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Nature Communications Feb 2023Antibiotics are a key control mechanism for synthetic biology and microbiology. Resistance genes are used to select desired cells and regulate bacterial populations,...
Antibiotics are a key control mechanism for synthetic biology and microbiology. Resistance genes are used to select desired cells and regulate bacterial populations, however their use to-date has been largely static. Precise spatiotemporal control of antibiotic resistance could enable a wide variety of applications that require dynamic control of susceptibility and survival. Here, we use light-inducible Cre recombinase to activate expression of drug resistance genes in Escherichia coli. We demonstrate light-activated resistance to four antibiotics: carbenicillin, kanamycin, chloramphenicol, and tetracycline. Cells exposed to blue light survive in the presence of lethal antibiotic concentrations, while those kept in the dark do not. To optimize resistance induction, we vary promoter, ribosome binding site, and enzyme variant strength using chromosome and plasmid-based constructs. We then link inducible resistance to expression of a heterologous fatty acid enzyme to increase production of octanoic acid. These optogenetic resistance tools pave the way for spatiotemporal control of cell survival.
Topics: Optogenetics; Anti-Bacterial Agents; Drug Resistance, Microbial; Tetracycline; Carbenicillin; Escherichia coli
PubMed: 36823420
DOI: 10.1038/s41467-023-36670-2 -
Microbial Cell Factories Feb 2024The improvement of yeast tolerance to acetic, butyric, and octanoic acids is an important step for the implementation of economically and technologically sustainable...
BACKGROUND
The improvement of yeast tolerance to acetic, butyric, and octanoic acids is an important step for the implementation of economically and technologically sustainable bioprocesses for the bioconversion of renewable biomass resources and wastes. To guide genome engineering of promising yeast cell factories toward highly robust superior strains, it is instrumental to identify molecular targets and understand the mechanisms underlying tolerance to those monocarboxylic fatty acids. A chemogenomic analysis was performed, complemented with physiological studies, to unveil genetic tolerance determinants in the model yeast and cell factory Saccharomyces cerevisiae exposed to equivalent moderate inhibitory concentrations of acetic, butyric, or octanoic acids.
RESULTS
Results indicate the existence of multiple shared genetic determinants and pathways underlying tolerance to these short- and medium-chain fatty acids, such as vacuolar acidification, intracellular trafficking, autophagy, and protein synthesis. The number of tolerance genes identified increased with the linear chain length and the datasets for butyric and octanoic acids include the highest number of genes in common suggesting the existence of more similar toxicity and tolerance mechanisms. Results of this analysis, at the systems level, point to a more marked deleterious effect of an equivalent inhibitory concentration of the more lipophilic octanoic acid, followed by butyric acid, on the cell envelope and on cellular membranes function and lipid remodeling. The importance of mitochondrial genome maintenance and functional mitochondria to obtain ATP for energy-dependent detoxification processes also emerged from this chemogenomic analysis, especially for octanoic acid.
CONCLUSIONS
This study provides new biological knowledge of interest to gain further mechanistic insights into toxicity and tolerance to linear-chain monocarboxylic acids of increasing liposolubility and reports the first lists of tolerance genes, at the genome scale, for butyric and octanoic acids. These genes and biological functions are potential targets for synthetic biology approaches applied to promising yeast cell factories, toward more robust superior strains, a highly desirable phenotype to increase the economic viability of bioprocesses based on mixtures of volatiles/medium-chain fatty acids derived from low-cost biodegradable substrates or lignocellulose hydrolysates.
