The Polyphasic Taxonomy And Antitumor Activity Analysis Of Actinomycetes Isolated From KaLa Mountains In Tibet

In this thesis,a brief summary was made on the research object of the taxonomy of actinomycetes.The significance of actinomycetes in human life and the biological history of it were reviewed.Polyphasic taxonomy and the range of that in actinomycetes were also introduced.The most important parts were polyphasic taxonomy and antitumour activeties of 14 actinomycete strains from Kala Mountain in Tibet.40 strains of actinomycetes were isolated from Kala mountains in Tibet and we selected 14 typical strains to do the polyphasic taxonomy.The study methods included morphological and cultural characteristic observation,physiological and chemical tests as well as 16SrDNA sequencing.The results showed that all strains belonged to Streptomyces,and they had a character that their cell memberanes contained some special saccharide.14 strains could liquefy glutin,46.1%of 14 strains congeal and peptonize milk or decompose protein to produce H₂S. 30.3%of strains had the ability to decompose starch.The results of 16SrDNA sequence indicated that there were some differences between the strains we analyzed and the foregone strains of Streptomyces.The similarity of 850040 reach to 98%with Streptomyces humidus,but it could produce pigment and H₂S,Streptomyces humidus could not.The taxonomy site of 850040 need to be identified through DNA-DNA hybridization.It was known that Z851031 was the only strain that had antitumour activity after being tested with the method of methylthiazole tetrazolium(MTT) among all strains.Its fermentation had 80%cytotoxicity to cancer cells.The fermentation also had antibacterial activity to Staphylococcus aureus,Bacillus subtilis and Saccharomyces cerevisiae.The lipid component extracted by thin layer chromatography(TLC) showed an absorption peak at 210.65nm with ultraviolet radiation scan.There was a stair-like absorption characteristic at 280nm,which was similar with calicheamicin.Z851031 is maybe a new strain of Streptomyces GW25-5,and its taxonomy site need to be identified through DNA-DNA hybridization.