Characterization and Purification of Xylanase Derived from Marine Bacillus subtilis AKM1 and its potential applications

Document Type : Original Article

Authors

1 Department of Biochemistry, Faculty of Science, Cairo University, Giza, Egypt.

2 Department of Biochemistry, faculty of Science, Cairo university, Giza, Egypt

3 Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt.

4 National Research Center

5 Microbial Biotechnology Department, Biotechnology Research Institute, National Research Centre, Giza 12622, Egypt.

Abstract

The synthesis, enhancement, and impact of the marine bacterial enzyme xylanase on agricultural waste was studied in order to prepare it for use in biotechnological applications. Bacillus subtilis AKM1 bacterial strain was obtained from the local coastal Red Sea in Hurghada, has accession number (MK377251) was identified using 16S rRNA as a perfect strain produced the enzyme. The optimal conditions for the production of xylanase were determined as follows: 48 hrs. incubation, pH 7.0, 50 rpm, and 40°C. The maximum enzyme production was obtained with wheat bran and KNO3 as carbon and nitrogen sources. After purification using gel filtration and ion exchange chromatography methods, xylanase exhibited its highest level of activity and stability at pH 7.0 and 50 °C. The residual activity enhanced by the presence of metal ions, specifically Mn2+, Ca2+, and Fe2+, proportionally with their concentrations increase. Conversely, the activity was entirely suppressed at higher concentrations of Ag+, SDS, and EDTA (2-10 mM). The molecular weight was 34 KDa, and the kinetic studies using a Lineweaver-Burk plot, with Km and Vmax 0.044 mM, and 22.22 U/ml respectively. Xylooligosaccharides generated through enzymatic hydrolysis utilizing pure xylanase demonstrated antibacterial efficacy against all tested organisms except E. coli, antioxidant activity using DPPH with IC50 of 121 µg/ml, and shown anti-cancer efficacy versus breast cancer cells and colon of cancer cells as well.

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