Fatty alcohols are widely used in various applications within a diverse set of industries, such as the soap and detergent industry, the personal care, and cosmetics industry, as well as the food industry. The total world production of fatty alcohols is over 2 million tons with approximately equal parts derived from fossil oil and from plant oils or animal fats. Due to the environmental impact of these production methods, there is an interest in alternative methods for fatty alcohol production via microbial fermentation using cheap renewable feedstocks. In this study, we aimed to obtain a better understanding of how fatty alcohol biosynthesis impacts the host organism, baker’s yeast Saccharomyces cerevisiae or oleaginous yeast Yarrowia lipolytica . Producing and non-producing strains were compared in growth and nitrogen-depletion cultivation phases. The multi-omics analysis included physiological characterization, transcriptome analysis by RNAseq, 13 Cmetabolic flux analysis, and intracellular metabolomics. Both species accumulated fatty alcohols under nitrogen-depletion conditions but not during growth. The fatty alcohol–producing Y. lipolytica strain had a higher fatty alcohol production rate than an analogous S. cerevisiae strain. Nitrogen-depletion phase was associated with lower glucose uptake rates and a decrease in the intracellular concentration of acetyl–CoA in both yeast species, as well as increased organic acid secretion rates in Y. lipolytica . Expression of the fatty alcohol–producing enzyme fatty acyl–CoA reductase alleviated the growth defect caused by deletion of hexadecenal dehydrogenase encoding genes ( HFD1 and HFD4 ) in Y. lipolytica . RNAseq analysis showed that fatty alcohol production triggered a cell wall stress response in S. cerevisiae . RNAseq analysis also showed that both nitrogen-depletion and fatty alcohol production have substantial effects on the expression of transporter encoding genes in Y. lipolytica . In conclusion, through this multi-omics study, we uncovered some effects of fatty alcohol production on the host metabolism. This knowledge can be used as guidance for further strain improvement towards the production of fatty alcohols.

Accessing aldehydes from carboxylate moieties is often a challenging task. In this regard, carboxylate reductases (CARs) are promising catalysts provided by nature that are able to accomplish this task in just one step, avoiding over-reduction to the alcohol product. However, the heterologous expression of CARs can be quite difficult due to the excessive formation of insoluble protein, thus hindering further characterization and application of the enzyme. Here, the heterologous production of the carboxylate reductase from Nocardia otitidiscaviarum (NoCAR) was optimized by a combination of i) optimized cultivation conditions, ii) post-translational modification with a phosphopantetheinyl transferase and iii) selection of an appropriate expression strain. Especially, the selection of Escherichia coli tuner cells as host had a strong effect on the final 110-fold increase in the specific activity of NoCAR. This highly active NoCAR was used to reduce sodium benzoate to benzaldehyde, and it was successfully assembled with an in vitro regeneration of ATP and NADPH, being capable of reducing about 30 mM sodium benzoate with high selectivity in only 2 h of reaction.

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This study investigated the effect of the topical treatment with meloxicam-loaded nanocapsules (M-NC) on symptoms, inflammatory response and oxidative parameters in an atopic dermatitis (AD) model in BALB/c mice. 2,4-Dinitrochlorobenzene (DNCB) was applied to the dorsal skin on days 1-3 for sensitization. Mice were challenged with DNCB on the ear (on days 14-29) and dorsal skin (on days 14, 17, 20, 23, 26, and 29). Treatments with blank nanocapsules (B-NC), free meloxicam (M-F) or M-NC were applied to the backs of the mice from days 14 to 29. On the day 30, skin severity scores and scratching behaviour were determined. After that, ears and dorsal skin were removed for determination of inflammatory parameters (edema and myeloperoxidase (MPO) activity) and oxidative parameters (thiobarbituric acid reactive species (TBARS) and non-protein thiol (NPSH) levels), respectively. DNCB increased the severity of skin lesions, scratching behaviour, edema and MPO activity of ears and dorsal skin TBARS levels. M-NC reversed skin severity scores, scratching behaviour and inflammatory response induced by DNCB. B-NC and M-F did not have effect in this model. In summary, meloxicam carried by polymeric nanocapsules reversed inflammatory response and ameliorated symptoms in an AD model.