放线菌Y23菌株发酵液抗菌活性及稳定性测定

Studies on Antimicrobial Activity and Stability of Fermentation Liquid from Actinomycete Y23 Strain

从山东临沂、日照等主产烟区烟田采集病株根际土壤,分离到一株有抗菌活性的放线菌Y23,经初步鉴定为链霉菌(streptomyces sp.)。分别采用抑制菌丝生长速率法和琼脂扩散法测定了Y23菌株发酵液对15种病原真菌、3种病原细菌的抗菌活性。结果表明,Y23菌株发酵液对3种供试真菌的菌丝生长抑制率达60%左右,占供试真菌数的20%;琼脂扩散法生测结果表明,Y23菌株发酵液只对布克氏杆菌有抑制作用。对Y23菌株发酵液的稳定性测定结果表明,发酵液低温贮藏效果好,对热、酸碱及紫外光照稳定性较强,对日光稳定性较差。

The strain of Y23 was isolated from the rhizosphere soil of tobacco in Linyi and Rizhao areas of Shandong Province, and was identified to be Streptomyces sp. Taking 15 pathogenic fungi and 3 bacteria as objects, the antimicrobial activity of Y23 strain was studied. The results showed that the fermentation liquid of Y23 had almost 60% inhibition rate to three pathogenic fungi （20% of the total）, while it was just effective to Ralstonia solanacearum measured by agar plate diffusion method. The stability research of the fermentation liquid indicated that Y23 still had high activity if stored up at 4℃, and was stable to heat, acid, alkali and ultraviolet, but was less stable to sunlight.