Identification of key genes involved in polysaccharide bioflocculant synthesis in Bacillus licheniformis.
The present study reports the sequenced genome of Bacillus licheniformis CGMCC 2876, which is composed of a 4,284,461 bp chromosome that contains 4,188 protein-coding genes, 72 tRNA genes, and 21 rRNA genes. Additional analysis revealed an eps gene cluster with 16 open reading frames. Conserved Domains Database analysis combined with qPCR experiments indicated that all genes in this cluster were involved in polysaccharide bioflocculant synthesis. Phosphoglucomutase and UDP-glucose pyrophosphorylase were supposed to be key enzymes in polysaccharide secretion in B. licheniformis. A biosynthesis pathway for the production of polysaccharide bioflocculant involving the integration of individual genes was proposed based on functional analysis. Overexpression of epsDEF from the eps gene cluster in B. licheniformis CGMCC 2876 increased the flocculating activity of the recombinant strain by 90% compared to the original strain. Similarly, the crude yield of polysaccharide bioflocculant was enhanced by 27.8%. Overexpression of the UDP-glucose pyrophosphorylase gene not only increased the flocculating activity by 71% but also increased bioflocculant yield by 13.3%. Independent of UDP-N-acetyl-D-mannosamine dehydrogenase gene, flocculating activity, and polysaccharide yield were negatively impacted by overexpression of the UDP-N-acetylglucosamine 2-epimerase gene. Overall, epsDEF and gtaB2 were identified as key genes for polysaccharide bioflocculant synthesis in B. licheniformis. These results will be useful for further engineering of B. licheniformis for industrial bioflocculant production. Biotechnol. Bioeng. 2017;114: 645-655. © 2016 Wiley Periodicals, Inc.
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Zhen
Z
Chen
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Peize
P
Liu
Fujian Provincial Key Laboratory of Fire Retardant Materials, College of Materials, Xiamen University, Xiamen, People's Republic of China.
Zhipeng
Z
Li
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Wencheng
W
Yu
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Zhi
Z
Wang
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Haosheng
H
Yao
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Yuanpeng
Y
Wang
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Qingbiao
Q
Li
College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, People's Republic of China.
Xu
X
Deng
Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, People's Republic of China.|Key Lab for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, 361005, People's Republic of China.
Ning
N
He
D000069976:Bacillus licheniformis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D016680:Genome, Bacterial / Q000235:genetics*; D060847:Metabolic Engineering / Q000379:methods*; D011135:Polysaccharides, Bacterial / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*
D011135:Polysaccharides, Bacterial
Bacillus licheniformis; comparative genomics; genome sequence; metabolic engineering; polysaccharide bioflocculant