-
Biotechnology For Biofuels 2018As a versatile platform chemical, construction of microbial catalysts for free octanoic acid production from biorenewable feedstocks is a promising alternative to...
BACKGROUND
As a versatile platform chemical, construction of microbial catalysts for free octanoic acid production from biorenewable feedstocks is a promising alternative to existing petroleum-based methods. However, the bio-production strategy has been restricted by the low capacity of inherent fatty acid biosynthesis. In this study, a combination of integrated computational and experimental approach was performed to manipulate the existing metabolic network, with the objective of improving bio-octanoic acid production.
RESULTS
First, a customized OptForce methodology was run to predict a set of four genetic interventions required for production of octanoic acid at 90% of the theoretical yield. Subsequently, all the ten candidate proteins associated with the predicted interventions were regulated individually, as well as in contrast to the combination of interventions as suggested by the OptForce strategy. Among these enzymes, increased production of 3-hydroxy-acyl-ACP dehydratase (FabZ) resulted in the highest increase (+ 45%) in octanoic acid titer. But importantly, the combinatorial application of FabZ with the other interventions as suggested by OptForce further improved octanoic acid production, resulting in a high octanoic acid-producing strain + Δ Δ Δ (TE10) (+ 61%). Optimization of expression, medium pH, and C:N ratio resulted in the identified strain producing 500 mg/L of C8 and 805 mg/L of total FAs, an 82 and 155% increase relative to wild-type MG1655 (TE10) in shake flasks. The best engineered strain produced with high selectivity (> 70%) and extracellularly (> 90%) up to 1 g/L free octanoic acid in minimal medium fed-batch culture.
CONCLUSIONS
This work demonstrates the effectiveness of integration of computational strain design and experimental characterization as a starting point in rewiring metabolism for octanoic acid production. This result in conjunction with the results of other studies using OptForce in strain design demonstrates that this strategy may be also applicable to engineering for other customized bioproducts.
PubMed: 29619083
DOI: 10.1186/s13068-018-1078-z -
ACS Synthetic Biology May 2021Octanoic acid is an industrially relevant compound with applications in antimicrobials or as a precursor for biofuels. Microbial biosynthesis through yeast is a...
Octanoic acid is an industrially relevant compound with applications in antimicrobials or as a precursor for biofuels. Microbial biosynthesis through yeast is a promising alternative to current unsustainable production methods. To increase octanoic acid titers in , we use a previously developed biosensor that is based on the octanoic acid responsive promotor coupled to GFP. We establish a biosensor strain amenable for high-throughput screening of an octanoic acid producer strain library. Through development, optimization, and execution of a high-throughput screening approach, we were able to detect two new genetic targets, and , which increased octanoic acid titers through combined overexpression by about 55% compared to the parental strain. Neither target has yet been reported to be involved in fatty acid biosynthesis. The presented methodology can be employed to screen any genetic library and thereby more genes involved in improving octanoic acid production can be detected in the future.
Topics: Biosensing Techniques; Caprylates; Fatty Acids; Flow Cytometry; Gene Expression; Gene Library; Green Fluorescent Proteins; High-Throughput Screening Assays; Metabolic Engineering; Microorganisms, Genetically-Modified; Phosphotransferases (Phosphate Group Acceptor); Promoter Regions, Genetic; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Serine Proteases
PubMed: 33979526
DOI: 10.1021/acssynbio.0c00600 -
The Journal of Physical Chemistry. C,... Feb 2024Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of...
Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent p at the air-water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the surface p values for OA and PFOA are determined to be 3.8 ± 0.1 and 2.2 ± 0.2, respectively. These results could provide insights into improved remediation of PFOAs and may impact climate modeling of perfluorinated alkyl chain molecules.
PubMed: 38352857
DOI: 10.1021/acs.jpcc.3c07235 -
British Journal of Pharmacology Sep 20115-Lipoxygenase (5-LO) is the key enzyme in the biosynthesis of pro-inflammatory leukotrienes (LTs) representing a potential target for pharmacological intervention with...
