卡利比克迈耶氏酵母对水果采后病害的抑制及对展青霉素的降解机制

为了明确拮抗酵母卡利比克迈耶氏酵母Meyerozyma caribbica对果实采后病害的抑制效果及其对毒素的降解机制, 本文研究了卡利比克迈耶氏酵母结合辅助因子褐藻寡糖(alginate oligosaccharide, AOS), 对草莓、梨、苹果、番茄的青霉病、灰霉病和黑斑病的抑制效果, 以及拮抗酵母不同处理液对展青霉素(patulin, PAT)体外降解的机制。结果表明, 浓度为1×108 cfu/mL的M. caribbica可有效抑制草莓、梨、苹果青霉病, 草莓、番茄、葡萄灰霉病以及番茄、梨、葡萄黑斑病的发生, 添加5 g/L的AOS能显著增强M. caribbica的抑制效果; M. caribbica发酵液可以有效降解苹果伤口处的PAT, 处理后8 d其降解率为30.35%, 经AOS诱导后, 其对PAT的降解效率达到39.15%。体外条件下, 接种M. caribbica后27 h可将10 μg/mL的PAT完全降解; M. caribbica主要是通过活细胞代谢降解PAT, 同时AOS可显著增加M. caribbica 的降解能力, 说明卡利比克迈耶氏酵母是一株生防潜力较好的菌株, 本研究为该生防菌株的进一步应用奠定了基础。

Inhibition on postharvest fruit diseases by Meyerozyma caribbica and its degradation mechanism to patulin

To determine the inhibitory effects of the antagonistic yeast Meyerozyma caribbica on postharvest fruit diseases and the mechanism of toxin degradation, we studied the combined effect of M.caribbica and alginate oligosaccharide (AOS) on penicilliosis, gray mold, and black spot in strawberries, pears, apples, and tomatoes. The mechanism of patulin (PAT) degradation in vitro was also explored using different treatment solutions of antagonistic yeast. The results showed that M.caribbica at a concentration of 1×108 cfu/mL could effectively inhibit the incidence of penicilliosis in strawberries, pears, and apples, gray mold in strawberries, tomatoes, and grapes, and black spot in tomatoes, pears, and grapes. Adding 5 g/L AOS could significantly enhance the inhibitory effect of M.caribbica. The fermentation broth of M.caribbica effectively degraded PAT in apple wounds, with a degradation rate of 30.35% eight days after treatment and 39.15% after AOS induction. PAT (10 μg/mL) could be completely degraded by M.caribbica within 27 h in vitro. Our study further revealed that M.caribbica mainly degraded PAT through intracellular enzymes produced in the normal metabolic process of living cells, and the degradation ability of M caribbica was significantly enhanced after AOS induction, highlighting its potential as a biocontrol strain with enhanced capabilities. This study lays a foundation for the future application of this biocontrol strain.