L-乳酸脱氢酶基因在乳酸乳球菌KLDS4.0325中表达.pdf

现代食品科技 Modern Food Science and Technology 2015, Vol.31, No.4 L-乳酸脱氢酶基因在乳酸乳球菌KLDS4.0325 中的表达 周颖，高晓峰，刘飞，谷春涛，霍贵成 （东北农业大学乳品科学教育部重点实验室，黑龙江哈尔滨150030 ） 摘要：本文研究了在mRNA 转录水平上三种L-乳酸脱氢酶基因在乳酸乳球菌KLDS4.0325 不同生长阶段的表达情况。以16s rRNA 作为内参基因，应用实时荧光定量 PCR 技术测定不同生长阶段的菌体中 L-乳酸脱氢酶基因（ldh、ldhX 和ldhB ）表达的动态变化规 律。该菌株的生长曲线呈S 型，培养2~6 h 为菌体的生长对数期，随后进入稳定期。生长曲线的测定表明该菌株生长力极其旺盛；16s rRNA、ldh、ldhX 和ldhB 基因的扩增效率曲线显示，内参基因与目的基因的扩增效率一致且接近100%，这说明利用相对荧光定量法 能够较好的反应目的基因的表达量；ldh、ldhX 和ldhB 基因在菌体生长的3 个时间点（6 h、9 h 和12 h ）都有一定量的表达，随着菌 体的不断生长，基因表达的变化均呈现显著性上升趋势，且上升幅度不断增加，在12 h 时基因表达量达到最大值。其中ldh 基因在的 表达量在菌体生长的3 个时间点存在显著性差异，而ldhX、ldhB 基因的表达量存在极显著差异。 关键词：乳酸乳球菌KLDS4.0325 ；L-乳酸脱氢酶基因；基因表达 文章篇号：1673-9078(2015)4-63-68 DOI: 10.13982/j.mfst.1673-9078.2015.4.011 Variations in the Expression of the L-lactate Dehydrogenase Gene during the Different Phases of Lactococcus lactis KLDS4.0325 Growth ZHOU Ying, GAO Xiao-feng, LIU Fei, GU Chun-tao, HUO Gui-cheng (Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, China) Abstract: The expressions of three L-lactate dehydrogenase genes at the mRNA transcription level during the different phases of Lactococcus lactis KLDS4.0325 growth were investigated in this study. Dynamic variations in the expressions of the three L-lactate dehydrogenase genes (ldh , ldhB, and ldhX) during the different growth phases were detected by fluorescence-based quantitative real time polymerase chain reaction (PCR), using the 16s rRNA gene as the internal standard. The growth curves of the strain were observed to be ‘S’-shaped, with the strains reaching the exponential phase of growth within 2~6 h of culture; subsequentl