Extraction optimization and bioactivity of polysaccharides from Aspergillus fumigatus AF1

Aspergillus fumigatus was used to produce polysaccharide using sodium hydroxide pretreated rice straw as the sole carbon source by submerged fermentation. Response surface methodology (RSM) was used to optimize the extraction of polysaccharide from the mycelia of A. fumigatus (PAF). A three-level, three-factor Box–Behnken design (BBD) was applied for experimental design and analyzed the results to obtain the optimal extraction parameters. RSM analysis indicated good correspondence between experimental and predicted values. The optimal conditions for polysaccharide extraction were extraction temperature 50 °C, extraction time 6 h, ratio of dried mycelia mass to water 0.03. PAF showed excellent antitumor activity in vitro and exert no damage to the normal cells. PAF also showed prominent antitumor activity in vivo against S180 and increased the spleen and thymus index significantly.