The Preliminary Study On Aerobic Fermentation Of Succinic Acid Produced By Mucor Racemosus SH-24

Succinic acid, a intermediate in citric acid cycle , is produced by microbial metabolism. As an important chemical raw material, succinic acid has widely potential and practical use in several field , such as medicine, food, surfactant et al.A high yield and stable succinic producing strain S-57 was obtained from the mutation of mucor S-1 treated with ultraviolet ray and NTG. After the strain S-57 was treated with He-Ne laser, a strain SH-24 was selected, the concentration of succinic acid was 21.25g/L in the fermentation broth in the same condition of fermentation, which was 343 times of the strain before mutagenesis.Then according to the critical method in common used of mold,the colony shape and procreation characteristics of the strain (SH-24) were observed and the physiological characteristics were studied.The results indicated that the strain was M. racemosus Fresenius which belonged to Racemousus,Muco,Mucoraceae,Mucorales,Phycomycetes in Fungi.The organic nitrogen and inorganic nitrogen of the liquid medium components of this strain were optimized by using single -factor test. On the base of it, the proportion of carbon and nitrogen in the medium were optimized by orthogonal test. Through the single-factor and orthogonal test, the best recipe was starch 1% , peptone 1%, NH4NO3 0.1%. And by using the least square method, the optimum condition for fermentation was as follows: the culture temperature was 32℃, and the primary pH was 5.1.