School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
School of Grain Science and Technology, Jiangsu University of Science and Technology, 2 Mengxi Road, Zhenjiang 212003, China.
Int J Food Microbiol. 2024 Jan 30;410:110480. doi: 10.1016/j.ijfoodmicro.2023.110480. Epub 2023 Nov 10.
Postharvest soft rot of eggplant fruits caused by Pectobacterium carotovorum is a bacterial disease with a high disease incidence and produces substantial economic losses. This study aimed to control postharvest soft rot of eggplant fruits by Bacillus velezensis and investigate the possible control mechanisms based on the effects of B. velezensis on P. carotovorum subsp. carotovorum (Pcc) and eggplant fruits, respectively. B. velezensis effectively controlled postharvest soft rot of eggplant fruits and directly inhibited Pcc growth in vitro. The volatile metabolites produced by B. velezensis showed no inhibition on Pcc. Whereas the cell-free filtrate of B. velezensis significantly inhibited the growth of Pcc in vitro and in vivo. Notably, methanol-soluble precipitates obtained from cell-free filtrate showed significant inhibition on Pcc, and the primary inhibitory substances were identified as surfactin isoforms. Besides, iturin and fengycin isoforms with much lower relative abundance were also detected in the methanol-soluble precipitates. Furthermore, B. velezensis enhanced the activities of reactive oxygen species (ROS) scavenging enzymes in eggplant fruits that alleviated ROS and oxidative damage; thereby, B. velezensis enhanced the fruits' disease resistance.
由果胶杆菌引起的茄子果实采后软腐病是一种细菌性病害，发病率高，造成了巨大的经济损失。本研究旨在利用解淀粉芽孢杆菌（Bacillus velezensis）防治茄子果实采后软腐病，并分别基于其对果胶杆菌亚种果胶致病变种（Pectobacterium carotovorum subsp. carotovorum，Pcc）和茄子果实的影响，探讨可能的控制机制。解淀粉芽孢杆菌有效控制了茄子果实的采后软腐病，并直接抑制了体外 Pcc 的生长。解淀粉芽孢杆菌产生的挥发性代谢物对 Pcc 没有抑制作用。然而，解淀粉芽孢杆菌的无细胞滤液在体外和体内均显著抑制了 Pcc 的生长。值得注意的是，从无细胞滤液中获得的甲醇可溶沉淀物对 Pcc 表现出显著的抑制作用，主要抑制物质被鉴定为表面活性剂同工型。此外，在甲醇可溶沉淀物中还检测到丰度较低的伊枯草菌素和芬枯草菌素同工型。此外，解淀粉芽孢杆菌增强了茄子果实中活性氧（ROS）清除酶的活性，从而减轻了 ROS 和氧化损伤，增强了果实的抗病性。
