摘要
Abstract
[Objective]To evaluate the antioxidant activity of Dictyophora echinovolvata mycelium during liquid submerged fermentation at different scales,and to provide a scientific basis for its development as a natural antioxidant.[Method]The ITS sequences of the target fungal strains were amplified via polymerase chain reaction(PCR)and subsequently aligned against the GenBank database for identification.With the scavenging rates of superoxide anions and DPPH free radicals as indicators,the dynamic changes in antioxidant activity were analyzed under differentaeration rates(0.25-1.50 vvm)and fermentation scales(5 L,30 L,and 50 L).[Result]The ITS sequence of the strain showed 99%similarity with the GenBank database.By comparing the antioxidant activity at different aeration rates,the optimal aeration rate was determined to be 1.00 vvm.When the aeration ratio was 1.00 vvm,the dry weight of the mycelium reached a maximum of 10.72 g/L on the 6th day;the highest DPPH free radical scavenging rate was 90.70%(on the 5th day)and still maintained at 89.07%on the 6th day;the scavenging rate of superoxide anions reached a peak of 91.25%on the 5th day.After scaling up the fermentation(5 L,30 L,and 50 L),the intracellular polysaccharide contents were 1.23,1.28,and 1.26 g/L respectively(on the 7th day);the DPPH free radical scavenging rates were 87.89%,90.10%,and 86.20%respectively(at a concentration of 20 mg/mL).The fluctuation of antioxidant activity among different scales was<5%,indicating significant stability.[Conclusion]The antioxidant activity of Dictyophora echinovolvata mycelium is closely associated with its growth,metabolism,and secondary metabolite synthesis.The 5th day of fermentation is the optimal harvesting period.The large scale application of liquid submerged fermentation technology is feasible.The mycelium has stable antioxidant performance and shows potential for industrial development as a natural antioxidant.关键词
棘托竹荪/菌丝体/通气速率/发酵规模/多糖/DPPH自由基清除率/超氧阴离子清除率Key words
Dictyophora echinovolvata/mycelium/aeration rate/fermentation scale/polysaccharides/DPPH free radical scavenging rate/superoxide anion scavenging rate分类
园艺学与植物营养学
