Hydrolysis of (R,S)2-aryl propionic esters by pure lipase B from Candida cylindracea

Relevance and bio-catalytic strategies for the kinetic resolution of ketoprofen towards dexketoprofen

This review presents the most relevant investigations concerning the biocatalytic kinetic resolution of racemic ketoprofen to dexketoprofen for the last 22 years. The advantages related to the administration of the dex-enantiomer in terms of human health, the so called "chiral switch" in the pharmaceutical industry and the sustainability of biotransformations have been the driving forces to develop innovative technology to obtain dexketoprofen. In particular, the kinetic resolution of racemic ketoprofen through enantiomeric esterification and hydrolysis using lipases as biocatalysts are thoroughly revised and commented upon. In this context, the biocatalysts, acyl-acceptors (alcohols), reaction conditions, conversion, enantiomeric excess, and enantiomeric ratio among others are discussed. Moreover, the investigations concerning scaling up processes in order to obtain an optically pure enantiomer of the profen are presented. Finally, some guidelines about perspectives of the technology and research opportunities are given.

Understanding Candida rugosa lipases: an overview

Candida rugosa lipase (CRL) is one of the enzymes most frequently used in biotransformations. However, there are some irreproducibility problems inherent to this biocatalyst, attributed either to differences in lipase loading and isoenzymatic profile or to other medium-engineering effects (temperature, a(w), choice of solvent, etc.). In addition, some other properties (influence of substrate and reaction conditions on the lid movement, differences in the glycosylation degree, post-translational modifications) should not be ruled out. In the present paper the recent developments published in the CRL field are overviewed, focusing on: (a) comparison of structural and biochemical data among isoenzymes (Lip1-Lip5), and their influence in the biocatalytical performance; (b) developments in fermentation technology to achieve new crude C. rugosa lipases; (c) biocatalytical reactivity of each isoenzyme, and methods for characterising them in crude CRL; (d) state-of-the-art of new applications performed with recombinant CRLs, both in CRL-second generation (wild-type recombinant enzymes), as well as in CRL-third generation, (mutants of the wt-CRL).

Covalent-Bonded Immobilization of Lipase on Poly(phenylene sulfide) Dendrimers and Their Hydrolysis Ability

Covalent-bonded immobilization of lipase from burkholderia cepacia onto two poly(phenylene sulfide) (PPS) dendrimers with different generations (two and three) was achieved using carbodiimide as a coupling reagent. The hydrolysis activity of olive oil to fatty acid was studied on enzyme-immobilized PPS dendrimers. Enzyme activity was proportional to the enzyme loading, and highest recovered activity was obtained at the medium enzyme loading for both G2 and G3 dendrimers. The immobilization improved the optimum pH and caused the temperature range to widen. Immobilization of enzyme has enhanced the thermal stability of enzyme activity in comparison with free enzyme. The immobilized enzyme as a biocatalyst for batch hydrolysis of olive oil retained 80 approximately 90% activity even after 20 times of recycling. This retention of activity after recycle is very valuable and powerful in enzyme technology. The present noteworthy and vital availability on enzyme reaction of the covalently bonded immobilized lipase on dendrimer came from the structure of dendrimer with a large number of functional terminal groups, which are easily available for immobilization of many lipases at the situation keeping reactive enzymes on the surface of dendrimer.

Immobilization of Candida rugosa lipase on a pH-sensitive support for enantioselective hydrolysis of ketoprofen ester

Candida rugosa lipase (Lipase OF) was immobilized by covalent binding to a pH-sensitive support showing reversibly soluble-insoluble characteristics with pH change. The immobilized lipase could carry out the enantioselective hydrolysis of ketoprofen ester in a soluble form yet be recovered after precipitation by simply adjusting pH. Its activity and enantioselectivity for hydrolysis of 2-chloroethyl ester of ketoprofen were enhanced 1.5-fold and 8.7-fold compared with those of free lipase. After eight catalytic cycles, the immobilized enzyme was still 46% active and its enantioselectivity remained unchanged.

