Studies On Fermentation Conditions For The Production Of Laccase By Flammulina Velutipes

Production of the laccase by Flammulina velutipes was investigated under flask culture. Different fermentative conditions were compared to investigate the influence on laccase secreted by Flammulina velutipes. Organic nitrogen is better than inorganic nitrogen for laccase secreted by Flammulina velutipes, and using peptone or yeastrel as nitrogen source in the culture after eight days fermentation the laccase activity arrived 45.7 IU/mL and 53.0 IU/mL respectively. Rich nitrogen is better too. Different carbon source in the culture have differently induced the laccase activity: using potato juice as carbon source the highest amount of laccase activity62 IU/mL was found in ten days; and using starch in the culture laccase activity was 42.1 IU/mL in ten days. Additional glucose in the culture could promote laccase activity in the prophase, the results showed with glucose the laccase activity arrived 55.5 IU/mL, which was over 2 times than it without glucose. Rich carbon source is good for laccase secreted by Flammulina velutipe, and using starch as carbon source in the culture after 8 days fermentation laccase activity of the concentration of 20g/L was 4 times and 2 times than the concentration of 7g/L and 12g/L. The mycelium'age is very important for laccase secreted by Flammulina velutipes, and proper age can promote the Flammulina velutipes to secrete laccase. The mycelium'age is four days compare to six days and two days inoculated into the culture after eight days the laccase activity is overall 1.5 fold and 3 fold. More frequent sampling could influence the laccase activity and the experimental parallel, and laccase activity in different two cultures raised about 28% and 85% after cutting down the frequency of sampling. It had little effect on laccase activity to change the shaking rate .Changing the outside air around three substrate , dissolved oxygen concentration increased, and laccase activity increased 2.4, 6 and 3.6 times accordingly. It was benefit for laccase activity to change the substrate's pH to 5.5~6.5 at the middle of fermentation. After changing pH number, the highest amount of laccase activity of substrate using peptone as nitrogen source was 144.4IU/mL in ten days, which was 3.8 times than original fermentation, and the highest amount of laccase activity used yeastrel as nitrogen source arrived 134.6IU/mL ,which was 2.7 times than original fermentation.