Topics: Saccharomyces cerevisiae; Caprylates; Fatty Acids; Saccharomyces cerevisiae Proteins
PubMed: 38419072
DOI: 10.1186/s12934-024-02309-0 -
Lipids Jul 2022Gastric emptying (GE) is the process of food being processed by the stomach and delivered to the small intestine where nutrients such as lipids are absorbed into the... (Review)
Review
Gastric emptying (GE) is the process of food being processed by the stomach and delivered to the small intestine where nutrients such as lipids are absorbed into the blood circulation. The combination of an easy and inexpensive method to measure GE such as the CO breath test using the stable isotope [ C]octanoic acid with semi-mechanistic modeling could foster a wider application in nutritional studies to further understand the metabolic response to food. Here, we discuss the use of the [ C]octanoic acid breath test to label the solid phase of a meal, and the factors that influence GE to support mechanistic studies. Furthermore, we give an overview of existing mathematical models for the interpretation of the breath test data and how much nutritional studies could benefit from a physiological based pharmacokinetic model approach.
Topics: Breath Tests; Caprylates; Carbon Isotopes; Gastric Emptying
PubMed: 35799422
DOI: 10.1002/lipd.12352 -
Brazilian Journal of Microbiology :... Mar 2022In the present investigation, we determined the in vitro antimicrobial activity of eight essential oils (EOs) and three medium-chain fatty acids (MCFAs) alone and in...
In the present investigation, we determined the in vitro antimicrobial activity of eight essential oils (EOs) and three medium-chain fatty acids (MCFAs) alone and in combination against Staphylococcus aureus ATCC 700698, Klebsiella pneumoniae ATCC 700603, and E. coli FcW5. The interactions between EOs and MCFAs were determined by fractional inhibitory concentration indices. Moreover, mode of action of selected bioactive components was studied by changes in bacterial surface charge, morphology, and membrane integrity assays. Among EOs, carvacrol (CAR), trans-cinnamaldehyde (TC), and thymol (TM) showed strong antimicrobial activity. In combination study, CAR+OA (octanoic acid), CAR+DA (decanoic acid), and TM+OA were observed as the most significant (P≤0.05) which were also confirmed through time-kill plots. Based on these results, CAR+OA were found to be most efficacious in terms of killing time (P≤0.05). Changes in the surface charge, morphology, and membrane integrity upon the combined treatment of CAR+OA were also observed, which ultimately leads to cell death. Results suggest that CAR+OA when used in combination offer a significant (P≤0.05) additive antimicrobial activity against the selected pathogenic bacteria. Therefore, these natural bioactive molecules could be interesting alternatives to conventional therapy for the control of mastitis caused by multi-drug-resistant pathogens in bovine animals to ensure the milk safety.
Topics: Animals; Anti-Bacterial Agents; Caprylates; Cattle; Cymenes; Escherichia coli; Female; Humans; Mastitis; Microbial Sensitivity Tests; Oils, Volatile; Pharmaceutical Preparations
PubMed: 34784023
DOI: 10.1007/s42770-021-00639-4 -
Journal of Food Science and Technology Aug 2022Intensification in synthesis of triglycerides of octanoic acid using a heterogeneous amberlyst-15 catalyst has been investigated with the application of ultrasound under...
UNLABELLED
Intensification in synthesis of triglycerides of octanoic acid using a heterogeneous amberlyst-15 catalyst has been investigated with the application of ultrasound under solvent-free conditions. Further, the frying characteristics of medium-chain triglycerides (tricaprin) are evaluated by deep frying of French fries in various combinations of palm oil and tricaprin. Understanding into the effect of parameters such as the temperature of the reaction (over the range of 40 °C-80 °C), loading of amberlyst-15 (1%-5%) and molar ratio of fatty acid to glycerol (3:1-3:5) along with the ultrasound conditions as duty cycle (40%-90%) and time on the conversion (%) has also been developed. Based on the outcomes of the study, optimum reaction conditions seen are 3:4 as the molar ratio of fatty acid (C8): glycerol, amberlyst-15 loading of 3% and a reaction temperature of 50 °C. It was further observed that the optimum ultrasound conditions required for maximum conversion of 99.8% were 240 W power, 80% duty cycle and 15 min as the ultrasound irradiation time. Under similar conditions, the conventional synthesis resulted in only 20% conversion in 15 min. Reusability studies also established that the acid-resin catalyst was effectively reused for 8 times. The PV, p-AV and TPC of frying oil combination containing higher tricaprin (50:50-palm oil: MCT) was 8.4 ± 0.8, 23.1 ± 0.01 and 29.8 ± 0.01 respectively, which were lowest as compared with other blends indicating the beneficial effects of MCT in frying applications. The work clearly shows that the ultrasound application for the synthesis of triglyceride of octanoic acid gives higher conversion (%) in a less time and also demonstrates that MCT could be a good alternative for deep frying of foods in combination with palm oil to enhance the shelf-life of food.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13197-022-05379-3.
