Microbial assimilation

The quantification of gross root production, rhizodeposition, microbial assimilation, and the production of organic materials in soil has made increasing progress ever since stable ( C) and radioactive ( C) carbon isotopes have been used (see Chap. 12). Measurements of soil organic matter dynamics without these isotopes are difficult due to the large amount present as compared to the smaller rates of input. 

P. S0rensen, J. N. Ladd, and M. Amato, Microbial assimilation of C of ground and unground plant materials decomposing in a loamy sand and a clay. soil. Soil Biol. Biochem. 2S 1425 (1996). 

Environmental organic pollutants may be degraded depending on their toxicity, solubility, distribution constant Kow because physical properties of hydrophobic chemicals may affect the solubility and therefore the amount of organic carbon available in the aqueous phase for microbial assimilation and further metabolism (Schwarzenbach and Westall 1981). Chemicals are subject to volatilization and such loss is not assessed in most of the study except for physical transformation and material balance purposes. Polyaromatic hydrocarbons (PAHs) are known to volatilized during incubation even with capping and more then 40% of the initial chemicals could be found lost (Yin and Gu, unpublished data). When proper control was not included and such... 

Fliessbach A, Mader P, Niggli U (2000) Mineralization and microbial assimilation of 14C-labeled straw in soils of organic and conventional agricultural systems. Soil Biol Biochem 32 1131-1139... 

Figure 7. Relationship between net mineralization and immobilization of nitrogen as a function of substrate C N ratio and microbial assimilation efficiency (F) for three different biomass nitrogen levels equivalent to C N ratios of 4-8-12 (after Bashkin, 1987 Fenchel et al., 1998).

Petsch, S. T., T. I. Eglinton, and K. J. Edwards. 2001. 14C-dead living biomass Evidence for microbial assimilation of ancient organic carbon during shale weathering. Science 292 1127-1131. 

Caraco, N. F., G. Lampman, J. J. Cole, K. E. Limburg, M. L. Pace, and D. Fischer. 1998. Microbial assimilation of DIN in a nitrogen rich estuary Implications for food quality and isotope studies. Marine Ecology Progress Series 18 59-71. 

It should be noted that although the relative content of PUFAs in total lipids is often diminished in cells after the microbial assimilation of exogenous... 

Petroff, A., A. Mailliat, A. Muriel and A. Fabien (2008) Aerosol dry deposition on vegetative canopies. Part I. Review of present knowledge. Atmospheric Environment 42, 3625-3653 Petsch, S. T, T. I. Eglinton and K. J. Edwards (2001) C-dead living biomass Evidence for microbial assimilation of ancient organic carbon during scale weathering. Science 292, 1127-1131... 

These results therefore indicate that the carbon dioxide detected in the respirometric experiment in the soil containing flask supplemented with PVAc-containing D film, can be attributed only to the microbial assimilation of low molecular weight polyols and PVA. 

Table 1 collects selected metric parameters and IR stretching frequencies (wno) fot a representative set of six-coordinated (6C) complexes of iron, ruthenium, and osmium, and few iron 5C-compounds. A number of Fe(III) heme proteins are involved in the regulation of the NO biosynthesis by the enzyme NO synthase, in NO transport (as vasodilator) in nitrophorins and in NO inhibition processes of cytochrome P450 and related enzymes (45). Heme enzymes are also intermediates in cyt cd nitrite reductases (NIRs), (46) and in NO reduction by a fungal cyt P450 NO reductase (47). The nonheme Fe(III) nitrile hydratase enzyme (NHase) is relevant to the microbial assimilation of organic nitriles, using... 

Ammonia is also produced from burning of coal and bacterial decomposition of proteinaceous organic matter. Conversion of ammonia to ammonium salts will occur rapidly both in the atmosphere and in the soil but will result in less acidity of the soil. It is not known to what extent ammonia reduces excess greenhouse gases such as carbon dioxide in the atmosphere to form ammonium carbamate. Microbial assimilation of ammonium compounds consumes alkalinity of the soil as well as converting ammonium ions to nitrate. Nitrification is carried out by many aerobic bacteria. Nitrification is pH sensitive. Denitrification, which is an anaerobic process, is also pH sensitive. 

Mineralization (corrversion to carbon dioxide, water and biomass via microbial assimilation at the same rate as natural materials (leaves, paper, grass and food scraps))... 

The term biodegradation indicates the predominance of biological activity in this phenomenon. Several studies about biodegradation of PLA show that the abiotic degradation precedes microbial assimilation [2,3]. Consequently, in nature, biotic and abiotic factors act syneigistically to decompose PLA (Fig. 8.1). 

Conversion of 90%+ of the test material s carbon to CO2 via microbial assimilation of the test polymer material in powder, film or granule form in 180 days or less -a laboratory-scale test method, as described in the previous section. 

During microbial assimilation (i.e. biotic step) a decrease in the keto-carbonyl groups is observed when short-chain carboxylic acids are released as degradation products to the surroundings [5-8]. 

Conversion to CO2, water biomass via microbial assimilation of the test polymer material in powder, film, or granule form. 

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