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Novel metaled fatty polyesters were prepared using polytransesterification reactions between dimethyl terephthalate (DMT) and different fatty metaled (Si/Ge) alcohol obtained from the undec-10-en-1-ol. The corresponding yields were excellent and the structure of the polyesters were determined by spectroscopic methods. Considering one hour of polymerization, the polymers exhibited acceptable molecular weights. The thermogravimetric analysis showed that these polyesters were more stable than their corresponding monomers and presented thermal degradation above 400°C. [ABSTRACT FROM AUTHOR]

The combination of surfactants and fatty alcohols leads to the formation of lamellar gel network (LGNs) which are widely used in cosmetic and pharmaceutical industries. Alkyl polyglucosides are known to stabilize oil-in- water emulsions and here, we report their use in combination with fatty alcohol for the stabilization of all-aqueous water-in-water (W/W) emulsions based on dextran-in-poly(ethylene glycol). Two different APGs were used: decyl glucoside and lauryl glucoside. We systematically studied the influence of the concentrations of APGs, and the molar ratio between the APGs and decanol as model fatty alcohol on the size and stability of the aqueous emulsion droplets with time. The self-assembled structure formed by decanol/APGs was characterized by using Small Angle X-ray Scattering and confocal microscopy, and shown to be lamellar in the bulk phase and probably also at the surface of dextran-rich droplets. We also demonstrated that the stabilization of W/W emulsions can be extended to other alkyl polyglucoside and to other fatty alcohols. In addition, we reported the production of a foam using such W/W emulsions as the continuous phase. Our results show that it is possible to stabilized W/W emulsions using LGNs based on different APGs and fatty alcohols, which will undoubtedly expand the use of W/W emulsions for various fields. [ABSTRACT FROM AUTHOR]

To evaluate a potential thermal battery material for thermal energy storage applications, this study prepared a stable organic nano-dispersed PCM (NDPCM) with 1-tetradecanol (TD) with a melting point and latent heat of 37.8 °C and 236.4 J/g, respectively, as base PCM and investigated its thermal properties. The high thermal conductive nano-additives of functionalized multi-walled carbon nanotubes (MWCNT-COOH) with a concentration range of 1 wt% to 5 wt% were infused in the pure PCM. As a result, MWCNT-COOH shows better dispersion stability. The SEM microimage confirms no agglomeration was observed for the prepared NDPCM. The supercooling was reduced from 10.6 °C for the pure TD to 7.7 °C for TD with 5 wt% of MWCNT. The latent heat of the NDPCM with 5 wt% MWCNT-COOH was 212.6 J/g with a 10% reduction compared to pure TD. The reduction in latent heat values is lower than the previously investigated TD composite PCM. The thermal stability study through gravimetric analysis confirms that the decomposition of the NDPCMs initiates at 200 °C, which will not be affected by thermal fluctuation in the system. The sample with 5 wt% of nano-additives had the most excellent thermal conductivity (TC) improvement, 56.2% in the liquid phase, whereas 50% in the solid phase. The reported values are significantly higher compared to the previous thermal conductivity improvement of TD using metallic nanoparticles. The prepared NDPCM shows better thermal properties than the pure PCM and can be a possible material for high-density thermal energy storage applications.

Abstract Efficient conversion of pentose sugars remains a significant barrier to the replacement of petroleum-derived chemicals with plant biomass-derived bioproducts. While the oleaginous yeast Rhodosporidium toruloides (also known as Rhodotorula toruloides) has a relatively robust native metabolism of pentose sugars compared to other wild yeasts, faster assimilation of those sugars will be required for industrial utilization of pentoses. To increase the rate of pentose assimilation in R. toruloides, we leveraged previously reported high-throughput fitness data to identify potential regulators of pentose catabolism. Two genes were selected for further investigation, a putative transcription factor (RTO4_12978, Pnt1) and a homolog of a glucose transceptor involved in carbon catabolite repression (RTO4_11990). Overexpression of Pnt1 increased the specific growth rate approximately twofold early in cultures on xylose and increased the maximum specific growth by 18% while decreasing accumulation of arabitol and xylitol in fast-growing cultures. Improved growth dynamics on xylose translated to a 120% increase in the overall rate of xylose conversion to fatty alcohols in batch culture. Proteomic analysis confirmed that Pnt1 is a major regulator of pentose catabolism in R. toruloides. Deletion of RTO4_11990 increased the growth rate on xylose, but did not relieve carbon catabolite repression in the presence of glucose. Carbon catabolite repression signaling networks remain poorly characterized in R. toruloides and likely comprise a different set of proteins than those mainly characterized in ascomycete fungi.

[Display omitted] Sculpting liquids into different shapes is usually based on the interfacial interactions of functionalized nanoparticles or polymers with specific ligands, leading to exciting material properties due to the combination of the mobility of liquid components with the solid-like characteristic of the arrested liquid/liquid interface. There is an intense interest in novel structured liquids produced from simple compounds with versatile application potentials. Complexes of oppositely charged commercial polyelectrolytes and traditional aliphatic surfactants are good candidates for this goal since they reveal rich structural features and could adsorb at various interfaces. However, they have not been applied yet for structuring liquids. The interfacial interactions and film formation between aqueous sodium poly(styrene) sulfonate solutions (NaPSS) and hexadecylamine (HDA) solutions in various alkanols were investigated by surface tension measurements and ATR-IR spectroscopy. 3D printing experiments also assessed the robustness of the formed films. Arrested fatty alcohol/water interfaces were formed due to the interfacial association of NaPSS, HDA, and alkanol molecules, which also act as cosurfactants in the surface region. These solid films enable the synthesis of temperature-sensitive all-in-liquid constructs and offer alternatives to bulk polyion/mixed surfactant assemblies prepared earlier through numerous synthesis steps. [ABSTRACT FROM AUTHOR]

Fatty alcohols are important products in the chemical industry, given that they are frequently used in the formulation of surfactants and lubricants. In this context, this work describes a catalytic heterogeneous approach for the production of 1-octadecanol (C18OH) from ethyl stearate (ES) using nanosized Ru-supported on tungstated zirconia (W/Zr). The activity and selectivity of this series of catalysts have been studied during the hydrogenation of ES in a batch reactor at 175 °C and PH2 = 40 bar. The so-prepared catalysts were characterized by a sort of characterization techniques (i.e., X-ray diffraction, H2-TPR, etc.), confirming the high dispersion and higher reducibility of Ru nanoparticles on the W/Zr surface (primarily tetragonal zirconia) with respect to pure zirconia. Overall, the catalysts were significantly active. In addition, a strong synergistic effect was revealed between Ru and W species, according to catalytic data. Finally, the reaction sequence towards fatty alcohol has also been elucidated, pointing to the ester hydrogenolysis to the aldehyde and ulterior hydrogenation of the latter as the main route for fatty alcohol formation. [ABSTRACT FROM AUTHOR]