PubMed: 35872730
DOI: 10.1007/s13197-022-05379-3 -
The Journal of Physical Chemistry. C,... May 2022The adsorption of carboxylic acid molecules at the calcite (104) and the muscovite (001) surface was investigated using surface X-ray diffraction. All four investigated...
The adsorption of carboxylic acid molecules at the calcite (104) and the muscovite (001) surface was investigated using surface X-ray diffraction. All four investigated carboxylic acid molecules, hexanoic acid, octanoic acid, lauric acid, and stearic acid, were found to adsorb at the calcite surface. Whereas the shortest two carboxylic acid molecules, hexanoic acid and octanoic acid, showed limited ordering and a flexible, disordered chain, the two longest carboxylic acid molecules form fully ordered monolayers, i.e., these form highly structured self-assembled monolayers. The latter molecules are oriented almost fully upright, with a tilt of up to 10°. The oxygen atoms of the organic molecules are found at similar positions to those of water molecules at the calcite-water interface. This suggests that in both cases, the oxygen atoms compensate for the broken bonds at the calcite surface. Under the same experimental conditions, stearic acid does not adsorb to K and Ca-functionalized muscovite mica because the neutral molecules do not engage in the ionic bonds typical for the mica interface. These differences in adsorption behavior are characteristic for the differences of the oil-solid interactions in carbonate and sandstone reservoirs.
PubMed: 35655936
DOI: 10.1021/acs.jpcc.2c01157 -
FEMS Yeast Research Mar 2021The medium-chain fatty acid octanoic acid is an important platform compound widely used in industry. The microbial production from sugars in Saccharomyces cerevisiae is...
The medium-chain fatty acid octanoic acid is an important platform compound widely used in industry. The microbial production from sugars in Saccharomyces cerevisiae is a promising alternative to current non-sustainable production methods, however, titers need to be further increased. To achieve this, it is essential to have in-depth knowledge about the cell physiology during octanoic acid production. To this end, we collected the first RNA-Seq data of an octanoic acid producer strain at three time points during fermentation. The strain produced higher levels of octanoic acid and increased levels of fatty acids of other chain lengths (C6-C18) but showed decreased growth compared to the reference. Furthermore, we show that the here analyzed transcriptomic response to internally produced octanoic acid is notably distinct from a wild type's response to externally supplied octanoic acid as reported in previous publications. By comparing the transcriptomic response of different sampling times, we identified several genes that we subsequently overexpressed and knocked out, respectively. Hereby we identified RPL40B, to date unknown to play a role in fatty acid biosynthesis or medium-chain fatty acid tolerance. Overexpression of RPL40B led to an increase in octanoic acid titers by 40%.
Topics: Biosynthetic Pathways; Caprylates; Fermentation; Gene Expression Profiling; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins
PubMed: 33599754
DOI: 10.1093/femsyr/foab011 -
The Journal of Physical Chemistry... Apr 2021Perfluorinated acids (PFAs) are widely used synthetic chemical compounds, highly resistant to environmental degradation. The widespread PFA contamination in remote...
Perfluorinated acids (PFAs) are widely used synthetic chemical compounds, highly resistant to environmental degradation. The widespread PFA contamination in remote regions such as the High Arctic implies currently not understood long-range atmospheric transport pathways. Here, we report that perfluorooctanoic acid (PFOA) initiates heterogeneous ice nucleation at temperatures as high as -16 °C. In contrast, the eight-carbon octanoic acid, perfluorooctanesulfonic acid, and deprotonated PFOA showed poor ice nucleating capabilities. The ice nucleation ability of PFOA correlates with the formation of a PFOA monolayer at the air-water interface, suggesting a mechanism in which the aligned hydroxyl groups of the carboxylic acid moieties provide a lattice matching to ice. The ice nucleation capabilities of fluorinated compounds like PFOA might be relevant for cloud glaciation in the atmosphere and the removal of these persistent pollutants by wet deposition.
