Alvares Jyothi Judith, Furtado Irene Jeronimo
Department of Microbiology, Goa University, Taleigao Plateau, Goa 403206 India.
3 Biotech. 2021 Feb;11(2):58. doi: 10.1007/s13205-020-02584-9. Epub 2021 Jan 11.
The present study was aimed to exploit the haloarchaeon GUSF-1 (KF796625) for the presence of biomolecules possessing antioxidant activity. The culture produced a bright orange pigment when grown aerobically in nutrient rich medium with 25% crude solar salt. Biomolecules from cell-free supernatant and from the cells of the culture were individually extracted through the assistance of solvents of different polarities, such as ethanol, methanol and hexane, and monitored for scavenging of stable free radicals. Each of the extracts showed varying capacities to scavenge DPPH(20, 31, and 80% DPPH RSA; 160.19, 248.29 and 640.76 AAE µg g of cells) at 1 mg mL. The extracellular ethanolic extract was polysaccharide in nature, equivalent to 47 µg mL of glucose when assayed with the phenol-sulfuric acid method. The Fourier Transform-Infra Red spectroscopy confirmed the characteristic glycosidic peaks between 2000 and 1000 cm. Similarly, the glycerol diether moiety separated from hydroxylated methanolysates through thin-layer chromatography scavenged free radicals (10.47% DPPH RSA; 80.03 AAE µg g of cells). Further, the hexanolic extract exhibited spectral characteristics of red carotenoids and resolved into distinct compounds when separated by thin-layer chromatography using different developing systems. All separated compounds were positive for the DPPH reaction (13-30% DPPH RSA; 100-240 AAE µg g). Chemical profiling of the hexanolic extract using the high resolution-liquid chromatography-mass spectroscopy-diode array detector analysis confirmed the presence of different carbon length isoprenoids; C: tetrahydrosqualene, C: 3-hydroxyechinenone, astaxanthin, canthaxanthin, lycopene, phytofluene, phytoene and C: bisanhydrobacterioruberin, monoanhydrobacterioruberin, bacterioruberin and haloxanthin. Thus, we conclude that the synergistic actions of all these components contribute to the antioxidant activity of the culture and that the antioxidant activity of the exopolysaccharide, glycerol dither moiety, tetrahydrosqualene, haloxanthin and 3-hydroxyechinenone is recorded as the first report for GUSF-1 (KF796625). Therefore, recommended for use in microbial industrial biotechnology.
The online version contains supplementary material available at 10.1007/s13205-020-02584-9.
本研究旨在探究嗜盐古菌GUSF-1（KF796625）中是否存在具有抗氧化活性的生物分子。该菌株在含有25%粗制日晒盐的营养丰富培养基中需氧培养时会产生亮橙色色素。通过不同极性溶剂（如乙醇、甲醇和己烷）辅助，分别从无细胞上清液和培养细胞中提取生物分子，并监测其对稳定自由基的清除能力。每种提取物在1mg/mL时对DPPH的清除能力各不相同（DPPH自由基清除率分别为20%、31%和80%；每克细胞的抗氧化活性当量分别为160.19、248.29和640.76μg）。细胞外乙醇提取物本质上是多糖，用苯酚-硫酸法测定时相当于47μg/mL葡萄糖。傅里叶变换红外光谱证实了2000至1000cm之间的特征糖苷峰。同样，通过薄层色谱从羟基化甲醇解产物中分离出的甘油二醚部分具有自由基清除能力（DPPH自由基清除率为10.47%；每克细胞的抗氧化活性当量为80.03μg）。此外，己烷提取物表现出红色类胡萝卜素的光谱特征，在使用不同展开系统的薄层色谱分离时可分解为不同化合物。所有分离出的化合物对DPPH反应均呈阳性（DPPH自由基清除率为13 - 30%；每克细胞的抗氧化活性当量为100 - 240μg）。使用高分辨率液相色谱-质谱-二极管阵列检测器分析对己烷提取物进行化学剖析，证实存在不同碳链长度的类异戊二烯；C：四氢鲨烯，C：3-羟基海胆酮、虾青素、角黄素、番茄红素、八氢番茄红素、六氢番茄红素和C：双脱水细菌红素、单脱水细菌红素、细菌红素和卤黄素。因此，我们得出结论，所有这些成分的协同作用有助于该培养物的抗氧化活性，并且胞外多糖、甘油二醚部分、四氢鲨烯、卤黄素和3-羟基海胆酮的抗氧化活性是关于GUSF-1（KF796625）的首次报道。因此，推荐用于微生物工业生物技术。
在线版本包含可在10.1007/s13205-020-02584-9获取的补充材料。
