Key Proteomics Tools for Fundamental and Applied Microalgal Research.

Microscopic, photosynthetic prokaryotes and eukaryotes, collectively referred to as microalgae, are widely studied to improve our understanding of key metabolic pathways (e.g., photosynthesis) and for the development of biotechnological applications.

Impact of nitrogen deficiency on succinic acid production by engineered strains of Yarrowia lipolytica.

Yarrowia lipolytica strains PGC01003 and PGC202 engineered for succinic acid production were studied and compared to the wild type strain W29. For the first time, these two strains were characterized in a chemically defined medium. Strain growth and organic acid production were investigated in fed-batch mode with glycerol as carbon and energy source.

A dansyl-derivatized phytic acid analogue as a fluorescent substrate for phytases: experimental and computational approach.

A new myo-inositol pentakisphosphate was synthesized, which featured a dansyl group at position C-5. The fluorescent tag was removed from the inositol by a 6-atom spacer to prevent detrimental steric interactions in the catalytic site of phytases. The PEG linker was used in order to enhance hydrophilicity and biocompatibility of the new artificial substrate.

Lipase-Catalyzed Ring-Opening Polymerization of Benzyl Malolactonate: An Unusual Mechanism?

The use of safe natural catalyst such as enzymes for ring opening polymerization (ROP) of β-substituted β-lactones such as benzyl malolactonate (MLABe) is an important objective considering the biomedical applications of the resulting (co)polymers. However, the preparation of well-defined polymeric materials using such systems requires an understanding of enzyme-substrate interactions. In this context, we investigated the mechanism of lipase-catalyzed ROP of MLABe, because it appears that it is probably not the same as the one widely described for other lactones such ε-caprolactone, propiolactone.

Interactions between trans-resveratrol and CpLIP2 lipase/acyltransferase: Evidenced by fluorescence and in silico.

We have examined the trans-resveratrol/lipase interaction by quantitative and qualitative analyses of fluorescence spectra, molecular docking and quantum-chemical calculations at DFT level. Interactions of CpLIP2 from C. parapsilosis CBS 604 and trans-resveratrol were confirmed with a major contribution of tryptophan residues to fluorescence quenching.

Effective Catalytic Delignification and Fractionation of Lignocellulosic Biomass in Water over ZnVO Mixed Oxide.

The conversion of poplar wood biomass to highly value-added chemicals and molecular building blocks was achieved by using the dispersed mixed oxide ZnVO (ZVO) in water under 100 kPa of 10% O/N at 160, 180, and 200 °C for 4 h. This nanostructured mixed oxide was prepared via the precipitation process and then characterized by several techniques. The results showed that this mixed oxide has interesting catalytic properties and is a versatile catalyst for biomass delignification and lignin and hemicellulose depolymerization.

Inhibition of CpLIP2 Lipase Hydrolytic Activity by Four Flavonols (Galangin, Kaempferol, Quercetin, Myricetin) Compared to Orlistat and Their Binding Mechanisms Studied by Quenching of Fluorescence.

The inhibition of recombinant CpLIP2 lipase/acyltransferase from was considered a key model for novel antifungal drug discovery and a potential therapeutic target for candidiasis. Lipases have identified recently as potent virulence factors in and some other yeasts. The inhibition effects of orlistat and four flavonols (galangin, kaempferol, quercetin and myricetin) characterized by an increasing degree of hydroxylation in B-ring, were investigated using ethyl oleate hydrolysis as the model reaction.

Furanolysis with Menthofuran: A New Depolymerization Method for Analyzing Condensed Tannins.

An improved analytical depolymerization method for characterizing condensed tannins was developed with menthofuran (3,6-dimethyl-4,5,6,7-tetrahydro-1-benzofuran) as the nucleophilic trapping reagent. Herein, menthofuran was compared with routinely used nucleophiles, phloroglucinol and 2-mercaptoethanol. At 30 °C and in the presence of 0.

Cell Uptake and Biocompatibility of Nanoparticles Prepared from Poly(benzyl malate) (Co)polymers Obtained through Chemical and Enzymatic Polymerization in Human HepaRG Cells and Primary Macrophages.

The design of drug-loaded nanoparticles (NPs) appears to be a suitable strategy for the prolonged plasma concentration of therapeutic payloads, higher bioavailability, and the reduction of side effects compared with classical chemotherapies. In most cases, NPs are prepared from (co)polymers obtained through chemical polymerization. However, procedures have been developed to synthesize some polymers via enzymatic polymerization in the absence of chemical initiators.

