In order to provide a line of thinking to produce a suitable selenium source, the selenium-enrichment fermentation conditions of Sarcodon aspratus was optimized adopting orthogonal design of four factors and three levels as tested indicators including mycelial biomass, selenium content, reducing sugar, ammonia nitrogen and soluble protein, and the effects of different concentrations of selenium on mycelial growth in solid culture and biological components in liquid culture of S. aspratus were studied. The results showed that high selenium concentration inhibited the mycelial elongation growth of S. aspratus. The extreme difference analysis results of orthogonal experiments showed the order of the four factor effects for testing indicators, combined with the results obtained by certifying experiment confirmed that the optimized combination of taking reducing sugar as a target was glucose 6% (w/v), yeast extract 3% (w/v), KH2PO4 0.1% (w/v), and Na2SeO3 0.6 mmol/L, and the mycelial biomass and the content of ammonia nitrogen were comparatively high. As compared with the control, after adding selenium the contents of ammonia nitrogen, reducing sugar, and total sugar in the liquid fermented broth of S. aspratus significantly increased (P<0.05), when the selenium concentration was at 0.5 mmol/L the ammonia nitrogen, reducing sugar and total sugar were all reached to the peak. The mycelial biomass and soluble protein content reached the maximum when the selenium concentration was at 0.2 mmol/L and 0.4 mmol/L respectively. The content of nutritional components in fermentation broth would change after S. aspartus was cultured in selenium enrichment. |