PPROUCTION OF PROPIONIC ACID FROM HYDROLYZED COD (GADUS MORHUA) GURRY AND STARCH HYDROLYSATE

In terms of carbohydrate cost, different concentrations of starch hydrolysate (2,3,4 and 5%) as a cheaper source of fermentable carbohydrates than glucose and Cod gury hydrolysate were used in the production of propionic acid. These fermentations were achieved using Propionibacterium acidipropionici ATCC 4875. Starch hydrolysate was prepared through hydrolysis of corn starch with amaylase enzyme (Fungamyl 800 L-Novo) which was added before and after gelatinization of the starch. Production of about 1.1% to 1.5% propionic acid plus 0.45% to 0.56% acetic acid with resulting pH values of 4.3 to 4.8 were achieved with steam sterilized hydrolysates after 192 h of incubation. The fermentation rates were clearly slow, which may be attributed to a nutritional defiency of a vitamin or growth factor in cod hydrolysate. This may give the chance for the growth of contaminated microorganisms at the beginning.