Karirat Thipphiya, Saengha Worachot, Sutthi Nantaporn, Chottanom Pheeraya, Deeseenthum Sirirat, Ma Nyuk Ling, Luang-In Vijitra
Natural Antioxidant Innovation Research Unit, Department of Biotechnology, Faculty of Technology, Mahasarakham University, Maha Sarakham 41150, Thailand.
Department of Agricultural Technology, Faculty of Technology, Mahasarakham University, Maha Sarakham 44150, Thailand.
Polymers (Basel). 2025 Jul 25;17(15):2029. doi: 10.3390/polym17152029.
This study explores the valorization of agro-industrial by-products-riceberry broken rice (RBR) and soybean meal (SBM)-as cost-effective substrates for enhancing exopolysaccharide (EPS) production by PS21. Eight strains were screened, and PS21 demonstrated the highest EPS yield (2.54 g/100 mL DW). The EPS displayed a strong antioxidant capacity with 65.5% DPPH and 80.5% hydroxyl radical scavenging, and a FRAP value of 6.51 mg Fe/g DW. Antimicrobial testing showed inhibition zones up to 10.07 mm against and 7.83 mm against . Optimization using central composite design (CCD) and the response surface methodology (RSM) revealed the best production at 5% (/) RBR, 3% (/) SBM, pH 6.66, and 39.51 °C, yielding 39.82 g/L EPS. This EPS is a moderate-molecular-weight (11,282 Da) homopolysaccharide with glucose monomers. X-ray diffraction (XRD) showed an amorphous pattern, favorable for solubility in biological applications. Thermogravimetric analysis (TGA) demonstrated thermal stability up to ~250 °C, supporting its suitability for high-temperature processing. EPS also exhibited anticancer activity with IC values of 226.60 µg/mL (MCF-7) and 224.30 µg/mL (HeLa) at 72 h, reduced colony formation, inhibited cell migration, and demonstrated anti-tyrosinase, anti-collagenase, and anti-elastase effects. This study demonstrates the successful valorization of agro-industrial by-products-RBR and SBM-for the high-yield production of multifunctional EPS with potent antioxidant, antimicrobial, and anticancer properties. The findings highlight the sustainable potential of these low-cost substrates in supporting the development of green and value-added bioproducts, with promising utilizations across the food, pharmaceutical, and cosmetic sectors.
本研究探索了将农业工业副产品——红米碎米（RBR）和豆粕（SBM）作为具有成本效益的底物，用于提高PS21产胞外多糖（EPS）的能力。筛选了8株菌株，PS21表现出最高的EPS产量（2.54 g/100 mL干重）。该EPS具有较强的抗氧化能力，对DPPH的清除率为65.5%，对羟基自由基的清除率为80.5%，铁还原抗氧化能力（FRAP）值为6.51 mg Fe/g干重。抗菌测试表明，其对[具体菌株1]的抑菌圈直径可达10.07 mm，对[具体菌株2]的抑菌圈直径可达7.83 mm。采用中心复合设计（CCD）和响应面法（RSM）进行优化，结果表明，当RBR含量为5%（/）、SBM含量为3%（/）、pH值为6.66、温度为39.51℃时，EPS产量最高，可达39.82 g/L。该EPS是一种中等分子量（11282 Da）的同多糖，由葡萄糖单体组成。X射线衍射（XRD）显示其为无定形结构，有利于在生物应用中的溶解性。热重分析（TGA）表明，其热稳定性高达约250℃，这支持了其适用于高温加工的特性。EPS还表现出抗癌活性，在72 h时对MCF-7和HeLa细胞的半数抑制浓度（IC）分别为226.60 µg/mL和224.30 µg/mL，可减少细胞集落形成，抑制细胞迁移，并具有抗酪氨酸酶、抗胶原酶和抗弹性蛋白酶的作用。本研究证明了成功地将农业工业副产品RBR和SBM用于高产生产具有强大抗氧化、抗菌和抗癌特性的多功能EPS。研究结果突出了这些低成本底物在支持绿色和高附加值生物产品开发方面的可持续潜力，在食品、制药和化妆品领域具有广阔的应用前景。
