茫崖翡翠湖嗜(耐)盐细菌资源及其对NaCl胁迫的响应

Halophilic and halotolerant bacterial resources and their response to NaCl stress in Emerald Lake of Mangya

摘要:

青海茫崖翡翠湖的高盐浓度，使其成为发掘嗜(耐)盐微生物的理想环境。目的 挖掘茫崖翡翠湖的嗜(耐)盐微生物资源，比较分析NaCl浓度下嗜(耐)盐菌的形态特征，并探究其对NaCl胁迫的响应机制。方法 采集茫崖翡翠湖的近岸湖水、湖盐及湖岸盐土3种样品，利用8种培养基和3个盐浓度梯度(10%、15%、20%)进行嗜(耐)盐菌的分离培养。通过光学显微镜、扫描电镜及透射电子显微镜观察3株嗜(耐)盐菌在不同NaCl浓度下的菌落形态、细胞形态及细胞内部结构。结果 共分离获得58株嗜(耐)盐细菌，其中包括31株耐盐菌和27株嗜盐菌，分属于16个属，其中喜盐芽孢杆菌属(Halobacillus)和芽孢杆菌属(Bacillus) 为优势属。嗜盐菌主要由Halobacillus组成(占40.7%)，耐盐菌主要由Bacillus组成(占19.3%)；对Na⁺、Mg²⁺、K⁺、Ca²⁺均有一定耐受性的菌株占总株数的84.5%。在不同NaCl浓度下，海岸枝芽孢杆菌(Virgibacillus litoralis) TRM 83602和咸鱼鱼芽孢杆菌(Piscibacillus salipiscarius) TRM 83622的细胞长度存在显著差异，而表皮短杆菌(Brevibacterium epidermidis) TRM 83610的细胞长度则无显著变化。结论 茫崖翡翠湖蕴藏着相对丰富的嗜(耐)盐菌资源。NaCl浓度对嗜(耐)盐菌的生长繁殖、菌落形态、细胞形态及细胞内部结构均产生影响。本研究不仅加深了对茫崖翡翠湖微生物资源的认识，还为嗜(耐)盐微生物的进一步开发利用提供了丰富的菌株资源。

Abstract:

The high salt concentration of Emerald Lake in Mangya, Qinghai Province, makes it an ideal environment for mining halophilic (halotolerant) microorganisms.Objective To mine the halophilic (halotolerant) microbial resources in the Emerald Lake, compare the morphological characteristics of halophilic (halotolerant) bacteria exposed to different concentrations of NaCl, and explore the response of halophilic (halotolerant) microorganisms to NaCl stress.Method Lake water, lake salt, and lakeshore saline soil samples were collected from the nearshore area of the Emerald Lake. The halophilic (halotolerant) bacteria were isolated by eight different media with three salt concentrations (10%, 15%, and 20%). The colony morphology, cell morphology, and internal structures of three strains of halophilic (halotolerant) bacteria exposed to different concentrations of NaCl were observed by optical microscopy, scanning electron microscopy, and transmission electron microscopy, respectively.Results A total of 58 strains of halophilic (halotolerant) bacteria were isolated, including 31 strains of halotolerant bacteria and 27 strains of halophilic bacteria, belonging to 16 genera. Halobacillus (40.7%) and Bacillus (19.3%) were the dominant genera of halophilic bacteria and halotolerant bacteria, respectively. The strains tolerant to Na⁺, Mg²⁺, K⁺, and Ca²⁺ accounted for 84.5%. The cell lengths of Virgibacillus litoralis TRM 83602 and Piscibacillus salipiscarius TRM 83622 exposed to different concentrations of NaCl were significantly different, while that of Brevibacterium epidermidis TRM 83610 did not change significantly.Conclusion The Emerald Lake harbors abundant halophilic (halotolerant) bacteria. NaCl concentrations can affect the growth, reproduction, colony morphology, cell morphology, and internal structures of halophilic (halotolerant) bacteria. This study enriches the understanding about the microbial resources in the Emerald Lake, providing abundant strain resources for further development and utilization of halophilic (halotolerant) microorganisms.