Microbiology Laboratory, Department of Botany and Forestry, Vidyasagar University, Midnapore 721 102, West Bengal, India.
Carbohydr Polym. 2013 Sep 12;97(2):627-34. doi: 10.1016/j.carbpol.2013.05.039. Epub 2013 May 25.
Endophytic fungi were less investigated for exopolysaccharide production. In this study endophytic Fusarium solani SD5 was used for optimization of exopolysaccharide production. One variable at a time method and response surface methodology were employed to explore the optimum medium compositions and fermentation conditions. The organism produced maximum exopolysaccharide after 13.68 days of incubation at 28 °C in potato dextrose broth supplemented with (g%/l) glucose, 9.8; yeast extract, 0.69; KCl, 0.05; KH₂PO₄, 0.05 with medium pH 6.46. Use of 50 ml medium in 250 ml Erlenmeyer flask gives highest exopolysaccharide production. The organism produced more than two times higher exopolysaccharide (2.276 ± 0.032 g/l EPS) at optimized condition compared to pre-optimized condition (0.96 ± 0.021). In vivo toxicity test established nontoxic nature of the EPS (≤400 mg EPS/Kg of body weight). The EPS slightly altered intestinal indigenous bacteria and influenced the growth of beneficial Lactobacillus spp.
内生真菌在胞外多糖生产方面的研究较少。本研究采用内生尖孢镰刀菌 SD5 优化胞外多糖的生产。采用单因素法和响应面法探索最佳培养基组成和发酵条件。该菌在 28°C 下，于添加葡萄糖（g%/l）9.8、酵母提取物 0.69、KCl 0.05、KH₂PO₄ 0.05 的马铃薯葡萄糖肉汤中培养 13.68 天后，可产生最大量的胞外多糖，培养基 pH 值为 6.46。在 250ml 锥形瓶中使用 50ml 培养基可获得最高的胞外多糖产量。与预优化条件（0.96±0.021 g/L EPS）相比，优化条件下该菌产生的胞外多糖（2.276±0.032 g/L EPS）高出两倍以上。体内毒性试验证实 EPS 无毒（≤400mg EPS/Kg 体重）。EPS 对肠道固有细菌略有影响，并影响有益乳杆菌的生长。
