Isolation,Identification And Biological Activity Of Alkaline Actinomycetes From Red Beach

Liaoning Panjin red beach is a shallow saline with abundant Suaeda salsa and contains abundant extreme environmental microbial resources with special functions because of its unique harsh natural environment,which provides a good place for us to study extreme environmental microorganism.Extremophiles including Alkalophilic actinomycetes has evolved with special function of genes,structure and metabolic product so as to adapt to survival in long-term selection pressure.They are important materials to discovery new species,extreme enzymes and bioactive products with novel structure,which has important value of development and utilization.42 strains of Alkaliphilic actinomycetes were isolated from the soil samples of Liaoning red beach,and 10 of them were identified by the combined method of morphology and molecular biology in this study.A strain named HHT-6 with strong activity was isolated after detection of enzyme activity and analysis of antimicrobial activity screening.Physiological and biochemical characteristics and growth curve of HHT-6 were determined,and optimal fermentation medium and culture conditions were obtained by single factor experiment and orthogonal experiment.The main results were as follows:1.42 strains of Alkalophilic actinomycetes were isolated from soil samples in Liaoning Panjin red beach,and 10 of them were identified as Nocardia and Streptomyces by morphology observation and molecular biology identification.2.It was showed by enzyme activity detection that 15 strains were able to produce amylase,7 strains were able to produce cellulose,14 strains were able to produce protease,and 17 strains were able to produce catalase among the 42 strains of Alkalophilic actinomycetes.None of them had activities of lipase or chitinase.3.It was showed by antibacterial activity detection that 7 strains had antibacterial effect on Streptococcus pneumonia among the 42 strains of Alkalophilic actinomycetes that.The radius of bacteriostatic ring of strain HHT-24 reached 8 mm.The radius of bacteriostatic ring of stain HHT-14 against Bacillus subtilis reached5 mm.None of 42 strains was found with anti-Staphylococcus aureus activity or anti-Escherichia coli activity.It was showed by the antagonistic test against plant pathogenic fungi that among the 42 strains of Alkalophilic actinomycetes,only 14 strains had inhibitory effects on different plant pathogens.HHT-6 strain hadbacteriostatic effects on five kinds of plant pathogenic bacteria including Botrytis cinerea,Sclerotinia sclerotiorum,and 0# spot,1# spot,2# spot on corn leaves,and its inhibitory rate against Sclerotinia sclerotiorum reached 80.79%.4.It was showed by physiological and biochemical tests that HHT-6 strain had the highest utilization rate to maltose,the lowest utilization rate to galactose,gelatin liquefaction positive,cellulose hydrolysis positive,hydrogen sulfide reaction negative,nitrate reducing negative,and ability to milk peptonization..5.It was showed by single factor and orthogonal tests that the optimal media for HHT-6 strain were 3% maltose,0.15% NaNO3,0.025% NaCl,0.075% K2HPO4,0.075% MgSO4,0.001% FeSO4;Optimal culture conditions were pH 10.0,culture volume 50% and flask fermentation by 120 rpm at 28? for 192 h.The highest salt tolerance was 5%.