Determination microorganisms

For groundwater not under direct influence of surface water, CT is determined in the same manner using enteric viruses or an acceptable viral surrogate as the determinant microorganism, because Giardia cysts will not be present. 

Many of the components in milk and dairy products can be analyzed by standard methods approved by the International Dairy Federation (IDF). In December 2000, the IDF and the International Organization for Standardization (ISO) agreed to publish standards jointly and these are printed, distributed, and sold exclusively by the ISO Secretariat. Many of the methods are also published by the Association of Official Analytical Chemists (AOAC). The World Health Organization (WHO) has approved certain methods. Some of the methods have been used for many years but, particularly in microbiology, there have been recent advances that have improved our ability to determine microorganisms more specifically. 

Of increased interest are PHB blends. PHB can be blended with many commercially available plastics such as polyethylene (PE). This produces a material with all the beneficial properties of the PE (e.g., cheap, readily available) with the biodegradable properties of the PHB. Investigation is required to determine the necessary blend parameters, as well as to determine microorganisms capable of biodegradation. This is the motivation for this chapter. Similar products on the market include d2W, produced by Symphony Environmental. d2W is an additive that changes the molecular structure of a plastic at the end of its useful life, producing a compound which can be bio-assimilated into the environment. 

The direct microscopic count determines the number of viable and dead microorganisms ia a milk sample. A small amount (0.01 mL) of milk is spread over a 1.0 cm area on a microscope sHde and allowed to dry. After staining with an appropriate dye, usually methylene blue, the sHde is examined with the aid of a microscope (oil immersion lens). The number of bacterial cells and clumps of cells per microscopic field is determined and, by appropriate calculations, is expressed as the number of organisms per milliliter of sample. 

Enzymatic Determination and Microbial Assay. In these methods, only the desired amino acid is detected ia spite of the presence of other amino acids. No expensive tools are needed for these determiaations. The required nutrients for microorganisms and practical operations for the microbial assay of amino acids have been reviewed (134,135). 

A bacteriological examination of water is primarily carried out to determine the possible presence of harmful microorganisms. Testing is actually done to detect relatively harmless bacteria called colon bacilli commonly called the coliform group, which are present in the intestinal tract of humans and animals. If these organisms are present in a water in sufficient number, then this is taken to be evidence that other harmful pathogenic bacteria may also be present. 

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

Environmental. In general, chlorinated paraffins biodegrade the rate is determined by chlorine content and carbon chain length. Microorganisms previously acclimatized to specific chlorinated paraffins show a greater ability to degrade the compounds than nonacclimatized organisms. Mammals and fish have been shown to metabolize chlorinated paraffins (8). 

Raw Gas Composition The suitabihty of the raw gas stream must first be determined. The raw gas stream must contain the following in order to ensure both reasonable removal efficiencies and microorganism hfe expectancy ... 

Promoting Optimal Response to Therapy The results of a culture and sensitivity test take several days because time must be allowed for the bacteria to grow on the culture media However, infections are treated as soon as possible In a few instances, the primary health care provider may determine that a penicillin is the treatment of choice until the results of the culture and sensitivity tests are known. In many instances, the primary health care provider selects a broad-spectrum antibiotic (ie, an antibiotic that is effective against many types or strains of bacteria) for initial treatment because of the many penicillin-resistant strains of microorganisms. 

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