Detection of Milk Clotting Enzyme Produced by Lactic Acid Bacteria Isolated from Fermented Food

Mohamed Muftah Ahmad and Zaiton Hassan

Lactic acid bacteria (LAB) are known to produce extracellular enzymes that could be exploited for use in the dairy industry. Two LABs isolated from fermented foods   (paste shrimp) were evaluated for extracellular proteinase production, milk clotting activity (MCA) and proteolytic activity (PA). The two isolates were identified by (API 50CHL) as Pediococcus acidilactici SH, and Lactobacillus paracasei CF1. These LABs showed proteolytic activity using skim milk agar as indicated by the visible clear zones developed in skim milk agar. P. acidilactici SH showed high MCA 50 SU/ml with PA 1.9 U/ml while L. paracasei CF1 showed MCA 44 SU/ml) with PA 3.5 U/ml using trypticase peptone as a nitrogen source in enzyme production media. MCA was not observed when the LABs were grown in MRS broth. This study indicates the possibility of exploiting LAB from food sources for the production of milk-clotting enzymes for dairy production.

Keywords: Lactic acid bacteria, Lactobacillus paracasei, Pediococcus acidilactici, Milk clotting enzyme, Proteolytic activity.