title: Cellulose digestion and metabolism induced biocatalytic transitions in anaerobic microbial ecosystems.
abstract: Anaerobic digestion of highly polymerized biomass by microbial communities present in diverse microbial ecosystems is an indispensable metabolic process for biogeochemical cycling in nature and for industrial activities required to maintain a sustainable society. Therefore, the evaluation of the complicated microbial metabolomics presents a significant challenge. We here describe a comprehensive strategy for characterizing the degradation of highly crystallized bacterial cellulose (BC) that is accompanied by metabolite production for identifying the responsible biocatalysts, including microorganisms and their metabolic functions. To this end, we employed two-dimensional solid- and one-dimensional solution-state nuclear magnetic resonance (NMR) profiling combined with a metagenomic approach using stable isotope labeling. The key components of biocatalytic reactions determined using a metagenomic approach were correlated with cellulose degradation and metabolic products. The results indicate that BC degradation was mediated by cellulases that contain carbohydrate-binding modules and that belong to structural type A. The degradation reactions induced the metabolic dynamics of the microbial community and produced organic compounds, such as acetic acid and propionic acid, mainly metabolized by clostridial species. This combinatorial, functional and structural metagenomic approach is useful for the comprehensive characterization of biomass degradation, metabolic dynamics and their key components in diverse ecosystems.
authors: Research Planning and Management Group, Kajima Technical Research Institute, Kajima Corporation, 2-19-1 Tobitakyu, Chofu, Tokyo 182-0036, Japan. akira@kajima.com.
authors: Akira
authors: A
authors: Yamazawa
authors: Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehirocho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. iikura@tsurumi.yokohama-cu.ac.jp.
authors: Tomohiro
authors: T
authors: Iikura
authors: Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehirocho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. maasii@tsurumi.yokohama-cu.ac.jp.
authors: Yusuke
authors: Y
authors: Morioka
authors: RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. amiu.shino@riken.jp.
authors: Amiu
authors: A
authors: Shino
authors: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 599-8531, Japan. ogata@plant.osakafu-u.ac.jp.
authors: Yoshiyuki
authors: Y
authors: Ogata
authors: Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehirocho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. amiu.shino@riken.jp.
authors: Yasuhiro
authors: Y
authors: Date
authors: Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehirocho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. jun.kikuchi@riken.jp.
authors: Jun
authors: J
authors: Kikuchi