The combination of surfactants and fatty alcohols leads to the formation of lamellar gel network (LGNs) which are widely used in cosmetic and pharmaceutical industries. Alkyl polyglucosides are known to stabilize oil-in-water emulsions and here, we report their use in combination with fatty alcohol for the stabilization of all-aqueous water-in-water (W/W) emulsions based on dextran-in-poly(ethylene glycol). Two different APGs were used: decyl glucoside and lauryl glucoside. We systematically studied the influence of the concentrations of APGs, and the molar ratio between the APGs and decanol as model fatty alcohol on the size and stability of the aqueous emulsion droplets with time. The self-assembled structure formed by decanol/APGs was characterized by using Small Angle X-ray Scattering and confocal microscopy, and shown to be lamellar in the bulk phase and probably also at the surface of dextran-rich droplets. We also demonstrated that the stabilization of W/W emulsions can be extended to other alkyl polyglucoside and to other fatty alcohols. In addition, we reported the production of a foam using such W/W emulsions as the continuous phase. Our results show that it is possible to stabilized W/W emulsions using LGNs based on different APGs and fatty alcohols, which will undoubtedly expand the use of W/W emulsions for various fields.

Sjögren–Larsson syndrome (SLS) is a rare inherited neurocutaneous disease characterized by ichthyosis, spastic diplegia or tetraplegia, intellectual disability and a distinctive retinopathy. SLS is caused by bi-allelic mutations in ALDH3A2, which codes for fatty aldehyde dehydrogenase (FALDH) and results in abnormal lipid metabolism. The biochemical abnormalities in SLS are not completely known, and the pathogenic mechanisms leading to symptoms are still unclear. To search for pathways that are perturbed in SLS, we performed untargeted metabolomic screening in 20 SLS subjects along with age- and sex-matched controls. Of 823 identified metabolites in plasma, 121 (14.7%) quantitatively differed in the overall SLS cohort from controls; 77 metabolites were decreased and 44 increased. Pathway analysis pointed to disrupted metabolism of sphingolipids, sterols, bile acids, glycogen, purines and certain amino acids such as tryptophan, aspartate and phenylalanine. Random forest analysis identified a unique metabolomic profile that had a predictive accuracy of 100% for discriminating SLS from controls. These results provide new insight into the abnormal biochemical pathways that likely contribute to disease in SLS and may constitute a biomarker panel for diagnosis and future therapeutic studies. [ABSTRACT FROM AUTHOR]

Fatty alcohols (FOHs) are important feedstocks in the chemical industry to produce detergents, cosmetics, and lubricants. Microbial production of FOHs has become an attractive alternative to production in plants and animals due to growing energy demands and environmental concerns. However, inhibition of cell growth caused by intracellular FOH accumulation is one major issue that limits FOH titers in microbial hosts. In addition, identification of FOH-specific exporters remains a challenge and previous studies towards this end are limited. To alleviate the toxicity issue, we exploited nonionic surfactants to promote the export of FOHs in Rhodosporidium toruloides, an oleaginous yeast that is considered an attractive next-generation host for the production of fatty acid-derived chemicals. Our results showed FOH export efficiency was dramatically improved and the growth inhibition was alleviated in the presence of small amounts of tergitol and other surfactants. As a result, FOH titers increase by 4.3-fold at bench scale to 352.6 mg/L. With further process optimization in a 2-L bioreactor, the titer was further increased to 1.6 g/L. The method we show here can potentially be applied to other microbial hosts and may facilitate the commercialization of microbial FOH production.

Abstract Background Construction of efficient microbial cell factories is one of the core steps for establishing green bio-manufacturing processes. However, the complex metabolic regulation makes it challenging in driving the metabolic flux toward the product biosynthesis. Dynamically coupling the biosynthetic pathways with the cellular metabolism at spatial–temporal manner should be helpful for improving the production with alleviating the cellular stresses. Results In this study, we observed the mismatch between fatty alcohol biosynthesis and cellular metabolism, which compromised the fatty alcohol production in Saccharomyces cerevisiae. To enhance the fatty alcohol production, we spatial-temporally regulated fatty alcohol biosynthetic pathway by peroxisomal compartmentalization (spatial) and dynamic regulation of gene expression (temporal). In particular, fatty acid/acyl-CoA responsive promoters were identified by comparative transcriptional analysis, which helped to dynamically regulate the expression of acyl-CoA reductase gene MaFAR1 and improved fatty alcohol biosynthesis by 1.62-fold. Furthermore, enhancing the peroxisomal supply of acyl-CoA and NADPH further improved fatty alcohol production to 282 mg/L, 2.52 times higher than the starting strain. Conclusions This spatial–temporal regulation strategy partially coordinated fatty alcohol biosynthesis with cellular metabolism including peroxisome biogenesis and precursor supply, which should be applied for production of other products in microbes.

Background: Construction of efficient microbial cell factories is one of the core steps for establishing green bio-manufacturing processes. However, the complex metabolic regulation makes it challenging in driving the metabolic flux toward the product biosynthesis. Dynamically coupling the biosynthetic pathways with the cellular metabolism at spatial–temporal manner should be helpful for improving the production with alleviating the cellular stresses. Results: In this study, we observed the mismatch between fatty alcohol biosynthesis and cellular metabolism, which compromised the fatty alcohol production in Saccharomyces cerevisiae. To enhance the fatty alcohol production, we spatial-temporally regulated fatty alcohol biosynthetic pathway by peroxisomal compartmentalization (spatial) and dynamic regulation of gene expression (temporal). In particular, fatty acid/acyl-CoA responsive promoters were identified by comparative transcriptional analysis, which helped to dynamically regulate the expression of acyl-CoA reductase gene MaFAR1 and improved fatty alcohol biosynthesis by 1.62-fold. Furthermore, enhancing the peroxisomal supply of acyl-CoA and NADPH further improved fatty alcohol production to 282 mg/L, 2.52 times higher than the starting strain. Conclusions: This spatial–temporal regulation strategy partially coordinated fatty alcohol biosynthesis with cellular metabolism including peroxisome biogenesis and precursor supply, which should be applied for production of other products in microbes. [ABSTRACT FROM AUTHOR]

