Petroleum hydrocarbons bacteria

Novelli, G.D. and ZoBell, C.E., Assimilation of petroleum hydrocarbons by sulfate-reducing bacteria, J. Bacteriol., 47, 447-448, 1944. 

Petroleum hydrocarbons may enter the enviromnent through accidents, from industrial releases, or as by-products from commercial or private uses such as direct release into water through spills or leaks. When release into water occurs, some of the hydrocarbons float on the water and form surface films, while others may sink and form bottom sediments. Bacteria and microorganisms in the water have the potential to break down some of the hydrocarbons over varying periods of time that are dependent on the ambient conditions. On the other hand, hydrocarbons that are spilled onto the soil may remain for a long time. 

Butt AI, Riazuddin S, Shakoori AR, et al. 1988. Isolation and identification of petroleum hydrocarbon degrading bacteria from the local environments. Pak J Zool 20(4) 391-399. 

The petroleum hydrocarbon contaminant is brought into direct contact with the specific microorganisms contained in BTS. These microscopic bacteria ingest the hydrocarbon molecules. For this entire process to begin, the contaminated soil and BTS product must be brought into direct contact. 

Electrokinetically enhanced bioremediation is an in situ process for the treatment of soils and groundwater contaminated with petroleum hydrocarbons and other compounds easily biodegraded under anaerobic conditions. Bench-scale tests have shown that the apphcation of an electric field provides electrokinetic transport of nutrients and biodegrading bacteria to areas of contamination. In addition, microbial growth is enhanced, nitrate transport can be predicted, and beneficial temperature increases can be achieved to areas of contamination. 

Desorption from the hydrocarbon is a critical part of the growth cycle of petroleum-degrading bacteria. Petroleum is a mixture of thousands of different hydrocarbon molecules. Any particular bacterium is only able to use a part of the petroleum. As the bacteria multiply at the hydrocarbon/water interface of a droplet, the relative amount of nonutilizable hydrocarbon continually increases, until the cells can no longer grow. For bacteria to continue to multiply, they must be able to... 

Ci uuc oil—complex, naturally occurring fluid mixture of petroleum hydrocarbons, yellow to black in color, and also containing small amounts of oxygen, nitrogen, and sulfur derivatives and other impurities. Crude oil was formed by the action of bacteria, heat, and pressure on ancient plant and animal remains, and is usually found in layers of porous rock such as limestone or sandstone, capped by an impervious layer of shale or clay that traps the oil (see reservoir). Crude oil varies in appearance and hydrocarbon composition depending on the locality where it occurs, some crudes being predominately naphthenic, some paraffinic, and others asphaltic. Crude is refined to yield petroleum products. See distillation, hydrocarbon, sour crude, sweet crude, asphalt, naphthene, paraffin. 

Kleikemper J., Schroth M. H., Sigler W. V., SchmucM M., Bernasconi S. M., and Zeyer J. (2002) Activity and diversity of sulfate-reducing bacteria in a petroleum hydrocarbon-contaminated aquifer. Appl. Environ. Microbiol. 68(4), 1516-1523. 

In aquatic environments, the heavier and less vola-tile/soluble compounds in crude oil will adsorb to suspended solids and subsequently settle in the sediments. Some heavy fractions with high density may sink into the sediment. This happens after the initial removal of the smaller and more volatile chemicals by either dissolution or volatilization. This is followed by biodegradation of those crude oil constituents that can serve as a food source for bacteria. Biodegradation is a significant mechanism for removal of hydrocarbons released into the environment. However, this generally occurs on the order of months and years. It is not believed that there is significant bioaccumulation of petroleum hydrocarbons in aquatic organisms. 

Bioremediation has been successfully demonstrated for a variety of contaminant classifications. The majority of the studies have focused on petroleum compounds (BTEX, gasoline, diesel, jet fuel, etc.) because of their widespread occurrence as a contaminant. The other major waste classifications where bioremediation has been successful are solvents (toluene, trichloroethylene, etc.), creosote, pulp and paper, pesticides, textiles, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Table 1 contains a partial list of the microbial genus successfully implemented for these contaminants. For aqueous petroleum contaminants, bacteria and yeasts are the most prevalent degraders. In contaminated soil systems, bacteria and fungi are the microorganisms responsible for degradation. ... 

It is important to note that there are specific bacteria-contaminant combinations that will be the exceptions to the trend. In addition, this list does not include the impact of bioavailability or concentration. For instance, normal alkanes are considered the most biodegradable of all petroleum hydrocarbons. However, at elevated concentrations the C5-C10 compounds inhibit the activity of several hydrocarbon degraders.Furthermore, the number, type, and position of substitutions will also influence the ease of degradation in branched chains, aromatics, and multiple ringed compounds. As the complexity of the compound s structure and the number of compounds present at a site increase, one microbial strain will... 

In most petroleum only 4% oxygen is present, while organic matter contains about 15 to 35%. This would raise the proportion of carbon and hydrogen, which combined into hydrocarbons. Bacteria of this kind is found in marine sediments and in the salt water of petroleum containing sediments. They are essentially the same as the bacteria found in swamps that cause the formation of methane or marsh gas. 

ZoBell, C. E. 1945. The role of bacteria in the formation and transformation of petroleum hydrocarbons. Science, 102, 364-369. 

Most of the increases in microbial populations were associated with chronic inputs of petroleum hydrocarbons. Petroleum hydrocarbons can limit the growth of bacteria in sediment and water in non-oil contaminated estuarine ecosystems, and may also result in selective decreases in algal and protozoan populations. Not all microbial populations increase or decrease in response to the addition of petroleum hydrocarbons some microorganisms show a neutral response to certain hydrocarbons, and, in these cases, population size of these organisms remains unchanged. 

The release of petroleum from collectors by the action of microorganisms — active cultures of bacteria increase the useful yield of petroleum deposits. After inoculating the deposit with the appropriate bacteria, microbial processes induce a decrease of the viscosity and density of petroleum. Due to the decomposition of heavy petroleum hydrocarbons, natural gas is released, thus increasing the pressure driving petroleum from porous spaces. Changes to phase boundaries in the system water - petroleum -collector also occur. 

The presence of a certain amount of petroleum substances in the soil increases the number of microorganisms which are able to decompose them. Thus, in petroleum helds, on the sites of former refineries and of the current petrochemical industry, in the soil layer under the surface we can find large amounts of bacteria utilizing petroleum hydrocarbons. 

In this study, oil-contaminated soil in Tianjin and was used for domestication at different temperatures. Two different communities of bacteria depend on crude oil as sole carbon source were foimd and the main foundation of temperature on the microbial community screening was researched and revealed. The biodegradation characteristic was studied then. The effect of combined remediation by winter wheat and cold-adapted degrading bacterial was examined. In order to explore the effect of combined remediation by bacterial and plant at low temperature on petroleum hydrocarbons contaminated sod, the TPH removal and the catalase activity were examined at different incubation time in different treatments. 

Obire, O. (1985). Studies on the Development of Bacteria Inocula to rid the Aquatic Environment of Spilled Petroleum Hydrocarbons. Ph. D. Thesis. University of Benin, Benin - City. 88p. 

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