific incorporation of 13 C from [ 13 C 7 ]‐toluene. In order to identify the toluene‐assimilating bacteria, the incorporation of carbon from both [ 13 C]‐α‐toluene and [ 13 C 7 ]‐toluene into rRNA was analyzed by stable isotope probing. Time and buoyant density‐resolved 16S rRNA gene‐based terminal restriction fragment length polymorphism profiles, combined with cloning and sequencing, revealed that an uncultured bacterium (99% sequence similarity) related to the genus Desulfocapsa was the main toluene‐degrading organism in the consortium. The ratio of the respective terminal restriction fragments changed over time, indicating trophic interactions within this consortium.