Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-7-2
pubmed:abstractText
Rhizopus oryzae is subdivided into two groups based on genetic and phenotypic differences. Type-I isolates accumulate primarily lactic acid when grown in the presence of a fermentable carbon source and contain two lactate dehydrogenase genes, ldhA and ldhB. Type-II isolates synthesize predominantly fumaric acid and only have an ldhB gene. In this study, we determined that ldhB transcript is only minimally expressed in the Type-II isolate R. oryzae 99-880. LdhB enzyme purified from gene clones isolated from the Type-I isolate R. oryzae NRRL 395 and the Type-II isolate R. oryzae 99-880 each showed reductive LDH activity (pyruvate to lactate), while no oxidative LDH activity (lactate to pyruvate) was detected in either preparation. A transformation system was then developed for the first time with R. oryzae 99-880, using a uracil auxotrophic isolate that could be complemented with an orotate phosphoribosyltransferase gene, pyrF, isolated in this study. Transformation of this Type-II isolate with the ldhA gene from R. oryzae NRRL 395 resulted in reductive LDH activity between 1.0 and 1.8 U/mg total protein. Additionally, transformed isolates grown with glucose accumulated up to 27 g lactic acid/l with a concurrent decrease in fumaric acid, ethanol, and glycerol compared with the untransformed and vector-transformed control strains.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0172-8083
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-33
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Native and modified lactate dehydrogenase expression in a fumaric acid producing isolate Rhizopus oryzae 99-880.
pubmed:affiliation
Bioproducts and Biocatalysis Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, 1815 N. University Street, Peoria, IL 61604, USA. Chris.Skory@ars.usda.gov
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural