The biobleaching potential of laccase produced from mandarin peelings : impetus for a circular bio-based economy in textile biofinishing

Abstract

The quest for circular bioeconomy has been on the rise in recent years, and it is anticipated to fulfil the environmental sustainability aspect of the sustainable development goals (SDG 2030). In this regard, our investigation attempted the biotechnological appraisal of an enzymatic derivative of bacterial (Pseudomonas sp. HRJ16) mandarin peelings (MP) fermentation as a vehicle for an environmentally benign and sustainable textile bioscouring. Production of the bacterial exudate (HRJ16 laccase) was optimized by response surface methodology (RSM), using the common low-cost agroindustrial waste (MP). HRJ16 laccase was further assessed for its advantageous biochemical and catalytic properties, and then applied in synthetic dye decolorization and denim bleaching. Results emphasized the extremotolerance of the exudate to temperature, pH, salts, cations and surfactants, when at least ca. 80 % residual activity was recollected after exposure to the different extreme operating conditions. The interesting capabilities of the HRJ16 in this study culminated in its successful bioscouring of denim fabric over 6 h and the spontaneous decolorization of the resultant effluent. This constitutive properties of HRJ16 might make it a crucial catalyst for achieving a circular bioeconomy in the textile industry.