Semi-continuous production of xanthan gum using self-immobilized Xanthomonas campestris cells in biofilm reactors was studied. Fermentation was carried out using two different designs of biofilm reactor equipped with a) stainless-steel support (SSS) and b) polyethylene support (PES). Fermentation was performed in three cycles with refreshing the media at the beginning of each: cycle 1, 0−27 h; cycle 2, 27−54 h; and cycle 3, 54–78.5 h. Results showed that the glucose consumption and the pH reduction in the PES biofilm reactor was faster compared to the SSS biofilm reactor. Scanning electron microscopy showed that the SSS was capable to immobilize more cells during the growth of X. campestris. The maximum concentration of xanthan gum in the SSS biofilm reactor obtained after 27 h (3.47 ± 0.71 g/L), while the maximum concentration of xanthan in the PES biofilm reactor obtained after 78.5 h (3.21 ± 0.68 g/L). Thermal stability analysis of xanthan using differential scanning calorimetry showed the presence of two fractures attributed to dehydration and degradation of polymer. The thermogram represented both endothermal and exothermal behaviour of xanthan polymer. Furthermore, the functional groups and molecular structure of the xanthan produced in this study was evaluated using Fourier transform infrared spectrometry and also proton nuclear magnetic resonance. in addition, the surface tension of (0.2 %, w/v) xanthan gum solution was in a range of 52.16–56.5 mN/m. Rheological analysis of xanthan showed that the G′ values were higher than the G″ in all frequencies demonstrating a relatively high elasticity of the produced xanthan gum.

研究了在生物膜反应器中使用自固定的油菜黄单胞菌细胞半连续生产黄原胶。使用两种不同设计的生物膜反应器进行发酵，该反应器配备 a) 不锈钢支架 (SSS) 和 b) 聚乙烯支架 (PES)。发酵分三个周期进行，在每个周期开始时刷新培养基：周期 1，0-27 小时；第 2 周期，27-54 小时；和周期 3, 54–78.5 h。结果表明，与 SSS 生物膜反应器相比，PES 生物膜反应器中的葡萄糖消耗和 pH 值降低更快。扫描电子显微镜显示 SSS 能够在野油菜生长过程中固定更多的细胞。SSS 生物膜反应器中黄原胶在 27 h 后获得的最大浓度（3.47 ± 0.71 g/L），而 PES 生物膜反应器中黄原胶在 78.5 h 后获得的最大浓度（3.21 ± 0.68 g/L）。使用差示扫描量热法对黄原胶的热稳定性分析表明存在两个归因于聚合物脱水和降解的裂缝。热谱图代表了黄原胶聚合物的吸热和放热行为。此外，本研究中产生的黄原胶的官能团和分子结构使用傅里叶变换红外光谱法和质子核磁共振进行了评估。此外，（0.2%，w/v）黄原胶溶液的表面张力在 52.16-56.5 mN/m 范围内。