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Heavy crude oil reserves are characterized by their high viscosity and density, largely due to significant quantities of asphaltenes. The removal of asphaltene precipitates from oil industry installations is crucial, as they can contaminate catalysts and obstruct pipelines. Therefore, this study aimed to bio-transform heavy oil asphaltenes into smaller molecules using the yeast Yarrowia lipolytica, known for its ability to efficiently degrade hydrophobic substrates. For this purpose, asphaltenes were extracted from crude oil samples, and yeast growth was assessed in a mineral medium containing 2, 5, or 10 g L -1 of asphaltenes. After 168 h of incubation, liquid-liquid extraction was conducted on samples from the Yarrowia lipolytica growth medium using chloroform. The extracted fractions were then quantified by gas chromatography. The results indicated that the yeast could utilize the asphaltenes as a carbon source for growth, though there was a delay in growth compared to the control (glucose as the carbon source), with a maximum biomass concentration of 2.26 g L -1 achieved at 144 h. From the experimental design, it was determined that a higher concentration of aromatic compounds was achieved under the conditions of 115 rpm, 2 g L -1 of asphaltenes, and 0.5 g L -1 of cell inoculum. Conversely, to obtain a higher concentration of saturated compounds, the optimal conditions were 160 rpm, 5 g L -1 of asphaltenes, and 1.0 g L -1 of cell inoculum. Molecular docking results indicated that asphaltenes have a high affinity for cytochrome P450, laccase, and Lip2, with interactions observed with their catalytic triads, suggesting a significant role for these enzymes in asphaltene bioconversion., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Yarrowia lipolytica has gained recognition as a microorganism with biological relevance and extensive biotechnological applications. Some of its features include a high enzyme secretion capacity and a high cell-density fermentation mode. Hexokinase (YlHxk) is a vital enzyme in Y. lipolytica growth since it catalyzes glucose metabolism through phosphorylation in the glycolytic pathway. Given the potential application of deep eutectic solvents (DES) as novel solvents in biotechnological processes, this study evaluated the influence of eighteen DES on the growth of Y. lipolytica. Furthermore, this work examined the effects of individual ions on the YlHxk enzyme by analyzing its enzymatic tunnel structure, molecule transport, and molecular docking. The results revealed a significant reduction in yeast growth in the presence of most DES compared to the control (medium without DES), with the exception of the [N 8881 ]Cl: hexanoic acid (1:1) DES. The growth varied between 11.95 ± 0.60 and 0.68 ± 0.17 g dry cell weight L -1 . According to the enzymatic tunnel analysis, DES components associated with the lowest microbial growth values were transported through tunnel 1. On the other hand, DES components had their pathway facilitated through tunnel 2 ([N 8881 ] + and hexanoic acid) and showed growth values close to the control. Molecular docking analysis identified a similarity between all the ligands in this tunnel (including substrate and product), presenting binding interactions with the ASN273 amino acid of the YlHxk active site. Combining experimental results with computational tools provided promising insights at the molecular level, while also potentially reducing analysis costs and time, paving the way for similar approaches in broad biocatalytic reactions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This work studies the partition of phenolic compounds, namely caffeic acid, syringic acid, vanillic acid, ferulic acid, and vanillin, in aqueous two-phase systems (ATPSs) formed by acetonitrile and deep eutectic solvents (DESs) based on choline chloride ([Ch]Cl) and carbohydrates (sucrose, d-glucose, d-mannose, arabinose, and d-xylose). The binodal curves built at 25 °C and 0.1 MPa using DES were compared with ATPS composed of [Ch]Cl and the same carbohydrates. The ability to form ATPS depends on the number and kind of hydroxyl groups in DES's hydrogen-bond donor compound (carbohydrates). ATPS based on DES showed biphasic regions larger than the systems based on [Ch]Cl and carbohydrates alone due to the larger hydrophilicity of DES. The ATPS were used to study the partition of the phenolic compounds. For all the systems, the biomolecules preferentially partitioned to the acetonitrile-rich phase (K > 1), and the best recovery in the top phase ranged between 53.36% (caffeic acid) and 90.09% (vanillin). According to the remarkable results, DES-based ATPS can selectively separate ferulic acid and vanillin for the top phase and syringic, caffeic, and vanillic acids for the bottom phase, achieving a selectivity higher than two.

Green chemistry and engineering are potential alternatives for achieving higher sustainability and lower generation of hazardous compounds in chemical product design, production, and use. Deep Eutectic Solvents (DES) are characterized as green solvents and have become increasingly attractive due to their characteristic design solvents. In this work, two DES (choline chloride (ChCl)/glycerol and ChCl/Urea), aqueous solutions of the DES-forming components, and green tea extracts obtained with DES were used as anti-ageing active in cosmetic products using in vitro tests to inhibit extracellular matrix metalloproteases (such as collagenase and elastase). Finally, the stability of the formulations with DES as a cosmetic active was also evaluated. The results showed that DES based on ChCl/Urea and ChCl/glycerol exhibited remarkable inhibition values of collagenase (91.1 and 92.7%, respectively) and elastase (49.8 and 45.7%, respectively). However, pure urea displayed better inhibition values (66%) for elastase, possibly due to its direct contribution to intramolecular hydrogen bonds. ChCl/glycerol showed remarkable stability in the average cube diameter values, which may indicate no change in the conformation of the micellar structure of the cosmetic formulation. Moreover, the formulation containing this DES remained stable at room temperature. Given the remarkable results, DES can be applied in cosmetic products for anti-ageing purposes., Competing Interests: Conflict of interestThe authors declare no competing interests., (© King Abdulaziz City for Science and Technology 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

This work reports, for the first time, an Ethanolic Two-Phase System (ETPS) based on polypropylene glycol 2000 (PPG 2000), mono-, di-, tri-ethylene glycol, and ethanol. An ionic liquid (IL) (1-butyl-3-methylpyridinium chloride) was used as an adjuvant. This ETPS shows promising results for the extraction of highly hydrophobic compounds. Bixin (model of hydrophobic compounds) migrates completely to the PPG 2000-rich phase, while ascorbic acid (hydrophilic compound) migrated to the opposite phase.