Utilization of Hydrolysis of Protein Concentrates Prepared From the Waste of Common Carp Fish using Trypsin Enzyme for the Growth of Lactic Acid Bacteria

This study aimed to use trypsin enzyme hydrolysates of protein concentrates prepared from the waste of common carp fish (Cyprinus carpio) for the growth of lactic acid bacteria. Trypsin enzyme has been used in the hydrolysis of acid and base protein concentrates for various times, including 60, 120, and 180 minutes. The solubility and emulsification property of the produced hydrolysates was studied. The EAI and ESI at pH 2 and 12 gave the highest values for solubility, , while the lowest values at pH 4. Hydrolysates were used to prepare culture media as an alternative to the MRS medium. Peptospecial and Beef extract were replaced in the commercial media with hydrolysates, and two types of culture media were prepared, one containing yeast extract and the other without it. The enzymatic reaction time had a significant effect on the number of Lactobacillus acidophilus and Bifidobacterium animalis colonies, and yeast extract had a significant effect on the number of colonies of Lactobacillus rhamnosus GG. In contrast, the enzymatic reaction time had not affected the number of colonies of Lactobacillus plantarum and Bifidobacterium infantis. This study is recommended to study the response of other types of lactic acid bacteria and the suitability of the culture media prepared in this study to their growth requirements.