T. Jeffries, USDA Forest Products Lab, Madison, WI.

Pachysolen tannophilus is a rare and unusual yeast, having been isolated only once by Boidin and Adzet in 1957 (3). P. tannophilus was the first yeast shown to convert xylose directly to ethanol (6, 7). It ferments glucose, mannose, xylose, galactose, and even glycerol to ethanol (5). P. tannophilus produces ethanol only slowly from xylose, but it proceeds under completely anaerobic conditions with the concomitant production of significant amounts of xylitol and some acetic acid. It uses nitrate as a nitrogen source, which stimulates the aerobic production of ethanol from xylose while blocking anaerobic xylose metabolism (2). Its xylose reductase (1) and xylulokinase
activities are induced and hexokinase rapidly inactivated (8) when cells are cultivated on xylose (4). It has been reported to have seven to eight chromosomes (4)

References

1. Bolen, P. L., G. T. Hayman, and H. S. Shepherd. 1996. Sequence and analysis of an aldose (xylose) reductase gene from the xylose-fermenting yeast Pachysolen tannophilus. Yeast 12:1367-1375.
2. Jeffries, T. W. 1983. Effects of Nitrate on fermentation of xylose and glucose by Pachysolen tannophilus. Bio-Technology 1:503-506.
3. Kurtzman, C. P. 1998. Pachysolen Boidin and Adzet, vol. Elsevier, Amsterdam.
4. Maleszka, R., and M. Skrzypek. 1990. Assignment of cloned genes to electrophoretically separated chromosomes of the yeast Pachysolen tannophilus. FEMS Microbiology Letters 69:79-82.
5. Maleszka, R., P. Y. Wang, and H. Schneider. 1982. Ethanol production from D-galactose and glycerol by Pachysolen tannophilus. Enzyme and Microbial Technology 4:349-352.
6. Schneider, H., P. Y. Wang, Y. K. Chan, and R. Maleszka. 1981. Conversion of D-xylose into ethanol by the yeast Pachysolen tannophilus. Biotechnology Letters 3:89-92.
7. Slininger, P. J., R. J. Bothast, J. E. Vancauwenberge, and C. P. Kurtzman. 1982. Conversion of D-xylose to ethanol by the yeast Pachysolen tannophilus. Biotechnology and Bioengineering 24:371-384.
8. Yang, V. W., and T. W. Jeffries. 1997. Regulation of phosphotransferases in glucose- and xylose-fermenting yeasts. Applied Biochemistry and Biotechnology 63-65:97-108.