Isolation And Identification Of One Strain Of Penicillium Producing Sclerotia And Analysis Of Its Biological Characteristics

Seventy-three strains of Penicillium were isolated from the soil samples collected from respectively coniferous forest and mixed forest of Shennongjia Nature Reserve in Hubei Province, Shanxi Guandi Mountain National Nature Reserve, Shanxi Beiyue Hengshan, Shanxi Wutai Mount, and Taihang Grand Canyon in Shanxi Changzhi. By observing colonies and individual morphology, one strain isolated from the pine trees soil in Shanxi Wutai Mountain was found to can produce sclerotia, and it was named as Q1 strain. In this study, the colonies and individual morphology characteristics of Q1 strain in four medium according to Pitt were observed. The results showed that Q1 strain could grow better in the surface of MEA and CYA medium and accumulate some pigment in sclerotia. The sclerotia color in CA medium was black, irregular, pinicilli monorerticilati strictly,5-8 whorls. Based the characters above,Q1 strain was identified to P.thomii series.This study examined the respective effect of various inorganic salts, carbon and nitrogen sources on sclerotia biomass of Q1 strain. The results showed that K2HP04 was more essential to the sclerotia formation for Q1 strain. Positive cooperative effect of K2HPO4+KCl+MgSO4 was the best. FeSO4 had some effect on the accumulation of pigment in Sclerotia, and had negative effect on the formation of sclerotia. All of five carbon sources tested could be utilized by the strain Q1. The maltose was the best carbon source and could result in higher significantly sclerotia biomass than other carbon sources. Three kinds of organic nitrogen sources favored the formation of sclerotia of strain Q1.The yeast extract was the best nitrogen source. The highest sclerotia biomass was obtained when the carbon and nitrogen content of the medium was maintained respectively at 20 g/L and 0.24-0.48 g/L.Full-wave UV spectra and TLC scanning results showed that the pigment in sclerotia of Q1 strain was carotenoids. At the same time, the stability of the pigment was studied. The pigment was sensitive to light, and under strong light easily decomposed. Under lower temperature the pigment was stable, but under high temperature it's structure would be destroyed and the pigment survival rate was significantly lower. The pigment was unstable under metal ions. So the pigment should avoid contact with metal objects in order to preserve it better.Penicillium PT95 strain was another strain which could form sclerotia. In this study, PT95 and Q1 strain were incubated in liquid culture media to observe the formation of sclerotia. The result showed that under standing culture, MEA liquid medium was the best medium. Liquid medium could shorten the time of sclerotia mature for 1-2 days as compared with the solid medium. The accumulation of pigment in sclerotia in liquid medium was also higher than that in solid medium.