An isolated cellulolytic Escherichia coli from bovine rumen produces ethanol and hydrogen from corn straw

• Published in: Biotechnology for biofuels Vol. 10; no. 1; p. 165
• Main Authors: Pang, Jian, Liu, Zhan-Ying, Hao, Min, Zhang, Yong-Feng, Qi, Qing-Sheng
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.06.2017; BioMed Central; BMC
• Subjects: Bacteria; Bacteriology; Biochemical characteristics; Biochemistry; Biodegradation; Biodiesel fuels; Biofuels; Biomass; Biomass energy; Cellulase; Cellulolytic Escherichia coli; Cellulose; Chemicals; Consolidation; Construction; Corn; Corn straw; Degradation; E coli; Endoglucanase; Enzymatic activity; Enzyme activity; Enzymes; Escherichia coli; Ethanol; Fermentation; Fuels; Fungi; Gene sequencing; Genes; Glucosidase; Hemicellulose; Isolation; Lignin; Lignocellulose; Microorganisms; pH effects; Physical characteristics; Properties; Researchers; rRNA 16S; Rumen; Straw; Studies; Zea mays; Cellulolytic Escherichia coli; Isolation; Rumen; Ethanol; Cellulase
• ISSN: 1754-6834; 1754-6834
• DOI: 10.1186/s13068-017-0852-7

Lignocellulosic biomass is the most abundant resource on earth. Lignocellulose is mainly composed of cellulose, hemicelluloses, and lignin. The special construction of three kinds of constituents led to the prevention of effective degradation. The goal of this work was to investigate the great potentials of bovine rumen for novel cellulolytic bacterial isolation, which may be used for chemicals and biofuel production from lignocellulose. A cellulolytic strain, ZH-4, was isolated from Inner Mongolia bovine rumen. This strain was identified as by morphological, physiological, and biochemical characteristics and 16S rDNA gene sequencing. The extracellular enzyme activity analysis showed that this strain produces extracellular cellulases with an exoglucanase activity of 9.13 IU, an endoglucanase activity of 5.31 IU, and a β-glucosidase activity of 7.27 IU at the pH 6.8. This strain was found to produce 0.36 g/L ethanol and 4.71 mL/g hydrogen from corn straw with cellulose degradation ratio of 14.30% and hemicellulose degradation ratio of 11.39%. It is the first time that a cellulolytic was isolated and characterized form the bovine rumen. This provided a great opportunity for researchers to investigate the evolution mechanisms of the microorganisms in the rumen and provided great chance to produce biofuels and chemicals directly from engineered using consolidated bioprocess.