Open AccessMutants of Bacillus stearothermophilus lacking NAD‐linked l ‐lactate dehydrogenase
Author(s) -
Payton Mark A.,
Hartley Brian S.
Publication year - 1985
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1985.tb01621.x
Subject(s) - lactic acid , fermentation , nad+ kinase , biochemistry , lactate dehydrogenase , ethanol , mutant , substrate (aquarium) , dehydrogenase , enzyme , biology , alcohol dehydrogenase , bacillales , ethanol fermentation , chemistry , bacteria , gene , ecology , genetics , bacillus subtilis
Bacillus stearothermophilus produces low levels of ethanol following fermentation of glucose at temperatures in excess of 60°C. A major by‐product is l ‐lactic acid. To improve ethanol yields mutants of this organism were isolated which lacked NAD‐linked l ‐lactate dehydrogenase, the enzyme responsible for lactic acid production. This was achieved by selection for resistance to a suicide substrate, fluoropyruvate. Such mutants no longer produced lactic acid and yields of ethanol from glucose were increased by at least a factor of two.