Open AccessCharacterization of microbial biofilms in a thermophilic biogas system by high‐throughput metagenome sequencing
Author(s) -
Rademacher Antje,
Zakrzewski Martha,
Schlüter Andreas,
Schönberg Mandy,
Szczepanowski Rafael,
Goesmann Alexander,
Pühler Alfred,
Klocke Michael
Publication year - 2012
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.1574-6941.2011.01265.x
Subject(s) - methanogenesis , biology , metagenomics , biofilm , anaerobic digestion , microbial population biology , bacteria , biogas , thermophile , archaea , microbiology and biotechnology , clostridium , pyrosequencing , food science , biochemistry , methane , gene , ecology , genetics
DNA s of two biofilms of a thermophilic two‐phase leach‐bed biogas reactor fed with rye silage and winter barley straw were sequenced by 454‐pyrosequencing technology to assess the biofilm‐based microbial community and their genetic potential for anaerobic digestion. The studied biofilms matured on the surface of the substrates in the hydrolysis reactor ( HR ) and on the packing in the anaerobic filter reactor ( AF ). The classification of metagenome reads showed C lostridium as most prevalent bacteria in the HR , indicating a predominant role for plant material digestion. Notably, insights into the genetic potential of plant‐degrading bacteria were determined as well as further bacterial groups, which may assist C lostridium in carbohydrate degradation. M ethanosarcina and M ethanothermobacter were determined as most prevalent methanogenic archaea. In consequence, the biofilm‐based methanogenesis in this system might be driven by the hydrogenotrophic pathway but also by the aceticlastic methanogenesis depending on metabolite concentrations such as the acetic acid concentration. Moreover, bacteria, which are capable of acetate oxidation in syntrophic interaction with methanogens, were also predicted. Finally, the metagenome analysis unveiled a large number of reads with unidentified microbial origin, indicating that the anaerobic degradation process may also be conducted by up to now unknown species.