Microorganisms, classification

The objective of taxonomy is to identify, describe and class microorganisms. Classification is made according to several hierarchical levels. For bacteria, the highest level corresponds with their classification among procaryotes. The lowest level is species. In a species of bacterium, strains grouped together share a number of identical characters. These characters radically differentiate them from other strains. 

Methane-oxidising microorganisms Classification and habitat requirements... 

Table 2. Classification and Distribution of Tetracycline Resistance Determinants in Microorganisms ...

The classification of antibiotics and the most popular antibiotic in its class are given in Table 6. Usually, the antibiotics excreted are partially metabolized and end up in sewage system. Some of the most commonly used antibiotics (e.g., sulfa drugs and p-lactam antibiotics) are difficult to biodegrade because of their complex structure, which protect them from the attack of wastewater biocoenosis. Moreover, the difficulty in biodegradation is also due to the lack of significant microorganism... 

The microorganisms determined as active biomass constitute a central platform for description of the processes in a sewer. Classification of the microorganisms will, however, not be dealt with as a major subject in this context. But, it is especially important to determine under which redox conditions the microorganisms are active. 

TABLE 3.1. Classification of the Nutritional Requirements of Microorganisms (adapted from Benefield and Randall, 1980). 

In addition to the redox conditions dealt with in Section 2.1, the nutritional requirements of the microorganisms are crucial. A classification of these requirements is shown in Table 3.1. 

Handling of specimen Is often not listed Classification of microorganisms Various types of microorganisms or their products are studied Animal and human experiments are often Included... 

Lungs were selected from three animals they were then weighed and 10% homogenates were prepared on sterile 0.85% NaCl solution and analyzed individually. The extracted microorganisms were identified in accordance with Bergey s classification. 

Obviously siderophores can be potent virulence factors of pathogenic bacteria. Siderophores in many cases have elaborate structures providing recognition only by the receptor site of the producing species. This renders a pirating by competing microorganisms more difficult. The structural specificities of siderophores have been used for classification purposes of bacterial species (see especially pyoverdins, Sect. 2.1). 

The classification presented here is based upon consistency brought about by differences in moisture content (soft, semisoft, hard, very hard), the manner of ripening (bacteria, mold, yeast, surface or interior microorganisms, combinations or unripened), the method by which the curd is produced (acid or coagulating enzymes, or by acid and high heat, or combinations), and the type of milk employed (National Dairy Council 1979). 

Temperature. Most microbe metabolisms and enzymatic processes function well only in the range of 10-60°C, but in particular cases the active spread of temperatures is only 5-10°C. A classification of microorganisms that is sometimes made is with respect to peak activities near 15°C or near 35°C or near 55°C. The maximum heat effects of metabolic processes can be estimated from heats of formation when the principal chemical participants are known, for instance ... 

Microorganisms are microscopic plants and animals. In relation to their presence as cooling water contaminants, we generally mean the mixed populations of bacteria, fungi (which includes yeasts), phytoplankton (algae), and zooplankton commonly found. Basic classifications and descriptions of microorganisms are discussed in the following sections. 

The necessity of establishing the presence of a structural element present in many endotoxins may be questioned, but it should be remembered that B.pertussis is a rather singular microorganism in every respect (6) whose classification itself is uncertain, and it has been observed by MacLennan, who first isolated this endotoxin (7), that the lethal toxicity of this material was considerably lower than that of enterobacterial endotoxins, an observation confirmed by both Kasai (8) and Nakase ( ). 

As evidenced by these data, the impact of the carotenoid features on the classification results is remarkable. Photodestruction of the carotenoid components is an efficient alternative to omitting all spectral regions where carotenoid bands may superimpose other features the latter being proposed, e.g. in studies on microorganisms [61]. The width of some of the carotenoid bands would force us to discard numerous important other spectral features hidden beneath the intense carotenoid signals. 

Part of the process to make cheese involves the flocculation of an electrostatically stabilized colloidal O/W emulsion of oil droplets coated with milk casein. The flocculation is caused by the addition of a salt, leading to the formation of networks which eventually gel. The other part of the process involves reaction with an enzyme (such as rennet), an acid (such as lactic acid), and possibly heat, pressure and microorganisms, to help with the ripening [811]. The final aggregates (curd) trap much of the fat and some of the water and lactose. The remaining liquid is the whey, much of which readily separates out from the curd. Adding heat to the curd (-38 °C) helps to further separate out the whey and convert the curd from a suspension to an elastic solid. There are about 20 different basic kinds of cheese, with nearly 1000 types and regional names. Potter provides some classification [811]. 

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