scholarly journals Chemotaxis of Pseudomonas putida F1 to Alcohols Is Mediated by the Carboxylic Acid Receptor McfP

2019 ◽  
Vol 85 (22) ◽  
Author(s):  
Xiangsheng Zhang ◽  
Jonathan G. Hughes ◽  
Gabriel A. Subuyuj ◽  
Jayna L. Ditty ◽  
Rebecca E. Parales
Keyword(s):  
Pseudomonas Putida ◽  
Carboxylic Acids ◽  
Energy Sources ◽  
Specific Cell ◽  
Dodecanoic Acid ◽  
Fermentation Products ◽  
Content Type ◽  
Linear Chains ◽  
Chemotaxis Proteins ◽  
Chain Lengths

ABSTRACT Although alcohols are toxic to many microorganisms, they are good carbon and energy sources for some bacteria, including many pseudomonads. However, most studies that have examined chemosensory responses to alcohols have reported that alcohols are sensed as repellents, which is consistent with their toxic properties. In this study, we examined the chemotaxis of Pseudomonas putida strain F1 to n-alcohols with chain lengths of 1 to 12 carbons. P. putida F1 was attracted to all n-alcohols that served as growth substrates (C2 to C12) for the strain, and the responses were induced when cells were grown in the presence of alcohols. By assaying mutant strains lacking single or multiple methyl-accepting chemotaxis proteins, the receptor mediating the response to C2 to C12 alcohols was identified as McfP, the ortholog of the P. putida strain KT2440 receptor for C2 and C3 carboxylic acids. Besides being a requirement for the response to n-alcohols, McfP was required for the response of P. putida F1 to pyruvate, l-lactate, acetate, and propionate, which are detected by the KT2440 receptor, and the medium- and long-chain carboxylic acids hexanoic acid and dodecanoic acid. β-Galactosidase assays of P. putida F1 carrying an mcfP-lacZ transcriptional fusion showed that the mcfP gene is not induced in response to alcohols. Together, our results are consistent with the idea that the carboxylic acids generated from the oxidation of alcohols are the actual attractants sensed by McfP in P. putida F1, rather than the alcohols themselves. IMPORTANCE Alcohols, released as fermentation products and produced as intermediates in the catabolism of many organic compounds, including hydrocarbons and fatty acids, are common components of the microbial food web in soil and sediments. Although they serve as good carbon and energy sources for many soil bacteria, alcohols have primarily been reported to be repellents rather than attractants for motile bacteria. Little is known about how alcohols are sensed by microbes in the environment. We report here that catabolizable n-alcohols with linear chains of up to 12 carbons serve as attractants for the soil bacterium Pseudomonas putida, and rather than being detected directly, alcohols appear to be catabolized to acetate, which is then sensed by a specific cell-surface chemoreceptor protein.

Morphology, Ionic-Molecular Interaction and Ionic Conductivity Behavior of PMMA/ENR 50 Electrolytes Containing Carboxylic Acids Modified SiO2 Fillers

2019 ◽  
Vol 821 ◽  
pp. 419-425
Author(s):  
Mohamad Zamri Sharil Fadli ◽  
Abdul Latif Famiza ◽  
Mohd Azuan Siti Izzati Husna
Keyword(s):  
Ionic Conductivity ◽  
Carboxylic Acids ◽  
Octanoic Acid ◽  
Silanol Group ◽  
Carbon Chain ◽  
Dodecanoic Acid ◽  
Casting Method ◽  
Acid Modification ◽  
Lithium Tetrafluoroborate ◽  
Chain Lengths

Carboxylic acids of various carbon chain lengths (Cn); i.e. butanoic acid (C4), octanoic acid (C8), dodecanoic acid (C12) and hexadecanoic acid (C16) have been used to organically modify silicon dioxide (SiO2). The acid modification involve replacing the hydrogen atom of the silanol group (Si-OH) of SiO2 with the RnCOO-of the acid via esterification technique. SiO2 and acid modified SiO2 (MoCn-SiO2) were used as filler in preparation of polymethyl methacrylate/50% epoxidized natural rubber electrolytes containing SiO2 (PEL-SiO2) and MoCn-SiO2 (PEL-MoCn-SiO2) via solvent casting method with lithium tetrafluoroborate (LiBF4) as dopant salt. Field-emission scanning electron microscopy (FESEM) analysis of PEL-SiO2 and PEL-MoCn-SiO2 films show LiBF4 accumulated to the fillers. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed formation of hydrogen bonding between LiBF4 with fillers and polymers in the polymer electrolyte films. Interestingly, the ionic conductivity of PEL-MoCn-SiO2 films increases as the Cn of acids increased with the highest ionic conductivity of 5.56 x 10-7 Scm-1 was achieved in PEL-MoC12-SiO2 film.