Characterization and Reshaping of a Large and Hydrophobic Nucleophile Pocket in Lipases/Acyltransferases.

Lipases/acyltransferases, such as CpLIP2 from Candida parapsilosis and CduLAc from Candida dubliniensis, catalyze acyl transfer preferentially over hydrolysis if a suitable nucleophile is present, even in a medium with a high thermodynamic activity of water (a ). These enzymes are related to CAL-A from Moesziomyces antarcticus, which, in comparison, displays a lower acyl transfer ability. The 3D structures of wild types and mutants of CAL-A, CpLIP2, and CduLAc revealed differences in size and hydrophobicity of a large pocket located under the catalytic triad.

Fucoxanthin and Polyunsaturated Fatty Acids Co-Extraction by a Green Process.

By their autotrophic nature and their molecular richness, microalgae are serious assets in the context of current environmental and societal challenges. Some species produce both omega-3 long chain polyunsaturated fatty acids (PUFAs) and xanthophylls, two molecular families widely studied for their bioactivities in the fields of nutrition and cosmetics. Whereas most studies separately deal with the two families, synergies could be exploited with extracts containing both PUFAs and xanthophylls.

Mechano-Enzymatic Deconstruction with a New Enzymatic Cocktail to Enhance Enzymatic Hydrolysis and Bioethanol Fermentation of Two Macroalgae Species.

The aim of this study was to explore the efficiency of a mechano-enzymatic deconstruction of two macroalgae species for sugars and bioethanol production, by using a new enzymatic cocktail (Haliatase) and two types of milling modes (vibro-ball: VBM and centrifugal milling: CM). By increasing the enzymatic concentration from 3.4 to 30 g/L, the total sugars released after 72 h of hydrolysis increased (from 6.

A glimpse into the specialization history of the lipases/acyltransferases family of CpLIP2.

Lipases/acyltransferases homologous to CpLIP2 from Candida parapsilosis belong to the α/β hydrolase superfamily as lipase A from Moesziomyces antarcticus (Candida antarctica), and constitute a consistent phylogenetic subgroup with at least 56% identity. Lipases/acyltransferases share the phenotypic characteristic of a high acyltransfer activity even in aqueous media with very high water thermodynamic activity. Previous mutagenesis and evolution strategies have given insights into the role of key residues and protein subdomains in the reaction and substrate specificities of these enzymes.

Revealing the Roles of Subdomains in the Catalytic Behavior of Lipases/Acyltransferases Homologous to CpLIP2 through Rational Design of Chimeric Enzymes.

The lipases/acyltransferases homologous to CpLIP2 of Candida parapsilosis efficiently catalyze acyltransfer reactions in lipid/water media with high water activity (a >0.9). Two new enzymes of this family, CduLAc from Candida dubliniensis and CalLAc8 from Candida albicans, were characterized.

Biodiesel production from crude jatropha oil catalyzed by immobilized lipase/acyltransferase from Candida parapsilosis in aqueous medium.

The lipase/acyltransferase from Candida parapsilosis (CpLIP2) immobilized on two synthetic resins (Accurel MP 1000 and Lewatit VP OC 1600) was used as catalyst for the production of biodiesel (fatty acid methyl esters, FAME) by transesterification of jatropha oil with methanol, in a lipid/aqueous system. The oil was dispersed in a buffer solution (pH 6.5) containing methanol in excess (2M in the biphasic system; molar ratio methanol/acyl chains 2:1).

Elucidation of a key position for acyltransfer activity in Candida parapsilosis lipase/acyltransferase (CpLIP2) and in Pseudozyma antarctica lipase A (CAL-A) by rational design.

Performing transesterifications in aqueous media is becoming a priority challenge in lipid biotechnology in order to develop more eco-friendly and efficient biocatalytic processes in systems containing both polar and apolar substrates. In this context, our group has explored for several years the high potential of the lipase/acyltransferase CpLIP2 from Candida parapsilosis and of several of its homologs, that catalyze efficiently acyltransfer reactions in lipid/water media with high water activity (aw>0.9).

The 3D model of the lipase/acyltransferase from Candida parapsilosis, a tool for the elucidation of structural determinants in CAL-A lipase superfamily.

