副干酪乳杆菌HD1.7群体感应行为  

Quorum-sensing behavior of Lactobacillus paracasei HD1.7

作　　者：葛菁萍[1] 房保柱[1] 苑婷婷[1] 平文祥[1] 

机构地区：[1]微生物黑龙江省高校重点实验室,黑龙江大学生命科学学院,哈尔滨150080

出　　处：《微生物学报》2011年第11期1561-1567,共7页Acta Microbiologica Sinica

基　　金：国家自然科学基金(31070446);黑龙江省教育厅重点项目(11551z011);黑龙江省科技攻关重大项目(GB05B401);哈尔滨市科技创新人才研究专项资金项目优秀学科带头人(RC2010XK002028);黑龙江大学高层次人才(创新团队)支持计划(Hdtd2010-17)~~

摘　　要：【目的】Paracin1.7是从副干酪乳杆菌(Lactobacillus paracasei)HD1.7发酵液中提取的一种细菌素,本文主要研究菌株HD1.7在发酵过程中调控Paracin1.7代谢的群体感应机制。【方法】利用杯碟法检测不同生长条件下菌株HD1.7培养液的抑菌活性,通过调整培养基营养成分的多寡,控制培养液中细胞密度。【结果】菌株HD1.7的抑菌活性与其细胞密度密切相关,只有当细胞密度达到一定的阈值(OD600为0.8,菌体干重为0.331 1 g/L)时,菌株才能表现抑菌活性;以发酵上清液作为信号分子,当添加不同浓度信号分子至低于阈值浓度培养液后,菌株抑菌活性受到不同程度的影响,并且在去除信号分子后,菌株的抑菌活性明显降低。【结论】细菌素Paracin1.7是存在于HD1.7发酵液中的特殊的群体感应信号分子,可进行自我诱导。细菌素Paracin1.7的抑菌活性受到HD1.7群体感应系统的调控。[Objective] Paracin 1.7 was a bacteriocin extracted from Lactobacillus paracasei HD1.7.In this study,we investigated quorum-sensing mechanism that regulates the metabolism of Paracin 1.7 in strain HD1.7.[Methods] The antibacterial activity of strain HD1.7 under different growth conditions was analyzed using an agar-well diffusion method,and the cell density was controlled by adjusting nutrient levels in the culture medium.[Results] The antibacterial activity of strain HD1.7 depended on cell density.Strain HD1.7 exhibited the antibacterial activity when the cell density reached a threshold（OD600 of 0.8 and cell dried weight of 0.331 1 g/L）.Addition of different concentrations of a signaling molecule in the supernatant of the fermentation broth affected the antibacterial activity.After removing the signal molecule,the antibacterial activity was significantly decreased.[Conclusion] Paracin1.7 was the quorum-sensing signaling molecule in the HD1.7 fermentation broth and it could be auto-induced.The antibacterial activity of Paracin1.7 was regulated by the quorum-sensing system in HD1.7.

关 键 词：副干酪乳杆菌HD1.7 细菌素Paracin1.7 群体感应 菌体密度 

分 类 号：Q935[生物学—微生物学]