2-(4-(Biphenyl-4-ylamino)-6-chloropyrimidin-2-ylthio)octanoic acid (HZ52)--a novel type of 5-lipoxygenase inhibitor with favourable molecular pharmacology and efficacy in vivo.
BACKGROUND AND PURPOSE
5-Lipoxygenase (5-LO) is the key enzyme in the biosynthesis of pro-inflammatory leukotrienes (LTs) representing a potential target for pharmacological intervention with inflammation and allergic disorders. Although many LT synthesis inhibitors are effective in simple in vitro test systems, they frequently fail in vivo due to lack of efficacy. Here, we attempted to assess the pharmacological potential of the previously identified 5-LO inhibitor 2-(4-(biphenyl-4-ylamino)-6-chloropyrimidin-2-ylthio)octanoic acid (HZ52).
EXPERIMENTAL APPROACH
We evaluated the efficacy of HZ52 in vivo using carrageenan-induced pleurisy in rats and platelet-activating factor (PAF)-induced lethal shock in mice. We also characterized 5-LO inhibition by HZ52 at the cellular and molecular level in comparison with other types of 5-LO inhibitor, that is, BWA4C, ZM230487 and hyperforin.
KEY RESULTS
HZ52, 1.5 mg·kg⁻¹ i.p., prevented carrageenan-induced pleurisy accompanied by reduced LTB(4) levels and protected mice (10 mg·kg⁻¹, i.p.) against PAF-induced shock. Detailed analysis in cell-based and cell-free assays revealed that inhibition of 5-LO by HZ52 (i) does not depend on radical scavenging properties and is reversible; (ii) is not impaired by an increased peroxide tone or by elevated substrate concentrations; and (iii) is little affected by the cell stimulus or by phospholipids, glycerides, membranes or Ca²⁺.
CONCLUSIONS AND IMPLICATIONS
HZ52 is a promising new type of 5-LO inhibitor with efficacy in vivo and with a favourable pharmacological profile. It possesses a unique 5-LO inhibitory mechanism different from classical 5-LO inhibitors and seemingly lacks the typical disadvantages of former classes of LT synthesis blockers.
Topics: Animals; Anti-Inflammatory Agents; Arachidonate 5-Lipoxygenase; Caprylates; Carrageenan; Leukotriene B4; Lipoxygenase Inhibitors; Male; Mice; Neutrophils; Nuclear Envelope; Platelet Activating Factor; Pleurisy; Protein Transport; Pyrimidines; Rats; Rats, Wistar; Shock
PubMed: 21506958
DOI: 10.1111/j.1476-5381.2011.01451.x -
The Laryngoscope Aug 2019The purpose of this study was to determine the effects of octanoic acid on acoustic, perceptual, and functional aspects of essential voice tremor (EVT). (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES/HYPOTHESIS
The purpose of this study was to determine the effects of octanoic acid on acoustic, perceptual, and functional aspects of essential voice tremor (EVT).
STUDY DESIGN
Prospective, double-blind, placebo-controlled, crossover study.
METHODS
Sixteen participants with a diagnosis of EVT were randomized to a 3-week dosing condition of octanoic acid or placebo, followed by a 2-week washout period and crossover to the other condition for an additional 3 weeks. Baseline and post-testing sessions were completed before and at the completion of each condition. Primary outcome measures were the magnitude of amplitude and frequency tremor, measured from the acoustic signal. Secondary outcomes were auditory-perceptual ratings of tremor severity and self-ratings of voice handicap.
RESULTS
Magnitude of amplitude and frequency tremor were significantly lower after 3 weeks of octanoic acid dosing as compared to the placebo condition. Auditory-perceptual ratings of tremor severity did not show significant differences between conditions. A trend toward better voice was seen for the sustained vowel ratings, but not the sentence-level ratings. No significant differences between conditions were seen on self-reported voice disability as assessed on the Voice Handicap Index-10.
CONCLUSIONS
The results of this controlled investigation support the potential utility of octanoic acid for reducing the magnitude of tremor in people with EVT. Further research is needed to determine whether different dosing or treatment combinations can improve functional communication in EVT.
