Affiliation:
1. College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
2. College of Life Science, Jilin Agricultural University, Changchun 130118, China
Abstract
A biocontrol Bacillus velezensis strain, NT35, was isolated from the rhizosphere soil of ginseng, and its sterile filtrate was obtained through a 0.22 μm filter which had a significant inhibitory effect against Ilyonectria robusta, which causes rusty root rot in Panax ginseng. In order to obtain the best sterile filtrate, the medium fermentation conditions of the strain NT35 were optimized using response surface methodology (RSM), and the best composition was obtained. Therefore, the fermentation medium was composed of yeast extract powder 2.5%, cornmeal 1.5%, K2HPO4 1.5%, and (NH4)2SO4 2.5%. The optimal inoculum amount was 6%, at an initial pH value of 7.0 and culturing at 34 °C at 180 rpm. The antifungal protein 1-4-2F was obtained through precipitation via 30% (NH4)2SO4 precipitation, desalting by Sephadex G-25, ion-exchange chromatography, and gel filtration chromatography. Tricine-SDS-PAGE showed that the purified protein had a relative molecular weight of approximately 6.5 kDa. The protein 1-4-2F was relatively stable and had better antifungal activity at pH 4–10 and 20–100 °C under ultraviolet irradiation of 30 W. The amino acid sequence of protein 1-4-2F was obtained using mass spectrometry, and had 100% similarity to a hypothetical protein from B. velezensis YAU B9601-Y2 (Accession No: AFJ62117). Its molecular weight was 10.176 kDa, the isoelectric point was 9.08, and its sequence coverage reached 49%. The EC50 value of the protein 1-4-2F against I. robusta was 1.519 μg·mL−1. The mycelia morphology of I. robusta changed significantly after treatment with antifungal protein under microscopic observation; the branches of the mycelia increased, distorted, partially swelled into a spherical or elliptical shape, and even ruptured; and the cells became vacuoles.
Funder
China Agriculture Research System
Jilin Science and Technology Development Project
Subject
Plant Science,Biochemistry, Genetics and Molecular Biology (miscellaneous),Food Science
Reference33 articles.
1. Textual research and modern review on ginseng;Wang;World Chin. Med.,2017
2. First Report of Ilyonectria robusta Causing Rusty Root of Asian Ginseng in China;Lu;Plant Dis.,2015
3. Lin, C., Tsai, C.H., Chen, P.Y., Wu, C.Y., Chang, Y.L., Yang, Y.L., and Chen, Y.L. (2018). Biological control of potato common scab by Bacillus amyloliquefaciens Ba01. PLoS ONE, 13.
4. Isolation, characterization and amino acid composition of a bacteriocin produced by Bacillus methylotrophicus strain BM47;Tumbarski;Food Technol. Biotechnol.,2018
5. Research progress on the characteristics and purification methods of antibacterial substances produced by biocontrol Bacillus;Zou;Xiandai Yuanyi Contemp. Hortic.,2017
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献