Soils anaerobic bacteria

A commercial technology (69), the SABRE process, treats contaminated water and soil ia a two-stage process by adding a readily degradable carbon and an inoculum of anaerobic bacteria able to degrade the contaminant. An initial aerobic fermentation removes oxygen so that the subsequent reduction of the contaminant is not accompanied by oxidative polymerization. 

Measurement of some of these parameters identifies the risk of a particular type of corrosion, for example pH measurements assess the risk of acid attack and redox potential measurements is used to assess the suitability of the soil for microbiological corrosion, a low redox potential indicates that the soil is anaerobic and favourable for the life cycle of anaerobic bacteria such as to sulphate-reducing bacteria. Other measurements are more general, resistivity measurements being the most widely quoted. However, as yet no single parameter has been identified which can confidently be expected to assess the corrosion risk of a given soil. It is therefore common practice to measure several parameters and make an assessment from the results. 

At many sites, the subsurface environment will be anoxic or even anaerobic due to the activity of aerobic and facultatively anaerobic bacteria in the surface layers of the soil. It is therefore essential to take into consideration the extent to which anaerobic degradation may be expected to be significant. Reactions may take place under sulfidogenic or methanogenic conditions, and the occurrence of sulfate at sites containing building material waste and the metabolic versatility of sulfate-reducing bacteria makes them particularly attractive. 

Molecular hydrogen is an important intermediate in the degradation of organic matter by microorganisms in anoxic habitats such as freshwater and marine sediments, wet land soils, and the gastrointestinal tract of animals. In these particular conditions H2 is produced during fermentation of carbohydrates, lipids, nucleic acids, and proteins by anaerobic bacteria and,... 

Peters V, Conrad R. 1995. Methanogenic and other strictly anaerobic bacteria in desert soil and other oxic soils. Appl Environ Microbiol 61 1673-6. 

The Simplot Anaerobic Biological Remediation (SABRE ) process is a patented, ex situ technology used to treat soils contaminated with nitroaromatic compounds. Researchers isolated a selection of anaerobic bacteria based on their ability to degrade nitroaromatic compounds with the total destruction of intermediate compounds by the completion of treatment. These bacteria are the basis of the SABRE process. 

The reduction of the oxy-salts.—The chlorates, bromates, iodates, and the oxy-salts generally lose their oxygen, and are converted into the corresponding chlorides, bromides, or iodides by heat or by certain reducing agents. A. Muntz10 found the anaerobic bacteria of soils effected the reduction. 

The greatest likelihood for As release in soils and sediments typically occurs upon transition from oxidizing to reducing conditions. Under saturated conditions, the rapid consumption of O2 by aerobic microbes combined with the low solubility of O2 induces anaerobic bacteria to utilize alternative electron acceptors. Arsenic may be displaced either through reduction of arsenate to arsenite or through mineralogical transformations (inclusive of dissolution) of the soil matrix. 

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