scholarly journals Microbial Community Succession during Lactate Amendment and Electron Acceptor Limitation Reveals a Predominance of Metal-Reducing Pelosinus spp.

2012 ◽  
Vol 78 (7) ◽  
pp. 2082-2091 ◽  
Author(s):  
Jennifer J. Mosher ◽  
Tommy J. Phelps ◽  
Mircea Podar ◽  
Richard A. Hurt ◽  
James H. Campbell ◽  
...  
Keyword(s):  
Electron Acceptor ◽  
Defined Medium ◽  
Flow Reactors ◽  
Content Type ◽  
Low Levels ◽  
Individual Variables ◽  
Continuous Flow Reactors ◽  
New Strategies

ABSTRACTThe determination of the success ofin situbioremediation strategies is complex. By using controlled laboratory conditions, the influence of individual variables, such as U(VI), Cr(VI), and electron donors and acceptors on community structure, dynamics, and the metal-reducing potential can be studied. Triplicate anaerobic, continuous-flow reactors were inoculated with Cr(VI)-contaminated groundwater from the Hanford, WA, 100-H area, amended with lactate, and incubated for 95 days to obtain stable, enriched communities. The reactors were kept anaerobic with N2gas (9 ml/min) flushing the headspace and were fed a defined medium amended with 30 mM lactate and 0.05 mM sulfate with a 48-h generation time. The resultant diversity decreased from 63 genera within 12 phyla to 11 bacterial genera (from 3 phyla) and 2 archaeal genera (from 1 phylum). Final communities were dominated byPelosinusspp. and to a lesser degree,Acetobacteriumspp., with low levels of other organisms, including methanogens. Four new strains ofPelosinuswere isolated, with 3 strains being capable of Cr(VI) reduction while one also reduced U(VI). Under limited sulfate, it appeared that the sulfate reducers, includingDesulfovibriospp., were outcompeted. These results suggest that during times of electron acceptor limitationin situ, organisms such asPelosinusspp. may outcompete the more-well-studied organisms while maintaining overall metal reduction rates and extents. Finally, lab-scale simulations can test new strategies on a smaller scale while facilitating community member isolation, so that a deeper understanding of community metabolism can be revealed.

Stability analysis of mobile cranes and determination of outriggers loading

2018 ◽  
Vol 16 (6) ◽  
pp. 938-958 ◽  
Author(s):  
Giuseppe Romanello
Keyword(s):  
Stability Margin ◽  
Content Type ◽  
Stability Behavior ◽  
Mobile Crane ◽  
Computer Codes ◽  
The Stability ◽  
Practical Implications

Purpose The purpose of this paper is to develop mathematical tools that are reliable and easily implementable in computer codes, which address the determination of the outriggers reaction of mobile cranes and the monitoring of the actual stability margin available during lift operations. Design/methodology/approach An algorithm that determines the load transmitted to the ground by a mobile crane with four outriggers has been developed. Static theory of rigid body is adopted for the development of the algorithm and the static indeterminancy, due to the presence of more than three outriggers, is eluded through the adoption of specific hypotheses. An analysis of crane stability is also performed, and a method to monitor the actual stability behavior during lift operations is suggested. Findings A case study is proposed to test the algorithm and outcomes show a good matching with the actual outriggers reaction measured during a test conduct in situ. Two indices are introduced as a measure of the stability margin. Research limitations/implications The method developed accounts only for gravitational forces statically applied. Future works should be addressed to extend the model to the effect of wind and inertial forces. Practical implications This paper supplies a reliable tool to assess, in the design phase of a lifting operation, the compliance between bearing capacity of the ground and loads transmitted by outriggers. The method proposed for the analysis of the stability behavior is suitable for the development of an anti-upset device. Originality/value This study contributes to efforts to increase safety during lifting operations with mobile cranes. The method proposed is applicable to cranes with any geometry of the outriggers pattern and is extensible to a number of outriggers greater than four. Furthermore, the evaluation of the measure in real time of the stability margin, is not affected by the data entered by the crane’s operator with the consequence that human factor does not affect this measure.

scholarly journals An Immunological Strategy To Monitor In Situ the Phosphate Starvation State in Thiobacillus ferrooxidans

1998 ◽  
Vol 64 (12) ◽  
pp. 4990-4993 ◽  
Author(s):  
Patricia Varela ◽  
Gloria Levicán ◽  
Francisco Rivera ◽  
Carlos A. Jerez
Keyword(s):  
Thiobacillus Ferrooxidans ◽  
Outer Membrane Proteins ◽  
Phosphate Starvation ◽  
Immunofluorescence Assay ◽  
Surface Proteins ◽  
Low Levels ◽  
Chemolithoautotrophic Bacteria ◽  
Starvation State

ABSTRACT Thiobacillus ferrooxidans is one of the chemolithoautotrophic bacteria important in industrial biomining operations. During the process of ore bioleaching, the microorganisms are subjected to several stressing conditions, including the lack of some essential nutrients, which can affect the rates and yields of bioleaching. When T. ferrooxidans is starved for phosphate, the cells respond by inducing the synthesis of several proteins, some of which are outer membrane proteins of high molecular weight (70,000 to 80,000). These proteins were considered to be potential markers of the phosphate starvation state of these microorganisms. We developed a single-cell immunofluorescence assay that allowed monitoring of the phosphate starvation condition of this biomining microorganism by measuring the increased expression of the surface proteins. In the presence of low levels of arsenate (2 mM), the growth of phosphate-starved T. ferrooxidans cells was greatly inhibited compared to that of control nonstarved cells. Therefore, the determination of the phosphorus nutritional state is particularly relevant when arsenic compounds are solubilized during the bioleaching of different ores.

