Iron bacteria detection

In summary, signihcant numbers of bacteria, detected with several different approaches, are present in landhll leachate plumes. Methanogens, sulfate reducers, iron reducers, manganese reducers, and denitrihers are believed to be widespread in leachate plumes. Microbial activity seems to occur throughout leachate plumes, although the actual activity (as measured by ATP, PLFA, and redox processes) is low compared to activity in topsoil. Several redox processes can take place in the same samples adding additional diversity to the concept of redox zones illustrated in Figure 3. 

Homogenization is a technique applied to rupture cells, including bacteria, and thus has a sterilizing effect on the drug product. Metal contamination from the homogenization process has been found to be very low. The most dominant contaminant, iron, was detected as less than 1 ppm after 20 cycles at a maximum pressure of 1500bar.P° l... 

These iron bacteria show a characteristic morphological structure and can be detected easily under the microscope. The bacterial cell of Gallionella ferruginea is kidney or bean shaped. It has a length of 1.5 pm and a diameter of 0.5 to 0.6 pm. It is attached to a long, flat, spirally wound stem. The front of the cell is convex, the back concave. Ferric hydroxide is deposited on the concave side of the cell and, together... 

ABC transporters involved in the uptake of siderophores, haem, and vitamin B]2 are widely conserved in bacteria and Archaea (see Figure 10). Very few species lack representatives of the siderophore family transporters. These species are mainly intracellular parasites whose metabolism is closely coupled to the metabolism of their hosts (e.g. mycoplasma), or bacteria with no need for iron (e.g. lactobacilli). In many cases, several systems of this transporter family can be detected in a single species, thus allowing the use of structurally different chelators. Most systems were exclusively identified by sequence data analysis, some were biochemically characterised, and their substrate specificity was determined. However, only very few systems have been studied in detail. At present, the best-characterised ABC transporters of this type are the fhuBCD and the btuCDF systems of E. coli, which might serve as model systems of the siderophore family. Therefore, in the following sections, this report will mainly focus on the components that mediate ferric hydroxamate uptake (fhu) and vitamin B12 uptake (htu). 

The first transporter of this type characterised as an iron-supply system that functions in the absence of any siderophore was the Sfu system of S. marcescens [224]. Later, similar systems were reported from Neisseria gonorrhoea and Neisseria meningitidis, and have been detected by analysing the genomes of a variety of bacteria, e.g. Actinobacillus pleuropneumoniae, B. halodurans, Campylobacter jejuni, Ehrlichia chaffeensis, Halobacterium sp., H. influenzae,... 

Table I also shows the great diversity of organisms in which iron—sulfur proteins have been detected. Thus far there is no organism which when appropriately examined has not contained an iron-sulfur protein, either in the soluble or membrane-bound form. Iron-sulfur proteins catalyze reactions of physiological importance in obligate anaerobic bacteria, such as hydrogen uptake and evolution, ATP formation, pyruvate metabolism, nitrogen fixation, and photosynthetic electron transport. These properties and reactions can be considered primitive and thus make iron-sulfur proteins a good place to start the study of evolution. These key reactions are also important in higher organisms. Other reactions catalyzed by iron-sulfur proteins can be added such as hydroxylation, nitrate and nitrite reduction, sulfite reduction, NADH oxidation, xanthine oxidation, and many other reactions (Table II).

The dioxygen reduction site of the key respiratory enzyme, cytochrome c oxidase [E.C. 1.9.3.1], is a bimetallic catalytic center comprised of a heme iron adjacent to a Type 2 mononuclear copper center (see Cytochrome Oxidase). The recent solution of the X-ray crystal structure of this enzyme revealed an entirely unanticipated covalent modification of the protein structure, a cross-link between a histidine and tyrosine side chain (23) within the active site (Figure 2)." This extraordinary posttranslational modification has been confirmed by peptide mapping and mass spectrometry, and has been detected as a conserved element in cytochrome c oxidases isolated from organisms ranging from bacteria to cows. The role of the cross-linked structure in the function of cytochrome c oxidase is still controversial." " ... 

Straub K. L. and Buchholz-Cleven B. E. E. (1998) Enumeration and detection of anaerobic ferrous iron-oxidizing, nitrate-reducing bacteria from diverse European sediments. Appl. Environ. Microbiol. 64, 4846-4856. 

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