Purification and properties of an extracellular esterase from a cold-adapted Pseudomonas mandelii

Abstract

An extracellular esterase, EstK, was purified from the psychrotrophic bacterium Pseudomonas mandelii grown at 25°C. Prior to harvest, cells were treated with 0.2 M MgCl2 to precipitate lipopolysaccharides in the outer membranes, which otherwise form aggregates with the secreted enzymes. EstK was purified to homogeneity using standard procedures. It had substrate specificity towards esters of short-chain fatty acids, particularly, p-nitrophenyl acetate. Optimum activity of EstK was at 40°C; at 4°C the activity was ~50% of its maximum. EstK has a unique substrate preference for p-nitrophenyl acetate and remains active at low temperatures.

An Organic Solvent-Tolerant Alkaline Lipase from Cold-Adapted <i>Pseudomonas mandelii</i>: Cloning, Expression, and Characterization

“…[7][8][9] Here, we report the cloning, expression, and characterization of an organic solvent-tolerant alkaline lipase, LipS (GenBank ID JQ071496), from Pseudomonas mandelii JR-1. P. mandelii is a cold-adapted bacterium that grows at 4 C but not at 37 C, with an apparent optimum temperature range of 25-30 C. 10,11) To produce a clone, we utilized the genome sequence of Pseudomonas fluorescens Pf0-1, 12) which is closely related to P. mandelii, from among completed microbial genomes. The lipS gene was cloned using primers based on the non-coding region sequences surrounding the P. fluorescens Pf0-1 lipase gene (UniProt ID Q3KIU1).…”

A novel cold-adapted esterase from Enterobacter cloacae: Characterization and improvement of its activity and thermostability via the site of Tyr193Cys

“…These characteristics were similar to those of other reported cold-adapted esterases. For instance, a cold-adapted EstK cloned from Pseudomonas mandelii [ 18 – 20 ]. Phthalate ester hydrolase gene was identified from biofilms of a wastewater treatment plant shows activity at low temperatures [ 21 ].…”

Organic Solvent-Tolerant Esterase from Sphingomonas glacialisBased on Amino Acid CompositionAnalysis: Cloning and Characterization of EstSP2

“…Contrary to the long list of microbial lipases, only a few microbial esterases are known, with fewer reports of cold-adapted esterases [34]. Many esterases show substrate preference for pNP butyrate [35], with limited esterases having a substrate preference for two-carbon molecules [36,37]. As EstSP2 belongs to the esterase family VII like hCE1 and hCE2, we measured the hydrolysis of aspirin by EstSP2.…”