Short peptides secreted by Bacillus subtilis inhibit the growth of mould on fresh-cut pumpkin (Cucurbita pepo).

BACKGROUND This study investigates the efficacy of short peptides secreted by Bacillus subtilis for fungal inhibition in fresh-cut pumpkin and for maintaining its shelf life. RESULTS Low-molecular-weight filtrate (LC < 1000 Da) of B. subtilis culture (BC) significantly lowered the total number of molds on fresh-cut pumpkin compared with the untreated control and a BC group after storage. Low-molecular-weight filtrate prevented the deterioration of sensory quality in a pumpkin incision, and reduced pectinase activity. It also inhibited the growth of Phytophthora capsici and Penicillium chrysogenum, and the activity of beta-1,3-glucan synthase (GS) secreted by both molds. Fifty-seven GS-inhibiting peptides were screened from 95 LC peptides with two to five amino acid residues. The two most potent peptides, AWYW and HWWY, had strongly suppressive effects on the growth of P. capsici and P. chrysogenum. CONCLUSION Our study demonstrated that short peptides present in B. subtilis culture can play an important role in the maintenance of fresh-cut pumpkin by suppressing fungal growth. (c) 2019 Society of Chemical Industry