1. Recombinant Expression and Characterization of a Novel Thermo-Alkaline Lipase with Increased Solvent Stability from the Antarctic Thermophilic Bacterium Geobacillus sp. ID17.
- Author
-
Salas-Bruggink D, Guzmán H, Espina G, and Blamey JM
- Subjects
- Antarctic Regions, Hydrogen-Ion Concentration, Bacterial Proteins genetics, Bacterial Proteins chemistry, Bacterial Proteins metabolism, Kinetics, Substrate Specificity, Temperature, Escherichia coli genetics, Escherichia coli metabolism, Geobacillus enzymology, Geobacillus genetics, Lipase genetics, Lipase chemistry, Lipase metabolism, Lipase isolation & purification, Enzyme Stability, Solvents chemistry, Recombinant Proteins chemistry, Recombinant Proteins metabolism, Recombinant Proteins genetics
- Abstract
Lipases are enzymes that hydrolyze long-chain carboxylic esters, and in the presence of organic solvents, they catalyze organic synthesis reactions. However, the use of solvents in these processes often results in enzyme denaturation, leading to a reduction in enzymatic activity. Consequently, there is significant interest in identifying new lipases that are resistant to denaturing conditions, with extremozymes emerging as promising candidates for this purpose. Lip7, a lipase from Geobacillus sp. ID17, a thermophilic microorganism isolated from Deception Island, Antarctica, was recombinantly expressed in E. coli C41 (DE3) in functional soluble form. Its purification was achieved with 96% purity and 23% yield. Enzymatic characterization revealed Lip7 to be a thermo-alkaline enzyme, reaching a maximum rate of 3350 U mg
-1 at 50 °C and pH 11.0, using p-nitrophenyl laurate substrate. Notably, its kinetics displayed a sigmoidal behavior, with a higher kinetic efficiency ( kcat / Km ) for substrates of 12-carbon atom chain. In terms of thermal stability, Lip7 demonstrates stability up to 60 °C at pH 8.0 and up to 50 °C at pH 11.0. Remarkably, it showed high stability in the presence of organic solvents, and under certain conditions even exhibited enzymatic activation, reaching up to 2.5-fold and 1.35-fold after incubation in 50% v / v ethanol and 70% v / v isopropanol, respectively. Lip7 represents one of the first lipases from the bacterial subfamily I.5 and genus Geobacillus with activity and stability at pH 11.0. Its compatibility with organic solvents makes it a compelling candidate for future research in biocatalysis and various biotechnological applications.- Published
- 2024
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