Determination of Optimal Conditions for the Activity and Stability of the Protease Produced from Bacillus Subtilis Isolated from Meat

Abstract

 26 different samples of red and white meat were collected from different areas in Erbil city for the period from 12-3-2019 until 15-6-2019, and the contaminated  bacteria types were isolated and diagnosed with the meat samples using the Vitek-2 device, as well as depending on the phenotypic characteristics and biochemical tests, which appeared to be prepared automatically. Types of E.coli, Klebsiella, Micrococcus luteus, Staphylococcus aureus, Staph epidermidis, Enterococcus faecalis, Streptococcus pneamoniae, Micrococcus luteus,  Pseudomonus aeruginosa, Bacillus cereus and B. Subtilis The isolate, which is believed to belong to B.subtilis, was selected, the phenotypic and microscopic characteristics of this bacteria  were studied, in addition to biochemical tests, where it was confirmed belong to B. subtilis bacteria, and used to produce the protease enzyme. Ionic and gel filtration  chromatography. The results showed that the optimum conditions for the enzyme activity were at o30°c, with enzymatic efficacy 2955 units / ml, pH 9.0, and enzymatic efficacy 544.5 units / ml. As for the stability of the enzyme, the best temperature for the stability of the enzyme was at 50°c, and the enzyme efficiency was 328.5 units / ml for a full 15 minutes. The pH is 8.0, with an enzymatic activity of 583.5 units / ml as the enzyme has retained 100% of its activity.

The effect of Nano carbon dot on pure protease enzyme was also studied with different pH numbers and the absorbance was obtained by Spectro photo meter as it was the highest absorbance at pH 5.0 as the protease activity was increased by 3 times of the free protease.