Solubilization of insoluble metal compounds by soil fungi: development of a screening method for solubilizing ability and metal tolerance

1995 ◽  
Vol 99 (8) ◽  
pp. 987-993 ◽  
Author(s):  
Jacqueline A. Sayer ◽  
Samantha L. Raggett ◽  
Geoffrey M. Gadd
Keyword(s):  
Soil Fungi ◽  
Metal Tolerance ◽  
Screening Method ◽  
Metal Compounds

scholarly journals A rational approach to heavy-atom derivative screening

2010 ◽  
Vol 66 (4) ◽  
pp. 358-365 ◽  
Author(s):  
M. Gordon Joyce ◽  
Sergei Radaev ◽  
Peter D. Sun
Keyword(s):  
Heavy Atom ◽  
Screening Method ◽  
Protein Structure Determination ◽  
Rational Approach ◽  
Trial And Error ◽  
Compound Identification ◽  
Metal Compounds ◽  
Large Numbers ◽  
Crystallization Conditions ◽  
Selection Of

Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the `classical' heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

scholarly journals Overexpression of ZNT1 and NRAMP4 from the Ni Hyperaccumulator Noccaea caerulescens Population Monte Prinzera in Arabidopsis thaliana Perturbs Fe, Mn, and Ni Accumulation

2021 ◽  
Vol 22 (21) ◽  
pp. 11896
Author(s):  
Elisa Fasani ◽  
Giovanni DalCorso ◽  
Gianluca Zorzi ◽  
Caterina Agrimonti ◽  
Rosaria Fragni ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Metal Tolerance ◽  
Toxic Metal ◽  
Metal Compounds ◽  
Over Expression ◽  
Thlaspi Arvense ◽  
Noccaea Caerulescens ◽  
Transgenic Lines ◽  
Ni Accumulation ◽  
Iron And Manganese

Metalliferous soils are characterized by a high content of metal compounds that can hamper plant growth. The pseudometallophyte Noccaea caerulescens is able to grow on metalliferous substrates by implementing both tolerance and accumulation of usually toxic metal ions. Expression of particular transmembrane transporter proteins (e.g., members of the ZIP and NRAMP families) leads to metal tolerance and accumulation, and its comparison between hyperaccumulator N. caerulescens with non-accumulator relatives Arabidopsis thaliana and Thlaspi arvense has deepened our knowledge on mechanisms adopted by plants to survive in metalliferous soils. In this work, two transporters, ZNT1 and NRAMP4, expressed in a serpentinic population of N. caerulescens identified on the Monte Prinzera (Italy) are considered, and their expression has been induced in yeast and in A. thaliana. In the latter, single transgenic lines were crossed to test the effect of the combined over-expression of the two transporters. An enhanced iron and manganese translocation towards the shoot was induced by overexpression of NcZNT1. The combined overexpression of NcZNT1 and NcNRAMP4 did perturb the metal accumulation in plants.

Heavy Metal Tolerance and Biotransformation of Toxic Metal Compounds by New Isolates of Wood-Rotting Fungi from Thailand

2016 ◽  
Vol 33 (3-4) ◽  
pp. 283-288 ◽  
Author(s):  
Benjawan Kaewdoung ◽  
Thanawat Sutjaritvorakul ◽  
Geoffrey M. Gadd ◽  
Anthony J.S. Whalley ◽  
Prakitsin Sihanonth
Keyword(s):  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Toxic Metal ◽  
Metal Compounds

Heavy Metal Tolerance and Copper Uptake in Yeast Isolated from Patagonia/ Argentina

2007 ◽  
Vol 20-21 ◽  
pp. 639-642 ◽  
Author(s):  
L. Lavalle ◽  
M. Portillo ◽  
P. Chiacchiarini ◽  
Edgardo R. Donati
Keyword(s):  
Metal Tolerance ◽  
Screening Method ◽  
Heavy Metal Tolerance ◽  
Agar Plate ◽  
Copper Uptake ◽  
Zinc Tolerance ◽  
Freundlich Model ◽  
Glucose Agar ◽  
Viable Biomass ◽  
Kinetics Of

In recent years the use of microbial methods for decontamination or recovery of heavy metals from environment has increased. Microorganisms such as yeasts are potential bioremediators, removing metals via active or passive uptake. Pink-coloured and pigment-less yeast strains isolated from Agrio River, Patagonia Argentina, were tested for copper, nickel, cadmium and zinc tolerance. An agar-plate qualitative screening method using YNB-glucose agar at different metal concentrations was employed. The tolerance to the metals varied depending on the strain tested. A pigmented yeast strain (Agrio 16) was selected by its tolerance. The ability of this strain to copper uptake was investigated. The kinetics of bioaccumulation/biosorption with increasing copper concentrations up to 622.8 mg l-1 were carried out using viable and nonviable biomass. The values of constants k and n obtained for the Freundlich model are 0.0418 and 0.7430, respectively. The maximun sorption uptake capacity (q) for viable biomass was 81.6 mg of copper/g of biomass.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

Is Colour Doppler Ultrasound a Sensitive Screening Method in Diagnosing Deep Vein Thrombosis after Hip Surgery ?

1996 ◽  
Vol 75 (02) ◽  
pp. 242-245 ◽  
Author(s):  
Marie Magnusson ◽  
Bengt I Eriksson ◽  
Peter Kãlebo ◽  
Ramon Sivertsson
Keyword(s):  
Deep Vein Thrombosis ◽  
High Risk ◽  
Doppler Ultrasound ◽  
Predictive Value ◽  
Screening Method ◽  
Colour Doppler ◽  
Vein Thrombosis ◽  
Colour Doppler Ultrasound ◽  
Asymptomatic Patients ◽  
Deep Vein

SummaryPatients undergoing orthopedic surgery are at high risk of developing deep vein thrombosis. One hundred and thirty-eight consecutive patients undergoing total hip replacement or hip fracture surgery were included in this study. They were surveilled with colour Doppler ultrasound (CDU) and bilateral ascending contrast phlebography. The prevalence of proximal and distal DVT in this study was 5.8% and 20.3% respectively.CDU has a satisfactory sensitivity in patients with symptomatic deep vein thrombosis, especially in the proximal region. These results could not be confirmed in the present study of asymptomatic patients. The sensitivity was 62.5% (95% confidence interval: C.I. 24-91%) and the specificity 99.6% (C.I. 98-100%) for proximal DVT; 53.6% (C.I. 34-73%) and 98% (C.I. 96-99%) respectively for distal thrombi. The overall sensitivity was 58.1% (C.I. 39-75%) and the specificity 98% (C.I. 96-99%). The positive predictive value was 83.3% (C.I. 36-99%) and 75% (C.I. 51-91%) for proximal and distal DVT respectively. The negative predictive value was 98.9% (C.I. 98-100%) and 94.9% (C.I. 92-98%) for proximal and distal DVT respectively. The results of this study showed that even with a highly specialised and experienced investigator the sensitivity of CDU was too low to make it suitable for screening purposes in a high risk surgical population.

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