Enhanced a novel β-agarase production in recombinant Escherichia coli BL21 (DE3) through induction mode optimization and glycerol feeding strategy

• Published in: Acta oceanologica Sinica Vol. 37; no. 2; pp. 110 - 118
• Main Authors: Chan, Zhuhua, Chen, Xinglin, Hou, Yanping, Gao, Boliang, Zhao, Chungui, Yang, Suping, Zeng, Runying
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Oceanography 01-02-2018; Springer Nature B.V; Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen 361021, China; State Key Laboratory Breeding Base of Marine Genetic Resource, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China%State Key Laboratory Breeding Base of Marine Genetic Resource, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China%State Key Laboratory Breeding Base of Marine Genetic Resource, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China; School of Life Sciences, Xiamen University, Xiamen 361102, China%Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen 361021, China
• Subjects: Acetates; Acetic acid; Agar; Agarase; Cell density; Cell growth; Climatology; Cosmetics; Cultivation; E coli; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Feeding; Food industry; Glycerol; Growth rate; Hydrolysates; Industrial production; Industry; Isopropyl thiogalactoside; Lactose; Marine & Freshwater Sciences; Oceanography; Optimization; Pharmaceutical industry; Powder; Recombinants; Strategy; Temperature effects; Yields; process optimization; neoagarooligosaccharide; β-agarase; glycerol feeding strategy; Escherichia coli
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-018-1172-x

Agarases are hydrolytic enzymes that act on the hydrolysis of agar and have a broad range of applications in food, cosmetics and pharmaceutical industries. In this study, a glycerol feeding strategy based on induction mode optimization for high cell density and β-agarase production was established, which could effectively control acetate yield. First, exponential feeding strategy of glycerol with different overall specific growth rates (
μ
) was applied in the pre-induction phase. The results showed that the low
μ
(
μ
=0.2) was suggested to be the optimal for cell growth and β-agarase production. Second, the effects of induction temperature and the inducer concentration on cell growth and β-agarase production were investigated in the post-induction phase. When induced by isopropyl-β-d-thiogalactoside (IPTG), the strategy of 0.8 mmol/L IPTG induction at 20°C was found to be optimal for β-agarase production. When cultivation was induced by continuous lactose feeding strategy of 1.0 g/(L·h), the β-agarase activity reached 112.5 U/mL, which represented the highest β-agarase production to date. Furthermore, the β-agarase was capable of degrading
G. lemaneiformis
powder directly to produce neoagarooligosaccharide, and the hydrolysates were neoagarotetraose (NA4) and neoagarohexaose (NA6). The overall research may be useful for the industrial production and application of β-agarase.