scholarly journals Considering the Specific Impact of Harsh Conditions and Oil Weathering on Diversity, Adaptation, and Activity of Hydrocarbon-Degrading Bacteria in Strategies of Bioremediation of Harsh Oily-Polluted Soils

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zulfa Al Disi ◽  
Samir Jaoua ◽  
Dhabia Al-Thani ◽  
Saeed Al-Meer ◽  
Nabil Zouari
Keyword(s):  
Carbon Sources ◽  
Nitrogen Sources ◽  
Weather Conditions ◽  
Metabolic Adaptation ◽  
Polluted Soils ◽  
Weathering Processes ◽  
Degrading Bacteria ◽  
Weathered Oil ◽  
First Time ◽  
Harsh Conditions

Weathering processes change properties and composition of spilled oil, representing the main reason of failure of bioaugmentation strategies. Our purpose was to investigate the metabolic adaptation of hydrocarbon-degrading bacteria at harsh conditions to be considered to overcome the limitations of bioaugmentation strategies at harsh conditions. Polluted soils, exposed for prolonged periods to weathered oil in harsh soils and weather conditions, were used. Two types of enrichment cultures were employed using 5% and 10% oil or diesel as sole carbon sources with varying the mineral nitrogen sources and C/N ratios. The most effective isolates were obtained based on growth, tolerance to toxicity, and removal efficiency of diesel hydrocarbons. Activities of the newly isolated bacteria, in relation to the microenvironment from where they were isoalted and their interaction with the weathered oil, showed individual specific ability to adapt when exposed to such factors, to acquire metabolic potentialities. Among 39 isolates, ten identified ones by 16S rDNA genes similarities, including special two Pseudomonas isolates and one Citrobacter isolate, showed particularity of shifting hydrocarbon-degrading ability from short chain n-alkanes (n-C12–n-C16) to longer chain n-alkanes (n-C21–n-C25) and vice versa by alternating nitrogen source compositions and C/N ratios. This is shown for the first time.

scholarly journals Comparative Proteomics of Marinobacter sp. TT1 Reveals Corexit Impacts on Hydrocarbon Metabolism, Chemotactic Motility, and Biofilm Formation

2020 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Saskia Rughöft ◽  
Nico Jehmlich ◽  
Tony Gutierrez ◽  
Sara Kleindienst
Keyword(s):  
Biofilm Formation ◽  
Oil Spills ◽  
Carbon Sources ◽  
Comparative Proteomics ◽  
Hydrocarbon Biodegradation ◽  
Solvent Tolerance ◽  
Marine Microorganisms ◽  
Degrading Bacteria ◽  
Oil Spill Response ◽  
First Time

The application of chemical dispersants during marine oil spills can affect the community composition and activity of marine microorganisms. Several studies have indicated that certain marine hydrocarbon-degrading bacteria, such as Marinobacter spp., can be inhibited by chemical dispersants, resulting in lower abundances and/or reduced biodegradation rates. However, a major knowledge gap exists regarding the mechanisms underlying these physiological effects. Here, we performed comparative proteomics of the Deepwater Horizon isolate Marinobacter sp. TT1 grown under different conditions. Strain TT1 received different carbon sources (pyruvate vs. n-hexadecane) with and without added dispersant (Corexit EC9500A). Additional treatments contained crude oil in the form of a water-accommodated fraction (WAF) or chemically-enhanced WAF (CEWAF; with Corexit). For the first time, we identified the proteins associated with alkane metabolism and alginate biosynthesis in strain TT1, report on its potential for aromatic hydrocarbon biodegradation and present a protein-based proposed metabolism of Corexit components as carbon substrates. Our findings revealed that Corexit exposure affects hydrocarbon metabolism, chemotactic motility, biofilm formation, and induces solvent tolerance mechanisms, like efflux pumps, in strain TT1. This study provides novel insights into dispersant impacts on microbial hydrocarbon degraders that should be taken into consideration for future oil spill response actions.