scholarly journals The Pseudomonas aeruginosa Isohexenyl Glutaconyl Coenzyme A Hydratase (AtuE) Is Upregulated in Citronellate-Grown Cells and Belongs to the Crotonase Family

2015 ◽  
Vol 81 (19) ◽  
pp. 6558-6566 ◽  
Author(s):  
Nirmal Poudel ◽  
Jens Pfannstiel ◽  
Oliver Simon ◽  
Nadine Walter ◽  
Anastassios C. Papageorgiou ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Active Site ◽  
Coenzyme A ◽  
Proteome Analysis ◽  
Energy Sources ◽  
Biotechnological Production ◽  
Content Type ◽  
Utilization Pathway ◽  
New Strategies

ABSTRACTPseudomonas aeruginosais one of only a fewPseudomonasspecies that are able to use acyclic monoterpenoids, such as citronellol and citronellate, as carbon and energy sources. This is achieved by the acyclic terpene utilization pathway (Atu), which includes at least six enzymes (AtuA, AtuB, AtuCF, AtuD, AtuE, AtuG) and is coupled to a functional leucine-isovalerate utilization (Liu) pathway. Here, quantitative proteome analysis was performed to elucidate the terpene metabolism ofP. aeruginosa. The proteomics survey identified 187 proteins, including AtuA to AtuG and LiuA to LiuE, which were increased in abundance in the presence of citronellate. In particular, two hydratases, AtuE and the PA4330 gene product, out of more than a dozen predicted in theP. aeruginosaproteome showed an increased abundance in the presence of citronellate. AtuE (isohexenyl-glutaconyl coenzyme A [CoA] hydratase; EC 4.2.1.57) most likely catalyzes the hydration of the unsaturated distal double bond in the isohexenyl-glutaconyl-CoA thioester to yield 3-hydroxy-3-isohexenyl-glutaryl-CoA. Determination of the crystal structure of AtuE at a 2.13-Å resolution revealed a fold similar to that found in the hydratase (crotonase) superfamily and provided insights into the nature of the active site. The AtuE active-site architecture showed a significantly broader cavity than other crotonase superfamily members, in agreement with the need to accommodate the branched isoprenoid unit of terpenes. Glu139 was identified to be a potential catalytic residue, while the backbone NH groups of Gly116 and Gly68 likely form an oxyanion hole. The present work deepens the understanding of terpene metabolism inPseudomonasand may serve as a basis to develop new strategies for the biotechnological production of terpenoids.

scholarly journals Rapid Microbial Production of Filamentous Sulfur Mats at Hydrothermal Vents

1999 ◽  
Vol 65 (5) ◽  
pp. 2253-2255 ◽  
Author(s):  
Craig D. Taylor ◽  
Carl O. Wirsen ◽  
Françoise Gaill
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Continuous Flow ◽  
Hydrothermal Vents ◽  
Flow Reactors ◽  
Organic Matter Production ◽  
Matter Production ◽  
Metabolic Capability ◽  
Continuous Flow Reactors

ABSTRACT During recent oceanographic cruises to Pacific hydrothermal vent sites (9°N and the Guaymas Basin), the rapid microbial formation of filamentous sulfur mats by a new chemoautotrophic, hydrogen sulfide-oxidizing bacterium was documented in both in situ and shipboard experiments. Observations suggest that formation of these sulfur mats may be a factor in the initial colonization of hydrothermal surfaces by macrofaunal Alvinella worms. This novel metabolic capability, previously shown to be carried out by a coastal strain in H2S continuous-flow reactors, may be an important, heretofore unconsidered, source of microbial organic matter production at deep-sea hydrothermal vents.

East-west divide between EU member states will deepen

2019 ◽  
Keyword(s):  
Soft Power ◽  
Rapid Change ◽  
Member States ◽  
Content Type ◽  
East European ◽  
Eu Member States ◽  
Low Levels ◽  
The Baltic ◽  
East West ◽  
New Strategies

Subject The EU’s de facto evolution into a ‘core/periphery’ Europe. Significance Central-East European (CEE) countries, except the Baltic states, are more or less failing to build positive images, successful coalition strategies and influence in Brussels. Growing internal challenges to liberal democracy in these countries, a slower level of integration than initially expected and low levels of constructive involvement in EU affairs have exhausted solidarity with newcomers and lowered confidence in their ability to deliver rapid change. Impacts Increased acceptance of the east-west divide will lead to further constraints and financial conditionality for newer EU member states. This will hobble the enlargement process and its transformative pull on the Eastern Partnership and Western Balkan countries. Russia will fill the gap left by the EU’s loss of authority and eroding soft power. Westward emigration will continue to depopulate eastern member states, requiring new strategies to compensate for smaller labour forces.

Scalable in Situ Diazomethane Generation in Continuous-Flow Reactors

2011 ◽  
Vol 16 (5) ◽  
pp. 1146-1149 ◽  
Author(s):  
Emiliano Rossi ◽  
Pierre Woehl ◽  
Michele Maggini
Keyword(s):  
Continuous Flow ◽  
Flow Reactors ◽  
Continuous Flow Reactors

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

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