D-Mannitol production from fructose by lactic acid bacteria(LAB,Lactobacillus plantarum HSC 235) and propionate acid bacteria(PAB,Propionibacterium freudenreichii HZP-35) was investigated.Fructose can be converted into mannitol and sorbitol.Three kinds of reaction systems of growing cells,resting cells,and free cell extract were compared in mannitol formation using fructose as substrate.The results showed that the growing cells reaction process gave out a higher mannitol yield at 38 g/L,the Yp/s at 27%,while the last two reaction processes had a similar low mannitol yield.This suggested that mannitol formation was coincided with the cell growth of LAB and PAB.Initial fructose concentration hadn't appear effect on mannitol formation between 50-150 g/L where the mannitol Yp/s was at 27%,but high up to 200 g/L fructose had a inhibition on the conversion process.Although LAB and PAB can grow together as in many food,but the mixed cultivation of the two bacteria would not produce more mannitol compared with any single pure strain fermentation.In the ability of mannitol production,LAB showed a high level to PAB.