Open AccessFunctionally redundant but dissimilar microbial communities within biogas reactors treating maize silage in co‐fermentation with sugar beet silage
Author(s) -
Langer Susanne G.,
Ahmed Sharif,
Einfalt Daniel,
Bengelsdorf Frank R.,
Kazda Marian
Publication year - 2015
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12308
Subject(s) - methanosaeta , biogas , silage , digestate , anaerobic digestion , fermentation , pulp and paper industry , biology , amplicon sequencing , raw material , food science , sugar beet , microbial population biology , microbiology and biotechnology , agronomy , methane , bacteria , 16s ribosomal rna , ecology , genetics , engineering
Summary Numerous observations indicate a high flexibility of microbial communities in different biogas reactors during anaerobic digestion. Here, we describe the functional redundancy and structural changes of involved microbial communities in four lab‐scale continuously stirred tank reactors ( CSTRs , 39°C, 12 L volume) supplied with different mixtures of maize silage ( MS ) and sugar beet silage ( SBS ) over 80 days. Continuously stirred tank reactors were fed with mixtures of MS and SBS in volatile solid ratios of 1:0 (Continuous Fermenter ( CF ) 1), 6:1 ( CF 2), 3:1 ( CF 3), 1:3 ( CF 4) with equal organic loading rates ( OLR 1.25 kgVS m −3 d −1 ) and showed similar biogas production rates in all reactors. The compositions of bacterial and archaeal communities were analysed by 454 amplicon sequencing approach based on 16 S rRNA genes. Both bacterial and archaeal communities shifted with increasing amounts of SBS . Especially pronounced were changes in the archaeal composition towards M ethanosarcina with increasing proportion of SBS , while M ethanosaeta declined simultaneously. Compositional shifts within the microbial communities did not influence the respective biogas production rates indicating that these communities adapted to environmental conditions induced by different feedstock mixtures. The diverse microbial communities optimized their metabolism in a way that ensured efficient biogas production.