Immobilization of recombinant E. coli thermostable lipase by entrapment inside silica xerogel and nanocarbon-in-silica composites

• Published in: Journal of molecular catalysis. B, Enzymatic Enzymatic, 2013-12, Vol.98, p.78-86
• Main Authors: Kovalenko, Galina A., Beklemishev, Anatoly B., Perminova, Larisa V., Mamaev, Aleksey L., Rudina, Nina A., Moseenkov, Sergey I., Kuznetsov, Vladimir L.
• Format: Article
• Language: English
• Subjects: bacteria; biocatalysts; carbon nanotubes; catalytic activity; Entrapment; enzyme activity; Escherichia coli; Heterogeneous biocatalysts; hydrolysis; Nanocarbon-in-silica composites; olive oil; Recombinant strain-producer rE.coli/lip; silica; thermal stability; Thermomyces lanuginosus; Thermostable lipase; triacylglycerols
• ISSN: 1381-1177; 1873-3158
• DOI: 10.1016/j.molcatb.2013.09.022

•Recombinant strain rE.coli/lip was constructed for producing thermostable lipase.•Lysates of rE.coli/lip were entrapped inside silica- or nanocarbon-in-silica xerogel.•Carbon nanotubes and “nano-onion” included had effect on the biocatalysts’ activity.•The best positive effect of aggregated “thick” nanotubes on activity was observed.•The heterogeneous biocatalysts were studied in oil-fat blend interesterification at 75°C. The multi-component heterogeneous biocatalysts were prepared by entrapment of whole cells or cells’ lysates of a recombinant strain Escherichia coli producing of thermostable lipase from Thermomyces lanuginosus (rE.coli/lip) inside silica xerogel and nanocarbon-in-silica composites. The properties of intracellular recombinant lipase and the prepared heterogeneous biocatalysts, such as enzymatic activity and stability, were studied in periodic process of triglycerides’ hydrolysis and interesterification. The thermal stability of recombinant lipase was studied by the heating bacteria rE.coli/lip in a buffer and olive oil at 60–100°C. The effects of nanocarbons included inside SiO2-xerogel, such as multi-walled carbon nanotubes with different diameters and dispersity, and “nano-onion”, on the properties of multi-component biocatalysts were investigated. The {nanocarbon-in-silica} biocatalysts prepared by entrapping cells’ lysates of rE.coli/lip together with aggregated “thick” nanotubes (20–22nm in diameter) were found to possess the highest hydrolytic activity close to 1000LU/g. The activity of composite biocatalysts containing cells’ lysates of rE.coli/lip and dispersed “thin” nanotubes (9–11nm in diameter) did not exceed 400LU/g. The similar effect of nanocarbons’ inclusion inside multi-component biocatalysts on the activities of entrapped whole cells, cells’ lysates and purified recombinant lipase was revealed.