Department of Biotechnology, School of BioScience and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
Appl Biochem Biotechnol. 2020 Feb;190(2):391-409. doi: 10.1007/s12010-019-03107-w. Epub 2019 Jul 31.
Microorganisms that survive in the high salt environment have been shown to be a potential source for metabolites with pharmaceutical importance. In the present study, we have investigated the effect of 5 and 10% (w/v) NaCl on growth, biochemical changes, and metabolite production in seven moderately halophilic bacteria isolated from the salterns/mangrove area of South India. Metabolite production by Bacillus VITPS3 increased by 3.18-fold in the presence of 10% (w/v) NaCl concentration. Total phenolic and flavonoid content increased in Bacillus VITPS5 (11.3-fold) and Planococcus maritimus VITP21 (5.99-fold) whereas β-carotene content was less at higher NaCl concentrations. VITP21 and VITPS5, in response to NaCl, produced metabolites with higher (6.72- and 4.91-fold) DPPH and ABTS radical scavenging activity. UV/visible spectrophotometry of the extracts confirmed the presence of flavonoids, phenolics, and related compounds. H-NMR spectra indicated substantial changes in the metabolite production in response to salt concentration. Principal component analysis (PCA) revealed that VITP21 extracts exhibited the highest antioxidant activity compared with other extracts. The present study presents the first report on the comparative analysis of pigment production by moderate halophilic bacteria, in response to the effect of salt and their relation to radical scavenging property.
在高盐环境中生存的微生物已被证明是具有药物重要性的代谢产物的潜在来源。在本研究中，我们研究了 5%和 10%（w/v）NaCl 对从印度南部盐田/红树林地区分离出的 7 种中度嗜盐细菌的生长、生化变化和代谢产物产生的影响。在 10%（w/v）NaCl 浓度下，芽孢杆菌 VITPS3 的代谢产物产量增加了 3.18 倍。芽孢杆菌 VITPS5（11.3 倍）和海洋芽孢杆菌 VITP21（5.99 倍）的总酚和类黄酮含量增加，而在较高 NaCl 浓度下β-胡萝卜素含量较低。VITP21 和 VITPS5 对 NaCl 的响应产生了具有更高（6.72-和 4.91-倍）DPPH 和 ABTS 自由基清除活性的代谢产物。提取物的 UV/可见分光光度法证实了类黄酮、酚类和相关化合物的存在。1H-NMR 谱表明，代谢产物的产生在盐浓度响应方面发生了实质性变化。主成分分析（PCA）表明，与其他提取物相比，VITP21 提取物表现出最高的抗氧化活性。本研究首次报道了中度嗜盐细菌对盐的影响及其与自由基清除特性的关系的比较分析。
