Department of Biotechnology, University of Verona, 37134, Verona, Italy.
Department of Biotechnology, University of Verona, 37134, Verona, Italy.
Food Microbiol. 2020 Aug;89:103446. doi: 10.1016/j.fm.2020.103446. Epub 2020 Jan 27.
Gray mold caused by Botrytis cinerea is a fungal disease that can determine significant economic losses of apple during the storage phase. An alternative to reduce the use of traditional synthetic fungicides is to employ the yeast Starmerella bacillaris as biological control agent (BCA), also with positive effect on apple juice fermentation for the production of cider. Thus, we aimed to evaluate the safety of 16 S. bacillaris strains and their ability to control B. cinerea. In addition, the fermentation performances in apple juice and the volatile organic compounds (VOCs) profile were assessed, both in single-strain and in sequential fermentations with Saccharomyces cerevisiae. The in vitro assays showed that all S. bacillaris strains can be considered safe from the analyzed virulence factors, and were able to significantly constrain the growth of B. cinerea, reducing mycelial growth of 50% in dual-culture and of 90% through VOCs. Moreover, in vivo antagonistic assays revealed a visible decrease of gray mold rot symptoms on apples confirming the potential of S. bacillaris as BCA. GC-MS analysis of the ciders obtained showed increased concentrations in the sequential fermentation of some higher alcohols and terpenes, positively correlated with the cider aromatic quality, and suggested the involvement of benzyl alcohol, known for its antimicrobial action, in the biocontrol efficacy.
灰霉病是由 Botrytis cinerea 引起的真菌病害，会导致苹果在贮藏期遭受重大经济损失。减少传统合成杀菌剂使用的一种方法是利用酵母 Starmerella bacillaris 作为生物防治剂（BCA），这对苹果汁发酵生产苹果酒也有积极影响。因此，我们旨在评估 16 株 S. bacillaris 菌株的安全性及其控制 B. cinerea 的能力。此外，评估了其在苹果汁中的发酵性能和挥发性有机化合物（VOCs）谱，分别在单一菌株和与酿酒酵母的顺序发酵中进行评估。体外试验表明，所有 S. bacillaris 菌株均可被认为是安全的，不会产生分析的毒力因子，并且能够显著抑制 B. cinerea 的生长，在双培养物中抑制菌丝生长 50%，通过 VOCs 抑制 90%。此外，体内拮抗试验显示，苹果上的灰霉病腐烂症状明显减少，证实了 S. bacillaris 作为 BCA 的潜力。对获得的苹果酒进行 GC-MS 分析显示，一些高级醇和萜烯的顺序发酵浓度增加，与苹果酒的香气质量呈正相关，这表明苯甲醇（具有抗菌作用）参与了生物防治的效果。
