杜比亚蟑螂共生真菌次生代谢产物及其生物活性

为探究杜比亚蟑螂体内共生真菌种类,测定共生真菌次生代谢产物的抑菌活性和抗氧化活性,筛选出具有抗菌和抗氧化活性的菌株,本研究采用组织块分离法分离杜比亚蟑螂体内的共生真菌,通过形态学和分子生物学相结合的方法对分离到的共生真菌进行鉴定;分别采用薄层层析-生物自显影法和DPPH法测定共生真菌次生代谢产物的抗细菌活性和抗氧化活性。结果表明,从杜比亚蟑螂体内共分离鉴定得到5种不同的共生真菌,主要分布于青霉属(1株)、曲霉属(3株)和聚孢霉属(1株)。活性测定的结果表明,菌株Bdf-2、Bdf-4和Bdf-5表现出较好的抗菌活性,且菌液提取物的抗菌活性要强于菌丝。Bdf-1,Bdf-2和Bdf-3菌液次生代谢产物表现出抗氧化活性,IC 50值分别为0.26 mg/mL、2.20 mg/mL和0.75 mg/mL。杜比亚蟑螂共生真菌以青霉属和曲霉属为主,且具有抗菌和抗氧化活性的次生代谢产物主要分布于菌液中。

Secondary metabolites of symbiotic fungi isolated from Blaptica dubia and their biological activities

This study was to explore the species of symbiotic fungi in Blaptica dubia,determine the antibacterial and antioxidant activities of secondary metabolites extracted from symbiotic fungi,and screen the strains with antibacterial and antioxidant activities.Tissue block separation method was used for the isolation of symbiotic fungi in B.dubia.Morphology observation associated with molecular biology assay was used for the identification of symbiotic fungi isolated from B.dubia.The antibacterial activity of the secondary metabolites produced by simbiotic fungi was determined by Thin Layer Chromatography-Bioautography assay and the antioxidant activity was determined by a microplate spectrophotometric method based on the reduction of DPPH.Five strains in total were identified from B.dubia.The simbiotic fungi were mainly distributed in Penicillium sp.(1 strain),Aspergillus sp.(3 strains)and Clonostachys sp.(1 strain).The results showed that Bdf-2,Bdf-4 and Bdf-5 displayed good antibacterial activities,and the antibacterial activities of extracts from broth were stronger than that of mycelia.Bdf-1,Bdf-2 and Bdf-3 broth extracts also showed better antioxidant activities,and the IC 50 values were 0.26 mg/mL,2.20 mg/mL and 0.75 mg/mL,respectively.Penicillium and Aspergillus species were the main symbiotic fungi of B.dubia,and the secondary metabolites with antibacterial and antioxidant activities were mainly distributed in the broth.