Antimicrobial Spectrum and Stability of Fermentation Broth Produced by Antagonistic Actinomycetes Strain ZZ-9
To study bacteriostatic spectrum of fermentation broth from actinomycetes strain ZZ-9 identified as Streptomyces rochei,and to verify the effect of it on stability of fermentation broth under biochemical and physical factors such as subculture,temperature,illumination,pH and ultraviolet conditions.As the tested phytopathogen,method of growth rate was used to determine antimicrobial spectrum of fermentation broth with 15 kinds of plant pathogenic fungus.With Cytospora sp.as indicator phytopathogen,the stability of fermentation broth under different conditions was measured.The bacteriostatic spectrum results showed that the fermentation broth of ZZ-9 strain had inhibitory effects at different degres on 15 kinds of pathogenic fungus.With growth inhibition rate of more than 96％ and the lasting effect,the fermentation broth of ZZ-9 strain had the best effect on Cytospora sp.and Rhizoctonia solani,and it had worse effect on Botryosphaeria piricola,Cladosporium cladosporioidesv and Ascochyta fabae,the inhibition rate was under 27 ％.The stability test showed that the activity of strain was stable until the 6th generation,it decreased significantly from the 7th generation,and the fermentation broth had high temperature resistance,good stability under strong acid and alkali,visible light and ultraviolet irradiation treatments.Moreover,the fermentation broth could be stored for at least 30 days at 4 ℃ and room temperature (20-25 ℃),the activity remained nearly unchanged.Therefore,the secondary metabolites of antagonistic actinomycetes ZZ-9 strain had broad-spectrum antibacterial activity and strong stability,and the potential could be developed into the microbial pesticide.
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NSTL
万方数据
维普
