Effect of growth conditions on cofactor linked xylose reductase activity in pachysolen tannophilus

Vancauwenberge, J.E.; Bolen, P.L.; Mccracken, D.A.; Bothast, R.J.

Enzyme and Microbial Technology 11(10): 662-667

1989


ISSN/ISBN: 0141-0229
DOI: 10.1016/0141-0229(89)90005-7
Accession: 007248887

Download citation:  
Text
  |  
BibTeX
  |  
RIS

Article/Abstract emailed within 0-6 h
Payments are secure & encrypted
Powered by Stripe
Powered by PayPal

Abstract
Xylose reductase (E.C.1.1.1.21) is the enzyme responsible for conversion of xylose to xylitol in the fermentation of pentoses to ethanol by the yeast P. tannophilus. Cell-free extracts from anaerobically grown cells yield two forms of xylose reductase. One form requires either NADPH or NADH as a cofactor and has an isoelectric point (pI) of 5.1. A second from requires only NADPH as a cofactor and has a pI of 6.4. Cell-free extracts from aerobically grown cells also yielded two reductase forms, but the NADPH-active form predominated. Both forms have a molecular weight of 36,000 daltons. These two forms exhibiting xylose reductase activity may exist as two separate proteins or possibly as a single protein that undergoes modification.