scholarly journals Heterologous Expression ofPseudomonas putidaMethyl-Accepting Chemotaxis Proteins YieldsEscherichia coliCells Chemotactic to Aromatic Compounds

2018 ◽  
Vol 84 (18) ◽  
Author(s):  
Clémence Roggo ◽  
Estelle Emilie Clerc ◽  
Noushin Hadadi ◽  
Nicolas Carraro ◽  
Roman Stocker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Aromatic Compounds ◽  
Environmental Concern ◽  
Bacterial Chemotaxis ◽  
Gene Encoding ◽  
Content Type ◽  
E Coli ◽  
Cell Accumulation ◽  
Chemotaxis Proteins

ABSTRACTEscherichia coli, commonly used in chemotaxis studies, is attracted mostly by amino acids, sugars, and peptides. We envisioned modifying the chemotaxis specificity ofE. coliby expressing heterologous chemoreceptors fromPseudomonas putidaenabling attraction either to toluene or benzoate. ThemcpTgene encoding the type 40-helical bundle (40H) methyl-accepting chemoreceptor for toluene fromPseudomonas putidaMT53 and thepcaYgene for the type 40H receptor for benzoate and related molecules fromP. putidaF1 were expressed from thetrgpromoter on a plasmid in motile wild-typeE. coliMG1655.E. colicells expressing McpT accumulated in chemoattraction assays to sources with 60 to 200 μM toluene, although less strongly than the response to 100 μM serine, but statistically significantly stronger than that to sources without any added attractant. An McpT-mCherry fusion protein was detectably expressed inE. coliand yielded weak but distinguishable membranes and polar foci in 1% of cells.E. colicells expressing PcaY showed weak attraction to 0.1 to 1 mM benzoate, but 50 to 70% of cells localized the PcaY-mCherry fusion to their membrane. We conclude that implementing heterologous receptors in theE. colichemotaxis network is possible and, upon improvement of the compatibility of the type 40H chemoreceptors, may bear interest for biosensing.IMPORTANCEBacterial chemotaxis might be harnessed for the development of rapid biosensors, in which chemical availability is deduced from cell accumulation to chemoattractants over time. Chemotaxis ofEscherichia colihas been well studied, but the bacterium is not attracted to chemicals of environmental concern, such as aromatic solvents. We show here that heterologous chemoreceptors for aromatic compounds fromPseudomonas putidaat least partly functionally complement theE. colichemotaxis network, yielding cells attracted to toluene or benzoate. Complementation was still inferior to native chemoattractants, like serine, but our study demonstrates the potential for obtaining selective sensing for aromatic compounds inE. coli.

scholarly journals Isolation of a Gene Responsible for the Oxidation oftrans-Anethole topara-Anisaldehyde by Pseudomonas putida JYR-1 and Its Expression in Escherichia coli

2012 ◽  
Vol 78 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Dongfei Han ◽  
Ji-Young Ryu ◽  
Robert A. Kanaly ◽  
Hor-Gil Hur
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Hypothetical Protein ◽  
Aldehyde Group ◽  
Agrobacterium Vitis ◽  
T7 Promoter ◽  
Content Type ◽  
E Coli ◽  
Cell Extracts ◽  
Isoeugenol Monooxygenase

ABSTRACTA plasmid, pTA163, inEscherichia colicontained an approximately 34-kb gene fragment fromPseudomonas putidaJYR-1 that included the genes responsible for the metabolism oftrans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyzetrans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter inE. colicatalyzed oxidative cleavage of a propenyl group oftrans-anethole to an aldehyde group, resulting in the production ofpara-anisaldehyde, and this gene was designatedtao(trans-anetholeoxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein ofAgrobacterium vitisS4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water intop-anisaldehyde using18O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase fromPseudomonas putidaIE27 andPseudomonas nitroreducensJin1, TAO fromP. putidaJYR-1 catalyzed isoeugenol,O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts ofE. coli(pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.

