Isolation and Characterization of Acid-Tolerant, Thermophilic Bacteria for Effective Fermentation of Biomass-Derived Sugars to Lactic Acid

• DOI: 10.1128/aem.72.5.3228-3235.2006
• Publication Date: 2006-05-04T02:49:21Z
• Authors: Milind A. Patel; Mark S. Ou; Roberta Harbrucker; Henry C. Aldrich; Marian L. Buszko; Lonnie O. Ingram; K. T. Shanmugam
• Keywords: Bacillus coagulans; Pentose; Hemicellulose

ABSTRACT Biomass-derived sugars, such as glucose, xylose, and other minor can be readily fermented to fuel ethanol commodity chemicals by the appropriate microbes. Due differences in optimum conditions for activity of fungal cellulases that are required depolymerization cellulose fermentable sugars growth fermentation characteristics current industrial microbes, simultaneous saccharification (SSF) is envisioned at not optimal cellulase activity, leading a higher-than-required cost SSF. We have isolated bacterial strains grew both glucose major components hemicellulose, respectively, l (+)-lactic acid 50°C pH 5.0, also activity. Xylose was metabolized these new isolates through pentose-phosphate pathway. As expected metabolism xylose pathway, [ 13 C]lactate accounted more than 90% total C-labeled products from C]xylose. Based on fatty profile 16S rRNA sequence, cluster with Bacillus coagulans , although B. type strain, ATCC 7050, failed utilize carbon source. These potential reduce SSF minimizing amount cellulases, significant component use biomass renewable resource, production fuels chemicals.