Kim Ji Min, Ra Chae Hun
Department of Food Science and Biotechnology, College of Engineering, Global K-Food Research Center, Hankyong National University, Anseong-Si, 17579, Republic of Korea.
Bioprocess Biosyst Eng. 2025 Mar;48(3):437-444. doi: 10.1007/s00449-024-03119-9. Epub 2024 Dec 18.
Levilactobacillus brevis KCL010 was fermented in a simple medium containing 8% (w/v) of rice bran extract. We modified the carbon, nitrogen, and initial pH conditions using 10 g/L of sucrose, 10 g/L of yeast extract, and 5.0 of pH, respectively. To minimize the pH increase due to decarboxylation, we fermented 100 mL of modified synthetic medium containing citrate-phosphate buffer (CPB, pH 5.0) of 25-200 mM in 250 mL Erlenmeyer flasks. After 72 h of fermentation with 50 mM CPB, the maximum GABA concentration and conversion efficiency were 3.42 g/L and 22.39%. Furthermore, the potential α-glucosidase inhibitory activity, MTT assay, and oil red O staining were determined by fermented extracts of L. brevis KCL010. At the highest concentration of 500 μg/mL, the α-glucosidase inhibition percentages for non-fermented rice bran (NFRB), rice bran fermented by L. brevis (RBFL), and GABA (analytical standard) extracts were 55.03%, 58.37%, and 59.48%, respectively. All extracts exceeded 80% viability, suggesting that there was no cytotoxic to 3T3-L1 adipocytes. The rice bran fermented by L. brevis (RBFL) extract shows a high inhibition of lipid accumulation by 29.33% compared to those of extracts.
短乳杆菌KCL010在含有8%（w/v）米糠提取物的简单培养基中进行发酵。我们分别使用10 g/L蔗糖、10 g/L酵母提取物和pH值5.0来改变碳源、氮源和初始pH条件。为了将脱羧作用导致的pH升高降至最低，我们在250 mL锥形瓶中对100 mL含有25 - 200 mM柠檬酸盐 - 磷酸盐缓冲液（CPB，pH 5.0）的改良合成培养基进行发酵。用50 mM CPB发酵72小时后，最大GABA浓度和转化效率分别为3.42 g/L和22.39%。此外，还通过短乳杆菌KCL010的发酵提取物测定了潜在的α - 葡萄糖苷酶抑制活性、MTT法和油红O染色。在最高浓度500 μg/mL时，未发酵米糠（NFRB）、短乳杆菌发酵米糠（RBFL）和GABA（分析标准品）提取物的α - 葡萄糖苷酶抑制率分别为55.03%、58.37%和59.48%。所有提取物的活力均超过80%，表明对3T3 - L1脂肪细胞无细胞毒性。与提取物相比，短乳杆菌发酵米糠（RBFL）提取物对脂质积累的抑制作用高达29.33%。
