越南槐内生真菌TRPH-21的抗菌活性及其鉴定

Antibacterial activities and taxonomic identification of endophytic fungus TRPH-21 isolated from Sophora tonkinensis Gapnep

目的为新型抗生素的研究提供有价值的菌种资源。方法以2株病原细菌大肠埃希菌ATCC25922和产肠毒素性大肠埃希菌多重耐药临床分离株为靶标菌,采用琼脂块法和改良的微量肉汤稀释法测定越南槐内生真菌TRPH-21的抗菌活性;根据形态和分子特征鉴定该菌株的分类学地位。结果该菌株的活菌块对大肠埃希菌ATCC25922的抑菌圈直径比阳性对照大;其代谢产物对2株病原细菌的最小抑菌浓度均为16μg/m L,仅为阳性对照的16倍;初步鉴定该菌株为尖孢镰孢菌。结论菌株TRPH-21鉴定为尖孢镰孢菌,对参试病原细菌均显示强的抗菌活性,具有较大的开发应用潜力。

Objective To provide a valuable strain resource for the research of novel antibiotics. Methods The in vitro antibacterial activity of endophytic fungus TRPH-21 isolated from Sophora tonkinensis Gapnep against two pathogenic bacteria including Escherichia coli ATCC25922 and multidrug-resistant enterotoxigenic E. coli in clinical was evaluated using the agar plug method and modified broth microdilution method; the taxonomic identification of this strain was based on morphological characters and molecular characters. Results The diameter of the inhibition zone from the mycelial plug of this strain against E. coli ATCC25922 was greater than that of the positive control. The minimal inhibitory concentration values of the metabolites from this strain against pathogenic E. coli ATCC25922 and enterotoxigenic E. coli were both 16gg/mL and were sixteen times higher than that of the positive control. This strain was preliminarily named as Fusarium oxysporum. Conclusion Strain TRPH-21 was preliminarily identified as E oxysporum and exhibited strong antibacterial activity against pathogenic bacteria E. coli ATCC25922 and enterotoxigenic E. coll. It should be an interesting isolate for further exploration and utilization.