Earticle

초록

영어

Three recombinant Escherichia coli strains expressing styrene monooxygenase (styAB) under T7 promoter were developed for the use in the conversion of styrene to (S)-styrene oxide, an important chiral building block in organic synthesis. By coexpression of chaperone proteins (GroEL-ES and DnaK-DnaJ-GrpE in plasmid pG-KJE8), disruption of NADH dehydrogenases (nuo-) involved in electron transport chain and over expression of styAB, individually or in combinations, the whole-cell StyAB activity was improved greatly. The highest activity (270 U/g CDW) was obtained with E. coli DnuoG haboring the plasmids for styAB and chaperon genes, which was around 2.5 folds higher than the one with the E. coli strain containing styAB in the pET plasmid. In addition, biotransformation in an organic/aqueous two-liquid phase system allowed the product to accumulate to 392 mM in the organic phase within 6 h, resulting in an average specific and volumetric productivity of 5.4 mmol/g dry cells/h and 65 mM/h, respectively, under mild reaction conditions. These results indicated that the high productivity and the high product yield on energy source were driven by the high enzyme activity. Therefore, it was concluded that oxygenase activity of whole-cell biocatalysts is one of the critical factors to determine their catalytic performance.

키워드

저자

• Hai-Bo LIU [ Department of Chemical and Biomolecular Engineering. Pusan National University, Busan 609-735, Korea. ]
• Shengfang ZHOU [ Department of Chemical and Biomolecular Engineering. Pusan National University, Busan 609-735, Korea. ]
• Sunghoon PARK [ Department of Chemical and Biomolecular Engineering. Pusan National University, Busan 609-735, Korea. ]

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발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국생물공학회 학술대회

• 간기

  반년간

• 수록기간

  1985~2013

• 십진분류

  KDC 476 DDC 576