来自内蒙古农业大学教育部乳品生物技术与工程重点实验室,上海交通大学农生学院的研究人员采用双向凝胶电泳和质谱分析技术,首次完成了干酪乳杆菌不同生长期蛋白表达参考图谱,这一研究成果公布在在国际蛋白质组学顶级杂志Molecular and Cellular Proteomics发表题目为“Proteomics Analysis of Lactobacillus casei Zhang,a New Probiotic Bacterium Isolated from Traditional Home-made Koumiss in Inner Mongolia of China.”的文章。
干酪乳杆菌是众多益生菌中重要的菌种之一。研究组2002年从内蒙古地区传统发酵酸马奶中自主分离、筛选获得1株性能优异的益生菌-L.casei Zhang,并对其益生特性进行了系统的研究。2008年5月18日完成了该菌株全基因组序列测定染色体基因组(GenBank accession No:CP001084)和质粒基因组plca36 (GenBank accession No:CP000935)序列测定和图谱绘制。
这篇文章是在传统生理生化和基因组学研究基础上对干酪乳杆菌进行的蛋白组学研究。研究采用双向凝胶电泳和质谱分析技术,首次完成了干酪乳杆菌不同生长期蛋白表达参考图谱,分别获得了487±21(对数期)和494±13(稳定期)个蛋白点;发现了47个蛋白点在对数期和稳定期表现显著的差异表达。进一步分析显示,这些差异表达蛋白更多属于胁迫应答蛋白或细胞代谢中关键蛋白,推测它们在菌体生长和代谢,尤其抵御和适应乳酸或其它环境变化中起重要作用。
蛋白质组学研究对明确益生乳酸菌遗传学背景,深入了解益生特性机理进而改造和选育优良益生菌奠定了基础,对提高我国益生乳酸菌研究的科技创新能力、自主知识产权益生菌品牌打造和我国乳酸菌产业发展具有重要意义。(生物谷Bioon.com)
生物谷推荐原始出处:
Molecular and Cellular Proteomics 2009, 8: 2321-2338
Proteomic analysis of Lactobacillus casei Zhang, a new probiotic bacterium isolated from traditionally home-made Koumiss in Inner Mongolia of China
Rina Wu, Weiwei Wang, Dongliang Yu, Wenyi Zhang, Yan Li, Zhihong Sun, Junrui Wu, He Meng, and Heping Zhang
Lactobacillus casei Zhang, isolated from traditional home-made koumiss in Inner Mongolia of China, was considered as a new probiotic bacterium by probiotic selection tests. We carried out a proteomic study to identify and characterize proteins expressed by L. casei Zhang in the exponential phase and stationary phase. Cytosolic proteins of the strain cultivated in MRS broth were resolved by two-dimensional gel electrophoresis using pH 4-7 linear gradients. The number of protein spots quantified from the gels was 487±21 (exponential phase) and 494±13 (stationary phase) respectively, among which a total of 131 spots were identified by MALDI-TOF/MS and/or MALDI-TOF/TOF according to significant growth phase-related differences or high expression intensity proteins. Accompanied with analysis of the COG, CAI, GRAVY value of each protein identified to the whole set of genes encoding proteins of L. casei Zhang, the study provided a very first insight into the profile of protein expression as a reference map of L. casei. Forty-seven spots were also found in the study showed statistically significant differences between exponential phase and stationary phase. Thirty-three of them increased at least 2.5-fold in the stationary phase in comparison with the exponential phase, and including nineteen protein spots (e.g., Hsp20, Dnak, GroEL, LuxS, PK, GalU) whose intensity up-shifted above 3.0-fold. The transcriptional profiles were conducted to confirm several important differential expression proteins by using real-time PCR. The analysis suggests that the differentially expressed proteins were mainly categorized as stress response proteins and key components of central and intermediary metabolism, implicating these proteins might play potential important role for the adaptation to the surroundings, especially the accumulation of lactic acid in the course of growth, and the physiological processes in bacteria cell.