AUTHOR=Kim Da Yeon , Han Jae Woo , Lee Jin Woo , Kim Bomin , Kim Yeong Seok , Kim Heung-Tae , Choi Gyung Ja , Kim Hun 

TITLE=Biocontrol potential of Chitinophaga flava HK235 producing antifungal-related peptide chitinocin

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1170673

DOI=10.3389/fmicb.2023.1170673

ISSN=1664-302X

ABSTRACT=<p><italic>Botrytis cinerea</italic> is a necrotrophic fungal pathogen with an extremely broad host range, causing significant economic losses in agricultural production. In this study, we discovered a culture filtrate of bacterial strain HK235, which was identified as <italic>Chitinophaga flava</italic>, exhibiting high levels of antifungal activity against <italic>B. cinerea</italic>. From the HK235 culture filtrate, we isolated a new antimicrobial peptide molecule designated as chitinocin based on activity-guided fractionation followed by characterization of the amino acid composition and spectroscopic analyses. The HK235 culture filtrate and chitinocin completely inhibited both conidial germination and mycelial growth of <italic>B. cinerea</italic> at a concentration of 20% and 200 μg/mL, respectively. In addition to antibiosis against <italic>B. cinerea</italic>, the active compound chitinocin had a broad antifungal and antibacterial activity <italic>in vitro.</italic> When tomato plants were treated with the culture filtrate and chitinocin, the treatment strongly reduced the development of gray mold disease in a concentration-dependent manner compared to the untreated control. Here, considering the potent antifungal property <italic>in vitro</italic> and <italic>in vivo</italic>, we present the biocontrol potential of <italic>C. flava</italic> HK235 for the first time.</p>