Cu/SBA-15 and Cu-NbO x /SBA-15 catalysts were prepared and evaluated in the hydrogenation of palmitic acid to palmitic alcohol. A high palmitic alcohol yield of 90.8% was obtained using palmitic acid as feedstock. NbO x has been considered to be crucial for the excellent performance and the synergy between Cu and NbO x was well investigated. The interaction between Cu species and NbO x -containing support was studied by various characterizations, such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), H 2 -temperature programmed reduction (H 2 -TPR) and X-ray photoelectron spectra (XPS) and Auger electron spectroscopy (AES). The kinetic data for rate determining step were also collected. The synergistic effect of Cu and NbO x to catalytic activity was discussed and the following insights were obtained: i) the NbO x doping led to form abundant Cu species with more electron-deficient, which is beneficial for the production of alcohol; ii) the oxygen affinity of NbO x promotes the adsorption of oxygen-containing group. Finally, the natural product of palm oil was taken as feedstock and an ideal yield 84.2% of palmitic alcohol was harvested. [Display omitted] • A catalyst Cu-NbO x /SBA-15 with uniform and small size Cu species supported on SBA-15 was obtained by introducing NbO x species. • The Cu-NbO x /SBA-15 performed excellently in hydrogenation of palmitic acid to palmitic alcohol, with a yield of 90.8%. • The high-efficiency of Cu-NbO x /SBA-15 is attributed to the synergistic effect between Cu and NbO x species. [ABSTRACT FROM AUTHOR]

Catalytic hydrotreating of fatty acid is respected to produce bio-based chemicals especially oleochemicals that can be applied as a high valuable raw material or intermediate materials for industries. Low-cost Ni/LY char and limonite catalysts can compensate the expensively commercial catalysts. Palmitic acid (PA) was represented as reactant. Chemical compositions of liquid product were analyzed and presented in compound group, carbon number distribution and product selectivity. Catalyst characteristics and liquid product properties were also investigated. BET surface area, pore volume, and pore size of the prepared Ni/LY char catalyst were 308 m2/g, 0.188 cm3/g and 2.43 nm, respectively, and those of limonite catalyst were 95 m2/g, 0.3 cm3/g and 12.59 nm, respectively. Based on the initial 3 MPa H2 at 300 °C, the obtained oleochemicals depended on catalyst type, reaction time and solvent. In case of Ni/LY char catalyst, ester was found in yield of 58.94% that mainly contained with isopropyl palmitate up to 82% of ester, meanwhile product from limonite was principally distributed in alcohol group with 51.84% in which n-pentadecanol was the major compound with 37.05% yield. The products showed the oxygen removal in range of 19.11–65.15 mol% and HHVs were increased to 32.11–34.13 MJ/kg when compared with PA.

Fatty alcohols are important products in the chemical industry, given that they are frequently used in the formulation of surfactants and lubricants. In this context, this work describes a catalytic heterogeneous approach for the production of 1-octadecanol (C18OH) from ethyl stearate (ES) using nanosized Ru-supported on tungstated zirconia (W/Zr). The activity and selectivity of this series of catalysts have been studied during the hydrogenation of ES in a batch reactor at 175 °C and PH2 = 40 bar. The so-prepared catalysts were characterized by a sort of characterization techniques (i.e., X-ray diffraction, H2-TPR, etc.), confirming the high dispersion and higher reducibility of Ru nanoparticles on the W/Zr surface (primarily tetragonal zirconia) with respect to pure zirconia. Overall, the catalysts were significantly active. In addition, a strong synergistic effect was revealed between Ru and W species, according to catalytic data. Finally, the reaction sequence towards fatty alcohol has also been elucidated, pointing to the ester hydrogenolysis to the aldehyde and ulterior hydrogenation of the latter as the main route for fatty alcohol formation.

Palm oil‐based fatty alcohol is a basic oleochemical with many different applications depending on its carbon chain length. The carbon chain distribution using a GC‐flame ionization detector (GC‐FID) is a quality control tool for monitoring the composition of either single or blended fatty alcohol. There is a published GC‐FID method but it requires a derivatization step. The objective of this work is to develop a derivatization‐free method with simple preparation steps. It can be used for routine analysis of the carbon chain distribution to determine the composition of palm‐based fatty alcohol. The GC‐FID method developed used a ZB‐FFAP (60 m × 0.25 mm i.d., 0.25 μm film thickness) consisting of polyethylene glycol bonded nitroterephthalic acid phase for separation of eight types of fatty alcohol with a run time of 40 min. The method showed good validation parameters performance in terms of accuracy (as compared with FAL standards), linearity (R2 > 0.9999) and intraday and intermediate precision (CV < 0.05% for retention time and CV < 1.5% for peak area). Monitoring of commercial FAL from local manufacturers showed that the composition was consistent with the required specifications. [ABSTRACT FROM AUTHOR]

Sjögren–Larsson syndrome (SLS) is a rare inherited neurocutaneous disease characterized by ichthyosis, spastic diplegia or tetraplegia, intellectual disability and a distinctive retinopathy. SLS is caused by bi-allelic mutations in ALDH3A2, which codes for fatty aldehyde dehydrogenase (FALDH) and results in abnormal lipid metabolism. The biochemical abnormalities in SLS are not completely known, and the pathogenic mechanisms leading to symptoms are still unclear. To search for pathways that are perturbed in SLS, we performed untargeted metabolomic screening in 20 SLS subjects along with age- and sex-matched controls. Of 823 identified metabolites in plasma, 121 (14.7%) quantitatively differed in the overall SLS cohort from controls; 77 metabolites were decreased and 44 increased. Pathway analysis pointed to disrupted metabolism of sphingolipids, sterols, bile acids, glycogen, purines and certain amino acids such as tryptophan, aspartate and phenylalanine. Random forest analysis identified a unique metabolomic profile that had a predictive accuracy of 100% for discriminating SLS from controls. These results provide new insight into the abnormal biochemical pathways that likely contribute to disease in SLS and may constitute a biomarker panel for diagnosis and future therapeutic studies.

[Display omitted] Catalytic hydrotreating of fatty acid is respected to produce bio-based chemicals especially oleochemicals that can be applied as a high valuable raw material or intermediate materials for industries. Low-cost Ni/LY char and limonite catalysts can compensate the expensively commercial catalysts. Palmitic acid (PA) was represented as reactant. Chemical compositions of liquid product were analyzed and presented in compound group, carbon number distribution and product selectivity. Catalyst characteristics and liquid product properties were also investigated. BET surface area, pore volume, and pore size of the prepared Ni/LY char catalyst were 308 m2/g, 0.188 cm3/g and 2.43 nm, respectively, and those of limonite catalyst were 95 m2/g, 0.3 cm3/g and 12.59 nm, respectively. Based on the initial 3 MPa H 2 at 300 °C, the obtained oleochemicals depended on catalyst type, reaction time and solvent. In case of Ni/LY char catalyst, ester was found in yield of 58.94% that mainly contained with isopropyl palmitate up to 82% of ester, meanwhile product from limonite was principally distributed in alcohol group with 51.84% in which n-pentadecanol was the major compound with 37.05% yield. The products showed the oxygen removal in range of 19.11–65.15 mol% and HHVs were increased to 32.11–34.13 MJ/kg when compared with PA. [ABSTRACT FROM AUTHOR]

