In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.

Entomopathogenic fungi are used to produce raw materials by applying solid culture technology using grains. But there are various problems such as low production efficiency and cross-contamination. Solvum Co., Ltd. conducted research on liquid culture technology to develop a method that can overcome these shortcomings of solid culture technology. We conducted research and development on using Beauveria bassiana 331R to observe the culture according to the seed inoculation amount in a 30 L fermenter, it was carried out at 1.0 % (v/v) and 10.0 % (v/v). Although there was a difference of 1 day, 1.0 %(v/v) seed inoculation was observed to be more than twice that, and active blastospores and yield were observed at over 95.0 %. As a results, it was determined that cost and efficient production would be possible during the culture process in mass production. Based on these experiments, a 300 L fermenter was cultured with 1.0 % (v/v) seed inoculation, resulting in a yield of 1.24E+09 CFU/mL on the 6th day of cultivation. As a result of freeze-drying using the final culture medium, it was confirmed that the production yield was improved by 113.0 % compared to the control.

Root-knot nematode (RKN), Meloidogyne incognita, inflicts significant greenhouse crop damage, causing over 40% economic losses. While chemical agents effectively control RKN, they leave harmful residue in soil and crops. To address this issue, we investigated soil-derived entomopathogenic fungi (EPF) in this study. We assessed the nematicidal impact of ten EPF species through in vivo and in vitro tests. Beauveria bassiana JEF-503 exhibited nematicidal effectiveness exceeding 65% in both experimental settings. In a semi-field test using greenhouse pots, we experimented with the application of B. bassiana JEF-503 suspension during tomato growth, which is an uncommon practice in comparison to chemical treatments due to residue concerns. B. bassiana JEF-503 was applied during transplantation, and the same application was repeated four weeks later. JEF-503 One-time and abamectin treatments were used as control groups. The JEF-503 two-time application notably reduced root damage compared to single JEF-503 or abamectin treatment. In conclusion, JEF-503 offers a promising, residue-free, and environmentally friendly alternative to chemical agents for RKN management.

Soybean aphid, Aphis glycines Matsumura has been identified as a pest of soybean in Korea, Japan, and China. The use of synthetic chemical insecticides is a major option to manage this pest, but the demand for environmental-friendly insecticide is increasing. Entomopathogenic fungus is one of the alternatives which is safe for the environment. In this bioassay, leaf dipping method was used to evaluate Beauveria bassiana (Balsamo) Vuillemin ARP14 and GHA. The mortality of both adults and nymphs was not significantly different between the two fungus strains. However, faster mortality rate in both life stages of aphid was found in ARP14 compared to GHA strain. Also, the mycosis rates of both adults and nymphs were higher in ARP14 than in GHA strain. Our results suggest that B. bassiana ARP14 can be an effective and an environmental-friendly control agent for A. glycines.

Tetranychus kanzawai Kishida (Acari: Tetranychidae) is a major pest on strawberry, reducing both the quality and quantity of fruit production. We compared the virulence of an entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin ARP14 with a commercial GHA strain against T. kanzawai. In the laboratory, leaf dipping method was conducted while a one-time spray was carried out on selected planting units in strawberry greenhouse with each fungus strain and Triton X-100 as control. Adult T. kanzawai showed lower LT50 when treated with ARP14 strain compared to GHA in the laboratory. The densities of both adult and nymph mites in the greenhouse were significantly reduced in the treatment of two fungus strains compared to the control. The mycosis rate of T. kanzawai in greenhouse was 97.9% at 14 days when treated with ARP14 strain while it was 85.5% when treated with GHA strain. The results suggest that B. bassiana ARP14 can be an effective mycoinsecticide against T. kanzawai.

The ladybird beetles have been used as biological control agents against several pest species. The aim of this study is to evaluate the compatibility between ladybird beetles and an entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin AAD16. The virulence of AAD16 strain was compared with that of commercial GHA strain on three developmental stages of two coccinellids; Harmonia axyridis Pallas and Chilocorus stigma Say. The topical application method was used for both adult and larval stage while dipping method was used for egg stage. The LT50 and mycosis rate for all life stages of two ladybird beetles tested were not significant between AAD16 and GHA strain. In larval stage, the mycosis rates of H. axyridis and C. stigma were 36 and 40% and 63 and 60% in AAD16 and GHA strain. In adult stage, the mycosis rates of H. axyridis (male and female) and C. stigma (unsexed) were 20, 23, and 23% and 26, 30, and 30% in AAD16 and GHA strain, respectively. Therefore, the two predatory coccinellids could be compatible with these two fungus strains due to their relatively lower mycosis rate.