Antagonistic and plant growth-promoting effects of bacillus velezensis BS1 isolated from rhizosphere soil in a pepper field

Abstract

Pepper (Capsicum annuum L.) is an important agricultural crop worldwide. Recently, Colletotrichum scovillei, a member of the C. acutatum species complex, was re-ported to be the dominant pathogen causing pepper an-thracnose disease in South Korea. In the present study, we isolated bacterial strains from rhizosphere soil in a pepper field in Gangwon Province, Korea, and assessed their antifungal ability against C. scovillei strain KC05. Among these strains, a strain named BS1 significantly inhibited mycelial growth, appressorium formation, and disease development of C. scovillei. By combined sequence analysis using 16S rRNA and partial gyrA sequences, strain BS1 was identified as Bacillus velezen-sis, a member of the B. subtilis species complex. BS1 produced hydrolytic enzymes (cellulase and protease) and iron-chelating siderophores. It also promoted chili pepper (cv. Nockwang) seedling growth compared with untreated plants. The study concluded that B. velezensis BS1 has good potential as a biocontrol agent of anthrac-nose disease in chili pepper caused by C. scovillei.