The Study On The Culturable Actinomycete Diversity Of The Saline-alkaline Soil In Shule River Basin In The Winter

Three types of saline-alkaline soil were collected from5sample spots in ShuleRiver basin at this research. The diversity of actinomycetes in the saline-alkaline soilwas researched. Simultaneously, combined with the soil properties, simple correlationanalysis and stepwise regression analysis were conducted. The relations amongactinomycetes diversity, soil enzymes and soil physical-chemical factors wereresearched. Further, we conducted physiological and biochemical identification, saltand alkali tolerance test and antibacterial test of20strains.Different media and soil sample pretreatment has a great influence on theseparation of actinomycetes, the result showed that Ganses No.1was the beseteffective medium for isolation of Streptomyces, and modified proline agar are goodmedium for selective isolation for rare actinomycetes.18actinomycetes genera were isolated from5soil samples, Streptomyces genusis a major component of actinomycetes, Nocardiopsis and Nocardia were only secondto Streptomyces in component of actinomycetes, and they were important exceptingStreptomyces.12groups were isolated from14groups of Streptomyces genus,Albosporus, Flavus, Roseosporus and Glaucus distributed wide comparatively,Albosporus was the most primary in Streptomyces genus.5samples has great differences in the distribution of actinomycetes, and theresult showed that the diversity of actinomycetes of NO.Ⅰ sample was the highest,whether the quantity of actinomycetes was Ⅴ＞Ⅲ＞Ⅳ＞Ⅰ＞Ⅱand the diversity ofStreptomyces was Ⅰ＞Ⅱ＞Ⅲ＞Ⅳ＞Ⅴ.The result indicate that the diversity of actinomycetes of secondary saline soilwas the highest in3saline soil types, and the quantity of Streptomyces was farmlandsoil＞secondary saline soil＞native saline soil and the species diversity wassecondary saline soil＞native saline soil＞farmland soil. whether the diversity of raregenus actinomycetes was secondary saline soil＞native saline soil＞farmland soil.Soil properties and the quantity of actinomycetes are closely correlated, and theresult of simple correlation analysis and stepwise regression analysis showed that thequantity of actinomycetes, Streptomyces and Nocardia were the most affected by thesoil properties and the catalase was the most important in these soil environmental factors.As the raise of soil fertility, the quantity of actinomycetes could be raised,while the diversity of actinomycetes could be dropped.One strain DA04417Producing blue pigment were screened and based onmorphological observation the strain was identified as Cyaneus.The blue pigmentfrom DA04417showed a maximum absorption peak at580nm and had goodsolubility in water. In addition, it was stable to heat and pH but unstable to light andlow concentrations of metalions had little effects on its stability.One strain DJ03207producing chitinase were screened from the soil of No. Ⅱ,and the strain DJ03207which could produce the most chitinase was identified asRoseosporus based on its morphological characteristics. The research results offermentation condition of DJ03207showed that different inducers, carbon andnitrogen sources had different impacts. Peptone powder was the most distinctivefactor, which enhanced the enzyme activity by50%compared with the comparison.Six actinomycete strains which showed inhibiting activity（DC03218，DB01257，DJ03207，DA04417，DB01265，DE03212, DB01213）were isolated from20actinomycete strains. Strain of DA04417showed strong inhibiting activity toFusdrium verticillioides, and strain of DJ03207showed strong inhibiting activity toRhizoctonia solani.