Horticultural Research Centre, Pavillon de l'Envirotron, Université Laval, Québec, Canada.
Fungal Biol. 2011 Mar;115(3):220-7. doi: 10.1016/j.funbio.2010.12.005. Epub 2010 Dec 21.
Muscodor albus (Xylariaceae, Ascomycetes) isolate CZ-620 produces antimicrobial volatile organic compounds (VOC), which appear to have potential for the control of various postharvest diseases. The effect of water activity (Aw) on the production of VOC by M. albus culture, and their inhibitory effects on the growth of three pathogens of potato tuber (Fusarium sambucinum, Helminthosporium solani, and Pectobacterium atrosepticum) and the development of diseases caused by the three pathogens (dry rot, silver scurf, and bacterial soft rot, respectively) were investigated. Rye grain culture of the fungus produced six alcohols, three aldehydes, five acids or esters, and two terpenoids. The most abundant VOC were: isobutyric acid; bulnesene, a sesquiterpene; an unidentified terpene; 2 and 3-methyl-1-butanol; and ethanol. However, the level of each of those VOC varied with Aw of the culture. Emission activity occurred mainly at Aw above 0.75 and high emission of most VOC occurred only at Aw above 0.90. The aldehydes (2-methyl-propanal and 3-methyl-butanal) were the only VOC produced in quantities below an Aw of 0.90. An Aw value of 0.96 favored maximum emission of acids, esters, and terpenoids. There was a higher production of alcohols and a decrease in aldehydes with increase in Aw. Isobutyric acid, which has been the main M. albus VOC monitored in previous studies as an indicator of antifungal activity, had a rather narrow optimum, peaking at Aw of 0.96 and declining sharply above 0.98. Results showed that substrate Aw affects the production dynamics of each group of VOC by the fungus, and suggest that VOC production can be prolonged by maintaining M. albus culture at a constant optimum Aw. The VOC was inhibitory to F. sambucinum, H. solani, and P. atrosepticum; and biofumigation with M. albus significantly reduced dry rot and soft rot development, and completely controlled silver scurf in inoculated tubers incubated at both 8°C and 22°C. The results show that Aw of grain culture affects the production of VOC by M. albus; and that the VOC inhibit the growth of the tested pathogens and the diseases caused by them in potato tubers.
白蘑菇（木霉科，子囊菌）分离株 CZ-620 产生抗菌挥发性有机化合物（VOC），这些化合物似乎具有控制各种采后疾病的潜力。本研究调查了水活度（Aw）对白蘑菇培养物 VOC 产生的影响，以及它们对三种马铃薯块茎病原菌（茄病镰刀菌、茄腐镰刀菌和果胶杆菌）生长的抑制作用，以及三种病原菌引起的疾病（干腐病、银腐病和细菌性软腐病）的发展。真菌的黑麦粒培养物产生了六种醇、三种醛、五种酸或酯和两种萜烯。最丰富的 VOC 是：异丁酸；丁子香烯，一种倍半萜烯；一种未鉴定的萜烯；2 和 3-甲基-1-丁醇；和乙醇。然而，每种 VOC 的水平都随培养物的 Aw 而变化。排放活性主要发生在 Aw 高于 0.75 时，大多数 VOC 的高排放仅发生在 Aw 高于 0.90 时。醛（2-甲基丙醛和 3-甲基丁醛）是 Aw 低于 0.90 时唯一大量产生的 VOC。Aw 值为 0.96 有利于酸、酯和萜烯的最大排放。随着 Aw 的增加，醇的产量增加，醛的产量减少。异丁酸是以前研究中作为抗真菌活性指标监测的白蘑菇主要 VOC，其产量有一个相当狭窄的最佳值，在 Aw 为 0.96 时达到峰值，在 Aw 高于 0.98 时急剧下降。结果表明，基质 Aw 影响真菌产生的每一组 VOC 的动力学，并且表明通过将白蘑菇培养物维持在恒定的最佳 Aw 下可以延长 VOC 的产生。该 VOC 对茄病镰刀菌、茄腐镰刀菌和果胶杆菌具有抑制作用；用白蘑菇进行生物熏蒸可显著降低 8°C 和 22°C 条件下接种块茎的干腐病和软腐病的发展，并完全控制银腐病。结果表明，谷物培养物的 Aw 影响白蘑菇 VOC 的产生；并且 VOC 抑制了马铃薯块茎中测试病原体的生长及其引起的疾病。
