Cloning, expression and characterization of a halotolerant esterase from a marine bacterium Pelagibacterium halotolerans B2T

Abstract

An esterase PE10 (279 aa) from Pelagibacterium halotolerans B2(T) was cloned and overexpressed in Escherichia coli Rosetta in a soluble form. The deduced protein was 29.91 kDa and the phylogenetic analysis of the deduced amino acids sequence showed it represented a new family of lipolytic enzymes. The recombinant protein was purified by Ni-NTA affinity chromatography column and the characterization showed its optimal temperature and pH were 45 °C and pH 7.5, respectively. Substrate specificity study showed PE10 preferred short chain p-nitrophenyl esters and exhibited maximum activity toward p-nitrophenyl acetate. In addition, PE10 was a halotolerant esterase as it was still active under 4 M NaCl. Three-dimensional modeling of PE10 suggested that the high negative electrostatic potential on the surface may relevant to its tolerance to high salt environment. With this halotolerance property, PE10 could be a candidate for industrial use.

Characterization of a novel hormone-sensitive lipase family esterase from Rhizomucor miehei with tertiary alcohol hydrolysis activity

“…Biochemical properties, in particular pH and temperature range and stability, determine the conditions under which a specific industrial process must operate [1]. The optimal pH of RmEstB is 7.5, which is similar to that of most other reported esterases [18,35,43], higher than that of a HSL esterase from Pyrobaculum calidifontis [4] and RmEstA from R. miehei [29], and lower than that of a HSL esterase from a soil DNA library [42] and EstK from P. mandelii [39]. Most microbial esterases exhibit narrow pH stabilities under alkaline conditions [11,38,44].…”

“…This is in contrast to other known esterases, whose activities are inhibited by one or two kinds of these organic solvents. For example, the esterase from P. halotolerans strain B2 is inhibited by acetonitrile and acetone [18], the esterase from a compost metagenomic library is inhibited by acetone [38], and the esterase from Bacillus sp. is inhibited by ethanol and propanol [35].…”

A Novel Cold Active Esterase from a Deep Sea Sponge Stelletta normani Metagenomic Library

“…Despite this there have been only a few reports of the identification of halotolerant or halophilic esterases in the literature. These include three halotolerant esterases EstKT4, EstKT7, and EstKT9 from a tidal flat sediment metagenomic library (Jeon et al, 2012), a halotolerant esterase (PE10) from the halophilic archaea Pelagibacterium halotolerans B2T (Jiang et al, 2012), a halophilic lipase (LipBL) from the moderately halophilic bacterium Marinobacter lipolyticus SM19 (Perez et al, 2011), and FIGURE 3 | Multiple sequence alignment of most closely related esterase sequences. The conserved GDSAG (GXSXG) and HGG motifs are shown in the black boxes.…”

A halotolerant aldose reductase from Debaryomyces nepalensis: gene isolation, overexpression and biochemical characterization

“…23 Conversely, DnAR was susceptible to Cu 2+ toxicity as like enzymes from C. tropicalis and C. parapsilosis. 23,32 Cu 2+ is known to exert its effect by induction of site specic oxidation in human aldose reductase 25 and probably the same mechanism might be applicable for DnAR.…”

“…Similarly, the halotolerant esterase from a marine bacterium Pelagibacterium halotolerans has been shown to have more negative surface electrostatic potential than the non-halotolerant esterase from Alicyclobacillus acidocaldarius. 32 A halotolerant carbonic anhydrase has been shown to have uniform negative surface electrostatic potential as seen in DnAR. 41 The presence of high number of acidic amino acids on the surface of the protein imparts negative surface electrostatic potential, thereby confers halotolerane to the protein.…”