Microbiology and Biotechnology Research Lab, Department of Environmental Sciences, Fatima Jinnah Women University, Rawalpindi, 46000, Pakistan.
Department of Biotechnology, Fatima Jinnah Women University, Rawalpindi, 46000, Pakistan.
Extremophiles. 2019 Jul;23(4):435-449. doi: 10.1007/s00792-019-01095-7. Epub 2019 May 7.
Hypersaline ecosystems offer unique habitats to microbial populations capable of withstanding extreme stress conditions and producing novel metabolites of commercial importance. Herein, we have characterized for the first time the production of bioactive pigments from newly isolated halophilic bacterial species. Halophilic bacteria were isolated from Khewra Salt Range of Pakistan. Three distinctly colored isolates were selected for pigment production. Selected colonies were identified as Aquisalibacillus elongatus MB592, Salinicoccus sesuvii MB597, and Halomonas aquamarina MB598 based on morphological, biochemical, and physiological evidences as well as 16S rRNA analysis. The optimum pigment production observed at mesophilic condition, nearly neutral pH, and moderate salinity was validated using response surface methodology. Different analytical techniques (UV spectroscopy, infrared spectroscopy, and HPLC) characterized these purified pigments as derivatives of bacterioruberin carotenoids. Antioxidant activity of pigments revealed up to 85% free-radical scavenging activity at the concentration of 30 µg ml. Pigments also showed significant antimicrobial activity against Bacillus subtilis, Bacillus pumilus, Enterococcus faecalis, Bacillus cereus, Klebsiella pneumoniae, Alcaligenes faecalis, Pseudomonas geniculata, Enterococcus faecium, Aspergillus fumigatus, Aspergillus flavus, Fusarium solani, and Mucor spp., suggesting potential biomedical applications.
高盐度生态系统为能够承受极端压力条件并产生具有商业重要性的新型代谢物的微生物种群提供了独特的栖息地。在此，我们首次对新分离的嗜盐细菌物种产生的生物活性色素进行了特征描述。从巴基斯坦的 Khewra 盐田分离出嗜盐细菌。选择三种颜色明显不同的分离物用于色素生产。根据形态学、生物化学和生理学证据以及 16S rRNA 分析，选定的菌落被鉴定为 Aquisalibacillus elongatus MB592、Salinicoccus sesuvii MB597 和 Halomonas aquamarina MB598。使用响应面法验证了在中温条件、接近中性 pH 和中等盐度下观察到的最佳色素产量。不同的分析技术（紫外光谱、红外光谱和 HPLC）将这些纯化的色素鉴定为细菌红紫质类胡萝卜素的衍生物。色素的抗氧化活性在 30 µg ml 的浓度下显示出高达 85%的自由基清除活性。色素还对枯草芽孢杆菌、短小芽孢杆菌、粪肠球菌、蜡状芽孢杆菌、肺炎克雷伯菌、粪产碱杆菌、假单胞菌、屎肠球菌、烟曲霉、黄曲霉、茄病镰刀菌和毛霉属等具有显著的抗菌活性，表明具有潜在的生物医学应用。
