Zhang Guoqing

Isolation, Identification, Culture Conditions, and Enzyme Production of a Wild Mushroom Lepista sp.*

For efficient application of wild mushrooms,a strain of GSM-11 was isolated from a wild mushroom fruiting body of the genus Lepista,from Huairou,Beijing,and identified based on its morphology and ITS sequence analysis.The optimum culture conditions,i.e.carbon source,nitrogen source,C/N rate,growth factor,temperature,and pH value were investigated.And the enzyme activities of laccase,protease,phytase,ribonuclease,and lectin in liquid fermentation were also determined.The results showed that the strain(GenBank accession number of ITS sequence: JQ519375) manifested very high sequence similarity with L.nuda samples from Liaoning(China),Miyagi(Japan),and Maryland(USA) based on polymeric analysis of ITS sequences,with similarity of 100%,99.98% and 99.93%,respectively.It was therefore identified as L.nuda.Culture conditions showed that the best carbon source was sucrose,the best nitrogen source was yeast extract,the best C/N rate was 20/1,the best growth factor was Vitamin C,the optimum temperature was 24 ℃,and the optimum pH was 7.0.Liquid fermentation studies showed that L.nuda demonstrated laccase activity in both mycelia and broth,but lack of the other four activities.A range of concentration of Cu2+ 1.0～2.0 mmol/L enhanced the laccase activity with a range of 149.2%～196.4% comparing with the control group.