发酵乳杆菌CECT 5716产胞外多糖培养基成分优化及抗氧化活性研究

采用单因素和正交试验对发酵乳杆菌(Lactobacillus fermentium)CECT 5716产胞外多糖(EPS)的培养基成分进行优化，并通过评价胞外多糖对1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基的清除活性以及其总抗氧化能力和Fe³⁺总还原力考察胞外多糖的抗氧化活性。结果表明，发酵乳杆菌CECT 5716产胞外多糖的最优培养基配方：麦芽糖2.0%、蔗糖1.0%、酵母膏2.5%、L-半胱氨酸盐酸盐0.2%、乙酸钠0.5%、磷酸氢二钾0.2%、硫酸镁0.02%、硫酸锰0.005%、柠檬酸氢二胺0.2%、吐温80 0.1%。在此条件下，EPS产量为(1 575±22.91)mg/L，是优化前的6.38倍。胞外多糖具有较好的抗氧化活性，并与其质量浓度成正比，当胞外多糖的质量浓度为8 mg/m L时，对DPPH自由基的清除率为(84.17±1.30)%、对ABTS自由基的清除率为(35.37±1.24)%，总抗氧化能力为0.31±0.01、Fe³⁺总还原力为0....

Optimization for medium components of exopolysaccharide production by Lactobacillus fermentum CECT 5716 and antioxidant activity

The medium composition of exopolysaccharide (EPS) production by Lactobacillus fermentum CECT 5716 was optimized by single factor and orthogonal experiments, and the antioxidant activity of EPS was investigated by evaluating the scavenging activity of exopolysaccharide against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2'-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, total antioxidant capacity and Fe3+ total reducing power of exopolysaccharide. The results showed that the optimal medium formula for exopolysaccharide production by L. fermentum CECT 5716 was as follows: maltose 2.0%, sucrose 1.0%, yeast extract 2.5%, L-cysteine hydrochloride 0.2%, sodium acetate 0.5%, dipotassium hydrogen phosphate 0.2%, magnesium sulfate 0.02%, manganese sulfate 0.005%, hydrogen citrate diamine 0.2%, and Tween 80 0.1%. Under these conditions, the exopolysaccharide yield reached (1 575±22.91) mg/L, which was 6.38 times that of before optimization. Exopolysaccharide had good antioxidant activity, which was directly proportional to its mass concentration. When the exopolysaccharide mass concentration was 8 mg/ml, the scavenging rates of DPPH and ABTS radicals were (84.17±1.30)% and (35.37±1.24)%, respectively, the total antioxidant capacity was 0.31±0.01, and the Fe3+ total reducing power was 0.55±0.01.