Microbial state function

Miki T, Ushio M, Fukui S, Kondoh M. Functional diversity of microbial decomposers facilitates plant coexistence in a plant-microbe-soil feedback model. Proceedings of the National Academy of Sciences of the United States of America, 2010.107 pp. 14251-14256. doi 10.1073/pnas.0914281107. 

The relative solubilities reported are very crude estimates based on equilibrium solubility products. These estimates do not take into account variations in solubility as a function of pH, ionic strength, activities of various solution species (e.g., HCO "), redox state, particle size, surface defect types and concentrations, the concentration of various types of adsorbates, including natural organic matter, on mineral surface, or the presence of different types of bacteria or microbial biofilms on mineral surfaces. 

In the broadest sense, stability of emulsions should be defined as maintenance of an initial state that was attained after homogenization of the two (or more) liquids (Sjoblom, 1996). The initial state of the emulsion can be defined by a set of internal parameters. The primary parameters used to describe the state of an emulsion are droplet size distribution and concentration, since the bulk properties of emulsions such as color, texture, and taste are primarily a function of these two colloidal parameters (McClements, 1999). In selected cases it may be necessary to include additional parameters such as pH and microbial load to further define the initial state of the emulsion. 

The short-term, in situ bioavailability of organic matter is a complex function of intrinsic factors, such as the chemical characteristics of the DOM itself, which include of molecular weight distribution, the nutrient contents, and the relative contribution of broad classes of compounds and are determined by the source and the diagenetic state of the matter (Amon et al., 2001). The utilization of DOM and its apparent lability are also affected by extrinsic factors regulating the metabolism of bacteria and, therefore, the utilization of the organic matter by the bacterial community. These factors include temperature, the availability of inorganic and trace nutrients, trophic interactions within microbial food webs, and even the... 

There is some confusion in the literature as to when it is appropriate to apply the term allelochemical to phenolic acids. Since phenolic acids and their derivatives are found essentially in all terrestrial soils, it should be understood that the presence of phenolic acids in soil does not automatically imply that these phenolic acids are functionally allelochemicals. In theory, phenolic acids in soils, depending on their chemical state, concentrations, and the organisms involved, can have no effect, a stimulatory effect, or an inhibitory effect on any given plant or microbial process. For phenolic acids in the soil to be classified as allelochemicals requires that a) the phenolic acids are in an active form (e.g., free and protonated), b) they are involved in chemically mediated plant, microbe, or plant/microbial interactions and c) the concentrations of the active forms in the soil solution are sufficient to modify plant or microbial behavior, either in a positive or negative manner.8,49 However, changes in microbial behaviour associated with the utilization of phenolic acids as a carbon or energy source would not qualify as an allelopathic response. 

Biotechnological transformation is powerful tool to effectively utilize a broad variety of plant oils, with the aim to modify their structure for the production of new lipid-based materials with demanded properties and functions. One method of plant oil transformation is based on the direct utilization by microorganisms. Employed oils can be converted to aimed compounds by submerged cultivation or oils, and/or oleaginous plant materials can be utilized during solid state fermentation to useful bioproducts enriched with demanded microbial products. Another biotransformation technique covers the enzymatic modification of oil components to structured lipids with biological properties. 

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