Bacillus velezensis TJS119 was isolated from the freshwater, and antagonistic activity against of pathogenic fungi. Strain TJS119 showed a broad spectrum of antagonistic activities many fungal pathogens, including the green muscardine fungus Metarhizium anisopliae. The whole-genome sequence of B. velzensis TJS119 was analyzed using the illumina platform. The genome comprises a 3,809,913 bp chromosome with a G + C content of 46.43%, 3,834 total genes, 10 rRNA and 73 tRNA genes. The genome contained a total of 8 candidate gene clusters (difficidin, fengycin, bacillaene, macrolactin, bacillibactin, bacilysin, surfactin and butirosin) to synthesize secondary metabolite biosynthesis. Overall, our data will aid future studies of the biocontrol mechanisms of B. velezensis TJS119 and promote its application in insect disease control.

Strawberry is one of the major economic crops in the modern agriculture industry worldwide. Fusarium wilt disease, caused by the Fusarium oxysporum f. sp. fragariae (FOF), is known as the most problematic factor in strawberry production. In a previous study, Streptomyces griseus S4-7 was isolated from the strawberry rhizosphere, exhibited an exceptional antifungal activity against the Fusarium wilt pathogen. However, sensitivity variation to S4-7 in the pathogen population was not evaluated. Therefore, we collected the pathogen nationwide and screened the sensitivity of FOF to the biological agent. A total of 96 FOF isolates was tested their sensitivity to the S4-7 and less-sensitive FOF isolates had lower cell wall degradation than the standard FOF strain. However, gene expression level of the cell wall organization (pkc1, gcn5) was not different between the less sensitive and the standard FOF strains. The results suggested that among the FOF population, some isolates may develop tolerance against a biocontrol agent through complex tolerance mechanisms.

Biological control has been tried for integrated pest management. It is often comparable, safe, and environment-friendly, making itself an alternative for chemical agents. Filamentous microorganisms, i.e., fungi and streptomystes, produce many kinds of useful metabolites, and some of them have been developed as a biocontrol agent. However, they still have a long way because of the concern of manufacturing cost. Therefore, process development was intensively studied to meet cost-effectiveness. Operating conditions of bioreactor, e.g., agitation and aeration, had an effect on biological and physiological responses such as mycelial morphology, oxygen and nutrient transfer. Understanding relationship between operating parameters and microbial responses in terms of growth, substrate and oxygen consumption, and production yield was critical for process development. This study dedicated to build strategies for mass production of biological control agent using aerobic filamentous microorganisms.

PDA배지에서 25℃로 배양할 때 초기 균사의 색은 흰색을 띄고 있었으며 배양 후기에 생성되는 포자의 색은 짙은 푸른색을 나타내고 있었다. 시간당 성장률은 1.1mm보다 빠른 것으로 나타났으며 성숙한 포자의 모양은 부드럽고 구형에 가까운 모양이었다. 이러한 형태학적 결과는 시간당 성장률이 0.5-0.7mm 이하인 Tricho-derma viride 및 T. hamatum의 특징과 성숙 포자의 모양이 실린더 모양인 T. koningii,

To develop eco-friendly microbial inoculants, siderophore-producing bacteria were isolated and identified, and their production characteristics and plant growth-promoting abilities were investigated. A strain S21 was isolated from rhizosphere of Korean perilla (Perilla frutescens) and identified as Enterobacter amnigenus by phenotypic properties and 16S rRNA gene sequencing. The highest siderophore production was obtained in a medium containing 0.5% fructose, 0.1% urea, 0.5% K2HPO4 and 0.1% succinic acid. By using this improved medium, siderophore production increased by 2.5 times compared to that of basal medium. The strain S21 showed insoluble phosphate solubilizing, ammonification and antifungal activities, and also produced hydrolytic enzymes (protease and lipase), indoleacetic acid and 1-aminocyclopropane-1-carboxylate deaminase. Our data suggest that E. amnigenus S21 is a potential candidate that can be used as eco-friendly biocontrol agent and biofertilizer.