Analysis of the Continuous Bioconversion of Glycerol by Promotion of Highly Glycerol-Resistant Glycerol-Degrading Bacteria
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We identified component microorganisms in a fed-batch operation by modulating the mixed flora via addition of glucose to achieve continuous bioconversion of hardly degradable glycerol.
To study the microbial community structure of the flora accumulated by the addition of glucose, 16S ribosomal RNA (rRNA) gene was sequenced using PCR with denaturing gradient gel electrophoresis (DGGE).
Burkholderia vietnamiensis, Burkholderia phenoliruptrix, Staphylococcus aureus, Bacillus licheniformis, and Clostridium pasteurianum were identified as component strains. Using the colony containing C. pasteurianum, the hydrogen yield was 0.34 mol/(mol glycerol). C. pasteurianum, B. licheniformis, B. vietnamiensis, and B. phenoliruptrix utilized both glycerol and glucose as substrates and could tolerate high glycerol loads. In early fermentation, predominance of the hydrogen-producing C. pasteurianum resulted in the conversion of glycerol into hydrogen and 1,3-propanediol. In contrast, in late fermentation, the auxiliary degradation of B. licheniformis and the two Burkholderia strains enabled continuous conversion of the glycerol to valuable compounds.
Glucose addition results in a stable flora by optimizing the ratio of highly glycerol-resistant glycerol-degrading bacteria, thereby establishing an anaerobic digestion process that allows continuous conversion of high loads of glycerol.
KeywordsCrude glycerol Fermentation promoter PCR-DGGE Hydrogen Fed-batch culture
This work was supported by JSPS KAKENHI Grant No. JP19656243 and JP21241022 from the Japan Society for the Promotion of Science, an Adaptable and Seamless Technology Transfer Program through Target-driven R&D (A-STEP) from the Japan Science and Technology Agency (JST), and a research grant from the Japan Soap and Detergent Association (JSDA). The sponsors had no role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 14.Speece, R.E.: Anaerobic Biotechnology for Industrial Wastewaters. Archae Press, Nashville (1996)Google Scholar
- 15.Tokumoto, H., Sakuda, N., Nagao, T., Yoshihara, A., Nomura, T.: Immobilization and growth of aceticlastic methanogen on bamboo charcoal. J. Environ. Biotechnol. 12, 155–161 (2012)Google Scholar
- 20.Muyzer, G., de Waal, E.C., Uitterlinden, A.G.: Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified gene coding for 16S rRNA. Appl. Environ. Microbiol. 59, 695–700 (1993)Google Scholar
- 24.Dabrock, B., Bahl, H., Gottschalk, G.: Parameters affecting solvent production by Clostridium pasteurianum. Appl. Environ. Microbiol. 58, 1233–1239 (1992)Google Scholar
- 26.Zhu, C., Nomura, C.T., Perrotta, J.A., Stipanovic, A.J., Nakas, J.P.: Production and characterization of poly-3-hydroxybutyrate from biodiesel-glycerol by Burkholderia cepacia ATCC 17759. Biotechnol. Prog. 26, 424–430 (2010)Google Scholar
- 29.Westerman, P., Ahring, B.K., Mah, R.A.: Threshold acetate concentration for acetate catabolism by aceticlastic methanogenic bacteria. Appl. Environ. Microbiol. 55, 514–515 (1989)Google Scholar
- 30.Henijnen, J.J.: Encyclopedia of Bioprocess Technology: Fermentation, Biocatalysis and Bioseparation. Wiley New York (1999)Google Scholar