Sjögren-Larsson syndrome (SLS) is a neurocutaneous disease caused by mutations in ALDH3A2 that result in deficient fatty aldehyde dehydrogenase (FALDH) activity and impaired fatty aldehyde and fatty alcohol oxidation. The pathogenesis of SLS is thought to involve accumulation of long-chain fatty aldehydes and alcohols and/or metabolically-related ether glycerolipids. Fatty aldehydes are particularly toxic molecules that can covalently react with proteins and certain amino-containing lipids such as phosphatidylethanolamine (PE), generating an unusual aldehyde adduct, N-alkyl-PE (NAPE). Using Faldh-deficient Chinese hamster ovary cells (FAA-K1A) as a cellular model for SLS, we investigated the ability of an aldehyde trapping agent, ADX-102 [2-(3-amino-6-chloro-quinolin-2-yl)-propan-2-ol], to mitigate the harmful effects of fatty aldehydes. FAA-K1A cells were protected from octadecanal (C18:0-al) induced cytotoxicity and apoptosis by ADX-102. Metabolism of C18:0-al to fatty alcohol (octadecanol) was also inhibited by ADX-102. FAA-K1A cells accumulated 5-fold more NAPE with C16- and C18-linked N-alkyl chains compared to wild-type cells, but NAPE levels decreased to normal after growth for 4 days with 50 μM ADX-102. Our results suggest that small aldehyde-reactive molecules, such as ADX-102, should be explored as novel therapeutic agents for SLS by preventing aldehyde adduct formation with critical cellular targets and inhibiting fatty aldehyde metabolism to fatty alcohol.

Context A variety of Acmella oleracea (L.) R.K. Jansen (Asteraceae) is used by the Mizo people of India and Myanmar for intestinal helminthiasis. Objective To perform a chemical analysis of the plant extract using gas chromatography-mass spectrometry (GC-MS) and test the anthelmintic activity on intestinal parasites. Materials and methods An extract of the aerial parts was prepared in hexane and analysed using GC-MS. Survival test was performed in vitro on the cestode, Taenia tetragona, and the nematode, Ascaridia perspicillum. Concentrations of 1.25, 2.5, 5, 10 and 20 mg/mL, prepared in phosphate-buffered saline (PBS) with 1% dimethylsulphoxide (DMSO), were tested. Negative control was maintained in PBS with DMSO, and albendazole was used as a reference drug. Each treatment consisted of six worms and was done until death was confirmed. Scanning electron microscopy was used to describe the structural changes. Results Nineteen compounds were detected. The major compounds were fatty alcohols such as 3,7,11,15-tetramethylhexadec-2-en-1-ol and (9Z)-9-hexadecen-1-ol. Important bioactive compounds including an alkylamide, N-isobutyl-(2E,4Z,8Z,10E)-dodecatetraenamide, and a triterpenoid, lupeol, were also confirmed. The lethal concentration (LC50) of the plant extract was 5128.61 ppm on T. tetragona and 8921.50 ppm on A. perspicillum. Tegumental shrinkage, erosion of microtriches, and distortion of the suckers were observed on the cestode. The nematode showed collapse of the lips and shrunk cuticle. Conclusions Acmella oleracea contains important bioactive compounds, which are responsible for the broad-spectrum anthelmintic activity. Further study on the pharmacology of the compounds is warranted.

SUMMARY: Suberin is a complex hydrophobic polymer of aliphatic and phenolic compounds which controls the movement of gases, water, and solutes and protects plants from environmental stresses and pathogenic infection. The synthesis and regulatory pathways of suberin remain unknown in Brachypodium distachyon. Here we describe the identification of a B. distachyon gene, BdFAR4, encoding a fatty acyl‐coenzyme A reductase (FAR) by a reverse genetic approach, and investigate the molecular relevance of BdFAR4 in the root suberin synthesis of B. distachyon. BdFAR4 is specifically expressed throughout root development. Heterologous expression of BdFAR4 in yeast (Saccharomyces cerevisiae) afforded the production of C20:0 and C22:0 fatty alcohols. The loss‐of‐function knockout of BdFAR4 by CRISPR/Cas9‐mediated gene editing significantly reduced the content of C20:0 and C22:0 fatty alcohols associated with root suberin. In contrast, overexpression of BdFAR4 in B. distachyon and tomato (Solanum lycopersicum) resulted in the accumulation of root suberin‐associated C20:0 and C22:0 fatty alcohols, suggesting that BdFAR4 preferentially accepts C20:0 and C22:0 fatty acyl‐CoAs as substrates. The BdFAR4 protein was localized to the endoplasmic reticulum in Arabidopsis thaliana protoplasts and Nicotiana benthamiana leaf epidermal cells. BdFAR4 transcript levels can be increased by abiotic stresses and abscisic acid treatment. Furthermore, yeast one‐hybrid, dual‐luciferase activity, and electrophoretic mobility shift assays indicated that the R2R3‐MYB transcription factor BdMYB41 directly binds to the promoter of BdFAR4. Taken together, these results imply that BdFAR4 is essential for the production of root suberin‐associated fatty alcohols, especially under stress conditions, and that its activity is transcriptionally regulated by the BdMYB41 transcription factor. [ABSTRACT FROM AUTHOR]

Fatty alcohols (FA-OH) are aliphatic unbranched primary alcohols with a chain of four or more carbon atoms. Besides potential industrial applications, fatty alcohols have important biological functions as well. In nature, fatty alcohols are produced as a part of a mixture of pheromones in several insect species, such as moths, termites, bees, wasps, etc. In addition, FA-OHs have a potential for agricultural applications, for example, they may be used as a suitable substitute for commercial insecticides. The insecticides have several drawbacks associated with their preparation, and they exert a negative impact on the environment. Currently, pheromone components are prepared mainly through the catalytic hydrogenation of plant oils and petrochemicals, which is an unsustainable, ecologically unfriendly, and highly expensive process. The biotechnological production of the pheromone components using engineered microbial strains and through the expression of the enzymes participating in the biosynthesis of these components is a promising approach that ensures ecological sustenance as well. The present study was aimed at evaluating the production of FA-OHs in the oleaginous yeast, Yarrowia lipolytica, with different lengths of fatty-acyl chains by expressing the fatty acyl-CoA reductase (FAR) BlapFAR4 from B. lapidarius, producing C16:0-OH, C16:1Δ9-OH, and lower quantities of both C14:0-OH and C18:1Δ9-OH, and BlucFAR1 from B. lucorum, producing FA-OHs with a chain length of 18–26 carbon atoms, in this yeast. Among the different novel Y. lipolytica strains used in the present study, the best results were obtained with JMY7086, which carried several lipid metabolism modifications and expressed the BlucFAR1 gene under the control of a strong constitutive promoter 8UAS-pTEF. JMY7086 produced only saturated fatty alcohols with chain lengths from 18 to 24 carbon atoms. The highest titer and accumulation achieved were 166.6 mg/L and 15.6 mg/g DCW of fatty alcohols, respectively. Unlike JMY7086, the BlapFAR4-expressing strain JMY7090 produced only 16 carbon atom-long FA-OHs with a titer of 14.6 mg/L.

