Biomolecular characterization, identification, enzyme activities of molds and physiological changes in sweet potatoes(Ipomea batatas) stored under controlled atmospheric conditions  

甘薯贮藏环境中霉菌的生物分子特征、鉴定和酶活性及甘薯生理变化的研究（英文）

作　　者：C.O.OLADOYE I.F.CONNERTON R.M.O.KAYODE P.F.OMOJASOLA I.B.KAYODE 

机构地区：[1]Division of Food Sciences, School of Biosciences, the University of Nottingham Sutton Bonington Campus [2]Division of Food Preservation, Microbial Biotechnology and Toxicology, Department of Home Economics and Food Science,University of Ilorin [3]Department of Microbiology, Faculty of Life Sciences, University of Ilorin

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2016年第4期317-332,共16页浙江大学学报（英文版）B辑（生物医学与生物技术）

摘　　要：Microbial attacks during storage are one of the primary causes of product deterioration, and can limit the process of prolonging the shelf-life of harvested food. In this study, sweet potatoes were stored at temperatures of 13, 21, and 29 ℃ for 4 weeks. Samples were collected during storage and plated on potato dextrose agar, from which axenic mold cultures were obtained and identified using 26S rRNA gene sequences. Physiological changes of potato tubers were assessed with respect to pathogenicity, enzyme activity, and atmospheric storage conditions. Six fungal species were identified, namely Penicillium chrysogenum （P. rubens）, P. brevicompactum, Mucor circinelloides, C/adosporium cladosporiodes, P. expansum, and P. crustosum. The following fungal isolates, namely P. expansum, P. brevicompactum, and Rhizopus oryzae, were recovered from the re-infected samples and selected according to their levels of enzyme activity. This study revealed high levels of activity for cellulase and pectinase, which were most notable during the initial three days of testing, and were followed by a steady decrease （P〈0.05）. Polygalacturonase activity was prominent with values ranging from 12.64 to 56.79 U/mg （P. expansum） and 18.36 to 79.01 U/mg （P. brevicompactum）. Spoilage was obvious in the control group, which had a 100% decay at the end of the experimental period compared with samples treated with iprodione and sodium hypochlorite, in which the decay rates were 5% and 55%, respectively. The data for the iprodione- and sodium hypochlorite-treated samples at the end of the 3-month storage period showed that they were significantly different （P=0.041）, with the sodium hypochlorite-treated samples producing twice the rate of infection compared to the iprodione-treated samples. The comparative rate of the pro- gression of decay in the treated samples can be expressed as iprodione〈sodium hypochlorite〈control. This study demonstrates that sweet potato tissue damage is due to the activities of microbial enzyme目的:鉴定甘薯贮藏环境中霉菌的生物分子特征和酶活性,并比较不同试剂处理后甘薯的生理变化。方法:从不同温度下保存的甘薯得到霉菌菌株,提取其细菌基因组DNA,进行聚合酶链反应(PCR)及测序鉴定。将甘薯分成扑海因处理组、次氯酸钠处理组和对照组,在为期三个月的贮藏时间内,对霉菌致病性、酶活性和空气条件对甘薯的生理变化的影响进行评估。结论:实验结束后,扑海因处理组的变质率为5%,次氯酸钠组为55%,对照组为100%。研究发现,甘薯组织变质主要由于不同的微生物酶的活动,尤其是受感染组织的果胶酶活性。因此,建议将扑海因作为甘薯贮藏之前的保鲜剂。

关 键 词：Controlled atmosphere Enzyme activity Molds characterization Potato spoilage Sodium hypochlorite IPRODIONE 

分 类 号：S435.31[农业科学—农业昆虫与害虫防治]