植物乳杆菌XN1904E产胞外多糖发酵条件优化

Optimization of Fermentation Conditions for Exopolysaccharide Production by Lactobacillus plantarum XN1904E

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。

The optimization of culture temperature,initial medium pH,and carbon and nitrogen sources for improved production 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 as follows: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/mL had antioxidant activity in terms of scavenging rate(27.54%)against 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical.