* To whom correspondence should be addressed.
Received April 23, 1999; Revision received October 4, 1999
Tungsten in the presence of molybdenum stimulates nitrate reductase activity and growth of the salt-tolerant yeast Rhodotorula glutinis on medium with nitrates. Tungsten is not incorporated in proteins possessing nitrate reductase activity. A significant increase in molybdenum cofactor in cells grown on medium with equimolar amounts of molybdenum and tungsten may relate to the stimulatory action of tungsten.
KEY WORDS: nitrate reductase, tungsten, molybdenum