The aim of this study was the evaluation of two different procedures for the one‐pot transformation of oil extracted from Citrus limon seeds to a mixture of fatty acid methyl esters (FAMEs) and glycerol derivatives for application as a potential biofuel. Lemon seed oil was obtained by Soxhlet extraction. The first procedure was realized by efficient irreversible transesterification of the oil in hexane by lipase B from Candida antarctica (Novozym 435 ® ) using dimethyl carbonate as the alcohol donor. For the realization of the second methodology an acid‐catalyzed transformation was carried out, dissolving the seed oil in methyl tert ‐butyl ether in a microwave tube using Amberlyst ® ‐36 dry form catalyst. Both procedures, in optimized conditions, led to the complete conversion of the triglycerides to give the corresponding FAMEs and a mixture of glycerol derivatives. The absence of free glycerol in the final mixtures makes the two herein described procedures considerably advantageous in terms of both cost and sustainability since they enable performance of the production of FAMEs without requiring steps to remove glycerol. These final mixtures may be used in the energy chain and exploited as biofuels. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons, Ltd.

A microbial fuel cell (MFC) is an anaerobic bioreactor where soluble metabolites liberated by hydrolysis and fermentation of macromolecules are simultaneously available for anode respiring bacteria (ARB). ARB can be influenced by chemical imbalances in the liquid phase of the bioreactor. The objective of the work was to explore the trend of electric signals generated by MFCs, in relation to anaerobic biodegradation of four different solid food industry residual substrates. Four sets of membraneless single-chamber MFCs were operated in batch mode, with solid waste substrates characterized by a different base component: i) mixed kitchen waste (fibers), ii) whey from dairy industries (sugar), fisheries residues previously processed to recover oils (proteins), iv) pulp waste from citrus juice production (acidic).All the tested MFCs were able to produce an electric output with different trends, depending on the principal component of the solid substrate. MFC potential varied as function of the COD and the feeding cycle, as well as of the substrate.The pH variability during the fermentative process significantly affected the electric output. Citrus (acidic) pulp fed MFCs started to operate only when the pH raised up 6.5. MFCs fed with mix kitchen wastes had a relatively stable electric signal; fish based waste caused spiking in the MFC signal and an averaging in the COD degradation trend. This phenomenon was attributed to a pH instability induced by proteins degradation forming ammonia.The fermentation process was strongly predominant with respect the electrochemical process in MFCs and the coulombic efficiency (CE) was low, ranging between 2 and 10%. This result call for a deeper exploration of harvesting power from solid wastes and pointed also to the possibility of using a MFC to monitor important parameters of fermentation processes in biotech production plants. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

For the first time, a bacterial strain expressing a nitrile hydratase/amidase activity was able to recognize a planar element of chirality: Rhodococcus rhodochrous PA-34 whole cells catalysed with a high level of enantioselectivity the biotransformation of a novel nitrile ferrocene derivative into its corresponding amide and/or acid. An important parameter in the enzymatic recognition is the choice of the inducer selected for the bacterial growth phase.

Bifidobacterium spp. can produce cell-bound or released exopolysaccharide (EPS) that is a beneficial trait mediating commensal-host interactions. However differences in the physico-chemical characteristics of EPS produced by different strains of Bifidobacterium spp. are determinant in adhesion ability and modulation of immune response. The aim of this study was to investigate the in vitro adhesion characteristics of Bifidobacterium longum W11 to intestinal epithelial cell-line HT-29, by Scanning Electron Microscopy (SEM), and chemical characteristics of its exopolysaccharide using Thin-Layer Chromatography (TLC) analysis. SEM observation showed a good adhesion of B. longum W11 to the HT-29 monolayer that could be increased by the production of exocellular polymers formation. TLC analysis of the purified and hydrolyzed EPS showed that the cell-surface and extracellular polysaccharide were composed mainly of fructose and glucose. Moreover, other sugars were present in smaller quantities. Information from this study on physico-chemical characteristics of EPS of B. longum W11 could contribute to understanding the physiology of bifidobacteria and their interaction with the host.

