State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and Department of Bioengineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
Title: Engineering of micro-organisms for production of bio-materials
Jian-Jiang Zhong
Bio-materials produced by microbial cells possesses a couple of merits towards commercialization. For example, bacterial nano-cellulose (BNC) is a high molecular polymer formed by beta-1,4-glycosidic bonds, which is distinguished from plant cellulose by its high purity and nano structure. Due to its high-crystallinity cellulose with high mechanical strength, good water holding capacity, and biodegradability, BNC is being widely used in food, cosmetic, biomedical and other fields. But, for reaching a cost-effective bio-production process, improvement of strain biosynthesis capacity is urgently required.
Spider dragline silk is a promising and outstanding protein polymer, which exhibits extraordinary mechanical properties of superior strength and toughness that make it outperform most of the natural and other synthetic fibers. Unfortunately, natural dragline silk of spiders could not be readily obtained by farming spiders because of their highly aggressive and territorial nature. Production of recombinant spider dragline silk proteins in a foreign host such as Escherichia coli has attracted great attention. However, their production titer remains low, because efficient expression of very large, highly repetitive, glycine-rich silk proteins is a challenge.
We have done a large scale micro-organisms screening as well as traditional mutation to obtain high-BNC-producing microbes. By using a mutated producer, we achieved more than 25 g/L of BNC in its liquid fermentation. We also conducted genetic engineering and fermentation engineering of Gluconacetobacter xylinus ATCC53524 towards hyper-production of BNC.
We demonstrate the design and high-level production of large dragline silk proteins of major ampullate spidroin 2 (MaSp2) in E. coli by synthetic biology approach. By combining induction temperature downshift with the glycyl-tRNA pool increase in E. coli, the enhanced biosynthesis of glycine-rich silk proteins was attained. A production titer of 3.6 g/L of MaSp2 was obtained in a 3-L bioreactor. The developed approach is useful to cost-effective large-scale production of silk proteins
Biography of the presenting author
JJ Zhong completed his PhD course in March 1993 from Osaka University. He was the director of State Key Lab. of Bioreactor Engineering at East China University of Science and Technology during Dec. 1998 – July 2006. Since April 2007, he has been a University Distinguished Professor of Shanghai Jiao Tong University and PI at the State Key Lab. of Microbial Metabolism. He has published more than 270 papers in international journals. Dr. Zhong was awarded the Cheung Kong Scholar Professorship from the Ministry of Education (MOE), National Science Fund for Distinguished Young Scholars by National Natural Science Foundation of China, the inaugural award of “Young Asian Biotechnologist Prize” by the Society for Biotechnology (Japan), the 1st-class Prize for Advancement of Science & Technology by MOE for twice (in 2004 & 2014), the “Research Exchange Award” from the Korean Society for Biotechnology and Bioengineering, and was a plenary/keynote/invited speaker in over 80 international conferences. He was the Secretary General of AFOB (Oct. 2012 – Sept. 2016) and is now on the editorial board of 10 SCI-cited international journals, including as former Editor-in-Chief (now: Associate Editor) of Process Biochemistry, and as Associate Editor of Biotechnology and Bioengineering and so on.
Presenting author details
Full name: Jian-Jiang Zhong
Contact number: +86 139 1616 9311
Email: jjzhong@sjtu.edu.cn
ResearcherID: D-8707-2012
ORCID: 0000-0002-2265-9338
Session name/ number: Industrial Biotechnology
Category: Oral presentation