Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand.
Walai Rukhavej Botanical Research Institute (WRBRI), Mahasarakham University, Maha Sarakham, 44150, Thailand.
Sci Rep. 2024 Mar 6;14(1):5563. doi: 10.1038/s41598-024-56307-8.
Byproducts from the sugarcane manufacturing process, specifically sugarcane molasses (SM) and sugarcane bagasse (SB), can be used as alternative raw materials for sorbitol production via the biological fermentation process. This study investigated the production of sorbitol from SM and sugarcane bagasse hydrolysate (SBH) using a thermally adapted Zymomonas mobilis ZM AD41. Various combinations of SM and SBH on sorbitol production using batch fermentation process were tested. The results revealed that SM alone (FM1) or a mixture of SM and SBH at a ratio of 3:1 (FM2) based on the sugar mass in the raw material proved to be the best condition for sorbitol production by ZM AD41 at 37 °C. Further optimization conditions for sorbitol production revealed that a sugar concentration of 200 g/L and a CaCl concentration of 5.0 g/L yielded the highest sorbitol content. The maximum sorbitol concentrations produced by ZM AD41 in the fermentation medium containing SM (FM1) or a mixture of SM and SBH (FM2) were 31.23 and 30.45 g/L, respectively, comparable to those reported in the literature using sucrose or a mixture of sucrose and maltose as feedstock. These results suggested that SBH could be used as an alternative feedstock to supplement or blend with SM for sustainable sorbitol production. In addition, the fermentation conditions established in this study could also be applied to large-scale sorbitol production. Moreover, the thermally adapted Z. mobilis ZM AD41 is also a promising sorbitol-producing bacterium for large-scale production at a relatively high fermentation temperature using agricultural byproducts, specifically SM and SB, as feedstock, which could reduce the operating cost due to minimizing the energy required for the cooling system.
制糖过程中的副产品，特别是糖蜜（SM）和甘蔗渣（SB），可以通过生物发酵工艺用作山梨醇生产的替代原料。本研究利用热驯化的运动发酵单胞菌 ZM AD41 从 SM 和甘蔗渣水解物（SBH）生产山梨醇。测试了分批发酵过程中使用 SM 和 SBH 的不同组合对山梨醇生产的影响。结果表明，单独使用 SM（FM1）或 SM 和 SBH 以 3:1 的比例混合（FM2）基于原料中的糖质量，是 ZM AD41 在 37°C 下生产山梨醇的最佳条件。进一步优化山梨醇生产的条件表明，糖浓度为 200 g/L，CaCl 浓度为 5.0 g/L 时，山梨醇含量最高。在含有 SM（FM1）或 SM 和 SBH 混合物（FM2）的发酵培养基中，ZM AD41 产生的最大山梨醇浓度分别为 31.23 和 30.45 g/L，与文献中使用蔗糖或蔗糖和麦芽糖混合物作为原料报道的浓度相当。这些结果表明，SBH 可作为替代原料，补充或与 SM 混合用于可持续的山梨醇生产。此外，本研究中建立的发酵条件也可应用于大规模山梨醇生产。此外，热驯化的运动发酵单胞菌 ZM AD41 也是一种很有前途的产山梨醇细菌，可在相对较高的发酵温度下使用农业副产品，特别是 SM 和 SB，作为原料进行大规模生产，由于最小化冷却系统所需的能源，可降低运营成本。
