Isolation and Characterization of an Antifungal and Plant Growth-Promoting Microbe

Se Won  Park1   Hee-Jong Yang1   Ji Won  Seo1   Ji Won  Kim1   Su-ji Jeong1   Gwangsu Ha1   Myeong Seon Ryu1   Hee Gun Yang1   Do-Youn Jeong1,*   Hyang Burm Lee2,*   

1Microbial Institute for Fermentation Industry (MIFI), Sunchang 56048, Korea
2Department of Agricultural Biological Chemistry, College of Agriculture & Life Sciences, Chonnam National University, Gwangju 61186, Korea>


Fungal diseases including anthracnose, stem rot, blight, wilting, and root rot of crops are caused by phytopathogens such as Colletotrichum species, Sclerotinia sclerotiorum, Phytophthora species, and Fusarium oxysporum and F. solani which threaten the production of chili pepper. In this study, to identify biological control agents (BCAs) of phytopathogenic fungi, potentially useful Bacillus species were isolated from the field soils. We screened out five Bacillus strains with antagonistic capacity that are efficiently inhibiting the growth of phytopathogenic fungi. Bacillus species were characterized by the production of extracellular enzymes, siderophores, and indole-3-acetic acid (IAA). Furthermore, the influence of bacterial strains on the plant growth promoting activity and seedling vigor index were assessed using Brassica juncea as a model plant. Inoculation with Bacillus subtilisSRCM 121379 significantly increased the length of B. juncea shoots and roots by 45.6% and 52.0%, respectively. Among the bacterial isolates, Bacillus subtilisSRCM 121379 showed the superior enzyme activities, antagonistic capacity and plant growth promoting effects. Based on the experimental results, Bacillus subtilisSRCM 121379 (GenBank accession no. NR027552) was finally selected as a BCA candidate.

Figures & Tables

Fig. 1. Antifungal activities of SRCM 121379 against several phytopathogenic fungal strains ([A-B], colonies on V8 juice agar and [C-D], potato dextrose agar) by dual culture. subtilis SRCM 121379 against KACC 40166 (A), Fusarium solani which isolated from hydroponically cultured (B), KACC 40042 (C), and KACC 41065 (D) by agar well diffusion method