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 Lactoba-cillus 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 degrees 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.