Journal of Pure and Applied MicrobiologyVol. 11 No. 1

Production, Partial Purification and Based SDS-PAGE Profiles of Caseinolytic Enzyme in two Bacillus Strains Isolated from Fermented Cassava leaves "Ntoba mbodi" in Congo Brazzaville

Soloka Mabika Armel Faly, Rachel Moyen, Etienne Nguimbi*, Gabriel Ahombo, Raoul Ampa, Aimé Christian Kayath, Alain Vouidibio, Cyr Jonas Morabandza and Simon Charles Kobawila

1Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, République du Congo. 2Unité de Microbiologie, Biologie moléculaire et Bio-informatique, Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, République du Congo. 3Institut de Recherche en Sciences Exactes et Naturelles, Ministère de la Recherche et de l’Innovation Technologique, Brazzaville, République du Congo.

Received on 05 October 2016 and accepted on 11 November 2016

 

ABSTRACT

Two Bacillus strains isolated from Ntoba mbodi : Bacillus megaterium (B.me NM 02) Bacillus licheniformis (B.li NM01), has shown a significant caseinolytic enzyme activity. We set optimization of growth and enzyme production conditions. Several parameters have been optimized: temperature, pH, various types of media, carbon and nitrogen sources. In both strains, growth is possible from 25 to 60 ° C with an optimum temperature at 37°C for B.li and at 35°C for B.me. Enzyme production was observed from 25 to 55 °C with an optimum temperature of 30 °C for B.li. Enzyme production was observed from 25 to 50 ° C with an optimum temperature of 35 ° C in B.me. For pH, growth and enzyme production can be at 5, 7 and 9 with an optimum at 7 for both strains. The LB medium is better for growth and enzyme production than TSB for B.li and B.me. Among the carbon sources used, fructose is better for growth after 48 hours of incubation in both strains (B.li: 0,93±0,001, B.me: 0,928±0,002), but for enzyme production fructose remains the best carbon source for B.li (14,33±1,24) , while starch is the best for B.me (14.66±1,24). Concerning nitrogen sources, in both strains the best source of growth is the yeast extracts (B.li: 0,969±0,015, B.me: 0,952±0,01). For enzyme production, the two sources can be used for B.li.(14,333±1,247) but for B .me (14,333±0,471) only the yeast extracts is the best as well as for growth and enzyme production. Furthermore, in both strains the produced enzyme was partially purified by using ammonium sulfate precipitation, and SDS-PAGE has been hold, profiles of specific bands are useful to give more information and differentiate the two strains.

Keywords : Optimization, caseinolytic enzyme, Ntoba mbodi, Bacillus licheniformis, Bacillus megaterium.