Anaerobic species

Microorganisms associated with corrosion are of two types, aerobic and anaerobic. Aerobic microorganisms readily grow in an environment containing oxygen, while the anaerobic species thrive in an environment virtually devoid of atmospheric oxygen. 

Anaerobic species Fe, Mg, coenzyme substrates c-AMP Internal network Sense of sources of nutrients... 

There is also a segmental distribution of the types of bacteria. Strict anaerobic species are normally confined to the oral cavity and the colon, habitats they densely colonize and predominate [1-5] (fig. 1). Bacteria indigenous to the upper respiratory tract (URT flora) and anaerobic bacteria of oral origin are swallowed with saliva and recovered from the upper gut at densities below 105 CFU/ ml. Under physiological conditions, they are considered transitory rather than indigenous to the upper gut. Facultative anaerobic bacteria are usually confined to the distal small bowel and colon, but transient species entering the gut with nutrients are occasionally recovered from the healthy upper gut at low counts. 

Bacteria Mainly Gram-positive bacteria Enterobacteriacea In severe forms strict anaerobic species of colonic type... 

In healthy individuals URT flora multiplies in gastric aspirate during treatment with antisecretory compounds and in particular proton pump inhibitors [34, 40, 44], This concerns viridans streptococci, coagulase-negative staphylococci, Haemophilus sp., diphtheroids, Moraxella sp., lactobacilli, and other streptococci, most of which are Gram-positive bacteria. With dedicated measures anaerobic species of oral origin are also recovered [66]. 

An anaerobic species of C/os/rMw/ biotransformed 1,1,1-trichloroethane to 1,1-dichloroethane, acetic acid, and unidentified products (Galli and McCarty, 1989). A microcosm composed of... 

There exists a rather broad agreement that the anaerobic ciliates evolved secondarily from aerobic ancestors since several ciliate taxa comprise both aerobic and anaerobic species. Phylogenetic studies indicate that hydrogenosomes have arisen independently at least three to four times in ciliates (Fig. 1 Clarke et al. 1993 Embley and Finlay 1994 Embley et al. 1995, 2003 Fenchel and Finlay 1995 Hirt et al. 1998 Hackstein et al. 2001,2002). The existence in... 

Both Archea and Bacteria include heterotrophs, i.e., creatures that can derive energy and carbon needed for the construction of their essential bioorganic molecules through the assimilation and oxidation of organic compounds. We know of aerobic and anaerobic species and facultative... 

Chstridiiim includes, in addition to the useful nitrogen-fixing C. pasteinianum, the dangerous anaerobic species C. tetani (causes tetanus, lockjaw"), C. hotulinum (causes botulism), and C. wekM (causes gas gangrene"). 

As the biofilm develops, the nutrient availability to the bulk biofilm may become affected. The biofilm, despite its voids and channels, offers a further resistance to mass transfer. The cells within the biofilm consume nutrients that diffuse through the biofilm in response to the difference in concentration between nutrients at the biofilm surface and the cells attached to the conditioning layer. As a consequence, it is entirely possible that cells in the region of the solid surface are likely to become starved of nutrients. The properties of the biofilm may be different, therefore, in the layers where nutrient is available compared with the regions where there is little or no nutrient. For instance, the lack of oxygen may encourage anaerobic species to develop (some bacteria can exist as aerobes or anaerobes), with attendant changes to the quality of the biofilm. 

Aerobic bacteria complete most of the petroleum bioremediation applications, particularly those above the groundwater table. Aerobes are those bacteria that require an oxygen source as their TEA. Conversely, anaerobic species require the absence of oxygen (anoxic conditions) for their respiration. In situ anaerobic bioremediation is typically only conducted in the saturated zone because of the difficulty in maintaining a strict anaerobic environment. In some instances, facultative anaerobes are utilized because they can alter the respiration to be metabolically active under both anaerobic and aerobic conditions. As such, the type of TEA available will dictate the metabolism and subsequent degradation mode. The most common TEAs used for bioremediation are listed in Table 2. Careful selection of microbe-TEA combinations can enable a specific degradation pathway to facilitate cometabolism and prevent undesired degradation by-products. 

Finally, the panel recommends monitoring of anaerobic species, especially where occlusive dressings are used. A statement of effectiveness as measured by the human or animal model was not provided for a product described as a skin wound protectant. 

Catalase catalyses the breakdown of hydrogen peroxide to oxygen and water. There are several methods of carrying out the test. A simple one is to place a few drops of 10% H2O2 on a slide and rub in a loopful of organisms. Evolution of gas can then be observed either with the naked eye or, if the result is uncertain, the slide may be placed under the low power of a microscope. This test is used for distinguishing aerobic from anaerobic species, especially Staphylococcus (catalasepositive) and Streptococcus (catalase negative). 

Case Study 4 Imipenem monohydrate (18, Scheme 23.7), which is the Af-formimidoyl derivative of thienamycin, is the first clinically available member of a new class of P-lactam antibiotics that possess the carbapenem ring system. Imipenem exhibits an extremely broad spectrum of activity against gram-positive and gram-negative aerobic and anaerobic species, which is due partly to its high stabiUty in the presence of P-lactamases. 

The antibacterial spectrum of metronidazole IX was studied in 51 species (400 strains) and was found to be most effective vs anaerobic species (MIC range of 0.03-8 yg/ml). Niridazole X was active against many Salmonella strains in vitro and was active against S. typhimurium in mice. In a group of 6 nitrobenzofurans, 3,7-dinitro-2-roethylbenzofuran was the most potent and had a similar antibacterial activity and mode of... 

Lignocellulose (plant material from several species) CO2 and CH4 radiotracer studies Soil sulture (swamp soil) for anaerobic species [139]... 

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