LEVEL OF EVIDENCE
1 Laryngoscope, 129:1882-1890, 2019.
Topics: Aged; Caprylates; Cross-Over Studies; Double-Blind Method; Essential Tremor; Female; Humans; Male; Middle Aged; Prospective Studies; Severity of Illness Index; Treatment Outcome; Voice; Voice Disorders
PubMed: 30585335
DOI: 10.1002/lary.27695 -
The Journal of Biological Chemistry Aug 2009The orphan G-protein-coupled receptor GPR109B is the result of a recent gene duplication of the nicotinic acid and ketone body receptor GPR109A being found in humans but...
The orphan G-protein-coupled receptor GPR109B is the result of a recent gene duplication of the nicotinic acid and ketone body receptor GPR109A being found in humans but not in rodents. Like GPR109A, GPR109B is predominantly expressed in adipocytes and is supposed to mediate antilipolytic effects. Here we show that GPR109B serves as a receptor for the beta-oxidation intermediate 3-OH-octanoic acid, which has antilipolytic activity on human but not on murine adipocytes. GPR109B is coupled to Gi-type G-proteins and is activated by 2- and 3-OH-octanoic acid with EC50 values of about 4 and 8 microM, respectively. Interestingly, 3-OH-octanoic acid plasma concentrations reach micromolar concentrations under conditions of increased beta-oxidation rates, like in diabetic ketoacidosis or under a ketogenic diet. These data suggest that the ligand receptor pair 3-OH-octanoic acid/GPR109B mediates in humans a negative feedback regulation of adipocyte lipolysis to counteract prolipolytic influences under conditions of physiological or pathological increases in beta-oxidation rates.
Topics: Adipocytes; Animals; CHO Cells; Caprylates; Cell Line; Cricetinae; Cricetulus; Humans; Ligands; Lipolysis; Mice; Models, Biological; Oxygen; Protein Binding; Receptors, G-Protein-Coupled; Receptors, Nicotinic
PubMed: 19561068
DOI: 10.1074/jbc.M109.019455 -
Foods (Basel, Switzerland) Feb 2023The solid-state fermentation of Baijiu is complicated by the co-fermentation of many microorganisms. The instability of the composition and abundance of the...
The solid-state fermentation of Baijiu is complicated by the co-fermentation of many microorganisms. The instability of the composition and abundance of the microorganisms in the fermentation process leads to fluctuations of product quality, which is one of the bottleneck problems faced by the Strong-flavor Baijiu industry. In this study, we established a combination of functional microorganisms for the stable fermentation of the main flavor compounds of Baijiu, including medium and long-chain fatty acid ethyl esters such as hexanoic acid, ethyl ester; butanoic acid, ethyl ester; octanoic acid, ethyl ester; acetic acid, ethyl ester; 9,12-octadecadienoic acid, ethyl ester; and decanoic acid, ethyl ester in the fermented grains. Our study investigated the effects of microbial combinations on the fermentation from three aspects: microbial composition, microbial interactions, and microbial association with flavor compounds. The results showed that the added functional microorganisms (, , , , and ) became the dominant species in the fermentation system and formed positive interactions with other microorganisms, while the negative interactions between microorganisms were significantly reduced in the fermentation systems that contained both Daqu and functional microorganisms. The redundancy analysis showed that the functional microorganisms (, , , , , , and ) showed strong positive correlations with the main flavor compounds (hexanoic acid, ethyl ester; lactic acid, ethyl ester; butanoic acid, ethyl ester; acetic acid, ethyl ester; and octanoic acid, ethyl ester). These results indicated that it was feasible to produce Baijiu with a functional microbial combination, and that this could promote stable Baijiu production.
