College of Food Science, Southwest University, Chongqing, 400715, PR China.
College of Food Science, Southwest University, Chongqing, 400715, PR China; Food Storage and Logistics Research Center, Southwest University, Chongqing, 400715, PR China.
Food Microbiol. 2020 May;87:103375. doi: 10.1016/j.fm.2019.103375. Epub 2019 Nov 8.
This study investigated the biocontrol efficiency of Metschnikowia citriensis strain FL01 against Geotrichum citri-aurantii, and evaluated possible mechanisms. The results showed that M. citriensis could effectively control the development of sour rot, and significantly inhibit the mycelial growth and spore germination of G. citri-aurantii. The population dynamics results and Scanning electron microscopy (SEM) analysis indicated that M. citriensis could rapidly colonize wounds and tightly adhere to the surface of the wounds to compete with G. citri-aurantii for nutrition and space. M. citriensis also showed the biofilm formation action in vitro. The response of G. citri-aurantii to different components of M. citriensis culture showed that only the yeast cells but not the extracellular metabolites and the volatile organic compounds (VOCs) exhibited inhibitory effect on the growth of G. citri-aurantii. M. citriensis adhered to the hyphae of G. citri-aurantii loosely and sparsely, and the production of lytic enzymes β-1, 3-glucanase (GLU) and Chitinase (CHI) could not be induced by G. citri-auranti. Iron affected the pulcherrimin pigment production and antagonism of M. citriensis indicating iron depletion as the most important antagonistic mechanism. Besides, M. citriensis also induced resistance of fruit against sour rot. These results suggested that M. citriensis could be used as the potential alternative of fungicides to control postharvest pathogens on citrus fruit.
本研究调查了橘青霉（Metschnikowia citriensis）菌株 FL01 对柑橘绿霉（Geotrichum citri-aurantii）的生防效率，并评估了可能的作用机制。结果表明，橘青霉可以有效控制酸腐病的发展，并显著抑制柑橘绿霉的菌丝生长和孢子萌发。种群动态结果和扫描电子显微镜（SEM）分析表明，橘青霉可以迅速定殖于伤口，并紧密附着于伤口表面，与柑橘绿霉竞争营养和空间。橘青霉在体外还表现出生物膜形成作用。柑橘绿霉对橘青霉培养物不同成分的反应表明，只有酵母细胞而不是胞外代谢物和挥发性有机化合物（VOCs）对柑橘绿霉的生长表现出抑制作用。橘青霉松散稀疏地附着在柑橘绿霉的菌丝上，并且不能诱导产生裂解酶β-1,3-葡聚糖酶（GLU）和几丁质酶（CHI）。铁影响了 pulcherrimin 色素的产生和橘青霉的拮抗作用，表明铁的耗尽是最重要的拮抗机制。此外，橘青霉还诱导了果实对酸腐病的抗性。这些结果表明，橘青霉可以作为杀菌剂的替代品，用于控制柑橘果实采后病原菌。
