Identification And Studies On The Fungicidal Activity Of Secondary Metabolic Products Of Actinomycetes Strain HND39

Actinomycetes is a kind of microorganism which is very important to human beings.They exist in various kinds of natural environments.They can produce many kinds of active products including antibiotics and non-antibiotics for controlling disease caused by bacteria,fungi,viruses,parasitic nematodes and tumor. Streptomyces is the mojor to producer of second metabolite and 90%antibiotics are produced by Streptomyces in Actinomycetes.By study on morphology,cultural characteristics,physiological and biochemical properties,16S rDNA and phylogenetic tree,HND39 was identified as Streptomyces subrutilus.The GenBank accession number for the 16S rDNA gene sequence of strain HND39 is EU030437.HND39,a Streptomyces strain isolated from the soil samples of Tianshan nature presentation zone.Optimum fermention conditions for HND39 was studied.HND39 was in the C-liquid medium shacked 72 hours.The optimum temperature and pH value were 27±1℃and 7.0,respectively.Meanwhile,the optimum foster way was shacked all day.Showed inhibitory activity against 15 tested plant pathogenic fungi in preliminary screening tests,suggesting that HND39 had a broad anti-fungal spectrum. In further test,culture filtrate of HND39(3 ml into each plate) showed high inhibition activity against Colletotrichum nicotianae,Sclerotinia sclerotiorum,Colletotrichum capsici,Phytophthora parasitica var.nicotianae with mycelium growth reduction of 54.2%,70.6%,51.9%and 58.7%respectively.The germination of pepper,carrot,lettuce seeds were promoted by the diluent of extract in the indoor environment test.Can significantly promote pepper,lettuce seeds radicle elongation.Evidently,actinomycosis HND39 in the fermentation process in the secretion of one or a variety of secondary metabolites,these metabolites is conducive to seed germination,the appropriate concentration of metabolites of seed germination role in promoting the most significant.