A novel rennin like protease from Lactobacillus plantarum 1.13 isolated from Indonesian fermented meat (Bakasam)

Cheese processing requires rennin during curdling process. A rennin like protease was extracted from Lactobacillus plantarum 1.13 isolated from Bakasam (traditional fermented meat) and characterized. The novel rennin like protease was purified by ammonium sulphate precipitation and gel filtration (Sephadex G-50) chromatography. The extracellular enzyme showed spesific Milk Clotting Activity (MCA) of 414.67 SU/mg after purification. The ratio of SMCA/SPA is 5.46 higher than Mucor pusillus QM 436 with value 1.81. Biochemical characterization indicated that optimum rennin like protease were at pH 4 at 40 °C. This enzyme was activated by 10 mM CaCl2 and 5 mM MgCl2, but inhibited by 5 mM EDTA and 0.5 mM PMSF. The SDS-PAGE and zymogram analysis indicated a 24.3 kDa enzyme with MCA/PA showed potential to be used as alternative of rennin in cheese making.