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Vanillin (4-hydroxy-3methoxybenzaldehyde) is one of the most employed aromatic and flavoring additives in food and cosmetic industry. The industrial interest in vanillin could also apply to its biodegradation products. The microbial transformation of vanillin can open the possibility of new products with new areas of application for products related to vanillin. For example, vanillyl alcohol, vanillic acid and ferulic acid are currently used in the pharmaceutical or food industry. Some species reported to biodegrade vanillin into the related products vanillyl alcohol and vanillic acid, are: Brettanomyces anomalus and Saccharomyces cerevisiae. Moreover, certain microorganisms possess the ability to accumulate lipids when cultivated on different carbon sources, opening the possibility of microbial lipid production as another industrial application. The present investigation focuses on the optimization of extraction methods for vanillin biodegradation products, as well as identifying the isolates of a collection of microorganisms originating from the Faroe Islands that are amenable to being cultivated on a lignin-based media. Finally, the potential for microbial lipid accumulation was also studied. Two analytical methods, Thin-Layer Chromatography (TLC) and Gas Chromatography (GC) were employed for characterizing the biodegradation products obtained after 24 hours and 72 hours of culture in growth medium supplemented with 1 mM of vanillin. The results showed that after 24 hours of incubation, the model microorganism, strain FMYD002, had consumed some of the vanillin and transformed it into biodegradation products. TLC retention factors and GC chromatograms revealed that the main biodegradation product after 24 hours - when compared to a standard – is likely to be to vanillyl alcohol. Furthermore, vanillin and its biodegradation products were relatively temperature-stable based on a temperature test of supernatant from a 24-hour culture, however, when the 72-hour culture had been subjected to the highest temperature (60 °C) some spontaneous decomposition occurred. The biodegradation pattern of the 72-hour culture evidenced by TLC revealed two additional biodegradation products, one of which migrates in a similar fashion to vanillic acid. After 72 hours of incubation, the biodegradation product presumed to be vanillyl alcohol was no longer observed. Acidification tests showed that the best route for extraction of the product believed to be vanillyl alcohol is to adjust the extracted sample to a pH of 9. The cultivation test of the isolates in media prepared from different lignin-based residual products showed that 26 out of 60 initial strains grew regardless of the concentration of lignosulfonates and vanillin. Moreover, 17 strains grew in nitrogen-limited medium. Eight of the strains accumulated lipids. A preliminary categorization of isolates based on their colony morphology and capacity of growth on different substrates showed that to some extent, their morphology can predict the ability to grow on lignin- and vanillin-based media. This could help future scientists to easily screen for and select isolates with interesting activity for the ligno-cellulose industry.

This study analyzes the reactivity and selectivity of Friedel-Crafts alkylations using benzylic alcohols and phenols in the presence of a Lewis acid, to synthesize methoxylated bisphenols as a benign alternative to BPA. The degree of methoxylation on the electrophile appears to affect the yield of the reaction while the degree of methoxylation on the nucleophile appears to affect the selectivity. A more methoxylated electrophile results in a lower yield whereas a more methoxylated nucleophile results in a change in ratio between the bisphenol isomers and/or causes other isomers to form. Neither the yield nor the selectivity appears to be affected significantly by the temperature.

Un procédé enzymatique sans solvant a été développé permettant la synthèse d'un ester phénolique de DHA. L'optimisation des paramètres réactionnels a permis d'atteindre des rendements élevés (440 g/L) d'ester de DHA et d'alcool vanillique (DHA-VE), dont les activités biologiques et le potentiel applicatif ont été évalués. L'activité inhibitrice du DHA-VE vis-à-vis des radicaux ABTS, DPPH et hydroxyle a été démontrée. Un effet neuroprotecteur de l'ester a également été mis en évidence sur des neurones primaires de rat, exposés aux oligomères du peptide [bêta]-amyloïde. Une étude in vivo a permis de montrer que le greffage d'alcool vanillique conduit à une augmentation du taux de DHA au niveau des globules rouges et des neurones, indiquant une biodisponibilité accrue du DHA lorsque celui-ci est couplé au composé phénolique. Aucune toxicité visible de l'ester n'a été constatée. Par ailleurs, l'incorporation de DHA-VE dans divers systèmes émulsionnés a permis d'accroître leur stabilité à l'oxydation, quelles que soient les conditions de stockage. Ceci montre le potentiel de cet ester pour enrichir diverses matrices alimentaires en DHA, tout en améliorant leur stabilité à l'oxydation. Le procédé enzymatique développé a été appliqué à de l'huile de saumon, utilisée comme source d'acides gras polyinsaturés de la série oméga-3. L'incorporation totale de l’alcool vanillique (50 g/L) a été obtenue après 24 h de réaction, conduisant à la production d'une grande variété d'esters, représentatifs de la composition initiale de l'huile en acides gras. Le milieu réactionnel brut issu de l'alcoolyse de l'huile présente une grande stabilité et des propriétés antioxydantes importantes par rapport à l'huile de saumon native. En conclusion, l'approche consistant à assembler des composés phénoliques et des lipides polyinsaturés au sein d'une même structure semble prometteuse pour renforcer le potentiel applicatif de ces deux familles de biomolécules et produire de nouveaux ingrédients bioactifs stables / An efficient solvent-free bioprocess was developed for the synthesis of DHA phenolic ester, using the lipase B from Candida antarctica. The protocol developed here led to high-level production (440 g/L) of DHA vanillyl ester (DHA-VE) that exhibits interesting application potential as food ingredient. DHA-VE was characterized by a high stability and a high radical scavenging activity towards DPPH, ABTS and hydroxyl radicals. Neuroprotective properties of DHA-VE were also demonstrated in rat primary neurons exposed to amyloid-[beta] oligomers. Enzymatic esterification of DHA with vanillyl alcohol (VA) led to increased DHA levels in erythrocytes and brain tissues of mice fed DHA-VE-supplemented diet comparing with DHA. No visible toxicity of the ester was found. Enrichment of emulsions with DHA-VE improved significantly their oxidative stability whatever the conditions of storage, showing the potential of DHA-VE to enrich various food matrices with DHA while protecting them against oxidation. The enzymatic process was applied to salmon oil as a source of omega-3 polyunsaturated fatty acids (PUFA). The total conversion of VA (50 g/L) was achieved after 24 h of reaction, leading to the production of a wide variety of esters that mirror the initial composition of the oil. The crude reaction medium recovered from salmon oil alcoholysis exhibited a high stability together with high antioxidant properties in comparison with native salmon oil. In conclusion, the approach that consists in bringing phenolic compounds and PUFA-rich lipids together within a single structure is expected to provide stable bioactive ingredients that should broaden the scope of application of omega-3 PUFAs whose health benefits are increasingly sought