一株引起麦汁浊度上升的细菌分离鉴定及其致浊物质研究  

Isolation and identification of a bacterium causing the increase of wort turbidities and analysis of its turbidity-causing substances

作　　者：佟恩杰 贾晶 王宇翕 苏红旭 俞志敏[2] 张春强 TONG Enjie;JIA Jing;WANG Yuxi;SU Hongxu;YU Zhimin;ZHANG Chunqiang(COFCO Malt(Dalian)Co.,Ltd.,Dalian 116200;Dalian Polytechnic University,Dalian 116034)

机构地区：[1]中粮麦芽(大连)有限公司,大连116200 [2]大连工业大学,大连116034

出　　处：《中国食品添加剂》2023年第7期125-132,共8页China Food Additives

摘　　要：本研究在大麦表面分离筛选出30株微生物,并在浸麦阶段添加,进行反侵染小型制麦实验,其中反侵染B26菌株的麦芽,其麦汁浊度出现明显增加,由0.6±0.1 EBC最大上升至7.7±0.2 EBC,可使麦汁浊度升高11倍多,结合其形态特征和生理生化特性及16S rDNA基因测序分析比对,确定其属于阿氏肠杆菌(Enterobacter asburiae)。在糖化过程中,将β-葡聚糖酶、中性蛋白酶、脂肪酶按不同比例添加到阿氏肠杆菌反侵染麦芽中,结果显示,脂肪酶可有效降低反侵染麦芽麦汁浊度,分别按每克麦芽添加0.002%和0.01%脂肪酶,可将麦汁浊度由7.7±0.2 EBC分别下降至4.1±0.1和2.9±0.1 EBC。通过液相分析对比阿氏肠杆菌反侵染麦芽与对照组的脂肪酸情况,C18∶1、C18∶2、C18∶3含量分别增加117%、113%、59%,添加脂肪酶后,C18∶1、C18∶2、C18∶3含量分别减少37%、38%、22%,确定阿氏肠杆菌反侵染麦芽中的致浊物质主要是C18∶1、C18∶2、C18∶3。30 strains of microorganisms were isolated and screened from the surface of barley,and they were added in the wheat leaching stage to carry out the small scale anti-infection wheat preparation experiment.Among them,the wort turbidity of the malts reversely infected with strain B26 increased significantly from 0.6±0.1 to 7.7±0.2 EBC,which increased the wort turbidity by more than 11 times.Based on its morphological,physiological and biochemical characteristics,16S rDNA gene sequencing comparison,it was determined to be Enterobacter asburiae.In the process of saccharification,β-glucanase,neutral protease and lipase were added to the Enterobacter altelli anti-infecting malt with different amount.The results showed that lipase could effectively reduce turbidibility of antiinfecting malt wort:adding 0.002%and 0.01%lipase in one gram malt respectively,the wort turbidity decreased from 7.7±0.2 EBC to 4.1±0.1 and 2.9±0.1 EBC,respectively.Liquid phase analysis showed that the contents of C18∶1,C18∶2 and C18∶3 increased by 117%,113%and 59%,respectively.The contents of C18∶1,C18∶2 and C18∶3 decreased by 37%,38%and 22%,respectively,after adding lipase.It was determined that the main turbiditic substances in the malt were C18∶1,C18∶2 and C18∶3.

关 键 词：大麦 细菌 阿氏肠杆菌 麦汁浊度 

分 类 号：TS201.3[轻工技术与工程—食品科学]