12 STROMELYSIN-l (MMP-3) REGULATION BY BIG ENDOTHELIN1 (BIG ET-l) IN HUMAN OSTEOARTHRITIC (OA) CHONDROCYTES M Roy-Beaudry!, J Martel-Pelletier!, JC Filep2, JP Pelletier!, F Shipkolye! and F Moldovan! IOsteoarthritis Research Unit, Research Centre University of Monteal Hospital Centre, Department of Medicine University of Montreal, Notre Dame Hospital, 1560 Sherbrooke Street, East, Montreal, H2L 4MI, Canada and 'Research Center, Maisonneuve-Rosemont Hospital and Department of Medicine, University of Montreal, 5415 Boulevard de I'Assomption, Montreal, HIT 2M4, Canada

For the first time, two bacterial strains expressing a nitrile hydratase/amidase activity were able to recognize the ferrocene framework: Rhodococcus erythropolis A4 and Rhodococcus rhodochrous PA-34. Important parameters for the enzymatic recognition are the specific structural features of the substrates, and the inducers adopted during the bacterial growth phase.

alpha-Linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been subjected to esterification with ethanol in presence of lipase B from Candida antarctica (Novozym 435®), in solvent free condition. The use of alcohol donors triethyl orthoformate (TEOF) or diethyl carbonate (DEC) instead of free ethanol, allowed working in irreversible esterification conditions and ALA-, EPA- and DHA-ethyl esters were obtained in quantitative yields.

A variety of novel cyano-cyclitols possessing complex stereochemistry have been synthesized. These compounds were subjected to the biocatalyzed hydrolysis of their nitrile groups. The bacterial strain Rhodococcus erythropolis A4, expressing a nitrile hydratase/amidase bienzymatic system, was able to recognize (1R,2S,3S,4R)/(1S,2R,3R,4S)-1-cyano-2,3,4-trihydroxy-cyclohex-5-ene and trans-3-cyanocyclohexa-3,5-diene-1,2-diol, and catalyze their transformations into the corresponding amides and acids. The kinetic and stereochemical trends of these biotransformations, a rare example of the enantiorecognition of a rigid bulky aliphatic substrate, are discussed.

A new route to synthesize cyclophellitol and epi-cyclophellitol from racemic starting materials in enantiopure forms has been developed. The synthesis involves a multi-enzymatic biotransformation pathway of the novel cyano-cyclitol (1R,4S,5R,6R)/(1S,4R,5S,6S)-4,5,6-trihydroxycyclohex-2-enecarbonitrile by a cooperative use of lipase, nitrile hydratase, and amidase.

Dimethyl carbonate was used as alcohol donor in the esterification of naproxen in the presence of immobilised lipase B from Candida antarctica (Novozym 435). The conjugation of hydrolysis of dimethyl carbonate and esterification of acid, created irreversible operative conditions so permitting the recovery of S-naproxen in high ee (>98%). The adopted procedure has a general use.

The photodegradation of the S(+)- and R(-)-ketoprofen (KP) enantiomers in the bovine serum albumin matrix was studied by steady-state photolysis with the use of lambda(irr) > 320 nm and transient absorption spectroscopy with lambda(exc) = 355 nm, at 1/1 and 2/1 KP/BSA molar ratios. R(-)-KP was found to be more labile than S(+). Triplet ketoprofen species were evidenced with lifetimes of 400 ns for S(+) and 600 ns for R(-)-KP. Further longer-lived transients with lifetimes of 2.6 and 6.0 mus for S(+) and R(-), respectively, were detected. On the basis of the binding constants of the drug enantiomers to the two main binding sites of the protein, obtained from circular dichroism experiments, the individual disappearance quantum yields of the 1:1 and 2:1 diastereomeric KP:BSA complexes could be estimated. The photoreactivity in the BSA matrix was rationalized on the basis of diastereoselective photodecarboxylation in the two main protein sites.

