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

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 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 HO. On the other hand, HO is needed as a co-substrate for the HRP, and the HO/dye ratio can greatly influence decolorization efficiency. Concentrations of HO 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 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.

The optimization of gold nanoparticles–horseradish peroxidase as peroxidase mimic using central composite design for the detection of hydrogen peroxide

“…The molecular mass of HRP expressed in plants typically ranges from 34 to 44 kDa [39]. However, the molecular mass of purified HRP was determined to be 40 kDa [40]. TEM analysis of the AUNPs and AuNPs-HRP systems revealed that the size distribution of AUNPs and the AuNPs-HRP system was estimated to be 18 nm.…”

Multioxide nanomaterials Zn, Cu, Mn: Combining nanozyme and photocatalyst functions for environmental applications

“…The biocatalytic activity achieved is only due to the enzyme-like behaviour of the nanomaterials. In the study by Janović et al (Janović et al 2017), the degradation of azo dye (RB52) by the enzyme horseradish peroxidase immobilised on chitosan material was carried out. The activity of the system was also compared with the pure, non-immobilised HRP enzyme.…”

Degradation of Anthraquinone Dyes from Effluents: A Review Focusing on Enzymatic Dye Degradation with Industrial Potential

“…So far the main aim of the studied examples seems to be the performance of the biocatalyst, without trying to minimize synthesis cost. The majority of examples examined are using lengthy synthesis procedures with many subsequent steps for the materials synthesis and the immobilization of the enzyme, and further hazardous chemicals and unsustainable practices are usually employed. ,,,,,− These lead to final products which might tick the performance brief, but by no means tick the industrial implementation brief, rendering them basically unusable. Research should focus on the identification of a golden mean between synthesizing a material–enzyme complex able to perform as a powerful dye degradation agent, but also have the potential for easy and economical scale up in order to be industrially relevant.…”