Fiber Heap Capsule Bacteria Epothilone Biosynthetic Gene Cluster Keto Synthase Gene Cloning And Analysis

Myxobacteria are capable of producing a great deal of bioactive compounds which show anticancer, antibacterial, fungicidal or immune-modulating effects. In the past two decades, about 100 basic structures and 600 structural variants have been discovered in myxobacteria and have been fully characterized chemically, which account for about 3.5% of the presently known secondary metabolites of microbial origin. Almost half of the myxobacterial bioactive secondary metabolites were identified from Sorangium cultures and almost 100% of the Sorangium strains produce some kind of compound with biological activity. The diversity of the chemical structure and action mechanisms from Sorangium can even be compared with those from Streptomyces. Currently, the genome sizes of sequenced model myxobacteria strains all exceed 9 Mb, and a large number of genes were extravagantly used for complex secondary metabolism product synthesis. Among myxobacteria, the strain Sorangium cellulosum So ce56 harbors the largest prokaryotic genome hitherto known, with a size of approximately 12.2 Mb, and it must hold abundant novel gene resources.The Sorangium So0157-2 is a facultative alkaliphile strain, which was isolated from the soil sample on ChengHai lake bank. Because of the special habitat, So0157-2 exhibited some unique characteristics in either morphogenesis or cultivating conditions. Our previous bioactivity screening analysis confirmed that So0157-2 is a promising strain for producing bioactive secondary metabolites. Choosing the So0157-2 and SuperCos 1 as our original materials, we successfully constructed a cosmid gene library of So0157-2 and then maintained the genebank properly. The acquired gene library can overlay the complete genome at least 16 times, which thus verified the integrity of the bank. The successful gene library of So0157-2 established a foundation for further screening and amplifying the genes or geneclusters involved in secondary metabolism, morphological development, physiological differentiation and regulatory.Polyketides are one important large family of complex natural products. The wide spectrum of activity of polyketides makes them one of the most valuable molecules for economic, clinical and industrial purposes. They are synthesized from simple carboxylic acid by sequential reactions catalyzed by the large multienzyme...