Because lipids are hydrophobic, the development of efficient bioconversions in aqueous media free of organic solvents is particularly challenging for green oleochemistry. Within this aim, enzymes exhibiting various abilities to catalyze acyltransfer reaction in water/lipid systems have been identified. Among these, CpLIP2 from Candida parapsilosis has been characterized as a lipase/acyltransferase, able to catalyze acyltransfer reactions preferentially to hydrolysis in the presence of particularly low acyl acceptor concentration and high thermodynamic activity of water (aw>0.

The mitochondrial-targeted antioxidant, MitoQ, increases liver mitochondrial cardiolipin content in obesogenic diet-fed rats.

Cardiolipin (CL), a unique mitochondrial phospholipid, plays a key role in several processes of mitochondrial bioenergetics as well as in mitochondrial membrane stability and dynamics. The present study was designed to determine the effect of MitoQ, a mitochondrial-targeted antioxidant, on the content of liver mitochondrial membrane phospholipids, in particular CL, and its fatty acid composition in obesogenic diet-fed rats. To do this, twenty-four 6week old male Sprague Dawley rats were randomized into three groups of 8 animals and fed for 8weeks with either a control diet, a high fat diet (HF), or a HF diet with MitoQ (HF+MitoQ).

Grape seed and apple tannins: emulsifying and antioxidant properties.

Tannins are natural antioxidants found in plant-based foods and beverages, whose amphiphilic nature could be useful to both stabilize emulsions and protect unsaturated lipids from oxidation. In this paper, the use of tannins as antioxidant emulsifiers was studied. The main parameters influencing the stability of emulsions (i.

Homologous yeast lipases/acyltransferases exhibit remarkable cold-active properties.

Lipases/acyltransferases catalyse acyltransfer to various nucleophiles preferentially to hydrolysis even in aqueous media with high thermodynamic activity of water (a w >0.9). Characterization of hydrolysis and acyltransfer activities in a large range of temperature (5 to 80 °C) of secreted recombinant homologous lipases of the Pseudozyma antarctica lipase A superfamily (CaLA) expressed in Pichia pastoris, enlighten the exceptional cold-activity of two remarkable lipases/acyltransferases: CpLIP2 from Candida parapsilosis and CtroL4 from Candida tropicalis.

High-cell-density cultivation of recombinant Escherichia coli, purification and characterization of a self-sufficient biosynthetic octane ω-hydroxylase.

We have recently described the biocatalytic characterization of a self-sufficent biosynthetic alkane hydroxylase based on CYP153A13a from Alcanivorax borkumensis SK2 (thereafter A13-Red). Despite remarkable regio- and chemo-selectivity, A13-Red suffers of a difficult-to-reproduce expression and moderate operational stability. In this study, we focused our efforts on the production of A13-Red using high-cell-density cultivation (HCDC) of recombinant Escherichia coli.

Comparative study of the mesostructure of natural and synthetic polyisoprene by size exclusion chromatography-multi-angle light scattering and asymmetrical flow field flow fractionation-multi-angle light scattering.

This paper presents results from the first analyses of the mesostructure of natural rubber (NR) by asymmetrical flow field flow fractionation (AF4). The results are compared with those obtained by size exclusion chromatography (SEC) in terms of average molar masses, radius of gyration and insoluble part (or gel quantity). Comparable results were obtained for the sample not containing gel.

Glycolipid composition of Hevea brasiliensis latex.

Glycolipids of fresh latex from three clones of Hevea brasiliensis were characterized and quantified by HPLC/ESI-MS. Their fatty acyl and sterol components were further confirmed by GC/MS after saponification. The four detected glycolipid classes were steryl glucosides (SG), esterified steryl glucosides (ESG), monogalactosyl diacylglycerols (MGDG) and digalactosyl diacylglycerols (DGDG).

Characterization of oxidized tannins: comparison of depolymerization methods, asymmetric flow field-flow fractionation and small-angle X-ray scattering.

Condensed tannins are a major class of plant polyphenols. They play an important part in the colour and taste of foods and beverages. Due to their chemical reactivity, tannins are not stable once extracted from plants.

High-level expression of Candida parapsilosis lipase/acyltransferase in Pichia pastoris.

Candida parapsilosis has been previously shown to produce a lipase/acyltransferase (EC 3.1.1.