Food contamination caused by microorganisms has become a threat to consumers' health. Exploring antagonistic endophytes from plants of food raw-material and applying bioactive metabolites to inhibit the contamination has been an alternative and safer solution. In this study, we isolated and screened potential antagonistic endophytes from fresh Camellia assamica leaves, which were widely used in tea beverage production. We focused on a strain that showed visible inhibitory activity to Gram-positive bacteria, Gram-negative bacteria, and fungi. It was identified as a member of Bacillus velezensis and named FZ06. The results of genome analysis showed the strain FZ06 had 167 single-copy specific genes, much higher than those of most related strains. Also, 11 potential gene clusters of antimicrobial metabolites were found. Three groups of lipopeptides (surfactin, iturin, and fengycin) were identified by UPLC-MS/MS in purified antimicrobial methanol fraction of strain FZ06. The results of minimum inhibitory concentration (MIC) test proved the lipopeptide extract showed significant inhibitory effect on food spoilage bacteria (MIC 512−2048 μg/mL) and toxigenic fungi (MIC 128−256 μg/mL). In conclusion, this study suggests that the endophytic B. velezensis FZ06 and its lipopeptide extract hold great potential applications in the inhibition of food spoilage bacteria and toxic fungi in food industry.

由微生物引起的食品污染已成为对消费者健康的威胁。从食品原料植物中探索拮抗内生菌并应用生物活性代谢物来抑制污染已成为一种替代且更安全的解决方案。在这项研究中，我们从新鲜茶树叶子中分离和筛选出潜在的拮抗内生菌，这些植物广泛用于茶饮料生产。我们专注于对革兰氏阳性菌、革兰氏阴性菌和真菌显示出明显抑制活性的菌株。它被确定为贝雷兹芽孢杆菌的成员并命名为FZ06。基因组分析结果显示，菌株FZ06具有167个单拷贝特异性基因，远高于大多数相关菌株。此外，还发现了 11 个潜在的抗菌代谢物基因簇。通过 UPLC-MS/MS 在 FZ06 菌株的纯化抗菌甲醇级分中鉴定了三组脂肽（表面活性素、伊图林和芬奇素）。最低抑菌浓度（MIC）测试结果证明，脂肽提取物对食品腐败菌（MIC 512-2048 μg/mL）和产毒真菌（MIC 128-256 μg/mL）有显着抑制作用。综上所述，本研究表明内生B. velezensis FZ06及其脂肽提取物在抑制食品工业中的食品腐败菌和有毒真菌方面具有巨大的潜在应用价值。