A strategic approach for direct recovery and stabilization of Fusarium sp. ICT SAC1 cutinase from solid state fermented broth by carrier free cross-linked enzyme aggregates

•Development of stable, robust and recyclable biocatalyst for industrial processes.•Direct recovery and stabilization of fungal cutinase from SSF broth by CLEA.•Easy and simple protocol for cutinase stabilization.•Effects of different additives on cutinase CLEA have been investigated.•Better operational, solvent, detergent stability with good recyclability was noted.

The major hurdles in commercial exploitation of cutinase (having both esterolytic and lipolytic activities) with potent industrial applications are its high production cost, operational instability and reusability. Although commercially available in immobilized form, its immobilization process (synthesis of support/carrier) makes it expensive. Herein we tried to address multiple issues of production cost, stability, and reusability, associated with cutinase. Waste watermelon rinds, an agroindustrial waste was considered as a cheap support for solid state fermentation (SSF) for cutinase production by newly isolated Fusarium sp. ICT SAC1. Subsequently, carrier free cross-linked enzyme aggregates of cutinase (cut-CLEA) directly from the SSF crude broth were developed. All the process variables affecting CLEA formation along with the different additives were evaluated. It was found that 50% (w/v) of ammonium sulphate, 125 μmol of glutaraldehyde, cross-linking for 1 h at 30 °C and broth pH of 7.0, yielded 58.12% activity recovery. All other additives (hexane, butyric acid, sodium dodecyl sulphate, Trition-X 100, Tween-20, BSA) evaluated presented negative results to our hypothesis. Kinetics and morphology studies confirmed the diffusive nature of cut-CLEA and BSA cut-CLEA. Developed CLEA showed better thermal, solvent, detergent and storage stability, making it more elegant and efficient for industrial biocatalytic process.

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