Disruption of the membrane-bound alcohol dehydrogenase-encoding gene improved glycerol use and dihydroxyacetone productivity in Gluconobacter oxydans.
Dihydroxyacetone (DHA) production from glycerol by Gluconobacter oxydans is an industrial form of fermentation, but some problems exist related to microbial DHA production. For example, glycerol inhibits DHA production and affects its biological activity. G. oxydans produces both DHA and glyceric acid (GA) from glycerol simultaneously, and membrane-bound glycerol dehydrogenase and membrane-bound alcohol dehydrogenases are involved in the two reactions, respectively. We discovered that the G. oxydans mutant DeltaadhA, in which the membrane-bound alcohol dehydrogenase-encoding gene (adhA) was disrupted, significantly improved its ability to grow in a higher concentration of glycerol and to produce DHA compared to a wild-type strain. DeltaadhA grew on 220 g/l of initial glycerol and produced 125 g/l of DHA during a 3-d incubation, whereas the wild-type did not. Resting DeltaadhA cells converted 230 g/l of glycerol aqueous solution to 139.7 g/l of DHA during a 3-d incubation. The inhibitory effect of glycerate sodium salt on DeltaadhA was investigated. An increase in the glycerate concentration at the beginning of growth resulted in decreases in both growth and DHA production.
Habe
Hiroshi
H
Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST). hiroshi.habe@aist.go.jp
Fukuoka
Tokuma
T
Morita
Tomotake
T
Kitamoto
Dai
D
Yakushi
Toshiharu
T
Matsushita
Kazunobu
K
Sakaki
Keiji
K
D000426:Alcohol Dehydrogenase / Q000235:genetics*; D002462:Cell Membrane / Q000201:enzymology*; D004098:Dihydroxyacetone / Q000096:biosynthesis*; D020600:Gluconobacter oxydans / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D005988:Glyceric Acids / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism*; D007700:Kinetics; D009154:Mutation
D005988:Glyceric Acids; C042971:glyceric acid; D000426:Alcohol Dehydrogenase; D004098:Dihydroxyacetone; D005990:Glycerol