AUTHOR=Uddin Jalal , Idrees Muhammad , Ahmed Humam , Batool Saima , Rahman Tanzeel Ur , Mehmood Shahzil , Tanoli Asad Khan , Muhsinah Abdullatif Bin , Ullah Hidayat , Musharraf Syed Ghulam 

TITLE=Biodegradation and decolorization of methylene blue, reactive Black-5, and toluidine blue-O from an aqueous solution using the polyphenol oxidase enzyme

JOURNAL=Frontiers in Sustainable Food Systems

VOLUME=7

YEAR=2024

URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2023.1320855

DOI=10.3389/fsufs.2023.1320855

ISSN=2571-581X

ABSTRACT=<p>In this study, a copper-containing polyphenol oxidase (PPO) enzyme was extracted from the selected agricultural food products, i.e.<italic>, Mangifera indica</italic> (L.), <italic>Solanum tuberosum</italic> (L.), and <italic>Luffa cylindrica</italic> (L.), which has efficiently degraded the azo dyes (Methylene blue, Reactive Black-5, and Toluidine Blue-O) into less toxic compounds. After preparing the dye solution at various concentrations, the PPO enzymes extracted with phosphate buffer were incubated with it for 2 hours. The percentage of decolorization was estimated by using the unprocessed dye solution. The degraded products were characterized by UV–vis and FT-IR. All sets of experiments followed pseudo-first-order kinetics. The highest kinetic degradation rate constant was observed at <italic>kt</italic> = 0.0213 min<sup>─1</sup> (<italic>R</italic><sup>2</sup> = 0.9258) and <italic>kt</italic> = 0.0244 min<sup>─1</sup> (<italic>R</italic><sup>2</sup> = 0.7627) in reactive black-5 from <italic>Mangifera indica</italic> (L.) and <italic>Solanum tuberosum</italic> (L.), respectively. The enzyme extracted from the peel of <italic>Solanum tuberosum</italic> (L.) decolorized Reactive Black-5 and Toluidine Blue-O dyes to a greater extent, i.e., 83.29 and 70.84% with reaction times of 120 and 90 min, respectively.</p>