A Low-Tech Bioreactor System for the Enrichment and Production of Ureolytic Microbes

• Main Authors: Masataka Aoki, Takuya Noma, Hiroshi Yonemitsu, Nobuo Araki, Takashi Yamaguchi, Kazuyuki Hayashi
• Format: Article
• Language: English
• Published: Exeley Inc. 2018-03-01
• Series: Polish Journal of Microbiology
• Subjects: DHS bioreactor system; enrichment culture; microbially induced carbonate precipitation (MICP); ureolytic microbes
• Online Access: https://www.exeley.com/exeley/journals/polish_journal_of_microbiology/67/1/pdf/10.5604_01.3001.0011.6144.pdf

Ureolysis-driven microbially induced carbonate precipitation (MICP) has recently received attention for its potential biotechnological applications. However, information on the enrichment and production of ureolytic microbes by using bioreactor systems is limited. Here, we report a low-tech down-flow hanging sponge (DHS) bioreactor system for the enrichment and production of ureolytic microbes. Using this bioreactor system and a yeast extract-based medium containing 0.17 M urea, ureolytic microbes with high potential urease activity (> 10 μmol urea hydrolyzed per min per ml of enrichment culture) were repeatedly enriched under non-sterile conditions. In addition, the ureolytic enrichment obtained in this study showed in vitro calcium carbonate precipitation. Fluorescence in situ hybridization analysis showed the existence of bacteria of the phylum Firmicutes in the bioreactor system. Our data demonstrate that this DHS bioreactor system is a useful system for the enrichment and production of ureolytic microbes for MICP applications.