Enhanced β-Carotene Biosynthesis in Recombinant Escherichia coli Harboring the Bottom Portion of Mevalonate Pathway of Enterococcus faecium VTCC-B-935 Isolated in Vietnam

Vũ Hoài Nam2, Huyền Trang HT2, Thu Huong LT1 and Duong Van Cuong1,2

1. Department of Biotechnology and Food Technology, Thai Nguyen University of Agriculture and Forestry, Vietnam

2. Division of Molecular Biology, Thai Nguyen University, Vietnam

Abstract
β-carotene is a carotenoid pigment which has commercial value. Biosynthesis of this pigment using recombinant E. coli has been reported. However, improvement of yield is remained necessary. In this case report, bottom portion of mevalonate partway was employed for enhancing metabolic flow to isopentenyl diphosphate, the building block of all carotenoid. Three genes including mvaK1 , mvaK2, and mvaD were cloned from Enterococcus faecium VTCC-B-935 isolated in Vietnam and placed into pET28a(+) vector resulted in pET28-K1K2D. Co-expression of this vector with pRSET-lEIBY which contains five enzymes responsible for biosynthesis of β-carotene in E. coli BL21 (DE3) resulted in approximately three fold higher yield of the compound. The high copy number vector pRSET-A showed better performance in production of β-carotene over low copy pET-22b(+). Addition of glycerol significantly enhanced E. coli cell growth and β-carotene biosynthesis

Keywords: β-carotene; Enterococcus faecium VTCC-B-935; mvaK1 ; mvaK2; mvaD;
Mevalonate pathway

Enhanced β-Carotene Biosynthesis in Recombinant Escherichia coli Harboring the Bottom Portion of Mevalonate Pathway of Enterococcus faecium VTCC-B-935 Isolated in Vietnam