Abstract: Disclosed is the production of difructose dianhydride IV from sugar. A sugar solution is subjected to reaction at room temperature or lower in an acidic buffer of pH 3.0-7.0 in the presence of a levansucrase derived from Z. mobilis to produce levan. The levansucrase is prepared by culturing E. coli BL21 (DE3)/pEL12 (KCTC 8661), harvesting and homogenizing the cells, and isolating levansucrase from the cell homogenate. Levan is purified from the reaction solution and subjected to reaction at 25-50° C. for 3-10 hours in an acidic buffer of pH 3.0-7.0 in the presence of a levan fructotransferase to produce difructose dianhydride IV. The levan fructotransferase is obtained from E. coli JUD81 (KCTC 0877BP). Also, disclosed are a gene coding for the levan fructotransferase and an expression vector pUDAF81 carrying the gene.

Abstract: The present invention relates to an animal feed containing the 0.04-2 (w/w) % simple polysaccharide on the basis of solid powder. The animal feed according to this invention is effective in improving the condition of evacuation, preventing the diarrhea and promoting the growth of animals.