侧孢短芽孢杆菌B8发酵液中抑菌物质理化性质研究

从烟草根际土壤中分离到一株生防菌侧孢短芽孢杆菌(Brevibacillus laterosporus)B8,其发酵液对烟草黑胫病菌(Phytophthora parasitica var.nicotianae)的抑菌圈直径可达到63 mm.为了明确生防菌株B8发酵液中抑菌物质的理化性质,对发酵液的稳定性进行了测定.结果...

Characteristic Analysis of Antagonistic Substances Produced by Brevibacillus laterosporus B8

Bacterial strain B8 was isolated from the rhizosphere soil of tobacco plants,and it was identified as Brevibacillus laterosporus.It showed significant inhibition against Phytophthora parasitica var.nicotianae and the inhibitory diameter was up to 63mm.The physicochemical properties of antagonistic substances were studied in order to determine the active ingredient in the fermentation broth filtrate of strain B8.The results showed that the antagonistic substances were thermal stable and could tolerate 100℃.The active pH range of the antagonistic substances against the pathogen was wide,from 3 to 12 and the inhibitory activity was stronger under acidic condition than alkaline condition.The inhibitory activity of antagonistic substances was unaffected after treatment by trypsin and proteinase K but partly affected by pepsin.The antagonistic substances could not be extracted by organic solvent and the majority could be able to be precipitated by ammonium sulfate under the saturation degree of 30% and 80%.The experimental data indicated that antagonistic substances might be a protein or peptide-like antibiotics.