Immobilisation of lipase from Candida rugosa on layered double hydroxides of Mg/Al and its nanocomposite as biocatalyst for the synthesis of ester

Synthesis of layered double hydroxides (LDHs) of Mg/Al-NO3− and Mg/Al-sodium dodecyl sulphate (SDS) of molar ratio of Mg/Al (4:1) were done by co-precipitation through continuous agitation. Their structures were determined using X-ray diffractometer (XRD). The spectra showed that basal spacing for synthesized Mg/Al-NO3− and Mg/Al-SDS were around 7.8 and 34.3 Å, respectively. The expansion of layered structure was observed to accommodate the surfactant anion between the interlayer for the Mg/Al-SDS. Lipase from Candida rugosa was immobilised onto these materials by physical adsorption method. The percentage of protein loaded into Mg/Al-SDS (70.8%) is higher than Mg/Al-NO3− (36.9%). The synthesis of butyl oleate using immobilised lipase as biocatalyst was investigated through esterification of oleic acid and 1-butanol as substrate and hexane as reaction medium. The effects of surface area, reaction temperature, thermal stability, leaching study, stability in organic solvent and storage were investigated. The stability was found to be the highest in the Mg/Al-SDS.