The aims of the present study were to optimize the operational parameters to maximize the yield of ultrasound-assisted polysaccharide extraction from Volvariella volvacea (straw mushroom) fruiting bodies by using for the first time one-factor-at-a-time and three-level Box-Behnken factorial designs. A maximum polysaccharide yield of 8.28 ± 0.23% was obtained under the optimized conditions of ultrasound power of 175 W, extraction temperature of 57 °C, extraction time of 33 min, and the ratio of liquid to raw material of 25:1, respectively. Compared to the hot-water extraction, the ultrasound-assistance favored the extraction of polysaccharides from V. volvacea for its higher polysaccharide yield and efficiency. Further preliminary polysaccharide structural characterization indicated that ultrasound treatment affected the monosaccharide compositions and ratios, and molecular weight range of polysaccharides extracted from V. volvacea.

Bacteriophages have the destructive damage on the industrial bioprocess. 2-Keto-gluconic acid (2KGA) producing bacteria had also been attacked and lysed by bacteriophages which lowered the glucose consumption and 2KGA yield and even stopped the fermentation process. In this study, we presented the characteristics of a novel virulent bacteriophage specifically infecting Pseudomonas fluorescens K1005 and proposed an efficient remedial action for this phage infection to reduce the production loss.