基于RT-PCR与平板计数法对比分析发酵香肠发酵过程中的乳酸菌数  

Comparative Analysis of the Number of Lactic Acid Bacteria in the Fermentation Process of Fermented Sausages Based on RT-PCR and Plate Counting Method

作　　者：杨明阳[1] 田建军[1] 赵丽华[1] 张开屏[2] 景智波 李权威 靳烨[1] Yang Mingyang;Tian Jianjun;Zhao Lihua;Zhang Kaiping;Jing Zhibo;Li Quanwei;Jin Ye(College of Food Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010018;Department of Food Engineering,Inner Mongolia Business Vocational College,Hohhot 010070)

机构地区：[1]内蒙古农业大学食品科学与工程学院,呼和浩特010018 [2]内蒙古商贸职业学院食品工程系,呼和浩特010070

出　　处：《中国食品学报》2020年第11期265-272,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金地区项目(31660439,31960514);内蒙古自治区科技计划项目(2019GG239);内蒙古自治区科技成果转化专项(2019C G066);内蒙古自治区自然科学基金重大专项(2020ZD11)。

摘　　要：为快速、准确检测发酵香肠发酵过程中乳酸菌数的动态变化,以自然发酵为对照组,植物乳杆菌F16为发酵剂制作发酵香肠,同时以植物乳杆菌CICC:6238为标准菌株进行标准品的制作,采用实时荧光定量PCR(RT-PCR)技术定量分析发酵香肠发酵过程中的乳酸菌数,并与传统计数方法作对比。结果表明:本方法所建立的标准曲线相关系数R2≧0.99,扩增效率为90%~100%,符合RT-PCR的检测要求;乳酸菌数呈先上升后下降趋势,定量结果与平板计数变化趋势相同,且在各取样点,因存在死亡细胞的DNA,故荧光定量所得结果高于平板计数1lg(CFU/g)左右。利用平板计数和荧光定量数值得出两者间的线性方程y=0.8116x+0.4254。任取1批发酵香肠做验证试验,根据线性方程所得活菌数与平板计数值之间的相似度达94%以上,说明可用线性方程预测乳酸菌活菌数。本试验所建立的RT-PCR技术为定量监测发酵香肠发酵过程中乳酸菌的动态变化提供一条快捷途径。In order to detect the dynamic changes of microorganisms during the fermentation of fermented sausages quickly and accurately.In this experiment,natural fermentation was used as a control group.Lactobacillus plantarum F16 was used as a fermenting agent to make fermented sausages,and the standard strain of Lactobacillus plantarum CICC:6238 was used to prepare standard substance.Quantitative analysis of lactic acid bacteria during fermentation of fermented sausages was performed by real-time fluorescence quantitative PCR and compared with traditional methods.The results showed that the correlation coefficient of the standard curve R2≧0.99,amplification efficiency was 90%-100%,which meet the requirements of RT-PCR.The quantitative results of lactic acid bacteria were the same as the plate counting which was incresed firstly and then decreased.The results of RT-PCR overestimated the plate count about 1lg(CFU/g),probably because of the presence of dead cells.The linear equation between the plate counting and the RT-PCR values was obtained which was y=0.8116x+0.4254.A batch of sausage was taken to verify the experiment.The agreement reached more than 94%that the number of live bacteria according to the equation and the plate counts.Therefore,the linear equation could be used to predict the number of living bacteria of lactic acid bacteria,the method of RT-PCR provides a rapid and effective way to monitor the dynamic changes of lactic acid bacteria in the fermentation process of of fermented sausages.

关 键 词：乳酸菌数 平板计数 RT-PCR 线性回归方程 

分 类 号：TS251.65[轻工技术与工程—农产品加工及贮藏工程]