Sánchez-León Enrique, Huang-Lin Elisa, Amils Ricardo, Abrusci Concepción
Departamento de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid, UAM, Cantoblanco, 28049 Madrid, Spain.
Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain.
Polymers (Basel). 2023 Mar 21;15(6):1550. doi: 10.3390/polym15061550.
The RT7 strain was isolated from an extreme acidic environment and identified. The biodegradation capabilities of the strain using different carbon sources (glucose, oleic acid, Tween 80, PEG 200, and the combination of glucose-Tween 80) were evaluated via an indirect impedance technique. The glucose-Tween 80 combination was further studied using nuclear magnetic resonance (NMR). The exopolysaccharide (EPS) that had been produced with the strain when biodegrading glucose-Tween 80 was isolated and characterised using different techniques (GC-MS, HPLC/MSMS, ATR-FTIR, TGA, and DSC), and its molecular weight was estimated. The results show that the average molecular weight of EPS was approximately 7.0794 × 10 Da and a heteropolysaccharide composed of mannose, glucose, galactose, and xylose (molar ratio, 1:0.5:0.1:0.1) with good thermostability. EPS showed good emulsifying activity against different natural oils and hydrocarbons at high concentrations (2 mg/mL) and at the studied pH range (3.1-7.2). It also presented good emulsifying activity compared to that of commercial emulsifiers. Lastly, EPS showed antioxidant capacity for different free radicals, a lack of cytotoxicity, and antioxidant activity at the cellular level. EPS has promising applications in bioremediation processes and other industrial applications.
RT7菌株是从极端酸性环境中分离并鉴定出来的。通过间接阻抗技术评估了该菌株利用不同碳源（葡萄糖、油酸、吐温80、聚乙二醇200以及葡萄糖 - 吐温80组合）的生物降解能力。使用核磁共振（NMR）对葡萄糖 - 吐温80组合进行了进一步研究。分离出该菌株在生物降解葡萄糖 - 吐温80时产生的胞外多糖（EPS），并使用不同技术（气相色谱 - 质谱联用仪、高效液相色谱/串联质谱仪、衰减全反射傅里叶变换红外光谱仪、热重分析仪和差示扫描量热仪）对其进行表征，并估算了其分子量。结果表明，EPS的平均分子量约为7.0794×10 Da，是一种由甘露糖、葡萄糖、半乳糖和木糖组成的杂多糖（摩尔比为1:0.5:0.1:0.1），具有良好的热稳定性。在高浓度（2 mg/mL）和研究的pH范围（3.1 - 7.2）下，EPS对不同天然油和碳氢化合物表现出良好的乳化活性。与商业乳化剂相比，它也具有良好的乳化活性。最后，EPS对不同自由基具有抗氧化能力，缺乏细胞毒性，并在细胞水平上具有抗氧化活性。EPS在生物修复过程和其他工业应用中具有广阔的应用前景。
