Microbial populations associated with fixed- and floating-bed reactors during a two-stage anaerobic process Authors Vikas Sonakya Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Neena Raizada Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Martina Hausner Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Peter A. Wilderer Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Keywords: Methanosaeta, Methanosarcina, anaerobic digestion, methanogenesis, bed reactors Abstract Microbial populations associated with methanogenic fixed- or floating-bed bioreactors used for anaerobic digestion of lignocellulosic waste were investigated. Fluorescent in situ hybridization (FISH) was used to characterize microorganisms in samples obtained from different heights in the reactors, which were operated in a semi-continuous manner (feeding and mixing once every 2 days). The FISH results showed that Methanosaeta concilii cells were most numerous at the bottom of both reactors. M. concilii cells were more abundant in the fixed-bed reactor (FXBR), which performed better than the floating-bed reactor (FLBR). Species of the Methanosarcina genera (mainly M. barkeri and M. mazei) were also observed in the FLBR but rarely in the FXBR. Methane production in each of the reactors ranged from 0.29 to 0.33 m3 CH4/kgCODrem (chemical oxygen demand removed). The removal of volatile fatty acids (VFA; 70–75 h) in the FXBR was more efficient than in the FLBR. [Int Microbiol 2007; 10(4):245-251] Author Biographies Vikas Sonakya, Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Neena Raizada, Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Martina Hausner, Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Peter A. Wilderer, Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Institute for Water Quality Control and Waste Management, Technical University of Munich, Garching, Germany Downloads PDF Published 2010-01-21 Issue Vol. 10 No. 4 (2007) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