Concerns about climate change and environmental destruction have led to interest in technologies that can replace fossil fuels and petrochemicals with compounds derived from sustainable sources that have lower environmental impact. Fatty alcohols produced by chemical synthesis from ethylene or by chemical conversion of plant oils have a large range of industrial applications. These chemicals can be synthesized through biological routes but their free forms are produced in trace amounts naturally. This review focuses on how genetic engineering of endogenous fatty acid metabolism and heterologous expression of fatty alcohol producing enzymes have come together resulting in the current state of the field for production of fatty alcohols by microbial cell factories. We provide an overview of endogenous fatty acid synthesis, enzymatic methods of conversion to fatty alcohols and review the research to date on microbial fatty alcohol production. The primary focus is on work performed in the model microorganisms, Escherichia coli and Saccharomyces cerevisiae but advances made with cyanobacteria and oleaginous yeasts are also considered. The limitations to production of fatty alcohols by microbial cell factories are detailed along with consideration to potential research directions that may aid in achieving viable commercial scale production of fatty alcohols from renewable feedstock.

Owing to their high energy density and composition, fatty acid-derived chemicals possess a wide range of applications such as biofuels, biomaterials, and other biochemical, and as a consequence, the global annual demand for products has surpassed 2million tons. With the exhausting petroleum reservoirs and emerging environmental concerns on using petroleum feedstock, it has become indispensable to shift to a renewable-based industry. With the advancement in the field of synthetic biology and metabolic engineering, the use of microbes as factories for the production of fatty acid-derived chemicals is becoming a promising alternative approach for the production of these derivatives. Numerous metabolic approaches have been developed for conditioning the microbes to improve existing or develop new methodologies capable of efficient oleochemical production. However, there still exist several limitations that need to be addressed for the commercial viability of the microbial cell factory production. Though substantial advancement has been made toward successfully producing these fatty acids derived chemicals, a considerable amount of work needs to be done for improving the titers. In the present review, we aim to address the roadblocks impeding the heterologous production, the engineering pathway strategies implemented across the range of microbes in a detailed manner, and the commercial readiness of these molecules of immense application. [ABSTRACT FROM AUTHOR]

A variety of Acmella oleracea (L.) R.K. Jansen (Asteraceae) is used by the Mizo people of India and Myanmar for intestinal helminthiasis. To perform a chemical analysis of the plant extract using gas chromatography-mass spectrometry (GC-MS) and test the anthelmintic activity on intestinal parasites. An extract of the aerial parts was prepared in hexane and analysed using GC-MS. Survival test was performed in vitro on the cestode, Taenia tetragona, and the nematode, Ascaridia perspicillum. Concentrations of 1.25, 2.5, 5, 10 and 20 mg/mL, prepared in phosphate-buffered saline (PBS) with 1% dimethylsulphoxide (DMSO), were tested. Negative control was maintained in PBS with DMSO, and albendazole was used as a reference drug. Each treatment consisted of six worms and was done until death was confirmed. Scanning electron microscopy was used to describe the structural changes. Nineteen compounds were detected. The major compounds were fatty alcohols such as 3,7,11,15-tetramethylhexadec-2-en-1-ol and (9Z)-9-hexadecen-1-ol. Important bioactive compounds including an alkylamide, N-isobutyl-(2E,4Z,8Z,10E)-dodecatetraenamide, and a triterpenoid, lupeol, were also confirmed. The lethal concentration (LC50) of the plant extract was 5128.61 ppm on T. tetragona and 8921.50 ppm on A. perspicillum. Tegumental shrinkage, erosion of microtriches, and distortion of the suckers were observed on the cestode. The nematode showed collapse of the lips and shrunk cuticle. Acmella oleracea contains important bioactive compounds, which are responsible for the broad-spectrum anthelmintic activity. Further study on the pharmacology of the compounds is warranted. [ABSTRACT FROM AUTHOR]

The heterocysts present in filamentous cyanobacteria such as Anabaena sp. PCC 7120 are known to be regulated by HetN and PatS, the repressors of heterocyst differentiation; therefore, the inactivation of these proteins will result in the formation of multiple heterocysts. To enhance the accumulation of fatty alcohols synthesized in the heterocyst, we introduced mutations of these repressors to increase heterocyst frequency. First, we isolated double mutants of hetN and patS and confirmed that the null mutation of these genes promoted higher frequencies of heterocyst formation and higher accumulation of heterocyst-specific glycolipids (Hgls) compared with its wild type. Next, we combined hetN and patS mutations with an hglT (encoding glycosyltransferase, an enzyme involved in Hgl synthesis) mutation to increase the accumulation of fatty alcohols since knockout mutation of hglT results in accumulation of very long chain fatty alcohol, the precursor of Hgl. We also observed retarded growth, lower chlorophyll content and up to a five-fold decrease in photosynthetic activity of the hetN/patS/hglT triple mutants. In contrast, the triple mutants showed three times higher heterocyst formation frequencies than the hglT single mutant and wild type. The production rate of fatty alcohol in the triple mutants attained a value 1.41 nmol/mL OD730, whereas accumulation of Hgls in the wild type was 0.90 nmol/mL OD730. Aeration of culture improved the accumulation of fatty alcohols in hetN/patS/hglT mutant cells up to 2.97 nmol/mL OD730 compared with cells cultured by rotation. Our study outlines an alternative strategy for fatty alcohol production supported by photosynthesis and nitrogen fixation.

