A study on screening of Auricularia auricular producing natural pigment and its physicochemical properties.

The strain Aua09,which can produce pigment,was selected by large-scale cultivation of 92 strains of Auricularia auricular from different origins.The effects of physicochemical factors including pH,temperature,light,oxidizing agent and reductant on the extracted pigment were studied.The pigment was sorrel,and the maximum absorption wavelength was 304 nm in alkaline solution.The pigment is well dissolved in alkaline solution,dissolved methanol,acetone,and not dissolved in ethyl ether.In acidic solution,the pigment deposits at pH 2.Its solubility increases with pH.The pigment solution is relatively stable under the irradiations of sunlight and very stable after treated with high temperature in alkaline solution.The pigment is resistant to H2O2 and NaHSO3.