植物乳杆菌XN1904E产胞外多糖发酵条件优化

为提高植物乳杆菌XN1904E胞外多糖产量，考察培养温度、培养基初始pH值、碳源和氮源对植物乳杆菌XN1904E胞外多糖产量的影响。通过单因素试验和正交试验确定植物乳杆菌XN1904E产胞外多糖的最佳培养条件。结果表明：最佳培养条件为培养基初始pH 6.5、培养温度37 ℃、半乳糖为最适碳源、鱼蛋白胨为最适氮源，此条件下验证实验结果表明，植物乳杆菌XN1904E胞外多糖产量为235.41 mg/L；植物乳杆菌XN1904E胞外多糖水溶液（0.2 mg/mL）对1,1-二苯基-2-三硝基苯肼自由基的清除率为27.54%，表明其具有一定的抗氧化能力。

Optimization of Fermentation Conditions for Exopolysaccharide Production by Lactobacillus plantarum XN1904E

The optimization of culture temperature, initial medium pH, and carbon and nitrogen sources for improvedproduction of extracellular polysaccharides by Lactobacillus plantarum XN1904E was carried out using one-factor-at-a-time(OFAT) and orthogonal array design methods. The results showed that the optimal culture conditions were determined asfollows: initial pH 6.5, temperature 37 ℃, galactose as the best carbon source, and fish peptone as the best nitrogen source.Under these conditions, the production of extracellular polysaccharide was 235.41 mg/L. The polysaccharide at 0.2 mg/mLhad antioxidant activity in terms of scavenging rate (27.54%) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.