Abstract Background The filamentous fungus Trichoderma reesei, the most widely used cellulase producer, also has promising applications in lignocellulose-based biorefinery: consolidated bioprocessing for the production of high value-added products. However, such applications are thwarted by the time-consuming metabolic engineering processes (design–build–test–learn cycle) for T. reesei, resulted from (i) the spore separation-mediated purification as the multinucleate hyphae, (ii) transformant screening for high expression levels since unavailable of episomal expression system, and (iii) cases of inexpressible heterologous proteins. Results In this study, a GFP-fusion coupled fluorescence-activated cell sorting (FACS) platform was established to speed up the build and test process of the DBTL cycle, by enabling rapid selection for expressible heterologous genes and bypassing both laborious spore separation and transformant screening. Here, the feasibility of flow cytometry in analyzing and sorting T. reesei cells harboring GFP-fused expressible protein was proven, as well as the application of the platform for constitutive promoter strength evaluation. As a proof-of-concept, the platform was employed to construct the first T. reesei strain producing fatty alcohol, resulting in up to 2 mg hexadecanol being produced per gram biomass. Pathway construction was enabled through rapid selection of functional fatty acyl-CoA reductase encoding gene Tafar1 from three candidate genes and strains with high expression level from spore pools. As a result of using this method, the total costed time for the build and test cycle using T. reesei, subsequently, reduced by approx. 75% from 2 months to 2 weeks. Conclusion This study established the GFP-fusion coupling FACS platform and the first filamentous fungal fatty alcohol-producing cell factory, and demonstrated versatile applications of the platform in the metabolic engineering of filamentous fungi, which can be harnessed to potentially advance the application of filamentous fungi in lignocellulose-based biorefinery.

Sjögren-Larsson syndrome is a genetic disease characterized by ichthyosis, mental retardation, spasticity and mutations in the ALDH3A2 gene coding for fatty aldehyde dehydrogenase, an enzyme necessary for oxidation of fatty aldehydes and fatty alcohols. We investigated the cutaneous abnormalities in 9 patients with Sjögren-Larsson syndrome to better understand how the enzymatic deficiency results in epidermal dysfunction. Histochemical staining for aldehyde oxidizing activity was profoundly reduced in the epidermis. Colloidal lanthanum perfusion studies showed abnormal movement of tracer into the extracellular spaces of the stratum corneum consistent with a leaky water barrier. The barrier defect could be attributed to the presence of abnormal lamellar bodies, many with disrupted limiting membranes or lacking lamellar contents. Entombed lamellar bodies were present in the cytoplasm of corneocytes suggesting blockade of lamellar body secretion. At the stratum granulosum-stratum corneum interface, non-lamellar material displaced or replaced secreted lamellar membranes, and in the stratum corneum, the number of lamellar bilayers declined and lamellar membrane organization was disrupted by foci of lamellar/non-lamellar phase separation. These studies demonstrate the presence of a permeability barrier abnormality in Sjögren-Larsson syndrome, which localizes to the stratum corneum interstices and can be attributed to abnormalities in lamellar body formation and secretion.

Abstract Background The ideal biofuel should not only be a regenerative fuel from renewable feedstocks, but should also be compatible with the existing fuel distribution infrastructure and with normal car engines. As the so-called drop-in biofuel, the fatty alcohol 1-octanol has been described as a valuable substitute for diesel and jet fuels and has already been produced fermentatively from sugars in small amounts with engineered bacteria via reduction of thioesterase-mediated premature release of octanoic acid from fatty acid synthase or via a reversal of the β-oxidation pathway. Results The previously engineered short-chain acyl-CoA producing yeast Fas1R1834K/Fas2 fatty acid synthase variant was expressed together with carboxylic acid reductase from Mycobacterium marinum and phosphopantetheinyl transferase Sfp from Bacillus subtilis in a Saccharomyces cerevisiae Δfas1 Δfas2 Δfaa2 mutant strain. With the involvement of endogenous thioesterases, alcohol dehydrogenases, and aldehyde reductases, the synthesized octanoyl-CoA was converted to 1-octanol up to a titer of 26.0 mg L−1 in a 72-h fermentation. The additional accumulation of 90 mg L−1 octanoic acid in the medium indicated a bottleneck in 1-octanol production. When octanoic acid was supplied externally to the yeast cells, it could be efficiently converted to 1-octanol indicating that re-uptake of octanoic acid across the plasma membrane is not limiting. Additional overexpression of aldehyde reductase Ahr from Escherichia coli nearly completely prevented accumulation of octanoic acid and increased 1-octanol titers up to 49.5 mg L−1. However, in growth tests concentrations even lower than 50.0 mg L−1 turned out to be inhibitory to yeast growth. In situ extraction in a two-phase fermentation with dodecane as second phase did not improve growth, indicating that 1-octanol acts inhibitive before secretion. Furthermore, 1-octanol production was even reduced, which results from extraction of the intermediate octanoic acid to the organic phase, preventing its re-uptake. Conclusions By providing chain length control via an engineered octanoyl-CoA producing fatty acid synthase, we were able to specifically produce 1-octanol with S. cerevisiae. Before metabolic engineering can be used to further increase product titers and yields, strategies must be developed that cope with the toxic effects of 1-octanol on the yeast cells.

This study reports the in-depth investigation of the thermophysical properties and thermal reliability of caprylic acid-stearyl alcohol (CA-SA) eutectic phase change material (PCM) for cooling applications. The phase diagram of CA-SA showed a eutectic point at a 90:10 molar ratio. The onset melting/freezing temperature and latent heat of fusion of caprylic acid-stearyl alcohol from the differential scanning calorimetry (DSC) were 11.4 °C/11.8 °C and 154.4/150.5 J/g, respectively. The thermal conductivity for the prepared eutectic PCM in the solid phase was 0.267 W/m.K (0 °C), whereas, in the liquid phase, it was 0.165 W/m.K (20 °C). In addition, the maximum relative percentage difference (RPD) marked at the end of 200 thermal cycles was 5.2% for onset melting temperature and 18.9% for phase change enthalpy. The Fourier transform infrared spectroscopy (FT-IR) result shows that the eutectic PCM holds good chemical stability. Corrosion tests showed that caprylic acid-stearyl alcohol could be a potential candidate for cold thermal energy storage applications.

This study focuses on the preparation, thermophysical and rheological characterization of phase change material nanoemulsions as latent functionally thermal fluids. Aqueous dispersions with fine droplets of cetyl alcohol (with a melting temperature at ~321 K) were prepared by means of a solvent-assisted method, combining ultrasonication with non-ionic and anionic emulsifiers. Eicosyl alcohol (melting at ~337 K) and hydrophobic silica nanoparticles were tested as nucleating agents. Droplet size studies through time and after freeze–thaw cycles confirmed the good stability of formulated nanoemulsions. Phase change analyses proved the effectiveness of eicosyl alcohol to reduce subcooling to a few Kelvin. Although phase change material emulsions exhibited thermal conductivities much larger than bulk cetyl alcohol (at least 60% higher when droplets are solid), reductions in this property reached 15% when compared to water. Samples mainly showed desirable Newtonian behavior (or slight shear thinning viscosities) and modifications in density around melting transition were lower than 1.2%. In the case of phase change material nanoemulsions with 8 wt.% content of dispersed phase, enhancements in the energy storage capacity overcome 20% (considering an operational temperature interval of 10 K around solid–liquid phase change). Formulated dispersions also showed good thermal reliability throughout 200 solidification–melting cycles.

