A Preliminary Study On The Biosynthesis Of LL-D49194 Congeners

LL-D49194 congeners,produced by Streptomyces vinaceusdrappus NRRL 15735,are special members of aromatic polyketide natural products,which possessing remarkable range of biological activities,such as anti-tumor and anti-bacteria activities.These compounds have the same anthraquinone skeleton,also including various post-translation structures and complex fused epoxide ring,that's the main reason to study the biosynthesis of LL-D49194 congeners.After optimizing of cultivation,the liquid fermentation condition of S.vinaceusdrappus was established,through 190-600nm UV-HPLC detection of fermentation extract,combined with LC-MS and 1HNMR,13CNMR analysis,the produce of LL-D49194 ?1 and ?2 was identified,which are the most significant two members of LL-D49194s.Two plasmids pIB 139 and pKC 1139 were used for gene manipulation system,and after tests,the highly effective conjugative transfer system between E.coli S17-1 with S.vinaceusdrappus was conformed,IWL-4 media is the best solid medium for this system.The Genomic DNA of S.vinaceusdrappus was extracted for next-generation sequence,after comparative analyzing of homologous genes and proteins,one putative gene cluster responsible for the produce of LL-D49194,which contains 58 genes,approximately 61 kb length,according to putative gene functions they were classed into six diferent sorts.Subsequently the KSa gene(orf51)deleted mutant was builded,HPLC profiles conformed the deduction.For more effective gene manipulation of Streptomyces vinaceusdrappus,the fosmid library covers whole genome was builded,thus Red/ET recombination system could be applied for future research.On the basis of establishment for fermentation system,conjugative transfer system and complemental genetic information,which would increase efficiency for further enzyme catalytic study.