Microbiological contaminants

Gordon, D. M. (2001). Geographical structure and host specificity in bacteria and the implications for tracing the source of coliform contamination. Microbiology 147, 1079-1085. 

Spices and spice preparations may be contaminated microbiologically to a greater or lesser degree depending on production process (e.g. fermentation). The degree of... 

Vimses are obligate intracellular parasites. They only exhibit activity by infecting other living organisms, thus they are not a practical concern in industrial microbiological fields. The exception is where viral contamination of the product or process represents a threat of transmission of disease. Microscopic insects and protozoans are also not addressed in this article (see Insectcontroltechnology). 

Open-loop systems have inherently long residence times which may be detrimental if the retentate is susceptible to degradation by shear or microbiological contamination. A feed-bleed or closed-loop configuration is a one-stage continuous membrane system. At steady state, the upstream... 

Sterile aqueous D-sorbitol solutions are fermented with y cetobacter subo >gichns in the presence of large amounts of air to complete the microbiological oxidation. The L-sorbose is isolated by crystallisation, filtration, and drying. Various methods for the fermentation of D-sorbitol have been reviewed (60). A.cetobacter suboyydans is the organism of choice as it gives L-sorbose in >90% yield (61). Large-scale fermentations can be carried out in either batch or continuous modes. In either case, stefihty is important to prevent contamination, with subsequent loss of product. 

Drinking water suppHed to carbonated soft drink manufacturing faciUties from private or municipal sources must comply with all regulatory requirements. Treated water must meet all U.S. Environmental Protection Agency primary maximum contaminant levels and may also be subject to additional state requirements. Treated water is routinely analyzed for taste, odor, appearance, chlorine, alkalinity, iron, pH, total dissolved soHds, hardness, and microbiological contamination. 

An entirely different type of contamination arises from the presence of microbiota in a product. As in the case of chemical contamination, compendial requirements for microbiological purity exists. Pharmacopoeial standards vary from country to country, and manufacturers must use the specifications and kill times that meet local requirements. As of this writing, the criteria in the British Pharmacopoeia are more stringent than those estabUshed by the CTFA, which are stricter than those in the United States Pharmacopoeia. In order to meet commonly accepted standards of microbial purity, manufacturing faciUties must be periodically cleaned and all products that can support microbial growth must contain an effective preservative (6). 

First of all, in the general part, the supply of herbal drugs and herbal mixtures, the indications and possible treatments, are dealt with, as well as explaining herbal preparations, how to make the lea, storage, and authentication. Short sections are devoted to the Standard Licences and the contamination of drugs (microbiological, heavy metal, fumigation, radioactive substances). 

One of the reasons why it is important to remove suspended solids in water is that the particles can act as a source of food and housing for bacteria. Not only does this make microbiological control much harder but, high bacteria levels increase the fouling of distribution lines and especially heat transfer equipment that receive processed waters (for example, in one s household hot water heater). The removal of suspended contaminants enables chemical treatments to be at their primary jobs of scale and corrosion prevention and microbial control. 

For all humidifiers, full consideration should be given to the possibility of the growth of fungi, algae, bacteria, and in particular Legionella pneumophila, the microbiological contamination that causes humidifier fever, etc. 

Capture efficiency is the fraction of generated contaminant that is directly captured by the hood. Measurement of capture efficiency involves measuring concentration of process-generated contaminant or a tracer material. Using process-generated contaminant requires use of instruments suited to each specific contaminant and its conditions (temperature, pressure, concentration, form, etc.). In order to facilitate these measurements, a tracer is often substituted for the process-generated contaminant. The tracer is usually a gas (sulfur hexafluoride, nitrous oxide, helium, or similar), but an aerosol (particles) can also be used (potassium iodide, polystyrene particles, microbiological particles, etc.). The chosen tracer should be as similar to the real contaminant as possible, but at the same time should... 

The trays are charged with the hot medium and, on cooling to 30°C, the inoculum is added. Two days are normally required for germination and growth and towards the end of this period the pH drops. These first two days are crucial in a microbiological sense because it is here that problems of contamination are most likely to occur. 

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