Nutrient transport —Microbial metabolism —Microbiology

Sulfatase Assay to Determine Influence of Plants on Microbial Activity in Soil

Authors: Anna Koprivova, Achim Schmalenberger and Stanislav Kopriva, date: 01/20/2020, view: 3798, Q&A: 0

[Abstract] Sulfatase activity is often used as a measure of the activity of soil microorganisms. It is thus a suitable tool to investigate the response of microbes to plants. Here we present a method to determine the influence of various Arabidopsis genotypes on the function of soil microbiota using the sulfatase as a quantitative measure. We grew ...

Quantification of Hydrogen Sulfide and Cysteine Excreted by Bacterial Cells

Authors: Sergey Korshunov and James A. Imlay, date: 05/20/2018, view: 5436, Q&A: 0

[Abstract] Bacteria release cysteine to moderate the size of their intracellular pools. They can also evolve hydrogen sulfide, either through dissimilatory reduction of oxidized forms of sulfur or through the deliberate or inadvertent degradation of intracellular cysteine. These processes can have important consequences upon microbial communities, because ...

Determination of Mn Concentrations in Synechocystis sp. PCC6803 Using ICP-MS

Authors: Fabian Brandenburg, Hanan Schoffman, Nir Keren and Marion Eisenhut, date: 12/05/2017, view: 6750, Q&A: 0

[Abstract] Manganese (Mn) is an essential micronutrient for all photoautotrophic organisms. Two distinct pools of Mn have been identified in the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis), with 80% of the Mn residing in the periplasm and 20% in cytoplasm and thylakoid lumen (Keren et al., 2002). In this protocol, we ...

Quantification of Extracellular Ammonium Concentrations and Transporter Activity in Yeast Using AmTrac Fluorescent Sensors

Authors: Cindy Ast, Wolf B. Frommer, Guido Grossmann and Roberto De Michele, date: 01/05/2015, view: 10453, Q&A: 0

[Abstract] AmTracs are the first example of “activity sensors”, since they report the activity of ammonium transporters by means of fluorescence readout in vivo (De Michele et al., 2013). AmTracs are based on a single fluorescent protein, a circularly permuted GFP (cpGFP), inserted into the cytosolic loop connecting the two ...

Measurement of Proton-driven Antiport in Escherichia coli

Authors: Scarlett R. Holdsworth and Christopher J. Law, date: 11/05/2014, view: 8180, Q&A: 0

[Abstract] Secondary active transport of substrates across the inner membrane is vital to the bacterial cell. Of the secondary active transporter families, the ubiquitous major facilitator superfamily (MFS) is the largest and most functionally diverse (Reddy et al., 2012). Recently, it was reported that the MFS multidrug efflux protein MdtM from ...

Measurement of the Electrogenicity of Bile Salt/H⁺ Antiport in Escherichia coli

Authors: Scarlett R. Holdsworth and Christopher J. Law, date: 11/05/2014, view: 6687, Q&A: 0

[Abstract] The transmembrane proton gradient (ΔpH) is the primary source of energy exploited by secondary active substrate/H⁺ antiporters to drive the electroneutral transport of substrates across the Escherichia coli (E. coli) inner membrane. Such electroneutral transport results in no net movement of charges across the ...

Determination of Oxygen Respiration Rates in Wetted Developmentally Arrested Spores of Streptomyces Species

Authors: Marco Fischer, Dörte Falke and R. Gary Sawers, date: 06/20/2014, view: 7898, Q&A: 0

[Abstract] Streptomyces species produce spores, which, while not as robust as endospores of Bacillus or Clostridium species, are capable of surviving for months or even years (Hopwood, 2006). During this time these spores remain viable, surviving by slowly degrading internal stores of carbon compounds, such as the carbohydrate ...

Rapid Nitrate Reduction Assay with Intact Microbial Cells or Spores

Authors: Marco Fischer, Dörte Falke and R. Gary Sawers, date: 06/20/2014, view: 7796, Q&A: 0

[Abstract] Many microorganisms have the capacity to use nitrate as a respiratory electron acceptor. Reduction of nitrate is catalyzed by a multi-subunit nitrate reductase that is often located associated with the cytoplasmic membrane and has its active site oriented toward the cytoplasm. This means that nitrate must be transported into the cell and often ...

Transport Assays in Aspergillus nidulans

Authors: Emilia Krypotou and George Diallinas, date: 11/20/2013, view: 7674, Q&A: 0

[Abstract] Transport assays allow the direct kinetic analysis of a specific transporter by measuring apparent K_m and V_max values, and permit the characterization of substrate specificity profiles through competition assays. In this protocol, we describe a rapid and easy method for performing uptake assays in the model ...

Choline Uptake Assay in Bacterial Cells

Authors: Lucas Bukata, Claudia K. Herrmann and Diego J. Comerci, date: 09/20/2013, view: 9653, Q&A: 0

[Abstract] Choline is a methylated nitrogen compound that is widespread in nature. It is a precursor of several metabolites that perform numerous biological functions and it is predominantly used for the synthesis of essential lipid components of the cell membranes. Since there is no evidence that prokariotes can synthesize choline de novo and ...

Microbiology

Protocol for Isolation of Cardiomyocyte from Adult Mouse and Rat

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