Rational strategy for the production of new crude lipases from Candida rugosa

Candida rugosa was cultured using different inducers (oleic acid, olive oil, sunflower oil, n-dodecanol and glycerol) as the only carbon source in batch conditions, as well as in several fed-batch fermentations (oleic acid as inducer) at variable feed rate conditions. The N-terminal analysis of each crude lipase revealed that, while the isoenzymes Lip2 and Lip3 are always secreted (at different proportions depending on the inducer), Lip1 was produced only using n-dodecanol (batch conditions) or oleic acid (fed-batch at high feed rate). The nature of the inducer controls the isoenzyme percentage; when this is fixed, as well as the feed rate in fed-batch fermentation, the isoenzymatic profile remained unaltered and the samples differed only in the activity of the lipases, as determined by heptyl oleate synthesis.

Isolation of an esterase-producing Trichosporon brassicae and its catalytic performance in kinetic resolution of ketoprofen

A yeast strain CGMCC 0574, identified as Trichosporon brassicae, was selected from 92 strains for its high (S) selectivity in the hydrolysis of ketoprofen ethyl ester. The effective strains of the microorganisms were isolated from soil samples with the ester as the sole carbon source. The ethyl ester proved to be the best substrate for resolution of ketoprofen among several ketoprofen esters examined. The resting cells of CGMCC 0574 could catalyze the hydrolysis of ketoprofen ethyl ester with an enantiomeric ratio of 44.9, giving (S)-ketoprofen an enantiomeric excess of 91.5% at 42% conversion.Key words: ketoprofen, biocatalytic resolution, enantioselective hydrolysis, microbial esterase, Trichosporon brassicae.

Purification and characterization of Lip2 and Lip3 isoenzymes from a Candida rugosa pilot-plant scale fed-batch fermentation

Previous purification of a crude extracellular enzyme preparation from Candida rugosa ATCC 14830 pilot-plant fed-batch fermentations showed the presence of two lipase isoenzymes, Lip2 and Lip3, differing in their molecular masses (58 and 62 kDa, respectively). These enzymes were purified but the lipases were forming active aggregates with a molecular mass higher than 200 kDa. In this work we developed a purification method following three steps: ammonium sulfate precipitation, sodium cholate treatment and ethanol/ether precipitation, and anion exchange chromatography which allowed the sequential disaggregation of the isoenzymes. Pure and monomeric Lip2 and Lip3 were characterized according to pI, glycosylation and activity for p-nitrophenol esters and triacylglycerols of varying acyl chain. Lip3 was the best catalyst for the hydrolysis of the simple esters and triacylglycerols with short and medium acyl chains.

Characterization of the Candida rugosa lipase system and overexpression of the lip1 isoenzyme in a non-conventional yeast

The fungus C. rugosa produces lipase isoenzymes (CRLs) homologous to the Geotrichum candidum and Yarrowia lipolytica lipases to which they share ca. 40 and 30% sequence identity, with a domain of sequence conservation at the N-terminal half of the protein. CRL proteins have high sequence homology but are not identical in their catalytic activity, therefore calling for the resolution of isoforms via heterologous expression. The non-conventional use of a serine codon in several Candida species frustrates overexpression in the currently available host systems. The LIP1 gene, coding for the major CRL form, was therefore expressed in C. maltosa, a related fungus with the same codon usage as C. rugosa. A recombinant lipase was produced and secreted in an active form in the culture medium upon engineering the 5' and 3' ends of the gene.

Physiological control on the expression and secretion of Candida rugosa lipase

The fungus Candida rugosa secretes an extracellular lipase whose production is induced by the addition of fatty acids to the culture broth. This lipase is indeed composed by several protein isoforms partly differing in their catalytic properties. Synthesis and secretion of lipase proteins by C. rugosa cells were studied in culture media containing either glucose or oleic acid as the carbon source. It was shown that, according to their regulation, lipase-encoding genes might be grouped in two classes, one of which is constitutively expressed and the other is induced by fatty acids. The synthesis of inducible enzymes is inhibited at the level of transcription by the addition of glucose and, conversely, oleic acid appears to hinder the synthesis of the constitutive lipase. Growth conditions supporting high level expression both in batch and in continuous culture give rise to the intracellular accumulation of enzyme, possibly due to the existence of a rate-limiting step in the transport of the newly synthesized protein. These results suggest the possibility to develop fermentation processes aimed at the control of the enzyme composition.