A combined approach using global analysis of circular dichroism multiwavelength data and time resolved fluorescence was applied to investigate the interaction of R-(-)- and S-(+)- ketoprofen with bovine serum albumin in buffer solution at neutral pH. A characterization of the most stable drug : protein adducts of 1 : 1 and 2 : 1 stoichiometry, as individual chemical species, was obtained. The stability constants and the absolute circular dichroism spectra of the diastereomeric complexes were determined. The spectra of the 1 : 1 conjugates are opposite in sign, those of the 2 : 1 complexes are both negative, but different in shape from each other ( peaks at 358 and 342 nm for S-( +)- and R-(-)- ketoprofen, respectively). A tryptophan residue was shown to be involved in the binding of the drug, in the primary site for the R-( -) and in the secondary site for the S-( +) enantiomer, thereby showing that chiral recognition by the protein causes the site of highest affinity being not the same for both optical antipodes.

Lipase from Candida antarctica has been successfully used to realise the selective esterification of the four 1-(1-hydroxyethyl)-3-ethylferrocene isomers, possessing central/planar chirality. In this reaction, the lipase recognises only the two isomers possessing an (R)-configuration, independently from planar chirality. This allows us to split the mixture into two couples of diastereoisomers, namely the (Sp,Rc)-/(Rp,Rc)- and (Rp,Sc)-/(Sp,Sc)-isomers, conveniently separated in the single constituents by crystallisation from hexane.

The 2-arylpropionic acid derivatives or ‘profens’ are an important group of non-steroidal anti-inflammatory drugs that have been used for the symptomatic treatment of various forms of arthritis. These compounds are chiral and the majority of them are still marketed as racemate although it is known that the (S)- form is the principal effective in the cyclooxygenase inhibition. However, recent findings suggest that certain pharmacological effect of 2-arylpropionic acids cannot be attributed exclusively to the (S)-(+) enantiomer. To obtain further insights into the pharmacological effect of profens, the present study investigated the influence of racemic and pure enantiomers of flurbiprofen on the production of nitric oxide and glycosaminoglycans, key molecules involved in cartilage destruction. The culture of human articular cartilage stimulated by interleukin-1β (IL-1β), which plays an important role in the degradation of cartilage, has been established, as a profit experimental model, for reproducing the mechanisms involved in the pathophysiology of arthritic diseases. Our results show that mainly (S)-(+)-flurbiprofen decreases, at therapeutically concentrations, the IL-1β induced cartilage destruction.

The reversible nature of the direct esterification of acids with alcohols limits the use of this process in the biocatalytic kinetic resolution of chiral acids. A new irreversible procedure, using orthoesters, has been developed.

The activity of different formulations of Candida antarctica lipase B (CALB), such as crude CALB, purified CALB, purified CALB lyophilized with PEG (CALB + PEG) or oleic acid (CALB + OA), and the commercial formulation Novozym 435, was determined in toluene, carbon tetrachloride, and 1,4-dioxane at various water activities (a(w)). The reaction between vinylacetate and 1-octanol was used as the model reaction and both transesterification (formation of 1-octylacetate) and hydrolytic (formation of acetic acid from vinylacetate) activities were determined. For equal amounts of lipase protein, CALB + PEG (and to a lesser extent CALB + OA) displayed higher activity than that of the other formulations; for instance, in toluene (a(w) < 0.1), it was 260-, 13-, and 1.8-fold more active than crude CALB, purified CALB, and Novozym 435, respectively. Moreover, the transesterification activity of CALB + PEG was of the same order of magnitude (51%) of the activity shown by the enzyme in the hydrolysis of vinylacetate in aqueous buffer. These results suggest that PEG and oleic acid could act as lyoprotectants, preventing the formation of intermolecular interactions during the lyophilization process that might be responsible for protein denaturation. No diffusional limitation was observed for CALB + PEG-catalyzed reactions. Purified CALB, in contrast to the other formulations, showed a marked activity increase (2.1 to 7.8-fold) as a function of a(w) and, in 1,4-dioxane, it was 3.5-fold more active when it was added to the solvent after previous dissolution of the lyophilized powder in water.