A novel extracellular cold-active esterase of Pseudomonas sp. TB11 from glacier No.1: Differential induction, purification and characterisation

• Single cream was found as a good inducer for esterase to catalyze short and medium—a novel esterase from a psychrotolerant strain of glacier No.1 was purified and characterized.
• Chain fat.
• An improved zymography method was developed, which is simpler and faster.
• It was proved EstTB11 had potential application in flavor development of dairy products.

The production, purification, characterization and application of a novel cold active esterase by Pseudomonas sp. TB11 are described herein. A new finding regarding the production of extracellular esterase activity depending upon single cream as an inducer used for growth was investigated in this study. The crude esterase was subjected to a three-step enzyme purification, which resulted in a 15.21-fold purification and the specific activity of the final purified esterase increased to 1526.2 U/mg protein and purified EstTB11 had a molecular mass of 65 kDa. The N-terminal sequence of ten amino acids were: GVYDYKNLTT. Peptide mass finger printing revealed that some peptides showed homologues sequences (29%) to polyurethanase of Pseudomonas sp. FH4. Furthermore, the enzyme displayed the optimum pH of 8.5 and optimum temperature of 25 °C and significantly high stability at 15–35 °C for 72 h. The enzyme was incubated with different metal ions at concentrations of 5 and 10 mM, the activity of esterase was increased in the presence of K+, Na+ and Mg2+ and decreased with Ca2+, Al3+, Mn2+, and Fe3+. Experiments indicated that EstTB11 could hydrolyze milk fat to produce short and medium-chain fatty acid and this result layed the foundation for the application in increased aroma of milk products.

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