CRIOF - Department of Agricultural Sciences, University of Bologna, Via Gandolfi, 19, 40057, Cadriano, Bologna, Italy; Department of Agricultural and Food Sciences, University of Bologna, Viale Fanin, 46, 40127, Bologna, Italy.
Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Belmeloro, 8/2, 40126, Bologna, Italy.
Food Microbiol. 2020 May;87:103395. doi: 10.1016/j.fm.2019.103395. Epub 2019 Nov 25.
Volatile compounds produced by L1 and L8 strains were assayed against mycelia and conidia growth of Monilinia laxa, M. fructicola, M. polystroma, and M. fructigena of stone fruits. Results showed that volatile metabolites inhibited significantly pathogens growth, in particular M. fructigena mycelium growth (70% by L1 and 50% by L8) and M. fructicola conidia germination (85% by L1 and 70% by L8) compared to the control. Moreover, the antagonistic activity was enhanced by the addition of asparagine (120 mg L) in the culture media composition. Synthetic pure compounds were tested in vitro on pathogens mycelial and conidia growth and their EC values were estimated, confirming 2-phenethyl as the most active compound. For this reason 2-phenethyl and VOCs of both yeast strains were assayed in vivo on cherry, peach, and apricot fruits. Regarding peach fruit, both treatments, yeasts and pure compounds, displayed the best inhibiting action against all the pathogens especially against M. laxa (100% by L1, 84% by L8 and 2-phenethyl). ATR/IR spectroscopy analysis showed how VOCs produced by both strains increase the fruit waxes complexity reducing the pathogens attack so playing an essential role in the antagonistic activity of both yeast strains and on fruit structural composition.
对 L1 和 L8 菌株产生的挥发性化合物进行了测试，以评估其对核果类病原菌（包括李囊孢菌、桃褐腐病菌、油桃褐腐病菌和油桃球腔菌）菌丝和分生孢子生长的影响。结果表明，挥发性代谢物显著抑制了病原菌的生长，特别是 L1 对李囊孢菌菌丝生长的抑制率为 70%，L8 为 50%；L1 对桃褐腐病菌分生孢子萌发的抑制率为 85%，L8 为 70%。此外，在培养基成分中添加天冬酰胺（120mg/L）可以增强拮抗活性。合成的纯化合物在体外对病原菌菌丝和分生孢子生长进行了测试，并估算了它们的 EC 值，证实 2-苯乙基是最具活性的化合物。因此，对两种酵母菌株的 2-苯乙基和 VOCs 进行了体内樱桃、桃和杏果实的测试。对于桃果实，酵母和纯化合物处理都对所有病原菌表现出了最佳的抑制作用，特别是对李囊孢菌（L1 为 100%，L8 为 84%，2-苯乙基为 84%）。ATR/IR 光谱分析表明，两种菌株产生的 VOCs 增加了果实蜡质的复杂性，从而减少了病原菌的攻击，因此在两种酵母菌株的拮抗活性以及果实结构组成中发挥了重要作用。
