Development of strong enzymatic biocatalysts for dye decolorization

An enzymatic system for decolorization of wastewater dyes using immobilized CueO laccase‐like multicopper oxidase on poly‐3‐hydroxybutyrate

“…S5), while longer incubation times allowed appreciable decolorizing efficiencies (reaching almost 100% for IC, Figs and ), resulting in improvements from 1.1‐fold (IC) to 1.4‐fold (RB5) and 1.7‐fold (NC) compared to the soluble protein. In particular, immobilized CueO‐mediated degradation of IC at neutral pH reached levels around 90% after 4 h, appreciably higher than those previously reported at pH 4.5 (7%) (Britos and Trelles, ). A striking case was methyl orange (MO), which was not degraded at all either by the soluble or immobilized enzyme in the tested conditions (data not shown).…”

“…on this substrate in the absence of mediators, that has been explained in terms of the lack of hydroxyl substituents in the molecule that would help promoting oxidation, leading to a very high redox potential (Pardo et al ., ). Nevertheless, a somewhat higher degradation of MO has been reported to occur at more acidic pH values (Britos and Trelles, ).…”

“…Although many oxidases from bacterial or fungal origin might possess better biotechnological properties in certain cases (Wesenberg et al ., ; Rodriguez Couto and Toca Herrera, ; Giardina et al ., ; Majeau et al ., ), we chose the CueO multicopper oxidase to establish the present proof‐of‐concept since this enzyme has already been thoroughly characterized both structurally and functionally for the oxidation of several organic substrates, including dyes (Zeng et al ., ; Britos and Trelles, ; Ma et al ., )…”

“…Enzymatic parameters of the hybrid BioF-CueO protein Although many oxidases from bacterial or fungal origin might possess better biotechnological properties in certain cases (Wesenberg et al, 2003;Rodriguez Couto and Toca Herrera, 2006;Giardina et al, 2010;Majeau et al, 2010), we chose the CueO multicopper oxidase to establish the present proof-of-concept since this enzyme has already been thoroughly characterized both structurally and functionally for the oxidation of several organic substrates, including dyes (Zeng et al, 2011;Britos and Trelles, 2016;Ma et al, 2017) To ensure a strong and specific adsorption of the CueO oxidase to PHB, a chimeric protein was constructed containing the BioF tag fused to the N-terminal of the CueO enzyme (Fig. S1).…”

“…A few studies have previously analysed the scope of substrates able to be oxidized by CueO (Kataoka et al, 2007;Li et al, 2007;Zeng et al, 2011), but have only recently included dye molecules (Britos and Trelles, 2016;Ma et al, 2017). Therefore, we aimed to study the activity of PHB-immobilized CueO on some representative dyes that were chosen to cover different structural families ( Fig.…”