Department of Biotechnology, Mepco Schlenk Engineering College (Autonmous), Sivakasi, 626005, Tamilnadu, India.
Appl Biochem Biotechnol. 2023 Jul;195(7):4583-4601. doi: 10.1007/s12010-023-04368-2. Epub 2023 Jan 27.
An exopolysaccharide (EPS)-producing soil bacterium was isolated and characterized using 16S rRNA as Bacillus sp. EPS003. EPS was precipitated using ethanol and % composition of total carbohydrate, and protein was determined. Monosaccharide composition was identified using thin layer chromatography (TLC), and it was found to be a levan. Fourier transform infrared (FTIR) spectrum revealed the peaks for carboxyl, hydroxyl, and amide functional groups. H nuclear magnetic resonance (NMR) spectrum further confirmed the presence of fructose monomer. Field emission scanning electron microscopic images (FE-SEM) revealed porous and amorphous characteristics of EPS which was further confirmed with broad peaks in X-ray diffraction (XRD) spectrum. Elemental composition was determined using energy-dispersive X-ray analysis (EDAX). Thermogravimetric analysis (TGA) of EPS resulted in a residual mass of 33.81% at 548 °C indicating high thermal stability. In addition, solubility index and water-holding capacity of EPS were found to be 56% and 264%, respectively, making EPS suitable for various applications. Further, antioxidant potential of EPS was studied using hydroxyl and DPPH radical scavenging assays. In vitro cytotoxicity assessment using L929 cells and SK-MEL-3 cell lines clearly indicated that the EPS produced by the novel isolate Bacillus sp. EPS003 could serve as a potential anticancer agent.
从土壤中分离出一株产胞外多糖（EPS）的细菌，并用 16S rRNA 鉴定为芽孢杆菌 EPS003。用乙醇沉淀 EPS，并测定总糖和蛋白质的含量。用薄层层析（TLC）鉴定单糖组成，发现它是一种果聚糖。傅里叶变换红外（FTIR）光谱显示了羧基、羟基和酰胺官能团的峰。核磁共振（NMR）光谱进一步证实了果糖单体的存在。场发射扫描电子显微镜图像（FE-SEM）显示 EPS 具有多孔和无定形的特征，这进一步通过 X 射线衍射（XRD）光谱中的宽峰得到证实。用能量色散 X 射线分析（EDAX）测定了元素组成。EPS 的热重分析（TGA）在 548°C 时产生 33.81%的残余质量，表明其具有较高的热稳定性。此外，EPS 的溶解度指数和持水能力分别为 56%和 264%，使其适用于各种应用。进一步研究了 EPS 的抗氧化潜力，采用羟基和 DPPH 自由基清除试验。用 L929 细胞和 SK-MEL-3 细胞系进行的体外细胞毒性评估清楚地表明，由新型芽孢杆菌 EPS003 产生的 EPS 可以作为一种潜在的抗癌剂。