Copyright of Al-Mustansiriyah Journal for Pharmaceutical Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The heterocysts present in filamentous cyanobacteria such as Anabaena sp. PCC 7120 are known to be regulated by HetN and PatS, the repressors of heterocyst differentiation; therefore, the inactivation of these proteins will result in the formation of multiple heterocysts. To enhance the accumulation of fatty alcohols synthesized in the heterocyst, we introduced mutations of these repressors to increase heterocyst frequency. First, we isolated double mutants of hetN and patS and confirmed that the null mutation of these genes promoted higher frequencies of heterocyst formation and higher accumulation of heterocyst-specific glycolipids (Hgls) compared with its wild type. Next, we combined hetN and patS mutations with an hglT (encoding glycosyltransferase, an enzyme involved in Hgl synthesis) mutation to increase the accumulation of fatty alcohols since knockout mutation of hglT results in accumulation of very long chain fatty alcohol, the precursor of Hgl. We also observed retarded growth, lower chlorophyll content and up to a five-fold decrease in photosynthetic activity of the hetN / patS / hglT triple mutants. In contrast, the triple mutants showed three times higher heterocyst formation frequencies than the hglT single mutant and wild type. The production rate of fatty alcohol in the triple mutants attained a value 1.41 nmol/mL OD730, whereas accumulation of Hgls in the wild type was 0.90 nmol/mL OD730. Aeration of culture improved the accumulation of fatty alcohols in hetN / patS / hglT mutant cells up to 2.97 nmol/mL OD730 compared with cells cultured by rotation. Our study outlines an alternative strategy for fatty alcohol production supported by photosynthesis and nitrogen fixation. [ABSTRACT FROM AUTHOR]

In oleogel food systems (based on the mixture between stearic acid and stearyl alcohol) the strong effect of the weight ratio (R) between these two components on the textural and structural properties is well described. The effect of R for other fatty acids and fatty alcohols is less explored. Moreover, they do not show an enhancement of the oleogel properties for specific R. The effect of R on the oleogel properties, for a mixture of fatty acid and fatty alcohol with longer alkyl chains (behenyl alcohol and behenic acid) in sunflower and soybean oils, which are raw materials widely used in cosmetic and pharmaceutical industries, was investigated. We characterized the oleogel properties as a function of R in terms of structuring potential: hardness, oil loss and gel stability. This information was correlated with microstructural data obtained at different length scales by coupling optical microscopy, DSC, SFC, SAXS and WAXS experiments. Our results highlight that R tunes the oleogel properties in a comparable manner to previous results obtained for stearic acid and stearyl alcohol-based oleogels. Two specific R (8:2 and 7:3) close to the 3:1 molecular ratio gave oleogels with both the highest hardness and stability. The morphology and size of the mixed crystals obtained for these R cannot solely explain why they are stronger gels with low oil loss in comparison to the other R. The almost complete crystallization for these two R is one of the key parameters controlling the oleogel properties. As described in the literature, we also suggest that the differences in oleogel properties come from the spatial distribution of the crystalline mass. In this study, we confirm that the effect of the 3:1 molecular ratio in mixed surfactant systems described more than 50 years ago for foams, emulsions and Langmuir monolayers occurs also on the crystallization of mixed fatty alcohol and fatty acid in oils leading to better oleogels properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fatty acid hydrogenated Ni 3 Fe/R-TiO 2 with an alcohol yield of 94.8%. • Hydrothermal treatment of rutile support can obtain high SSA, Ov and basic sites. • Ni and Fe loading on Ov and basic sites promote the formation of Ni 3 Fe clusters. • Ni 3 Fe clusters anchored on Ov changing electron distribution affecting adsorption behaviour. Ni 3 Fe clusters anchored on rutile (R-TiO 2) were synthesized by hydrothermal (HT), coprecipitation (CP) and impregnation (IM) methods, and the catalytic performance of different NiFe/R-TiO 2 catalysts were investigated for hydrogenation of fatty acid into alcohol. Notably, HT-NiFe/R-TiO 2 catalyst, with the highest specific surface area and Ni 3 Fe nanoparticles dispersion, exhibited the best hydrogenation activity towards alcohol production, with complete conversion and yield reach of 92.5 % at 4 MPa H 2 , 210 ℃ and 6 h. The structure–reactivity relationship was investigated by a series of catalysts characterization, DFT calculation and corroborated through hydrogenation performance evaluations. Anchoring Ni 3 Fe clusters onto highly dispersed basic site surfaces with different Ov concentrations can change the electron distribution and strength of the metal-support interaction, causing more stable adsorption of the H and acids molecular toward fatty alcohol production. This work provides further insight into the structure–activity of NiFe/TiO 2 catalysts synthesized through different methods. [ABSTRACT FROM AUTHOR]

Alkyl poliglucosides (APG) is nonionic surfactant prepared from renewable raw materials based on carbohydrate and vegetable oils namely glucose and fatty alcohol. Glucose is the main raw material which is supplied the hydrophilic group, and fatty alcohol as hydrophobic group. APG was prepared using fatty alcohol varying in chain lengthsof C12 and C16 by two step methods (butanolysis and transasetalisation process). The catalyst of methyl ester sulfonic acid (MESA) was added. The effect of catalyst concentrations (1.5, 2, and 2.5%) was investigated. The product evaluated for surface active properties. The chemical structures of the products were confirmed using fourier transform infrared spectroscopy (FTIR).The effects of fatty alcohol and concentration of catalyst were not significantly different to the pH and density. The result showed that reduction surface tension, reduction interfacial tension, and emulsion stability increased with increasing alkyl chain length and foam height decreases as the alkyl chain length increases. The best APG was obtained from C16 fatty alcohol (hexadecanol) and 2.5% of MESA catalyst, with the ability to reduce surface tensions at 1% concentration were 68.12%; the ability to reduce interfacial tensions of 98.14%, stability of emulsion of64%, foam height of 7.12% and pH of 7.69.

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, 13Cmetabolic 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.

