Response surface methodology-based optimization of glucose acylation bio-catalyzed by immobilized lipase

Abstract

This paper describes in detail the selection and optimization of immobilized lipases for enhanced regioselective acylation of glucose into glucose monolaurate (GlcML). Initially, nature of biocatalyst, immobilization approach, reaction media, glucose, and lauric acid concentration were screened out. Finally, lipases from Rhizopus arrhizus immobilized on dead mycelia were investigated under various reaction conditions (Temperature, shaking speed, enzyme dose, and water content) following a fully rotatable central composite design (FRCCD) to optimize the activity of lipases. The immobilized lipases-based biocatalysts in the presence of polar solvents (tertiary alcohols) and higher concentrations of substrates i.e. glucose and lauric acid (100 and 300 mmol L⁻¹, respectively) offered conversion rate of 1.5 mmolmin⁻¹ L⁻¹. Moreover, optimization of reaction conditions revealed that 162.5 lipase units/100mL at 31.25 °C, 3% water content, and 105 RPM shaking speed enhanced the conversion rate by 0.5 mmolmin⁻¹ L⁻¹ rendering the reaction more economical. Hence, lipases-based immobilized biocatalysts may provide an intelligent and green choice for commercial scale synthesis of GlcML for food and pharmaceutical industries.

Keywords:

• Biocatalyst
• immobilization
• optimization
• acylation
• glucose monolaurate

Acknowledgements

The authors are grateful to Professor Dr. Anayt Hussain, Department of statistics, University of Agriculture, Faisalabad, for assisting statistical analysis of data. The Administration of Government College University, Lahore is greatly acknowledged for their financial assistance during present research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The Administration of Government College University, Lahore is acknowledged for their financial assistance during present research.