PubMed: 36766173
DOI: 10.3390/foods12030644 -
World Journal of Gastrointestinal... Aug 2016In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome... (Review)
Review
In the field of gastroenterology, breath tests (BTs) are used intermittently as diagnostic tools that allow indirect, non-invasive and relatively less cumbersome evaluation of several disorders by simply quantifying the appearance in exhaled breath of a metabolite of a specific substrate administered. The aim of this review is to have an insight into the principles, methods of analysis and performance parameters of various hydrogen, methane and carbon BTs which are available for diagnosing gastrointestinal disorders such as Helicobacter pylori infection, small intestinal bacterial overgrowth, and carbohydrate malabsorption. Evaluation of gastric emptying is routinely performed by scintigraphy which is however, difficult to perform and not suitable for children and pregnant women, this review has abridged the 13C-octanoic acid test in comparison to scintigraphy and has emphasized on its working protocol and challenges. A new development such as electronic nose test is also highlighted. Moreover we have also explored the limitations and constraints restraining the wide use of these BT. We conclude that breath testing has an enormous potential to be used as a diagnostic modality. In addition it offers distinct advantages over the traditional invasive methods commonly employed.
PubMed: 27574563
DOI: 10.4291/wjgp.v7.i3.256 -
Journal of Dairy Science Nov 2019To determine the key aroma compounds in Chinese milk fan cheese, samples from 6 of the most popular handmade milk fan workshops in Yunnan province of China were analyzed...
To determine the key aroma compounds in Chinese milk fan cheese, samples from 6 of the most popular handmade milk fan workshops in Yunnan province of China were analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), sensory evaluation, aroma recombination and omission experiments. Seventy-one aroma compounds were identified by GC-MS, and 31 odor-active compounds were detected by GC-O. The relationships between the 31 odor-active compounds and 10 sensory evaluation properties were explored by partial least squares discriminant analysis. The results identified 23 initial key aroma compounds, which were used to simulate the aroma profile of milk fan in aroma recombination experiments. Aroma omission experiments identified propanoic acid, butanoic acid, octanoic acid, octanal, nonanal, 2-nonanone, and ethyl hexanoate as the key aroma compounds. Propanoic acid and butanoic acid contributed to cheese and rancid aromas, octanal and nonanal to the fat aroma, octanoic acid and 2-nonanone to the cheese aroma, and ethyl hexanoate to the fruity aroma of milk fan.
Topics: Aldehydes; Animals; Cattle; Cheese; China; Gas Chromatography-Mass Spectrometry; Ketones; Least-Squares Analysis; Milk; Odorants; Olfactometry
PubMed: 31477286
DOI: 10.3168/jds.2019-16796 -
FASEB Journal : Official Publication of... Jun 2012A physiological relationship between iron, oxidative injury, and fatty acid metabolism exists, but transduction mechanisms are unclear. We propose that the iron storage...
A physiological relationship between iron, oxidative injury, and fatty acid metabolism exists, but transduction mechanisms are unclear. We propose that the iron storage protein ferritin contains fatty acid binding sites whose occupancy modulates iron uptake and release. Using isothermal microcalorimetry, we found that arachidonic acid binds ferritin specifically and with 60 μM affinity. Arachidonate binding by ferritin enhanced iron mineralization, decreased iron release, and protected the fatty acid from oxidation. Cocrystals of arachidonic acid and horse spleen apoferritin diffracted to 2.18 Å and revealed specific binding to the 2-fold intersubunit pocket. This pocket shields most of the fatty acid and its double bonds from solvent but allows the arachidonate tail to project well into the ferrihydrite mineralization site on the ferritin L-subunit, a structural feature that we implicate in the effects on mineralization by demonstrating that the much shorter saturated fatty acid, caprylate, has no significant effects on mineralization. These combined effects of arachidonate binding by ferritin are expected to lower both intracellular free iron and free arachidonate, thereby providing a previously unrecognized mechanism for limiting lipid peroxidation, free radical damage, and proinflammatory cascades during times of cellular stress.
Topics: Apoferritins; Arachidonic Acid; Binding Sites; Calorimetry; Caprylates; Crystallography, X-Ray; Fatty Acids; Ferritins; Iron; Models, Molecular
PubMed: 22362897
DOI: 10.1096/fj.11-198853