Yu Ting, Wang Lianping, Yin Yun, Wang Yixi, Zheng Xiaodong
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, 310029, People's Republic of China.
Int J Food Microbiol. 2008 Feb 29;122(1-2):44-8. doi: 10.1016/j.ijfoodmicro.2007.11.059. Epub 2007 Nov 29.
This study was designed to evaluate the impact of chitin on the antagonistic activity of Cryptococcus laurentii against the postharvest blue mold rot caused by Penicillium expansum in pear fruit. The results showed that the antagonistic activity of C. laurentii obtained from the culture media of nutrient yeast dextrose broth (NYDB) amended with chitin at 0.5-1.0% was improved greatly compared with the case that without chitin. The addition of chitin to NYDB did not influence the growth of C. laurentii, however, its population was found to increase rapidly thereafter in pear fruit wounds compared to that harvested from NYDB without chitin. Moreover, the cell-free filtrate of the chitin-supplement culture media in which the yeast was incubated for 24 h emerged a direct antifungal activity against P. expansum in pear fruit wounds, with the associated high level of chitinase activity. These results suggested that the use of chitin may be an effective method to induce the antagonistic activity of C. laurentii. To our knowledge, this is the first report regarding the chitin could enhance the efficacy of postharvest biocontrol yeasts.
本研究旨在评估几丁质对罗伦隐球酵母拮抗由扩展青霉引起的梨采后青霉病的活性的影响。结果表明，与未添加几丁质的情况相比，从添加了0.5%-1.0%几丁质的营养酵母葡萄糖肉汤（NYDB）培养基中获得的罗伦隐球酵母的拮抗活性得到了极大提高。向NYDB中添加几丁质不会影响罗伦隐球酵母的生长，然而，与从不含几丁质的NYDB中收获的相比，其数量此后在梨果实伤口中迅速增加。此外，酵母在其中孵育24小时的添加几丁质的培养基的无细胞滤液对梨果实伤口中的扩展青霉表现出直接的抗真菌活性，并伴有高水平的几丁质酶活性。这些结果表明，使用几丁质可能是诱导罗伦隐球酵母拮抗活性的有效方法。据我们所知，这是关于几丁质可增强采后生物防治酵母功效的首次报道。
