Specific Suppression Killing Microcystis Aeruginosa Actinomycetes

Microcystis water-bloom is a serious ecological problem. The control, particularly bio-control is the research hot spot these years. How to apply marine actinomycetes as the new water-bloom-controlling method was discussed in this paper.464 strains of actinomycetes were seperated from the seabeachs in Jiangsu. 18 Microcystis-killing strains were selected. Two strains of them , NT0401 and YC0412, had stronger killing acvtivties.The mophorlogical characters of strains NT0401 and YC0412 were observed, their physilogical and biochemical characters were studied and the components of their cell walls were analysed. In addition we sequenced the 16SrDNA of strain NT0401. From about all, strains NT0401 and YC0412 were prelimenarily identified as Streptomyces griseovariabilis and Streptomyces globisporus var. flavofuscus.Studying the effective factors of NT0401 and YC0412 on inhibition of microcystis aeruginosa suggested NT0401 and YC0412 were easier to accumulate the effective factors when their fermenting conditions were as follow: soluble starch as carbon resources, KNO3 as nitrogen resources, pH 7.5, 150mL medium in 500mL flasks, 28 ℃, 150rpm, 7days and 6 days culturing, respectivly.The effective factors of NT0401 were water-soluble, and were not soluble in normal organic solvents. It had no effects on the other tested micro-algae and the 8 model strains of bacteria, actinomycetes and fungi. So the effective factors of NT0401 could effectively inhibit the growth of Microcystis aeruginosa but do little harm to the other microorganinsms in ecological environment.The effective factors of strain-YC0412 were liposoluble. It had different effects on the 8 model strains of bacteria, actinomycetes and fungi, which are used in new antibiotic screening; and inhibit the growth of Synechocystis and Anabaena.The sensitivity of the effective factors of NT0401 and YC0412 to pH andtemperature was also determined. The effective factors of NT0401 was steady, but the effective factors of YC0412 was sensitive.