Screening of protease-producing bacteria from fermented shrimp products (terasi) for meat tenderization

Terasi is a traditional fermented product that is popularly used as condiment in several Indonesian cuisines. Based on its raw materials, namely shrimp and marine fish, terasi provides a substrate for various protease-producing microorganisms. This study aimed to isolate protease-producing bacteria from terasi and to assess their crude enzyme as meat tenderizer. Seven terasi samples from different regions were used as sources for proteolytic bacteria. They were inoculated on skim milk agar media, on which 137 isolates were found with 1-2 cm clear zones and 41 isolates with more than 2 cm clear zones, implying their proteolytic activity. Most of the isolates were Gram-positive bacteria. The crude enzymes from twenty selected isolates were assessed for meat tenderization, by dipping the meat cut into solution of crude proteolytic enzymes. Measurement of the shear force value (SFV) of meat treated with crude enzymes from 20 isolates showed that 14 of the 20 treatments had lower SFV (21.52 to 34.12 g/cm2) than the control (34.77 g/cm2). The three isolates that showed the best meat tenderizing activity were isolates Tr18, Tr13 and Tr4 with SFV 21.52 g/cm2, 21.54 g/cm2, and 25.77g/cm2, respectively. These isolates are interesting to be used in the future study for further characterization.