Bacteria bacterial spores

Virus, bacteria, bacterial spores, as well as toxins have been found to be degraded by MgO chlorine adducts. The bacterial outer membrane appears to be ruptured by the oxidizing action of the chlorine as well as the abrasive action of the MgO crystals. It also appears that the polar bacterial DNA (deoxyribonucleic acid) is strongly adsorbed by the MgO. 

Formaldehyde vapour generated from formaldehyde solution is an effective space disinfectant for decontaminating rooms or buildings. It inactivates vegetative bacteria, bacterial spores, and viruses. Formaldehyde... 

Protein sensing involves detection of the protein component of the pathogenic bacteria, viruses, and individnal toxins. It requires minimal sample preparation. Specificity is achieved by using antibodies, receptors, or aptamers raised or selected to specifically bind surface proteins or whole bacteria, bacterial spores, viral particles, or individual toxins. 

Atmospheric particles may consist of organic or inorganic materials or mixtures of both. Solid pollutant particles include very small combustion nuclei residues from fuel combustion, cement dust, silica dust from sandblasting, and soil dust mobilized by cultivation practices. Sulfuric acid droplets produced by oxidation of pollutant sulfur dioxide in the atmosphere are the most common kind of pollutant liquid droplets. Many kinds of particles are of biological origin and can be considered pollutants when they contribute to respiratory problems. These include bacteria, bacterial spores, fungal spores, and pollen. 

Gram- positive bacteria Gram- negative bacteria Bacterial spores druses Fungi... 

Very small, solid particles include carbon black, silver iodide, combustion nuclei, and sea-salt nuclei formed by the loss of water from droplets of seawater. Larger particles include cement dust, wind-blown soil dust, foundry dust, and pulverized coal. Liquid particulate matter, mist, includes raindrops, fog, and sulfuric acid droplets. Some particles are of biological origin, such as viruses, bacteria, bacterial spores, fungal spores, and pollen. Particulate matter may be organic or inorganic both types are very important atmospheric contaminants. 

At 70—140°C, peroxide is vaporised. Peroxide vapor has been reported to rapidly inactivate pathogenic bacteria, yeast, and bacterial spores in very low concentrations (133). Experiments using peroxide vapor for space decontamination of rooms and biologic safety cabinets hold promise (134). The use of peroxide vapor and a plasma generated by radio frequency energy releasing free radicals, ions, excited atoms, and excited molecules in a sterilising chamber has been patented (135). 

Mycobacteria are more resistant than other non-sporulating bacteria to a wide range of biocides. Examples of such organisms axe Mycobacterium tuberculosis, theM avium-intracellulare (MAI) group andM. chelonae (M. chelonei). Of the bacteria, however, the most resistant of all to biocides are bacterial spores, e.g. Bacillus subtilis, B. cereus. 

Bacterial resistance to biocides (Table 13.2) is usually considered as being of two types (a) intrinsic (innate, natural), a natural property of an organism, or (b) acquired, either by chromosomal mutation or by the acquisition of plasmids or transposons. Intrinsic resistance to biocides is usually demonstrated by Gram-negative bacteria, mycobacteria and bacterial spores whereas acquired resistance can result by mutation or, more frequently, by the acquisition of genetic elements, e.g. plasmid- (or transposon-) mediated resistance to mercury compounds. Intrinsic resistance may also be exemplified by physiological (phenotypic) adaptation, a classical example of which is biofilm production. 

Food may be contaminated with toxins produced by bacteria, such as botulinum toxin. This is produced by the bacterium Clostridium botulinum and is one of the two most potent toxins known to humans (the other being ricin). As little as one hundred-millionth of a gram (1 X 10-8 g) of the toxin would be lethal for a human. Fortunately, the toxin is destroyed by heat so that cooked food is unlikely to be contaminated (although the bacterial spores are quite resistant). The bacteria grow in the absence of air (they are anaerobic), and consequently, the foodstuffs most likely to be contaminated are those that are bottled or canned and eaten without cooking, for example, raw or lightly cooked fish. 

A striking accumulation of Mn2+ often occurs within bacterial spores (Chapter 32). Bacillus subtilus absolutely requires Mn2+ for initiation of sporulation. During logarithmic growth the bacteria can concentrate Mn2+ from 1 pM in the external medium to 0.2 mM internally during sporulation the concentrations become much higher.593... 

Sporulation. Bacteria of the genera Bacillus and Clostridium form metabolically inert spores when deprived of adequate nutrients (Fig. 32-1L83,203,20 1 Bacterial spores are remarkably resistant to heat and can survive boiling water for prolonged periods. 

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