Identification and Characterization of Bacillus tequilensis GYUN-300: An Antagonistic Bacterium Against Red Pepper Anthracnose Caused by Colletotrichum acutatum in Korea

Abstract

Anthracnose is a fungal disease caused by Colletotrichum species and has detrimental effects on many crops, including red pepper. This study used Bacillus tequilensis GYUN-300 (GYUN-300), which exhibit antagonistic activity against the fungal pathogen, Colletotrichum acutatum. This pathogen causes anthracnose that manifests primarily as a fruit rot in red pepper. There have been little efforts to identify antagonistic bacteria from mushrooms; this strain of bacteria was identified as B. tequilensis using BIOLOG and 16S rDNA sequencing analysis. The genetic mechanism underpinning the biocontrol traits of GYUN-300 was characterized using the complete genome sequence of GYUN-300, which was closely compared to related strains. GYUN-300 inhibited mycelial growth and spore germination of C. acutatum under in vitro conditions. Important antagonistic traits, such as siderophore production, solubilization of insoluble phosphate, and production of lytic enzymes (cellulase, protease, and amylase), were observed in GYUN-300, These trains promoted growth in terms of seed germination and vigorous seedling growth compared to the non-treated control. When red pepper fruits were treated with GYUN-300, the preventive and curative effects were 66.6 and 38.3% effective, respectively, in wounded red pepper fruits; there was no difference between the preventive and curative effects in non-wounded red pepper fruits. Furthermore, GYUN-300 was resistant to several commercial fungicides, indicating that GYUN-300 bacterial cells may also be used synergistically with chemical fungicides to increase biocontrol efficiency. Based on in vitro results, GYUN-300 played a role to control anthracnose disease effectively in field conditions when compared to other treatments and non-treated controls. The results from this study provide a better understanding of the GYUN-300 strain as an effective biocontrol agent against red pepper anthracnose; this form of biocontrol provides an environment-friendly alternative to chemical fungicides.

Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid

“…Previous studies found that B. tequilensis can quickly and stably colonize plants, and has a high propagation rate and a strong proliferative capacity [ 30 ]. B. tequilensis has high efficiency and broad-spectrum resistance to plant pathogens, has a combined treatment effect on plant diseases such as anthracnose [ 31 ] and black spot disease [ 32 ], has a high prevention effect, and has good application prospects for the prevention and control of plant diseases [ 33 ]. However, it has never been reported for γ-PGA production; therefore, B. tequilensis BL01 was selected for subsequent experiments.…”

Characterization and evaluation of Bacillus subtilis GYUN-2311 as a biocontrol agent against Colletotrichum spp. on apple and hot pepper in Korea

“…Similarly, Shin et al (2021) demonstrated that the application of the antagonistic bacteria, B. velezensis BS1 at a concentration of 10 5 × CFU/mL significantly ( p < 0.05) reduced the anthracnose disease caused by Colletotrichum scovillei on hot pepper fruits when compared to the untreated control group. Furthermore, Kwon et al (2022) achieved red pepper anthracnose control using Bacillus tequilensis GYUN-300 with only 14% disease incidence under field conditions. In contrast, Kim et al (2023) recently demonstrated disease control of anthracnose caused by C. acutatum in red peppers with a significant ( p < 0.05) reduction of disease rate (0.4%) by pre-immersion with Brevibacillus halotolerans B-4359 when compared to foliar spray and soil drench methods under field conditions.…”

“…A field experiment was carried out to investigate the biological control of hot pepper anthracnose using GYUN-2311 antagonistic bacteria in Korea. Initially, the seedlings were grown in plastic trays (36 pots per tray) with one seed per pot ( Kwon et al, 2022 ). Three-week-old hot pepper (cv.…”

Enhanced poly-γ-glutamic acid production by a newly isolated Bacillus tequilensis BL01

“…Previous studies found that B. tequilensis can quickly and stably colonize plants, and has a high propagation rate and strong in proliferative capacity (Shultana et al 2021). B. tequilensis has high e ciency and broad-spectrum plant pathogen resistance, has a combined treatment effect on plant diseases such as anthracnose (Kwon et al 2022) and black spot disease (Xu et al 2021), has a high prevention effect, and has good application prospects for the prevention and control of plant diseases (Guerrero-Barajas et al 2020). However, it has never been reported for γ-PGA production; therefore, B. tequilensis BL01 was selected for subsequent experiments.…”