Bal Jyotiranjan, Yun Suk-Hyun, Chun Jeesun, Kim Beom-Tae, Kim Dae-Hyuk
Department of Molecular Biology, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju 54896, Korea.; Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju 54896, Korea.
Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju 54896, Korea.
Mycobiology. 2016 Sep;44(3):155-161. doi: 10.5941/MYCO.2016.44.3.155. Epub 2016 Sep 30.
The most economically important species used in a wide range of fermentation industries throughout Asia belong to section , which are morphologically and phylogenetically indistinguishable, with a few being toxigenic and therefore a major concern. They are frequently isolated from Korean fermentation starters, such as and . The growing popularity of traditional Korean alcoholic beverages has led to a demand for their quality enhancement, therefore requiring selection of efficient non-toxigenic strains to assist effective fermentation. This study was performed to classify the most efficient strains of section isolated from various types of traditional wheat , based on a polyphasic approach involving molecular and biochemical evaluation. A total of 69 strains were isolated based on colony morphology and identified as / based on internal transcribed spacer and calmodulin gene sequencing. Interestingly, none were toxigenic based on PCR amplification of intergenic regions of the aflatoxin cluster genes - and the absence of aflatoxin in the culture supernatants by thin-layer chromatography analysis. Saccharification capability of the isolates, assessed through α-amylase and glucoamylase activities, revealed that two isolates, TNA24 and TNA15, showed the highest levels of activity. Although the degrees of variation in α-amylase and glucoamylase activities among the isolates were higher, there were only slight differences in acid protease activity among the isolates with two, TNA28 and TNA36, showing the highest activities. Furthermore, statistical analyses showed that α-amylase activity was positively correlated with glucoamylase activity ( < 0.001), and therefore screening for either was sufficient to predict the saccharifying capacity of the strain.
在亚洲广泛的发酵工业中使用的经济上最重要的物种属于 组,它们在形态学和系统发育上难以区分,其中一些具有产毒能力,因此是一个主要关注点。它们经常从韩国发酵起始物中分离出来,如 和 。韩国传统酒精饮料越来越受欢迎,导致对其质量提升的需求增加,因此需要选择高效的非产毒菌株来辅助有效的发酵。本研究基于多相方法,包括分子和生化评估,对从各种类型的传统小麦 中分离出的 组最有效的菌株进行分类。基于菌落形态共分离出69株菌株,并根据内部转录间隔区和钙调蛋白基因测序鉴定为 / 。有趣的是,基于黄曲霉毒素簇基因 和 的基因间区域的PCR扩增以及通过薄层色谱分析在培养上清液中不存在黄曲霉毒素,没有一株是产毒的。通过α-淀粉酶和糖化酶活性评估分离株的糖化能力,结果显示两株分离株TNA24和TNA15表现出最高水平 的活性。虽然分离株之间α-淀粉酶和糖化酶活性的变化程度较高,但分离株之间酸性蛋白酶活性只有轻微差异,其中两株TNA28和TNA36表现出最高活性。此外,统计分析表明α-淀粉酶活性与糖化酶活性呈正相关( < 0.001),因此筛选其中任何一种都足以预测 菌株的糖化能力。