BioChem - DOS

High-level expression of recombinant thermostable β-glucosidase in Escherichia coli by regulating acetic acid

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

Shi, Xuejia; Xie, Jingcong; Liao, Shiyong; Wu, Tao; Zhao, Lin-Guo; Ding, Gang; Wang, Zhenzhong; Xiao, Wei

<P><B>Abstract</B></P> <P>In the fermentation progress, fermentation parameters including the feed rate, induction temperature, and induction pH evidently regulate the accumulation of acetic acid generated by recombinant <I>E. coli</I> in the medium. The production of thermostable &beta;-glucosidase (Tpebgl3) was increased by optimizing the parameters mentioned step by step. The optimal conditions were obtained with the highest enzyme expression (560.4U/mL) and the maximum DCW (65g/L) at the pre-induction specific growth rate of 0.2h<SUP>&minus;1</SUP> followed by a post-induction specific growth rate (0.18h<SUP>&minus;1</SUP>); induction temperature is 39&deg;C; the pH is 7.2; the concentration of acetic acid was maintained all along below 0.9g/L. Results show it is necessary for the synthesis of Tpebgl3 to regulate the accumulation of acetic acid at the premise of feeding to meet the normal growth of <I>E. coli</I>. The production of Tpebgl3 by recombinant <I>E. coli</I> is the highest reported to date.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of the acetic acid on Tpebgl3 production by <I>E. coli</I> was studied. </LI> <LI> The acetic acid excretion was controlled by optimal fermentation conditions. </LI> <LI> The Tpebgl3 activity reached 560.4U/mL with acetic acid kept below 0.9g/L. </LI> </UL> </P>

2017

Elsevier

0960-8524

241

pp.795-801

10.1016/j.biortech.2017.05.105

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART78160790

Acetic acid; Fermentation; Optimal condition; β-Glucosidase