Enhanced production of butanol and acetoin by heterologous expression of an acetolactate decarboxylase in Clostridium acetobutylicum.
Butanol is an important industrial chemical and an attractive transportation fuel. However, the deficiency of reducing equivalents NAD(P)H in butanol fermentation results in a large quantity of oxidation products, which is a major problem limiting the atom economy and economic viability of bio-butanol processes. Here, we integrated the butanol fermentation process with a NADH-generating, acetoin biosynthesis process to improve the butanol production. By overexpressing the α-acetolactate decarboxylase gene alsD from Bacillus subtilis in Clostridium acetobutylicum, acetoin yield was significantly increased at the cost of acetone. After optimization of fermentation conditions, butanol (12.9g/L), acetoin (6.5g/L), and ethanol (1.9g/L) were generated by the recombinant strain, with acetone no more than 1.8g/L. Thus, both mass yield and product value were greatly improved. This study demonstrates that reducing power compensation is effective to improve the atom economy of butanol fermentation, and provides a novel approach to improve the economic viability of bio-butanol production.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Xiaoning
X
Shen
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China. Electronic address: liudong@njtech.edu.cn.
Dong
D
Liu
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Jun
J
Liu
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Yanyan
Y
Wang
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Jiahui
J
Xu
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Zhengjiao
Z
Yang
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Ting
T
Guo
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China.
Huanqing
H
Niu
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China. Electronic address: yinghanjie@njtech.edu.cn.
Hanjie
H
Ying
D000093:Acetoin / Q000378:metabolism*; D001412:Bacillus subtilis / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D056804:Biofuels; D000440:Butanols / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000096:biosynthesis* / Q000235:genetics; D046969:Clostridium acetobutylicum / Q000201:enzymology*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D015870:Gene Expression; D005818:Genetic Engineering
D001426:Bacterial Proteins; D056804:Biofuels; D000440:Butanols; D000431:Ethanol; D000093:Acetoin; D002262:Carboxy-Lyases; C023746:acetolactate decarboxylase
Acetoin; Acetolactate decarboxylase; Butanol; Clostridium acetobutylicum; Zinc supplementation