Evaluation of Enzymatic Potentialities of Bacillus subtilis using as Substrate Different Animal Raw Materials Feed

Abstract

In the present investigation, the production of amylase, cellulase, and protease activity by Bacillus subtilis ATCC 6051a was evaluated on different raw materials (soybean meal, peas, sorghum flour, corn) and combined feed (CF). The effect of various fermentation conditions (24-72 h) on enzymatic production through shake-flask culture (Erlenmeyer 100 mL) in optimum conditions (150 rpm, pH 7.0±0.2, 37◦C) was investigated. The inoculum strain presents 1.907 optical density (OD) 600 nm with a concentration of 1.6 x 10⁹ CFU/mL. The screening showed a capacity of amylase, cellulase, and protease strain production. The maximum amylase level was obtained at 72 h when the strain was cultured in CF fermentation medium (13.19±0.15 U/mL), followed by corn (11.72±0.15 U/mL), peas (9.22±0.11 U/mL), soybean meal (7.29±0.19 U/mL) and sorghum (6.31±0.2 U/mL). For production of cellulase by DNS method, the activity was noticed in corn (4.39±0.04 U/mL), sorghum (4.05±0.02 U/mL), peas (2.94±0.06 U/mL), soybean meal (2.87±0.04 U/mL) and CF medium (1.41±0.02 U/mL). Maximum protease activity was observed after 24 h in CF (4.91±0.08 U/mL), with minimum enzyme production in the rest of fermentation media, both at 48 h and 72 h. In conclusion, qualitative analysis revealed that Bacillus subtilis ATCC 6051a could be successfully used for high scale production of amylase, cellulase and to less extend protease, particularly in fermented medium containing CF or corn, and may be considered a potential candidate for supplementation of animal feed.