Tailor-made biocatalysts based on scarcely studied acidic horseradish peroxidase for biodegradation of reactive dyes

Barbara S Janović; Milica Lj Mićić Vićovac; Zoran M Vujčić; Miroslava T Vujčić

doi:10.1007/s11356-016-8100-4

Tailor-made biocatalysts based on scarcely studied acidic horseradish peroxidase for biodegradation of reactive dyes

Environ Sci Pollut Res Int. 2017 Feb;24(4):3923-3933. doi: 10.1007/s11356-016-8100-4. Epub 2016 Dec 1.

Authors

Barbara S Janović¹, Milica Lj Mićić Vićovac², Zoran M Vujčić², Miroslava T Vujčić³

Affiliations

¹ Department of Chemistry, Institute of Chemistry, Technology, and Metallurgy, Njegoševa 12, P.O. Box 815, Belgrade, 11000, Serbia. bjanovic@chem.bg.ac.rs.
² Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia.
³ Department of Chemistry, Institute of Chemistry, Technology, and Metallurgy, Njegoševa 12, P.O. Box 815, Belgrade, 11000, Serbia.

PMID: 27909924
DOI: 10.1007/s11356-016-8100-4

Abstract

Peroxidases (EC 1.11.1.7) have enormous biotechnological applications. Usage of more abundant, basic isoforms of peroxidases in diagnostic kits and/or in immunochemistry has led to under exploitation and disregard of horseradish peroxidase (HRP) acidic isoforms. Therefore, acidic horseradish peroxidase (HRP-A) isoenzyme was used for the preparation of a biocatalyst with improved ability in dye decolorization. Ten biocatalysts were prepared by covalent binding of enzyme to chitosan and alginate, adsorption followed by cross-linking on inorganic support (aluminum oxide), and encapsulation in spherical calcium alginate beads via polyethylene glycol. Model dyes of 50 to 175 mg l^-1 were removed by the biocatalysts. Among the tested biocatalysts, the three with the highest specific activity and biodegradation rate were further studied (Chitosan-HRP, Al-Gel-HRP and Al-HRP-Gel). The impact of hydrogen peroxide concentration on dye decolorization was examined on the Chitosan-HRP biocatalyst, since the HRP is susceptible to inhibition/inactivation by high H₂O₂. On the other hand, H₂O₂ is needed as a co-substrate for the HRP, and the H₂O₂/dye ratio can greatly influence decolorization efficiency. Concentrations of H₂O₂ ranging from 0.22 to 4.4 mM showed no difference in terms of impact on the biocatalyst decolorization efficiency. The high decolorization efficiency of the biocatalysts was validated by the removal of 25 and 100 mg l^-1 anthraquinone (Remazol Brilliant Blue R (RBBR)), triphenylmethane (Coomassie Brilliant Blue (CBB)), acridine (Acridine Orange (AO)), and formazan metal complex dye (Reactive Blue 52 (RB52)). After the seven consecutive decolorization cycles, the decolorization was still 53, 78, and 67% of the initial dye for the Al-HRP-Gel, Al-Gel-HRP, and Chitosan-HRP immobilizate, respectively. The results obtained showed potential of otherwise neglected acidic HRP isoforms as a cost-effective biocatalyst with significant potential in wastewater dyestuff treatment.

Keywords: Biocatalyst; Decolorization; Horseradish peroxidase; Immobilization; Isoenzymes; Reactive dyes.

MeSH terms

Biocatalysis
Biodegradation, Environmental
Coloring Agents / metabolism*
Horseradish Peroxidase / metabolism*
Hydrogen Peroxide / metabolism
Isoenzymes / metabolism

Substances

Coloring Agents
Isoenzymes
Hydrogen Peroxide
Horseradish Peroxidase