Evaluation of the growth and sporulation of different entomopathogenic fungi in different liquid and solid media at varied concentrations

2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.
Keyword(s):  
Entomopathogenic Fungi ◽  
Large Scale ◽  
Insect Pests ◽  
Culture Media ◽  
Virulent Strain ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Maximum Growth ◽  
Nutritional Requirements ◽  
Virulent Strains

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.

scholarly journals Cloud icing by mineral dust and impacts to aviation safety

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Slobodan Nickovic ◽  
Bojan Cvetkovic ◽  
Slavko Petković ◽  
Vassilis Amiridis ◽  
Goran Pejanović ◽  
...  
Keyword(s):  
Mineral Dust ◽  
Weather Conditions ◽  
Ice Nucleation ◽  
Aircraft Accidents ◽  
Ice Nuclei ◽  
Loss And Damage ◽  
Cloud Ice ◽  
Convective Weather ◽  
First Time ◽  
Engine Power

AbstractIce particles in high-altitude cold clouds can obstruct aircraft functioning. Over the last 20 years, there have been more than 150 recorded cases with engine power-loss and damage caused by tiny cloud ice crystals, which are difficult to detect with aircraft radars. Herein, we examine two aircraft accidents for which icing linked to convective weather conditions has been officially reported as the most likely reason for catastrophic consequences. We analyze whether desert mineral dust, known to be very efficient ice nuclei and present along both aircraft routes, could further augment the icing process. Using numerical simulations performed by a coupled atmosphere-dust model with an included parameterization for ice nucleation triggered by dust aerosols, we show that the predicted ice particle number sharply increases at approximate locations and times of accidents where desert dust was brought by convective circulation to the upper troposphere. We propose a new icing parameter which, unlike existing icing indices, for the first time includes in its calculation the predicted dust concentration. This study opens up the opportunity to use integrated atmospheric-dust forecasts as warnings for ice formation enhanced by mineral dust presence.

To bee or not to beet with neonicotinoids

2021 ◽  
Vol 23 (2) ◽  
pp. 103-109
Author(s):  
Lynda M. Warren
Keyword(s):  
Sugar Beet ◽  
Weather Conditions ◽  
The European Union ◽  
Environmental Standards ◽  
Economic Interests ◽  
Precautionary Approach ◽  
The United Kingdom ◽  
Commercial Sugar ◽  
The Uk ◽  
First Time

In January 2021 the UK government granted an application for authorisation to use thiamethoxam, a neonicotinoid pesticide, to protect commercial sugar beet crops from attack by viruses transmitted by aphids. This was the first time such an authorisation had been granted in the United Kingdom (UK) and there were concerns that it signalled a weakening of environmental standards now that the UK was no longer part of the European Union. In fact, similar authorisations had been granted by several European Member States in the last 2 years, despite the ban on the use of neonicotinoids introduced in 2018. Nevertheless, the reasons for granting the authorisation do suggest that the balance between adopting a precautionary approach to environmental protection and taking emergency action to protect economic interests may have shifted. It was acknowledged that the proposed mitigation to safeguard bees and other wildlife was not entirely satisfactory. In the end, due to unforeseen weather conditions it meant that the pesticide is not necessary, which in itself demonstrates that short-term emergency measures are unsuitable for dealing with the problem. If the sugar beet industry is to continue to prosper in the UK, it will need to be managed in a way that provides resistance to virus infection without the use of controversial chemicals.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

scholarly journals Identification of Listeria monocytogenes Genes Contributing to Intracellular Replication by Expression Profiling and Mutant Screening

2006 ◽  
Vol 188 (2) ◽  
pp. 556-568 ◽  
Author(s):  
Biju Joseph ◽  
Karin Przybilla ◽  
Claudia Stühler ◽  
Kristina Schauer ◽  
Jörg Slaghuis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Proteins ◽  
Carbon Sources ◽  
Brain Heart Infusion ◽  
Nitrogen Sources ◽  
Pentose Phosphate ◽  
Intracellular Growth ◽  
Cell Infection ◽  
Phosphotransferase System ◽  
Isoleucine Leucine

ABSTRACT A successful transition of Listeria monocytogenes from the extracellular to the intracellular environment requires a precise adaptation response to conditions encountered in the host milieu. Although many key steps in the intracellular lifestyle of this gram-positive pathogen are well characterized, our knowledge about the factors required for cytosolic proliferation is still rather limited. We used DNA microarray and real-time reverse transcriptase PCR analyses to investigate the transcriptional profile of intracellular L. monocytogenes following epithelial cell infection. Approximately 19% of the genes were differentially expressed by at least 1.6-fold relative to their level of transcription when grown in brain heart infusion medium, including genes encoding transporter proteins essential for the uptake of carbon and nitrogen sources, factors involved in anabolic pathways, stress proteins, transcriptional regulators, and proteins of unknown function. To validate the biological relevance of the intracellular gene expression profile, a random mutant library of L. monocytogenes was constructed by insertion-duplication mutagenesis and screened for intracellular-growth-deficient strains. By interfacing the results of both approaches, we provide evidence that L. monocytogenes can use alternative carbon sources like phosphorylated glucose and glycerol and nitrogen sources like ethanolamine during replication in epithelial cells and that the pentose phosphate cycle, but not glycolysis, is the predominant pathway of sugar metabolism in the host environment. Additionally, we show that the synthesis of arginine, isoleucine, leucine, and valine, as well as a species-specific phosphoenolpyruvate-dependent phosphotransferase system, play a major role in the intracellular growth of L. monocytogenes.

