New Recombinant Cold-Adapted and Organic Solvent Tolerant Lipase from Psychrophilic Pseudomonas sp. LSK25, Isolated from Signy Island Antarctica

• Published in: International Journal of Molecular Sciences
• Main Authors: Leelatulasi Salwoom, Raja Noor Zaliha Raja Abd. Rahman, Abu Bakar Salleh, Fairolniza Mohd. Shariff, Peter Convey, Mohd Shukuri Mohamad Ali
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2019
• Subjects: Antarctica; cold adapted lipase; Pseudomonas sp. LSK25; purification; organic solvent tolerant; Antarctic; Signy Island; Signy Station; South Orkney Islands; Antarc*
• Online Access: https://doi.org/10.3390/ijms20061264

In recent years, studies on psychrophilic lipases have become an emerging area of research in the field of enzymology. The study described here focuses on the cold-adapted organic solvent tolerant lipase strain Pseudomonas sp. LSK25 isolated from Signy Station, South Orkney Islands, maritime Antarctic. Strain LSK25 lipase was successfully cloned, sequenced, and over-expressed in an Escherichia coli system. Sequence analysis revealed that the lipase gene of Pseudomonas sp. LSK25 consists of 1432 bp, lacks an N-terminal signal peptide and encodes a mature protein consisting of 476 amino acids. The recombinant LSK25 lipase was purified by single-step purification using Ni-Sepharose affinity chromatography and had a molecular mass of approximately 65 kDa. The final recovery and purification fold were 44% and 1.3, respectively. The LSK25 lipase was optimally active at 30 °C and at pH 6. Stable lipolytic activity was reported between temperatures of 5–30 °C and at pH 6–8. A significant enhancement of lipolytic activity was observed in the presence of Ca2+ ions, the organic lipids of rice bran oil and coconut oil, a synthetic C12 ester and a wide range of water immiscible organic solvents. Overall, lipase strain LSK25 is a potentially desirable candidate for biotechnological application, due to its stability at low temperatures, across a range of pH and in organic solvents.