Effects of biocontrol bacteria Bacillus amyloliquefaciens LY-1 culture broth on quality attributes and storability of harvested litchi fruit

Abstract

Effects of postharvest biocontrol treatment with antagonistic bacteria Bacillus amyloliquefaciens LY-1 on quality attributes and storability of harvested litchi fruit were investigated. “Wuye” litchi fruit were immersed in 1.0×108 colony-forming units (CFU) mL−1B. amyloliquefaciens LY-1 culture broth (BLCB) or sterile water (control) for 5min, respectively. Litchi fruit were then air-dried and stored at 25±1°C and 85%–90% relative humidity. Comparing to control litchi fruit, the BLCB-treated litchi fruit exhibited lower pericarp browning index, and percentages of fruit decay and weight loss. Moreover, the BLCB-treated litchi fruit maintained higher contents of total soluble solids, titratable acidity, total soluble sugars and vitamin C in pulp, as well as higher activities of disease resistance-related enzymes (phenylalanine ammonia lyase, chitinase, and β-1, 3-glucandase) and higher content of natural disease-resistive material like lignin in pericarp. Thus, it can be concluded that the 1.0×108 CFUmL−1 BLCB treatment delayed the progress of pericarp browning, lowered fruit decay and weight loss, and maintained higher quality of harvested “Wuye” litchi fruit during storage, which might suggest that the BLCB treatment was a promising and effective biological control method for prolonging the shelf-life of harvested litchi fruit.