Elisée Ferré

Lipase-Catalyzed Syntheses of N-Octyl-Alkylamides in Organic Media

Abstract Various lipases can be used in anhydrous hexane to obtained N-octyl-alkylamides in moderate yields.

Lipase-catalyzed ester formation in organic solvents. Partial resolution of primary allenic alcohols

Abstract Candida cylindracea lipase catalyzes enantioselective esterifications of racemic primary allenic alcohols.

Reduction of allenic alcohols by Saccharomyces cerevisiae

Abstract α-Allenic alcohols are reduced by Saccharomyces cerevisiae into the corresponding β-ethylenic alcohols whereas β-allenic alcohols undergo an isomerization leading to their γ -acetylenic counterparts.

Microbial transformations: A stereoselective pathway to oxidize allenic alcohols

SummaryA bacterial strain, Pseudomonas aeruginosa (ATCC 17504), was selected to oxidize diversely substituted allenic alcohols. Primary α-allenic alcohols were oxidized to the corresponding acids with a ponderal yield varying from 60% to 90%. At the end of the experiment, the allenic chain was not altered, whereas absolute configurations were inverse for alcohol (S) and acid (R). This result corresponds to an enantiomeric separation of the initial racemic compound.An enantiomeric excess was also obtained with α-secondary and β-allenic alcohols. Substituents close to the allenic function decrease the ponderal yield.Existence of enzymes enable to recognize an axial chirality was shown.

Chemical characterization of the biomass of an edible medicinal mushroom, Agaricus subrufescens, via solid-state 13C NMR.

The biomass of 18 strains of Agaricus subrufescens and of 13 strains of Agaricus bisporus was chemically analyzed using solid-state (13)C NMR. The study focused on polysaccharides because they can play a major role as antitumor molecules. The study also examined whether biomass chemical properties varied between the vegetative mycelium and the fruiting bodies of A. subrufescens, and these data were compared with the mycelium of A. bisporus. Qualitative differences between vegetative mycelia and fruiting bodies were observed, whereas quantitative differences were measured between the two species with a higher percentage of polysaccharides in the biomass of A. subrufescens. This Agaricus species is thus an interesting potential source of polysaccharides with medicinal properties, both from vegetative mycelium obtained in liquid cultures and from fruiting bodies produced on composts.

Oxidation of α-allenic alcohols by yeast alcohol dehydrogenase

Abstract The kinetic constants (Km and Vm) of allenic alcohol oxidation by commercial alcohol dehydrogenase extracted from Saccharomyces cerevisiae (YADH) were compared to those measured for ethanol. For all the substrates DMF was used as solvent. Allenic chaining of butadienol does not induce any notable inhibition of the enzymatic reaction. The introduction of a substituent in the allenic alcohol molecule induces a decrease of enzymatic activity which becomes greater the closer substituent is located to the hydroxyl function.

Microbial Oxidation of Amines: A Preliminary Investigation on the Resolution of Racemic 1-Phenylethyl Amine

The microorganisms Pichia pastoris, Pichia membranaefaciens, Candida boidinii and Aureobasidium sp. were screened for their ability to use amine as a nitrogen source. The range of amines accepted varied from organism to organism. P. pastoris used f -unsubstituted amines, while the other three strains used transformed f -substituted amines like cyclohexyl, 2-butyl and 1-phenylethyl amines. Biotransformation occurred via an oxidative pathway leading mainly to the production of the corresponding ketones. Investigation of the kinetic resolution of racemic 1-phenylethyl amine showed that the optically pure ( S ) enantiomer was obtained with Aureobasidium sp. experiments, and that with P. membranaefaciens or C. boidinii, the ( R ) enantiomer could also be produced, but with lower stereoselectivity (52%<ee<70%). This resolution process constitutes a new method for the production of optically active amines.

Capacity for colonization and degradation of horse manure and wheat-straw-based compost by different strains of Agaricus subrufescens during the first two weeks of cultivation

The potential of Agaricus subrufescens strains to colonize and transform horse manure and wheat-straw-based mushroom compost under the physico-chemical conditions typically used for Agaricus bisporus was assessed. Lignocellulolytic activities, H2O2 production and substrate transformation (assessed via CP/MAS NMR of (13)C) for certain A. subrufescens strains were similar or even greater than those obtained for an A. bisporus strain used as control. Moreover, the functional diversity of the microbial communities of the substrate was not altered by the growth of A. subrufescens after 2weeks. These findings obtained with mesocosms simulating the incubation phase of the mushroom production process hold promise for the improvement of cultivation of this tropical Agaricus species on European standard mushroom compost.

Do spawn storage conditions influence the colonization capacity of a wheat-straw-based substrate by Agaricus subrufescens?

Storage conditions of the spawn of edible fungi are of major importance to facilitate the production of mushrooms. Here, standard storage conditions at 10°C or 15°C were used and the potential of colonization of standard European compost by the tropical species Agaricus subrufescens was assessed during the spawn running phase. Two lignocellulolytic activities, laccase and CMC-cellulase, were enhanced after storage compared to control as well as substrate transformation, as described by the aromaticity ratio and a humification ratio calculated from NMR data. This result indicates that mycelium growth probably occurred during storage at 10 or 15°C, leading to a larger amount of biomass in the inoculum. Moreover, the microbial functional diversity of the substrate was favored, showing that the electivity of the substrate was maintained. Thus, these findings indicate that recommendations for the mushroom producers can be established for A.xa0subrufescens cultivation under European standard conditions.

Evaluation of the Effect of Chemical or Enzymatic Synthesis Methods on Biodegradability of Polyesters

This work compares the biodegradability of polyesters produced by an esterification reaction between glycerol and oleic di-acid (D 18:1) issued from green chemical pathways, via either classical thermo-chemical methods, or an enzymatic method using the immobilized lipase of Candida antartica B (Novozym 435). An elastomeric polymer synthesized by enzymatic catalysis is more biodegradable than an elastomeric thermo-chemical polyester synthesized by a standard chemical procedure. This difference lies in percentage of the dendritic motifs, in values of the degree of substitution, and certainly in cross-links inducing an hyper-branched structure less accessible to the lipolytic enzymes in a waste treatment plant. However, when the elastomeric polymer synthesized by enzymatic catalysis is processed at high temperature as required for certain industrial applications, it presents an identical rate of biodegradation than the chemical polyester. The advantages of the thermo-chemical methods are greater speed and lower cost. Enzymatic synthesis appears be suited to producing polyesters, devoid of metallic catalysts, which must be used without processing at high temperature to keep a high biodegradability.