Degrees of order of solubilized alkanes, alcohols, carboxylates, and carboxylic acids in oriented lyomesophases

1977 ◽  
Vol 55 (12) ◽  
pp. 2404-2410 ◽  
Author(s):  
Douglas M. Chen ◽  
Fred Y. Fujiwara ◽  
Leonard W. Reeves
Keyword(s):  
Carboxylic Acids ◽  
Chain Length ◽  
Linear Increase ◽  
Short Chain ◽  
Appreciable Amount ◽  
Linear Region ◽  
Short Chain Length ◽  
Chain Lengths ◽  
Degree Of Order ◽  
Limiting Value

The degree of order of solubilized molecules and ions in oriented lyomesophases has been determined at specifically deuterated C—D bond axes from the quadrupole splitting of the deuterium magnetic resonance. Mixtures at low concentration of specifically deuterated alkanes, alcohols, carboxylic acids, and carboxylates of different chain length have been observed in host cationic and anionic lyomesophases. The degree of order of a given C—D position in alcohols increases strongly with chain length up to a length comparable with the host detergent. A broad series of carboxylic acids and carboxylate ions from C2 to C16 have been deuterated in the α position. The α-C—D bond axis in the solubilisate increases in order with chain length, the anion having lower order than the parent acid. An accurately linear increase in the degree of order of the α position is observed for intermediate chain lengths. At chain lengths approximately equal to the host chain lengths the α position reaches a limiting value in the degree of order and further segments do not influence the order. At short chain lengths the degree of order is less than that predicted from extrapolation of order in the linear region. This has been interpreted in terms of distribution into the aqueous compartment by the solubilisates of short chain length. Acetic acid and the acetate, propionate, butanoate, and pentanoate ions spend an appreciable amount of time in the aqueous region. An estimate has been made of these distributions based on reasonable assumptions.

Problems of adoption of solar power and subsequent switching behavior: an exploration in India

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Subhadip Roy ◽  
Subhalaxmi Mohapatra
Keyword(s):  
Behavioral Intentions ◽  
Structural Equation ◽  
Alternative Energy ◽  
Solar Power ◽  
Switching Behavior ◽  
Energy Sources ◽  
Energy Usage ◽  
Content Type ◽  
Household Level ◽  
Alternative Energy Sources

Purpose The challenges and factors of household adoption and the use of alternative energy sources have been a point of discussion among researchers. The purpose of this study is to apply a variant of the unified theory of adoption and use of technology (i.e. UTAUT 2) to explore the effect of various constructs that influence technology adoption on the consumers’ intention to adopt (and use) solar power generators (SPG) at the household level and the subsequent switching behavior. Design/methodology/approach Based on survey data collected from six cities in India (n = 1,246), factor analysis and structural equation modeling are applied for data analysis and testing the study hypotheses. Findings The results of the structural equation model found UTAUT constructs performance expectancy, effort expectancy, social influence and hedonic to positively affect behavioral intentions to adopt SPG. However, facilitating conditions and perceived value was not found to affect behavioral intentions to adopt SPG. Behavioral intentions to adopt SPG was found to positively influence the switching behavior. Research limitations/implications The present study augments the domain of alternative energy usage behavior by applying the UTAUT 2 in the adoption of alternative energy sources (namely, solar) and subsequent switching behavior from traditional sources at the household level. Practical implications The findings from the present study will guide the marketers and policymakers on the consumer attitudinal and behavioral aspects of solar energy usage at the household level and subsequent switching behavior. Originality/value The present study is novel as it moves beyond household-level behavioral intention to use solar energy and includes the switching behavior to shift to solar power from traditional energy sources.

Energy transition demand will elevate aluminium prices

2021 ◽  
Keyword(s):  
Supply Chain ◽  
Middle East ◽  
High Power ◽  
Energy Transition ◽  
Green Energy ◽  
Power Markets ◽  
Energy Sources ◽  
Content Type

Significance Aluminium smelters are being hampered by high power prices and shortages amid the switch towards green energy sources. China has been forced to start importing aluminium at record levels to tackle domestic shortages. Impacts The green energy transition will strain power markets, increasing the challenge of producing energy-intensive aluminium. Supply will gradually diversify as outputs stagnates in China but looks set to rise in Argentina, Brazil, the Middle East and Russia. Consumers and governments in importing nations will increase aluminium recovery and recycling to cut pressure on the supply chain.