scholarly journals Photosynthetic apparatus efficiency, phenolic acid profiling and pattern of chosen phytohormones in pseudometallophyte Alyssum montanum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ewa Muszyńska ◽  
Krzysztof M. Tokarz ◽  
Michał Dziurka ◽  
Mateusz Labudda ◽  
Kinga Dziurka ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Acid Synthesis ◽  
Metabolic Adaptation ◽  
Transport Pathways ◽  
Adverse Conditions ◽  
Benzoic Acid Derivatives ◽  
Tyrosine Ammonia Lyase ◽  
Treated Culture ◽  
First Time

AbstractThe present study investigated the response of non-metallicolous (NM) and metallicolous (M) Alyssum montanum shoots cultured in vitro on a medium supplemented simultaneously with heavy metals (HMs) to identify mechanisms involved in alleviating metal-induced damage. Plant status in respect to photosynthetic apparatus efficiency was determined and linked with changes in biochemical composition of shoots, namely phenolic acids’ and stress-related phytohormones. Results showed the considerable inter-ecotype differences in (1) the photosynthetic pigments’ amount, (2) the functioning of membrane electron transporters as well as (3) the linear and alternative electron transport pathways, whose lower values were reported in NM than in M HM-treated culture. Photosynthetic apparatus protection in M specimens was assured by the activation of cinnamic acid synthesis (by phenylalanine ammonia lyase) and its further transformations to benzoic acid derivatives with high ability to counteract oxidative stress, that was accompanied by the overexpression of jasmonic acid stimulating antioxidant machinery. In turn, detrimental HM effects on NM shoots could result from the diminution of most phenolics’ accumulation, and only the content of coumarate (produced by bifunctional phenylalanine/tyrosine ammonia lyase) and rosmarinic acid increased. All these together with an enhanced concentration of abscisic acid might suggest that NM strategy to cope with HMs is based mostly on a restriction of metal movement with transpiration flow and their limited distribution in leaves. Summarizing, our findings for the first time point out the physiological and metabolic adaptation of pseudometallophyte A. montanum to adverse conditions.

Metallasilsesquioxane-derived ultrathin porous carbon nanosheet 3D architectures via an “in situ dual templating” strategy for ultrafast sodium storage

2021 ◽  
Vol 9 (10) ◽  
pp. 6423-6431
Author(s):  
Xieji Lin ◽  
Yue Dong ◽  
Xiaohong Chen ◽  
Haiyan Liu ◽  
Zhaobin Liu ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Carbon Sources ◽  
Carbon Nanosheets ◽  
Different Dimensions ◽  
First Time ◽  
Sodium Storage

It is the first time that metallasilsesquioxanes are introduced into the synthesis of porous carbon nanosheets. Lithium hepta(i-butyl)silsesquioxane trisilanolate is a multifunctional precursor for both carbon sources and templates with different dimensions.

Energy Harvesting Under Harsh Conditions for the Oil & Gas Upstream Industry

2021 ◽  
Author(s):  
José Correia ◽  
Cátia Rodrigues ◽  
Ricardo Esteves ◽  
Ricardo Cesar Bezerra de Melo ◽  
José Gutiérrez ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Oil And Gas ◽  
Electrical Energy ◽  
Development Stage ◽  
Gas Extraction ◽  
Power Monitoring ◽  
Operational Conditions ◽  
Wide Range ◽  
First Time ◽  
Harsh Conditions

Abstract Environmental and safety sensing is becoming of high importance in the oil and gas upstream industry. However, present solutions to feed theses sensors are expensive and dangerous and there is so far no technology able to generate electrical energy in the operational conditions of oil and gas extraction wells. In this paper it is presented, for the first time in a relevant environment, a pioneering energy harvesting technology based on nanomaterials that takes advantage of fluid movement in oil extraction wells. A device was tested to power monitoring systems with locally harvested energy in harsh conditions environment (pressures up to 50 bar and temperatures of 50ºC). Even though this technology is in an early development stage this work opens a wide range of possible applications in deep underwater environments and in Oil and Gas extraction wells where continuous flow conditions are present.

Sign in / Sign up

Export Citation Format

Share Document