Environmental Biotechnology Laboratory, Life Science Division, Institute of Advanced Study in Science and Technology, Guwahati, India.
Chemical Biology Laboratory I, Life Science Division, Institute of Advanced Study in Science and Technology, Guwahati, India.
J Basic Microbiol. 2023 Jul;63(7):746-758. doi: 10.1002/jobm.202200608. Epub 2023 Apr 14.
The nutrient-rich vermicompost which is used as manure for the growth and development of plants is rich in microbial flora. These microbes protect the plants against several infectious pathogenic microbes. As certain microbes are known to produce biosurfactants as metabolites, an investigation was carried out to isolate biosurfactant-producing bacterial strains from vermicompost with the efficient antifungal property. From the study, it was revealed that biosurfactant-producing bacterial strains are present in the vermicompost. A total of nine bacterial strains were isolated from the vermicompost. Among them, one most efficient biosurfactant-producing bacterial strains with antifungal properties have been screened. After molecular characterization of the isolated strain, it was revealed that the bacterial strain is Bacillus licheniformis strain SCV1. The strain produces 3.4 ± 0.1 g/L of crude biosurfactant, which when column purified yields 3.1 ± 0.1 g/L of biosurfactant. The biosurfactant exhibited excellent emulsifying activity (E ) of 96.56% against crude oil. The produced biosurfactant was identified as a lipopeptide consisting of a mixer of surfactin and iturin. Furthermore, the biosurfactant exhibited significant antifungal activity against a wide range of phytopathogens, showing 76.3% inhibition against Sclerotinia sclerotiorum, 53% inhibition against Colletotrichum gloeosporioides, 51% against Fusarium verticillioides, and 36% against Corynespora cassicolla. Along with antifungal activities, the stain was found to exhibit multiple plant growth-promoting traits. This study, thus indicates that vermicompost might contain biosurfactant-producing microbes which can render protection to the plant against various phytopathogens by the production of biosurfactants and can also stimulate plant growth.
用作植物生长和发育肥料的营养丰富的蚯蚓粪富含微生物菌群。这些微生物可以保护植物免受多种传染性病原微生物的侵害。由于某些微生物已知会产生生物表面活性剂作为代谢物，因此进行了一项研究，以从具有高效抗真菌特性的蚯蚓粪中分离出产生生物表面活性剂的细菌菌株。研究表明，蚯蚓粪中存在产生生物表面活性剂的细菌菌株。从蚯蚓粪中分离出了总共 9 株细菌。其中，筛选出了一株具有抗真菌特性的最有效的产生物表面活性剂的细菌菌株。对分离菌株进行分子鉴定后，发现该菌株为地衣芽孢杆菌菌株 SCV1。该菌株产生 3.4±0.1g/L 的粗生物表面活性剂，经柱纯化后可产生 3.1±0.1g/L 的生物表面活性剂。生物表面活性剂对原油表现出出色的乳化活性（E）为 96.56%。所产生的生物表面活性剂被鉴定为由表面活性剂和伊枯草菌素组成的脂肽。此外，该生物表面活性剂对多种植物病原菌表现出显著的抗真菌活性，对核盘菌的抑制率为 76.3%，对炭疽菌的抑制率为 53%，对镰刀菌的抑制率为 51%，对柯尔本斯孢叶点霉的抑制率为 36%。除了抗真菌活性外，该菌株还表现出多种促进植物生长的特性。因此，这项研究表明，蚯蚓粪可能含有产生生物表面活性剂的微生物，这些微生物可以通过产生生物表面活性剂来保护植物免受各种植物病原菌的侵害，同时还可以刺激植物生长。