PubMed: 33789043
DOI: 10.1021/acs.jpclett.1c00604 -
Molecules (Basel, Switzerland) Nov 2021In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body...
In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body dissatisfaction. According to our expertise, caprylic acid and propanediol would not have a direct action on . Despite this, we investigated the existence of a synergistic effect among xylitol, caprylic acid and propanediol as a mixture of compounds representing a single topical active ingredient that could benefit the treatment against acne. In vitro and in vivo assays were performed to challenge and to prove the efficacy of propanediol, xylitol and caprylic acid (PXCA) against acne. PXCA had its MIC challenged against (formerly ) and , resulting in concentrations of 0.125% and 0.25%, respectively, and it also developed antimicrobial activity against (time-kill test). PXCA was able to reduce the 5-alpha reductase expression in 24% ( < 0.01) in comparison with the testosterone group. By the end of 28 days of treatment, the compound reduced the skin oiliness, porphyrin amount and the quantity of inflammatory lesions in participants. According to the dermatologist evaluation, PXCA improved the skin's general appearance, acne presence and size.
Topics: Acne Vulgaris; Anti-Bacterial Agents; Anti-Inflammatory Agents; Caprylates; Clinical Trials as Topic; Disease Management; Disease Susceptibility; Humans; Microbial Sensitivity Tests; Propylene Glycols; Staphylococcus aureus; Treatment Outcome; Xylitol
PubMed: 34771112
DOI: 10.3390/molecules26216704 -
BMC Biology Feb 2022In insects, airborne chemical signals are mainly detected by two receptor families, odorant receptors (ORs) and ionotropic receptors (IRs). Functions of ORs have been...
BACKGROUND
In insects, airborne chemical signals are mainly detected by two receptor families, odorant receptors (ORs) and ionotropic receptors (IRs). Functions of ORs have been intensively investigated in Diptera and Lepidoptera, while the functions and evolution of the more ancient IR family remain largely unexplored beyond Diptera.
RESULTS
Here, we identified a repertoire of 26 IRs from transcriptomes of female and male antennae, and ovipositors in the moth Agrotis segetum. We observed that a large clade formed by IR75p and IR75q expansions is closely related to the acid-sensing IRs identified in Diptera. We functionally assayed each of the five AsegIRs from this clade using Xenopus oocytes and found that two receptors responded to the tested ligands. AsegIR75p.1 responded to several compounds but hexanoic acid was revealed to be the primary ligand, and AsegIR75q.1 responded primarily to octanoic acid, and less so to nonanoic acid. It has been reported that the C-C medium-chain fatty acids repel various insects including many drosophilids and mosquitos. We show that the C-C medium-chain fatty acids elicited antennal responses of both sexes of A. segetum, while only octanoic acid had repellent effect to the moths in a behavioral assay. In addition, using fluorescence in situ hybridization, we demonstrated that the five IRs and their co-receptor AsegIR8a are not located in coeloconic sensilla as found in Drosophila, but in basiconic or trichoid sensilla.
CONCLUSIONS
Our results significantly expand the current knowledge of the insect IR family. Based on the functional data in combination with phylogenetic analysis, we propose that subfunctionalization after gene duplication plays an important role in the evolution of ligand specificities of the acid-sensing IRs in Lepidoptera.
Topics: Animals; Arthropod Antennae; Brassica napus; Caprylates; Diptera; Female; In Situ Hybridization, Fluorescence; Insect Proteins; Ligands; Male; Moths; Phylogeny; Receptors, Odorant
PubMed: 35130883
DOI: 10.1186/s12915-022-01235-0