Differences in protease expression of mutants Bacillus licheniformis F11

Ace Baehaki^1*, Dahrul Syah², Sukarno², Siswa Setyahadi³, and Maggy T. Suhartono³

¹Department of Fisheries Product Technology, Faculty of Agriculture, Sriwijaya University, Indralaya, South Sumatera, Indonesia ²Department of Food Science and Technology, Bogor Agricultural University, Darmaga Campus IPB Bogor 16002, Indonesia ³Agency for the Assessment and Application of Technology,  Jakarta,  Indonesia

DOI : http://dx.doi.org/10.13005/bbra/1871

ABSTRACT: 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.

KEYWORDS: Protease; Bacillus licheniformis F11.1; F11.4; Bacillus licheniformis F11.1; F11.4; expresion

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