Journal of Pure and Applied MicrobiologyVol. 7 No. 4

Effect of Environmental Stresses on Heparosan Biosynthesis by Escherichia coli K5

Haichan Huang, Xueliang Li, Ning Li and Weihong Zhong*

College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, 310032, PR China.

Received on 23 September 2013 and accepted on 06 November 2013



Heparosan, the capsular polysaccharide (CPS) of some pathogenic microorganisms, play an important role in protecting bacteria from the effects of the enviromental stresses. It is almost identical to haprin and can be used as the key precursor for the preparation of bioengineered heparin and heparan sulfate. In this study, the heparosan production and growth of Escherichia coli K5 under the stresses, of osmotic,?SnCl2,?organic?solvents (ethanol, formamide, and hexane), and H2O2, were evaluated. The results indicated that the growth of E. coli K5 was not affected, while the production of heparosan was influenced under these stresses. The addition of appropriate amount of methinine, glycine, SnCl2, and organic?solvents, is helpful to heparosan production. High concentration of NaCl and H2O2 are unfavourable for heparosan production. Moreover, E. coli KT (with waaR gene deletion) showed the similar response to the above stress.

Keywords : Escherichia coli, CPS, Heparosan, Stress, waaR.