Abstract: The accumulating Selenium culturing conditions and mechanism by Pleurotus eryngii was studied by adding Sodium Selenite into the fermentation medium in this experiment. Selenium content in mycelia went up with the Se content in fermentation culture medium, stabilized at 40μg/ml Se, the biomass was suppressed by adding the Sodium Selenite. In this condition, the content of Se in the mycelium got 1253.55μg/g. The SOD and POD activity increased with Se concentration. It got respective highest value at 30μg/ml and 40μg/ml Se. The organic Se was 98% to total Se in the mycelium. There was 1360.66μg Se in every gram soluble protein. The amino acid to total mycelium was increased 19.68% than CK’s when adding Se in the culture medium. The Cystine was the only amino acid that decreased when adding Se to the culture medium. It just got 86.36% of ck’s. This was in according with the mechanism that Se substituting S of the Cystine in the protein. The effects of six kind of additive to the Se accumulating were compared which including cellulose, starch, Methionine, peptone, citric acid, and glycerin. It was found that glycerin was best for accumulating Se. The other conditions benefit to accumulating including:initial pH 6.0, 20℃,18% inoculation and 80ml medium filled in a 250ml conical flask.

Key words: Pleurotus eryngii, accumulating, Selenium, organic Se, Se-protein