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 Our research directions include metabolic regulation and metabolic engineering of industrial microorganisms such as Clostridia, actinomycetes, and Bacillus subtilis; protein engineering and the relationship between structure and function of industrial enzymes; development and application of new technologies for engineering genes, genomes，proteins and metabolic pathways. The goal of our work is to develop and optimize genetically-based bioproducts and bioprocesses.
Lab homepage: http://www.sippe.ac.cn/ep2-2_jiangwh.asp
Principal Investigators: Dr. Wei-Hong Jiang, Professor. Email: whjiang@sibs.ac.cn; Dr. Sheng Yang, Professor. Email: syang@sibs.ac.cn
Staff: Dr. Ji-Ping Shi, Professor; Dr. Yin-Hua Lu, Research Associate; Jun Chen, Senior Technician; He Huang, Research Assistant; Dr. Jing-Bo Zhao, Research Assistant; Hui-Qi He, Engineer; Pan Wang, Research Intern; Xin Song, Research Intern; Hong Zhu, Research Intern; Li-Xia Niu, Research Intern; Chong-Mao Xu, Assistant Technician; Feng Dong, Assistant Technician; Yun-Liu Yang, Professor (emeritus)
Postdoctoral Fellows: Dr. Yang Gu; Dr. Chuan-Zeng Cao; Dr. Xiang-Yang Fu; Dr. Yu Jiang; Dr. Xu-Dong Liu
Graduate Students: Wei-Hua Wang; Jun-Jie Yang; Yuan-Heng Cai; Shi-Yuan Hu; Zhou-Tong Sun; Li-Jun Shao; Rui Wang; Liu-Yang Diao; Da-Long Zhang; Li Zhu; Jian Li; Han Xiao; Cong Ren; Zhen-Yu Yu
Graduated Students: Lei Chen, 2004 (PhD); Dan Shu, 2005 (PhD)
Comprehensive Research of Biobutanol-producing Bacterium Clostridium acetobutylicum
Butanol is not only an important chemical but also a new generation biofuel. Clostridium acetobutylicum, as an important industrial strain applied in butanol production in China, was extensively studied in our laboratory in the following areas:
1) Biological studies on high butanol ratio isolate C. acetobutylicum EA 2018 . Compared with the type strain C. acetobutylicum ATCC 824, C. acetobutylicum EA 2018 shows several special biological characteristics, including higher solvents production, higher butanol ratio, shorter fermentation time and no spore formed. Our results showed that EA 2018 can utilize glucose and xylose more quickly and completely than the control strain ATCC 824, whereas produce lower hydrogen and acids as compared to ATCC 824. In addition, the transcriptional level of genes involved in butanol formation are higher in EA 2018 than in ATCC 824, while the transcriptional level of genes involved in acetone formation is contrary. These studies will improve our understandings on the mechanism of hyper-butanol production in C. acetobutylicum EA 2018, and are also crucial for further genetic modification of this strain.
2) Metabolic engineering of C. acetobutylicum EA 2018. Using the group II intron-based TargeTron plasmids pSY6/pSY7, we constructed the buk and solR mutants of C. acetobutylicum ATCC 824, which produced 40 % and 38 % more solvents than the wild type, respectively. The plasmids pSY6/pSY7 can also be used for metabolic engineering of an industrial C. acetobutylicum strain EA 2018. The EA 2018 mutant with disruption of acetoacetate decarboxylase gene (adc) showed a drastic reduction in acetone production (from 50 mM to 5 mM), without affecting the solvents yield but causing an increase in butanol ratio.
3) Analysis of xylose metabolism pathway in C. acetobutylicum. Through integrated bioinformatics analysis, gene knockout and functional-complementing experiments, we identified six genes encoding key enzymes involved in xylose metabolism pathway of C. acetobutylicum. Deletion of some of them caused the loss of ability in xylose utilization by C. acetobutylicum. Further RT-PCR analysis showed that the transcription of these genes are all induced by xylose and inhibited by glucose. These data will be useful for further modification of xylose metabolism pathway of C. acetobutylicum.
Publications:
Chen L, Lu Y, Chen J, Zhang W, Shu D, Qin Z, Yang S and Jiang W. (2008) Characterization of a negative regulator AveI for avermectin biosynthesis in Streptomyces avermitilis NRRL8165. Applied Microbiolology and Biotechnology 80: 277-286. Jiang S, Li C, Zhang W, Cai Y, Yang Y, Yang S and Jiang W. (2007) Directed evolution and structural analysis of N-carbamoyl-D-amino acid amidohydrolase provide insights on recombinant protein solubility in Escherichia coli. Biochemical Journal 402: 429-437. Shao L, Hu S, Yang Y, Gu Y, Chen J, Yang Y, Jiang W and Yang S. (2007) Targeted gene disruption by use of a group II intron (targetron) vector in Clostridium acetobutylicum. Cell Research 17: 963-965. Zhang W, Liu Y, Zheng H, Yang S, Jiang W. (2005) Improving the activity and stability of GL-7-ACA acylase CA130 by site-directed mutagenesis. Applied and Environmental Microbiology 71: 5290-5296.
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