Heterogeneous effect of oil production on environmental degradation: panel evidence from OPEC member countries

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ismail Aliyu Danmaraya ◽  
Aminu Hassan Jakada ◽  
Suraya Mahmood ◽  
Bello Alhaji Ibrahim ◽  
Ahmad Umar Ali
Keyword(s):  
Renewable Energy ◽  
Environmental Degradation ◽  
Environmental Quality ◽  
Oil Production ◽  
The Body ◽  
Energy Sources ◽  
Asymmetric Effect ◽  
Content Type ◽  
Long Run ◽  
Opec Member

Purpose The purpose of this paper is to look at the asymmetric effect of oil production on environmental degradation in OPEC member countries from 1970–2019. Design/methodology/approach The authors build a nonlinear panel ARDL–PMG model using the Shin et al. (2014) nonlinear autoregressive distributed lag (ARDL) approach in panel form to assess both the short- and long-run impact of positive and negative oil production movements on CO2 emissions. Findings The result demonstrates that the variables are cointegrated. According to the linear long run coefficients, oil production, FDI inflows and economic growth both have a positive and significant relationship with CO2 emissions, implying that they deteriorate environmental quality in OPEC countries, while renewable energy has a negative relationship with CO2, implying that increasing renewable energy improves environmental quality. The asymmetric findings prove that positive and negative shocks of oil production exert a positive effect on carbon emissions in short run and long run. Research limitations/implications To begin with, the empirical assessments do not include all OPEC member nations; researchers are advised to resolve this constraint by looking at the economies of other OPEC members. Albeit the lack of data for other energy sources may serve as another constraint of this research, future research is expected to broaden the current framework via other energy sources such as nuclear, electricity, biomass, solar as well as wind. Originality/value The research adds to the body of knowledge as many of the prevailing studies in the literature failed to look at the asymmetric effect of oil production on the quality of environment. This is another gap in the literature that the current study is set out to fill. This study adds oil production as an explanatory variable and helps to extend the existing literature for OPEC countries, which could propose a solution to deal with ensuing environmental issues.

US shale sector will grow cautiously

2021 ◽  
Keyword(s):  
Oil Prices ◽  
Energy Transition ◽  
Business Environment ◽  
Energy Sources ◽  
Content Type ◽  
Corporate Strategies ◽  
Value Growth

Significance With weaker oil prices possible next year, investors see better prospects in technologies and energy sources aligned with the green transition. While US shale output is set to grow, companies in the sector are likely to retain defensive corporate strategies. Impacts Divestment of non-core hydrocarbons assets by oil majors could provide opportunities for smaller shale players. The outlook for US oil services companies is improving but the business environment will remain very competitive. The shale sector is aware that investor perceptions of value growth are switching heavily towards energy transition technologies.

scholarly journals Changing Dietary Calcium-Phosphorus Level and Cereal Source Selectively Alters Abundance of Bacteria and Metabolites in the Upper Gastrointestinal Tracts of Weaned Pigs

2013 ◽  
Vol 79 (23) ◽  
pp. 7264-7272 ◽  
Author(s):  
Barbara U. Metzler-Zebeli ◽  
Evelyne Mann ◽  
Stephan Schmitz-Esser ◽  
Martin Wagner ◽  
Mathias Ritzmann ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Gut Health ◽  
Weaned Pigs ◽  
Fermentation Products ◽  
Content Type ◽  
Young Pigs ◽  
Bacterial Microbiota ◽  
Calcium Phosphorus ◽  
And Performance ◽  
The Stability

ABSTRACTSeveral dietary ingredients may affect the bacterial community structure and metabolism in the porcine gut and may therefore influence animals' health and performance. This study investigated the effects of cereal source and calcium-phosphorus (CaP) level in the diet on bacterial microbiota and metabolites, nutrient intake, and gut environment in weaned pigs. Pigs (n= 8/treatment) were fed wheat-barley- or corn-based diets with an adequate or high CaP level for 14 days. Effects on microbiota in the stomach, ileum, and midcolon were assessed using quantitative PCR. Data showed thatEnterobacteriaceae,Campylobacterspp., andHelicobacterspp., which all contain highly immune reactive lipopolysaccharide (LPS), were abundant at all gut sites. Diet effects on bacteria and metabolites were moderate and occurred mainly in the upper gut, whereas no effects on bacteria, fermentation products, and LPS could be observed in the colon. Differences in carbohydrate intake with corn versus wheat-barley diets selectively stimulatedBifidobacteriumin the stomach and ileum. There was a growth advantage for a few bacterial groups in the stomach and ileum of pigs fed the high versus adequate CaP level (i.e., gastricEnterobacteriaceaeand ilealEnterococcus,Bacteroides-Prevotella-Porphyromonas, andCampylobacter). Interestingly, gastrointestinal pH was not affected by dietary CaP level. The present findings demonstrate the stability of the bacterial community and gut environment toward dietary changes even in young pigs. The results on stimulation of gastric and ilealBifidobacteriumby corn diets may be employed in nutritional strategies to support gut health after weaning.

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