This study aims to explore the fermentative production and physicochemical properties of an exopolysaccharide (EPS) produced from agricultural isolate, Bacillus subtilis S1 in submerged culture. The structural characterization (Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and 13 C Nuclear magnetic resonance spectrometry) revealed that the EPS is an acidic heteropolymer consisting of glucose, glucuronic acid, pyruvic acid, and succinic acid. The non-Newtonian shear thickening nature of EPS with a 1.55 × 107 Da molecular weight is confirmed by rheology analysis. The extracted EPS was 61.3% amorphous with partial crystallinity (38.7%) as confirmed by X-ray diffraction analysis. The EPS shows two-step decomposition and thermal stability up to 300 °C as confirmed by thermogravimetric analysis and differential scanning calorimetry analysis. The EPS has a small Z-average particle size (74.29 nm), high porosity (92.99%), high water holding (92.39%), and absorption capacity (1,198%). The biocompatible nature is confirmed by cytotoxic testing on the human keratinocytes cell line. The demonstrated unique characteristics of Bacillus EPS presents it as a choice of biomaterial for diverse applications.

中文翻译：

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从农业分离株枯草芽孢杆菌生产和表征多方面的胞外多糖。

这项研究旨在探讨在深水培养中从农业分离株枯草芽孢杆菌S1产生的胞外多糖（EPS）的发酵生产和理化特性。结构表征（紫外可见光谱，傅立叶变换红外光谱和13 C核磁共振光谱）显示EPS是一种酸性杂聚物，由葡萄糖，葡萄糖醛酸，丙酮酸和琥珀酸组成。流变分析证实了分子量为1.55×107 Da的EPS的非牛顿剪切增稠特性。通过X射线衍射分析证实，提取的EPS为61.3％的非晶态，具有部分结晶度（38.7％）。通过热重分析和差示扫描量热分析证实，EPS表现出两步分解和高达300°C的热稳定性。EPS具有较小的Z平均粒径（74.29 nm），高孔隙率（92.99％），高持水率（92.39％）和吸收能力（1,198％）。通过对人角质形成细胞系的细胞毒性测试证实了其生物相容性。芽孢杆菌EPS的独特性能证明它是用于多种应用的生物材料的选择。