Nature Biotechnology Publishes Pichia stipitis Sequence, Generated by DOE-JGI
Xylose is a major constituent of plant lignocellulose, a key component of plant cell walls and therefore a major constituent of the biomass that this Nation, under the President’s Advanced Energy Initiative, will explore for Bioenergy to reduce dependence on foreign oil. A team headed by Tom Jeffries of the USDA Forest Products Lab in Madison, WI, working closely with scientists at the DOE Joint Genome Institute, has determined the complete 15.4 million base pair genome sequence of the yeast Pichia stipitis. P. stipitis is a well-studied, native xylose-fermenting yeast whose mechanism and regulation of xylose metabolism have been characterized. P. stipitis, under optimum culture conditions, can ferment xylose to ethanol with 80% of theoretically maximum yields. The sequence data have revealed unusual aspects of genome organization, numerous genes for bioconversion, a preliminary insight into regulation of central metabolic pathways. The sequence of P. stipitis can be expected to provide additional biological “parts” for the determination and possible assembly of metabolic pathways that can efficiently generate ethanol from xylose and play a role in a biomass-to-biofuel economy.