Study On The Secondary Metabolites Produced By Three Actinobacterial Strains From Extreme Environments

As the wide use of antibiotics, new drug-resistant bacteria has increased dramatically, and the treatment effect of the existing antibiotics has reduced greatly, make the task of searching new bioactive drugs extremely urgent. In recent years, the more study of natural metabolites of actinobacteria, and exploite of terrestrial actinobacteria, the harder to find new type of compounds, thus making people change their research interests to actinobactria from the extreme environments. Under the long-term of natural selection, actinobacteria from extreme conditions have their unique structures, function and gene, and possess their special way of metabolism, can produce many novel structure and complex bioactive compounds.This research selected15actinobacterial strains which were isolated from extreme environments by our group, and made use of small-scale fermentation to incubate all of these strains by means of three different broth media. After obtaining the crude extract, in combination with TLC, HPLC chemical diversity screening, three strains of them amplified to large-scale fermentation, then isolated and purified their main products. Among these three strains, two of them were from Xinjiang arid-saline desert environments, which were named as Nocardiopsis sp. EGI80425and Streptomyces sp. LQ13, and another one Amycolatopsis sp. YIM M13163, was from deep-sea sediment of the South China Sea.In this research, we amplified fermentation of EGI80425, LQ13, YIM M13163to7.5L,14L,14L, respectively, combined with a variety of isolation and purification methods, we had totally obtained5compounds. Two of them were identified as ansamitocins isolated from EGI80425, two compounds from strain LQ13, of which one is an unknown polypeptide and the other one is new polyketide, the left one compound is an efrotomycin derivative isolated from YIM M13163.This study shows that actinobacteria from extreme environments can produce aboundant secondary metabolites and produce plenty of complex bioactive substances. Actinobacteria in extreme environments can be used as an important source of new natural products and future new drag development.