Study On The Screening And Fermentation Of Lipstatin Producing Strain

With the development of science, the improvement of people's life and an increasingly fat-rich diet, obesity has become a global epidemic. So far, there are many agents available in various countries in treatment of obesity. Among them, a non-centrally acting anti-obesity agent orlistat has been proven the efficacy and safety by various clinical studies. It has been sold in more than 100 countries and used by over 9 million obese patients.Orlistat is a chemically synthesised hydrogenated derivative of lipstatin, a naturally occurring lipase inhibitor produced by Streptomyces toxytricini. In this research work, various ways of mutagensis treatment, such as UV, NTG, MW, were carried out to study the effectiveness of increasing the productivity of lipstatin producing strain S. toxytricini. Results showed that the UV radiation combined with NTG treatment was the most effective one. By this mean, mutant SIPI-UN-21 was obtained, and its productivity of lipstatin was increased by 350% over the parent strain.Furthermore, the ingredients of culture media were optimized. Many influencing factors were studied, such as carbon sources, nitrogen sources, phosphates, and so on. And then by designed orthogonal experiments, an optimum culture medium was established.Meanwhile, the fermentation conditions were also optimized. Through studying the effects of many parameters (pH, temperature, DO) on fermentation, an optimum fermentation condition was established.