|Group Leader |
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Dr. Mo Xian, Professor, Director of CAS Key Laboratory of Bio-based materials, winner of the State Council special allowance and CAS "Hundred Talents Program". Prof. Xian has worked as associate professor at Qingdao University of Science and Technology (1998-2003), postdoctoral fellow at CNRS (2003-2004) and research fellow at Michigan State University (2003-2007). From 2007, as leader of bio-based chemicals group at QIBEBT, he focused on the directional and fundamental research on the chemo/bio-conversion of chemicals from renewable biomass. Prof. Xian has more than 100 publications in JACS, PNAS, JOC and other peer-reviewed scientific journals, and has applied 40 Chinese invention patents.
|Research Focus |
To meet the national needs in chemicals, materials and related fields, our recent research emphasizes the design and development of new techniques to convert renewable biomass into important chemicals using green chemical, biological and interdisciplinary approaches. Currently, our major products are fatty acids, bio-phenols, bio-isoprene, bio-diols and their derivatives.
Research directions of Bio-based chemicals
|Research Activities |
To solve the bottleneck problems in bio-based materials and chemicals synthesis, we have carried out a series of works as following:
(1) Sustainable and inexpensive raw materials
Glucose was usually used as the raw material for biosynthesis of materials and chemicals, resulting in high cost. We modified the relevant metabolic pathways of E. coli using synthetic biology methods, and a set of engineered strains were constructed and used for chemicals biosynthesis. They can metabolize inexpensive carbon sources such as fat, cellulosic hydrolysate, post-extracted algae residue, and so on. Based on these results, 2 papers were published and 8 Chinese invention patents were applied.
Pathway for P3HP biosynthesis from glycerol in the engineered strain of E. coli. (Bioresour Tech, 2013, 131:548-551.)
(2) Technique design and development
For chemicals which are not natural metabolites of microorganisms, the de novo biosynthetic pathway design and construction were performed. For example, the biosynthesis of methylacetoin was first accomplished by reversing its biodegradation, which involved modifying the associated enzyme complex and coupling the process to an exothermic reaction. To improve the synthetic efficiency, systematic modifications including engineering of key enzymes in synthetic pathways, elevation of metabolic efficiency and growth of host cells, and establishment of genetically stable biosystem, were achieved, resulting in significant improvement of chemicals production. Due to the low titer and intracellular localization, the biobased products are hard to be purified and the separation process accounts for a large portion of total production cost. To deal with this problem, inducible cell lysis system and product secretion system were built up to release products from microbial cells. Integrated with on-line extraction unit, they greatly simplified the product separation process. Additionally, we developed some new methods for metabolic engineering, like in vitro assembly of multiple DNA fragments and temperature-inducible gene regulation system, which provide us a convenient way in strain development. In sum, we successfully established the technology platform for biosynthesis of chemicals and materials, have published 11 research papers and applied 5 Chinese invention patents.
left: Biodegradation-inspired construction of the biosynthetic pathways. (Scientific Reports, 2013, 3:2445)
right: Scheme of SHA (take a 6-SF assembling for example). (PLoS ONE, 2012, 7(1):e30267)
Based on the above works, we have developed three categories of products with fatty acids, isoprene, and 3-hydroxypropionate as representatives, respectively, placing our group on a sustainable footing.
The bio-based Chemicals and Materials of our group
Ton-scale pilot system has been built up for the fermentation and recovery of bio-phenols. In the pilot experiments, several hundred kilograms of bio-phenols have been produced with qualified purity (>99%) and feasible unit cost (one third of the cost by chemical methods).
Pilot scale fermentation and recovery system for bio-phenols
|Selected Publications |
Yanning Zheng, Qiang Liu, Lingling Li, Wen Qin, Jianming Yang, Haibo Zhang, Xinglin Jiang, Tao Cheng, Wei Liu, Xin Xu, Mo Xian*. Metabolic engineering of Escherichia coli for high-specificity production of isoprenol and prenol as next generation of biofuels. Biotechnology for Biofuels 2013, 6: 57.
Jianming Yang, Qingjuan Nie, Meng Ren, Hongru Feng, Xinglin Jiang, Yanning Zheng, Min Liu, Haibo Zhang*, Mo Xian*. Metabolic engineering of Escherichia coli for the biosynthesis of alpha-pinene. Biotechnology for Biofuels 2013, 6:60.
Qi Wang, Peng Yang, Changshui Liu, Yongchang Xue, Mo Xian*, Guang Zhao*. Biosynthesis of poly(3-hydroxypropionate) from glycerol by recombinant Escherichia coli. Bioresource Technology 2013, 131: 548-551.
Xinglin Jiang, Haibo Zhang, Jianming Yang, Yanning Zheng, Dexin Feng, Wei Liu, Xin Xu, Yujin Cao, Huibin Zou, Rubin Zhang, Tao Cheng, Fengjiao Jiao, Mo Xian*. Biodegradation-inspired bioproduction of methylacetoin and 2-methyl-2,3-butanediol. Scientific Reports 2013, 3: 2445.
Huibin Zou, Zaiqiang Wu, Mo Xian*, Hui Liu, Tao Cheng, Yujin Cao. Not only osmoprotectant: betaine increased lactate dehydrogenase activity and L-lactate production in lactobacilli. Bioresource Technology 2013, 148: 591-595.
Xinglin Jiang, Jianming Yang, Haibo Zhang, Huibin Zou, Cong Wang, Mo Xian. In Vitro Assembly of Multiple DNA Fragments Using Successive Hybridization. PLoS ONE. 2012, 7(1): e30267.
Yanning Zheng, Lingling Li, Qiang Liu, Wen Qin, Jianming Yang, Yujin Cao, Xinglin Jiang, Guang Zhao, Mo Xian*. Boosting the free fatty acid synthesis of Escherichia coli by expression of a cytosolic Acinetobacter baylyi thioesterase. Biotechnology for Biofuels 2012, 5: 76.
Xinglin Jiang, Haibo Zhang, Jianming Yang, Min Liu, Hongru Feng, Xiaobin Liu, Yujin Cao,Dexin Feng , Mo Xian. Induction of gene expression in bacteria at optimal growth temperatures. Applied Microbiology and Biotechnology.2012, 97:5423-5431.
Jianming Yang, Guang Zhao, Yuanzhang Sun, Yanning Zheng, Xinglin Jiang, Wei Liu, Mo Xian*. Bio-isoprene production using exogenous MVA pathway and isoprene synthase in Escherichia coli. Bioresource Technology 2012, 104: 642-647.
Xiangwei Wang, Guoming Zhao*, Huibin Zou, Yujin Cao, Yongguang Zhang, Rubing Zhang, Fan Zhang, Mo Xian*. The base-free and selective oxidative transformation of 1, 3-propanediol into methyl esters by different Au/CeO2 catalysts. Green Chemistry 2011, 13: 2690-2695.
Alex Necoda, Mo Xian, Insight into the selectivity and gating function of KcsA, PNAS, 2007,104: 4342-4346.
Mo Xian, Se´bastien Alaux, et al., Chemoenzymatic Synthesis of Glutamic Acid Analogues: Substrate Specificity and Synthetic Applications of Branched Chain Aminotransferase from Escherichia coli, J Org Chem. 2007, 72 (20):7560-6.
Jihane Achkar, Mo Xian. Biosynthesis of phloroglucinol, J. Am. Chem. Soc., 2005, 127(15); 5332-5333.