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Poster Presentation 2-11
Construction of Xylose Utilizing Zymomonas mobilis Integrants Based on Strain ATCC31821
Yat-Chen Chou, William Howe, Kent Evans, Min Zhang
Biotechnology Division for Fuels and Chemicals, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401
Telephone: (303) 384-7766; Fax: (303) 384-7752; E-mail: yatchen_chou@nrel.gov
Z. mobilis has been recognized as a viable alternative to yeast for ethanol production from biomass for its high conversion yield, high ethanol tolerance, resistance to pretreated hardwood hydrolysate, and fermentation capability at lower pH. In previous research of Zymomonas metabolic engineering, we developed genomically integrated Z. mobilis ATCC39676-based strains, which can ferment pentose sugars (D-xylose and L-arabinose) and glucose simultaneously to ethanol. While ATCC39676-based strains are suitable for the SSCF process (e.g., corn stover hydrolysate) in which total sugar concentration is moderate and glucose very low, we found that Z. mobilis ATCC31821-based, plasmid-bearing strains demonstrated superior performance in hydrolysates containing high soluble sugars (such as corn fiber, and rice straw from concentrated acid hydrolysis) and are tolerant to higher temperature and acetic acid. Strain ATCC38121 has been very difficult for genetic manipulation; however, we have overcome the major barriers for genetic engineering and will report the process of gene integration of xylose utilization pathway in the genome of Z. mobilis ATCC 31821.
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