Poster 6-13

Kui Hong, Yan Ma, Meiqiu Li, and Jiangtao Zhao

Division of Research Affairs
South China University of Tropical Agriculture
Danzhou, Hainan, 571737, China

Telephone: +86-890-330-0316; Fax: +86-890-330-0545; E-mail: kuihong@21cn.com

Large quantities of cassava dregs are produced in tropical areas as by-products in cassava starch processing. In this work, the solid fermentation of phytase from cassava dregs was studied. Analyses showed that the protein and inorganic acid contents in cassava dregs were low. Cassava dregs could be employed for phytase synthesis only after adding wheat bran, rice bran, or inorganic salts. The phytase accumulation was repressed by a high level of phosphate. Optimized-medium compositions using cassava dregs as the sole carbon source were found by adding mineral salts as follows: NH₄NO₃, 2%; K₂HPO₄, 0.015%; MgSO₄@7H₂O, 0.05%; KCl, 0.05%; and FeSO₄@7H₂O, 0.01%. A maximum phytase yield of 6730 U/g dry koji was obtained.