Microbial processes microorganisms

Microorganisms have been identified and exploited for more than a century. The Babylonians and Sumerians used yeast to prepare alcohol. There is a great history beyond fermentation processes, which explains the applications of microbial processes that resulted in the production of food and beverages. In the mid-nineteenth century, Louis Pasteur understood the role of microorganisms in fermented food, wine, alcohols, beverages, cheese, milk, yoghurt and other dairy products, fuels, and fine chemical industries. He identified many microbial processes and discovered the first principal role of fermentation, which was that microbes required substrate to produce primary and secondary metabolites, and end products. 

Ecologically, copper is a trace element essential to many plants and animals. However, high levels of copper in soil can be directly toxic to certain soil microorganisms and can disrupt important microbial processes in soil, such as nitrogen and phosphorus cycling. Copper is typically found in the environment as a solid metal in soils and soil sediment in surface water. There is no evidence that biotransformation processes have a significant bearing on the fate and transport of copper in water. 

Bioremediation is defined as the use of microorganisms or microbial processes to degrade environmental contaminants. Bioremediation has numerous applications, including cleanup of groundwater, soils, lagoons, sludge, and process waste streams. 

Giller, K.E., Witter, E. and McGrath S.P(1998). Toxicity of heavy metals in microorganisms and microbial processes in agricultural soils a review , Soil Biology and Biochemistry, 30, 1389-1421. 

The temperature in a sewer depends on a number of different conditions, e.g., climate, source of wastewater and system characteristics. The microbial community developed in a sewer is typically subject to annual temperature variations and, to some extent, a daily variability. Different microbial systems may be developed under different temperature conditions, and process rates relevant for the microorganisms vary considerably with temperature. Long-term variations may affect which microbial population will develop in a sewer, whereas short-term variations have impacts on microbial processes in the cell itself as well as on the diffusion rate of substrates. 

ECOLOGICAL IMPACT OF PPCPs ON MICROORGANISMS AND MICROBIAL PROCESSES... 

Baath, E. (1989). Effects of heavy metals in soil on microbial processes and populations (a review). Water, Air, and Soil Pollution, 47, 335—79-Babich, H. Stotzky, G. (1980). Environmental factors that influence the toxicity of heavy metal and gaseous pollutants to microorganisms. Critical Reviews in Microbiology, 8,99-145. Babich, H. Stotzky, G. (1985). Heavy metal toxicity to microbe-mediated ecologic... 

Both pilot-plant and plant-scale processes for cellulose hydrolysis or digestion by acids, enzymes, and microorganisms have been built (I, 7,15,27). Acid and enzyme processes usually have as their objective the production of a sugar syrup, while the microbial process usually results in microbial protein for animal feed. Figure 10 is illustrative of a microbial process (29) that has been developed to convert the unused cellulosic material in manure to recycle feed. Similar processes have been developed... 

Other processes which may explain changes in DMS concentration with depth, on a short time scale, are those related to bacteria. Studies conducted in sediments (31-39.62) have shown that DMS can be consumed by microorganisms. Based on sulfur requirements of microorganisms, the availability of sulfur from sulfate in these environments far exceeds that of DMS. However, as a carbon source, the concentration of DMS is similar to other compounds of low molecular weight and may be cycled by microorganisms to serve as both a carbon ana sulfur source. Although the utilization of DMS aerobically has been reported (63.64). the extent to which similar processes exist in oceanic environments is not known. For futher discussions of the microbial processes related to DMS the reader is referred to another Chapter of this book (65). 

The first step in the formation of coal is the alteration of plant material into peat by biochemical (i.e., microbial) processes. The overall properties and composition of a given peat depend upon the environmental conditions that existed during the alteration period after burial. During the biochemical stage, microorganisms can reduce the sulfate in saline pore water to an active form of sulfur, e.g., H2S. H2S will react with components of the sediment, forming pyrite when iron is present and forming... 

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