Studies On The Submerged Fermentation Conditions Of Morchella Esculenta And Its Bioaccumulation Of Ferrum, Zinc, Selenium

Morchella esculenta was collected from the hillside about 200～600 meters of Mount Tai in China. In this research, we use Morchella esculenta as original strain to study its optimum fermentation culture and conditions. According to Morchella esculenta's super ability of accumulating trace elements, we obtained the mycelia which accumulated Fe, Zn and Se, then studied the mycelia's accumulations and its capacity of biotransformation. The research work was reported in this paper. The major contents are as follows: The optimal fermentation conditions were worked out through orthogonal test and single factor test. The optimum fermentation culture and fermentation conditions of dry weight and EPS produced by Morchella esculenta were obtained. The experiments show that glucose and NH₄NO₃ are the optimum carbon and nitrogen sources. The fermentation medium obtained by orthogonal tests of the fermentations contains bran 200g/L,glucose 30g/L, NH₄NO₃ 2g/L,KH₂PO₄ 2g/L,MgSO₄·7H₂O 1.5g/L. The optimum fermentation conditions are initial pH 6.5, 200r/min, 4 days of the fermentation time, 10% of inoculation volume, fermentation temperature 20℃and 100mL liquid medium per flask. Morchella esculenta produces EPS with the productivity of 2135.441μg/mL under the fermented conditions, 46.8% higher than that under the original conditions (1454.639μg/mL). The mycelia dry weight is 0.83g/100mL, 27.7 % higher than that under the original conditions (0.65g/100mL). The characters about the bioaccumulation of Fe, Zn and Se were investigated by single element bioaccumulation, then the functional ingredients in the mycelia enriched with Fe, Zn and Se were analyzed. The result indicates that Morchella esculenta can accumulate Fe, Zn and Se efficiently, and these trace elements with optimal concentration can highly accelerate the mycelia growth and also can increase the content of organic trace elements. We investigated the Se-accumulating characters of Morchella esculenta mycelia which was submerged fermented in liquid media of 200 ppm Se content. The result shows that the capacity of Se-accumulating is high. The content of amino acid in the Se-accumulating mycelia gathered by submerged fermentation is obviously higher than that of contrast. 8 essential amino acids in the Se-accumulating mycelia are 53.4% higher than that in the CK. And the distribution and combined forms of Se in Se-enriched mycelia were also studied. It is found that 74.13% of Se in Se-enriched mycelia is present in...