eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2015-12-25 12 3 2023 2035 10.13005/bbra/1871 3517 article Ace Baehaki 1 Dahrul Syah 2 Sukarno 2 Siswa Setyahadi 3 Maggy T. Suhartono 3 Department of Fisheries Product Technology, Faculty of Agriculture, Sriwijaya University, Indralaya, South Sumatera, Indonesia Department of Food Science and Technology, Bogor Agricultural University, Darmaga Campus IPB Bogor 16002, Indonesia Agency for the Assessment and Application of Technology, Jakarta, Indonesia The objective of the study was to investigate the differences in protease productions of mutans Bacillus licheniformis F11. In this study B. licheniformis F11.1 (DchiA; Dpga) and B. licheniformis F11.4 (DchiAB; Dpga) was used. Two types  (LB and MLB + collagen) of media were used for bacterial growth, protease production and zymogram analysis : Luria Broth  (LB)  and  Modified Luria Broth plus collagen (MLB +collagen)  media.  The LB media contained  tryptone 1%, NaCl 1% dan yeast extract 0.5%.  The Modified  LB + collagen media contained  tryptone 0.5%;  NaCl 1%,  yeast extract 0.25% and  collagen 5%.  Two protease producing B. licheniformis F11 mutans were screened from Palembang Indonesia, Bacillus licheniformis F11.1 (DchiA; Dpga) and Bacillus licheniformis F11.4 (DchiAB; Dpga).  Both mutants showed different growth pattern and protease production in media containing collagen. F11.1 displays a higher protease activity than F11.4 in Luria Bertani media with an optimum after 15 hours for F11.1 and 15-25 hours for F11.4.  Upon addition of collagen to LB medium F11.4 overmatched F11.1 with respect to collagenolytic activity.  The presence of collagen led to a shift in the substrate preference of the two strains towards collagen compared to other protein substrates (gelatin, fibrin and casein). Zymogram analysis on gel embedded substrates suggests a higher molecular variation for strain F11.4.The different genetic mutation of the same species (Bacillus licheniformis F11.1 and F11.4) displayed different protease production patterns and substrate specificities especially on collagen. https://www.biotech-asia.org/vol12no3/differences-in-protease-expression-of-mutants-bacillus-licheniformis-f11/ Protease; Bacillus licheniformis F11.1; F11.4; Bacillus licheniformis F11.1; F11.4; expresion