Cofactor imbalance obstructs the productivities of metabolically engineered cells. Herein, we employed a minimally perturbing system, xylose reductase and lactose (XR/lactose), to increase the levels of a pool of sugar phosphates which are connected to the biosynthesis of NAD(P)H, FAD, FMN, and ATP in Escherichia coli. The XR/lactose system could increase the amounts of the precursors of these cofactors and was tested with three different metabolically engineered cell systems (fatty alcohol biosynthesis, bioluminescence light generation, and alkane biosynthesis) with different cofactor demands. Productivities of these cells were increased 2-4-fold by the XR/lactose system. Untargeted metabolomic analysis revealed different metabolite patterns among these cells, demonstrating that only metabolites involved in relevant cofactor biosynthesis were altered. The results were also confirmed by transcriptomic analysis. Another sugar reducing system (glucose dehydrogenase) could also be used to increase fatty alcohol production but resulted in less yield enhancement than XR. This work demonstrates that the approach of increasing cellular sugar phosphates can be a generic tool to increase in vivo cofactor generation upon cellular demand for synthetic biology., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

• Aldehyde/alcohol ratios differ largely in αDox- or CAR-catalyzed biotransformations. • Catabolic redox state of CAR-expressing probably the reason for the high aldehyde reduction activity. • Undecanal product titer 10 mM using αDox, dodecanol product titer 6 mM using Car. • E. coli fatty aldehyde dehydrogenase activity produces C 12 , C 11 , C 10 and C 9 fatty acids. Fatty aldehydes are among the most important flavor and fragrance compounds. Most biotechnological production approaches make use of the one step conversion of fatty acids from renewable sources by the enzymes α-dioxygenase (αDox) or carboxylic acid reductase (CAR). Their reaction mechanisms and cofactor dependencies are very different. In contrast to heme-containing αDox which requires only oxygen as cosubstrate, CAR needs NADPH and ATP, which is a clear argument for the application of a whole cell catalyst. Therefore we compared fatty acid biotransformations with growing Escherichia coli cells expressing αDox or CAR to investigate their suitability for fatty aldehyde and also fatty alcohol production. Our results show the main product of fatty acid conversions with αDox-expressing cells to be the expected C n-1 aldehyde. However, 14% of the products consist of the corresponding alcohol, but in addition, 17% of the products consist of further shortened aldehydes, alcohols and acids that result from the consecutive activity of αDox and a putative endogenous fatty aldehyde dehydrogenase activity in E. coli. Conversely, CAR-expressing cells produced only the unshortened fatty aldehyde and alcohol, whereby the latter surprisingly accounts for at least 80% of the products. The considerably higher extend of aldehyde reduction of CAR-expressing cells was shown to be causally connected to the CAR-mediated fatty acid conversion. Our study provides an overview about the applicability of αDox- or CAR-based whole cell catalysts and gives a detailed description of side products as well as suggestions for tailored strain engineering. [ABSTRACT FROM AUTHOR]

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, 13Cmetabolic 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. [ABSTRACT FROM AUTHOR]

Abstract Long chain fatty acids and alcohols are low volatile species in continental and marine aerosols. We established a surface film model by Langmuir trough to investigate the interfacial properties of sea salts droplets coated by surface active molecules—stearic acid (SA), oleic acid (OA), 1-octadecanol (C18OH) and their mixtures. The aim of this work was to verify the impact of the head group, saturation degree, mixing ratio of different surfactants on miscibility and stability between these compounds in monolayers at the air–water interface. Compared to the organic-coated water droplets, the surface properties of mixed fatty acid and alcohol-coated aqueous sea salt particles are substantially different. Mixed SA/C18OH monolayers are less stable than pure SA or C18OH monolayer at high surface pressure. From the point of view of the geometry, steric hindrance of unsaturated chain is the crucial factor in loose packing of OA monolayer. The negative values of excess mixing areas (Δ A ex) for OA/C18OH monolayer on artificial seawater result from the attractive interaction between tail groups. The maximum negative value of excess Gibbs free energies (Δ G ex) appears at the equimolecular OA and C18OH. Surface pressure−area (π–A) isotherm combined with equilibrium spreading pressure (ESP) confirms that the tightly packed monolayer formed by C18OH molecules can minimize water evaporation rate of the potential droplet. Different surface properties of organic films coated on aqueous aerosol must have a significant impact on interaction droplet growth. The interactions between fatty acid and alcohol at the air-water interface provide an insight into the nucleation and growth mechanism of droplets covered by film-forming species. Highlights • A Langmuir film model simulated organic-coated aqueous aerosol surface. • OA/C18OH mixture was more stable on artificial seawater than on pure water. • SA/C18OH mixture was not as stable as single SA and C18OH components. • The condensed organic film on aerosol influence cloud droplet nucleation. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Hypothesis Caffeoyl malate anhydride, as a good nucleophilic acceptor, can react with lipophilic fatty alcohols to yield interface-confined amphiphiles. The resulting novel molecules are hypothesized to deliver combined functionalities of parent natural building blocks, as emulsifier, stabilizer, ion chelator and free radical scavenger. Experiments Ring-opening reactions of caffeoyl malate anhydride with fatty alcohols of different chain lengths generated a new group of antioxidant amphiphiles. Structural verification was by MS (mass spectrometry), 1H/13C NMR (nuclear magnetic resonance) and FT-IR (Fourier transform infra-red) spectroscopy. Physicochemical characterization was done by use of DSC (differential scanning calorimetry), FT-IR, determinations of critical micelle concentrations (CMC) and calculations of HLB. Antioxidant activity was assessed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and hydroxyl radical scavenging activities. Dynamic light scattering (DLS) studies demonstrated surface-activity of G8 – G18. Inhibition of iron- and thermally-accelerated lipid oxidation was monitored by thiobarbituric acid reactive substances (TBARS) assay. Findings Derivatization of caffeoyl malate anhydride with fatty alcohols maintained free radical scavenging activity, and improved hydroxyl radical scavenging activity of caffeic acid. Lipid oxidation at 22 °C was significantly inhibited (up to 3.5 times) in emulsions stabilized by G8 – G18 with or without chitosan compared to emulsions stabilized by commercial emulsifiers and stabilizers. Thermal oxidation (at 80 °C) was 10 times less in emulsions facilitated by G8 – G18 in combination with chitosan compared to emulsions stabilized by commercial emulsifiers and stabilizers. This study has developed a simple and straightforward approach for developing value-added compounds from underexplored fatty alcohols. [ABSTRACT FROM AUTHOR]

Pharmaceutical eutectics are solid mixtures, where the crystals of active pharmaceutical ingredients (APIs) are finely divided in the phase-separated microstructures. The size reduction makes the eutectic formation a viable option to improve the dissolution rate of the poorly soluble APIs. In the present study, ibuprofen, naproxen, and sorafenib were investigated in terms of their phase behaviors with fatty alcohols, such as tetradecanol, octadecanol, and docosanol. Among the studied APIs, only ibuprofen was able to form eutectics with the fatty alcohols, and this was in agreement with the feasibility prediction based on the van ’t Hoff equation and solubility parameters. In vitro release behavior was significantly improved for the ibuprofen/octadecanol eutectic mixture, although the practical insolubility of octadecanol in water was the opposite of the outstanding hydrophilicity of usual eutectic formers. The feasibility prediction and the choice of eutectic formers in the present study will be useful in advancing the utility of the pharmaceutical eutectics.