鲜天麻内生菌分离鉴定及功能活性探究

目的:明确天麻内生菌及其代谢产物的活性。方法:采用组织匀浆法和划线法从秦巴地区鲜天麻中分离纯化内生菌,测定其抗菌、抗氧化及抗肿瘤活性,并对高活性菌株进行分子生物学鉴定。结果:从鲜天麻内部分离得到4株菌,其中内生菌B1、B2对大肠杆菌和金黄色葡萄球菌具有良好的抗菌活性,内生菌B2对金黄色葡萄球菌抑菌圈直径达26.33 mm。4株菌均有一定的抗氧化活性,其中,内生菌B1对DPPH自由基的清除能力为69.13%。内生菌B2、B3、B4对HEK293T细胞有一定的抑制作用,其中内生菌B2的最高抑制率可达40.40%。分子生物学方法鉴定结果表明,内生菌B1、B2为贝莱斯芽孢杆菌(Bacillus velezensis),内生菌B3为Lelliottia sp.,内生菌B4为水生拉恩菌(Rahnella aquatilis)。结论:分离纯化的鲜天麻内生菌具有抑菌和抗氧化活性。

Isolation and identification of endophytic bacteria from fresh Gastrodia elata and preliminary study on its functional activity

Objective: This study aimed to elucidate the activities of endophytic bacteria and their metabolites of Gastrodia elata BI, and to provide theoretical reference for the development of new natural food antibacterial agents and antioxidants.Methods: The endophyte of fresh G. elata in Qinba area was isolated and purified by tissue homogenization and streaking method. The antibacterial, antioxidant and anti-tumor activities of the extract were determined. Furthermore, molecular biology identification was applied for the highly active strains.Results: In this study, four strains were isolated from the inside of fresh G. elata, among which, endophytic bacteria B1 and B2 have good antibacterial activity against Escherichia coli and Staphylococcus aureus . The inhibition zone diameter of endophytic bacteria B2 against S. aureus was 26.33 mm. The four strains all have good antioxidant activities, among which, the percentage of scavenging DPPH scavenges for endophytic bacteria B2 was as high as 69.13%. Endophytic bacteria strain B2, endophytic bacteria B3, and endophytic bacteria B4 have a potential inhibitory effect on HEK293T cells. Among them, endophytic bacteria B2 showed the highest inhibition rate which was 40.40%. The results of molecular biological identification showed that the endophytic bacteria strain B1 and B2 all belonged to Bacillus velezensis , while, endophytic bacteria B3 was Lelliottia sp., and endophytic bacteria B4 was Rahnella aquatilis .Conclusion: The endophyte of fresh G. elata in Qinba area was isolated and purified had antibacterial activity and antioxidant activity.