title: Yeast adaptation on softwood prehydrolysate.
abstract: Several strains and genera of yeast, including Saccharomyces cerevisiae D5A, Pachysolen tannophilus, S. cerevisiae K-1, Brettanomyces custersii, Candida shehatae, and Candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared to the wild type.
authors.affiliation: Biotechnology Center for Fuels and Chemicals National Renewable Energy Laboratory, Golden, CO 80401 USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Keller
authors.forename: D
authors.initials: D
authors.lastname: Bates
authors.forename: R
authors.initials: R
authors.lastname: Ruiz
authors.forename: Q
authors.initials: Q
authors.lastname: Nguyen
mesh_terms: D000222:Adaptation, Physiological; D002175:Candida / Q000502:physiology; D003120:Colorado; D003470:Culture Media; D032462:Cycadopsida; D005285:Fermentation; D011134:Polysaccharides / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000502:physiology; D015003:Yeasts / Q000502:physiology*
chemical_list: D003470:Culture Media; D011134:Polysaccharides; C007916:hemicellulose