Isolation and yield optimization of lipopeptides from Bacillus subtilis Z‐14 active against wheat take‐all caused by Gaeumannomyces graminis var. tritici

Abstract

Wheat take‐all, caused by the soil‐borne fungus Gaeumannomyces graminis var. tritici, is one of the major constraints on wheat production worldwide. Bacillus subtilis Z‐14 exerts significant biocontrol activity against wheat take‐all, and lipopeptide antibiotics are the main antifungal substances. Herein, lipopeptide antibiotics C14–C15 iturin A, C14–C16 fengycin A, and C15–C17 fengycin B from B. subtilis Z‐14 culture filtrates were separated and identified by high‐performance liquid chromatography, matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry, and mass spectrometry/mass spectrometry, respectively. The optimal medium components for Z‐14 lipopeptide antibiotic production were 3.85 g/L corn flour, 1.57 g/L soybean meal, 0.03 g/L FeSO4·7H2O, 0.2 g/L NaH2PO4·2H2O, and 0.4 g/L Na2HPO4·2H2O. Quantification analysis by high‐performance liquid chromatography showed that fengycins played a main role in antifungal activity against Gaeumannomyces graminis var. tritici. Quantitative reverse transcription polymerase chain reaction showed that lipopeptide synthesis genes fenD and ituC reached maximum expression levels after 48 h of fermentation. The strongest control of wheat take‐all by Z‐14 was achieved by adding 30 mL of culture filtrate per 350 g of soil in pot experiments, during which disease reduction reached 88.15%. This study provides theoretical support and a material basis for the prevention and treatment of wheat take‐all disease.

Metabolomic and Transcriptome Analysis of the Inhibitory Effects of Bacillus subtilis Strain Z-14 against Fusarium oxysporum Causing Vascular Wilt Diseases in Cucumber

“…It resulted in the significant control of the take-all disease in the disease caused by Gaeumannomyces graminis var. tritici and fruit gray mold caused by Botrytis cinerea. − The fungus FOC was donated by Professor Jin Cheng of the Institute of Microbiology, Chinese Academy of Sciences . Uncoated cucumber seeds (Jinyan No.…”

Activity of Fengycin and Iturin A Isolated From Bacillus subtilis Z-14 on Gaeumannomyces graminis Var. tritici and Soil Microbial Diversity

“…Using lipopeptides directly to control plant diseases is not economical at present. However, as research on their synthetic regulatory mechanism and the yield optimization of lipopeptides progresses (Dang et al, 2019;Zhang et al, 2021), it will become increasingly realistic to use lipopeptides to control plant diseases to compensate for the deficiencies of using intact cells (Chakraborty et al, 2020;Kourmentza et al, 2021).…”

“…Methanol extracts of strain Z-14 fermentation supernatant were shown to contain three lipopeptide antibiotic families (surfactins, iturins, and fengycins). The combination of isolation using high performance liquid chromatography (HPLC), antifungal activity measurement via a diffusion plate assay, and component detection using MALDI-TOF MS analysis demonstrated that iturins and fengycins were the main antifungal metabolites of strain Z-14 (Zhang et al, 2021). The present study aimed to determine the differences in the antifungal mechanisms against the phytopathogenic fungus of iturins and fengycins purified from strain Z-14 fermentation supernatant, and their inhibitory spectrum against fungi and bacteria, using the wheat take-all pathogen and all the microorganisms in soil as indicators.…”

Validation of reference genes for the normalization of RT-qPCR gene expression in Bacillus siamensis 1021 grown in different culture media

“…This class of lipopeptides was synthesized by modular nonribosomal peptide synthetases (NRPSs) ( 18 ). Previous studies in other Bacillus species suggested that NRP production correlated with expression of NRPS genes ( 19 – 20 ). Several regulatory genes of NRP biosynthesis were also determined ( 21 – 22 ).…”