Metabolic engineering and characterization of phaC1 and phaC2 genes from Pseudomonas putida KCTC1639 for overproduction of medium-chain-length polyhydroxyalkanoate.
Two PHA synthase phaC1 and phaC2 genes cloned from the new strain Pseudomonas putida KCTC1639 were metabolically engineered for the overproduction of medium-chain-length polyhydroxyalkanoate (mcl-PHA). The overexpressed phaC1 and phaC2 genes in P. putida KCTC1639 were compared in terms of the biosynthesis of mcl-PHA, fatty acid assimilation, distribution of 3-hydroxylacyl monomer units, granular morphology, and thermophysical properties of the accumulated mcl-PHA. The biosynthesis of mcl-PHA was enhanced only by the overexpressed phaC1 gene up to 2.86-fold, in contrast, the phaC2 gene did not activate the biosynthesis of mcl-PHA. The overexpressed phaC1 gene tended to form enlarged, high molecular weight, and lower crystalline mcl-PHA granules, whereas the amplified phaC2 gene induced the fragmentation of mcl-PHA into a few small-sized granules. The transformant P. putida KCTC1639 overexpressing the phaC1 gene encoding PHA synthase I was cultivated by pH-stat fed-batch cultivation, and the concentration and content of mcl-PHA increased up to 8.91 g L-1 and 70.5%, respectively.
Kim
Tae-Kwon
TK
Department of Genetic Engineering, College of Natural Sciences, Kyungpook National University, Daegu 702-701, S. Korea.
Jung
Young-Mi
YM
Vo
Minh Tri
MT
Shioya
Suteaki
S
Lee
Yong-Hyun
YH
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D024861:Genetic Enhancement / Q000379:methods*; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D000473:Alkanes; D011108:Polymers; D011994:Recombinant Proteins; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase