Bacterial decay

Figure Bl.15.16. Two-pulse ESE signal intensity of the chemically reduced ubiqumone-10 cofactor in photosynthetic bacterial reaction centres at 115 K. MW frequency is 95.1 GHz. One dimension is the magnetic field value Bq, the other dimension is the pulse separation x. The echo decay fiinction is anisotropic with respect to the spectral position.

Methane also is commonly produced by the decomposition of organic matter by a variety of bacterial processes, and the gas is used as a fuel in sewage plants (see Water, sewage). Methane also is called marsh gas because it is produced during the decay of vegetation in stagnant water. 

Fluorides. Most woddwide reductions in dental decay can be ascribed to fluoride incorporation into drinking water, dentifrices, and mouth rinses. Numerous mechanisms have been described by which fluoride exerts a beneficial effect. Fluoride either reacts with tooth enamel to reduce its susceptibihty to dissolution in bacterial acids or interferes with the production of acid by bacterial within dental plaque. The multiple modes of action with fluoride may account for its remarkable effectiveness at concentrations far below those necessary with most therapeutic materials. Fluoride release from restorative dental materials foUow the same basic pattern. Fluoride is released in an initial short burst after placement of the material, and decreases rapidly to a low level of constant release. The constant low level release has been postulated to provide tooth protection by incorporation into tooth mineral. 

A number of biological processes result in the marine production of gases that have a greenhouse role, similar to water vapour and COj. In low oxygen environments, of the sort discussed in the next section, methane is produced by anaerobic bacterial decay ... 

Alkali metal nitrates can be prepared by direct reaction of aqueous nitric acid on the appropriate hydroxide or carbonate. LiN03 is used for scarlet flares and pyrotechnic displays. Large deposits of NaN03 (saltpetre) are found in Chile and were probably formed by bacterial decay of small marine organisms the NH3 initially produced... 

Lee, J., Wang, Y., and Gibson, B. G. (1990). Recovery of components of fluorescence spectra of mixtures by intensity- and anisotropy decay-associated analysis the bacterial luciferase intermediates. Anal. Biochem. 185 220-229. 

Modern toothpaste has to do many things. It must have abrasives to scour off bacterial films. It must have fluorides to harden the teeth against decay. It must have a strong enough pleasant... 

Consequently, the signal fractions of 51 f(r)/51 f(0) can be calculated and compared with simulations. For samples prepared by bacterial expression, correction of the background signals can be carried out in a similar fashion [48, 53, 54], It is noteworthy that spin geometries deviated from linearity, which may occur in the side-chain 13C nuclei such as C , would produce more rapid signal decays and smaller residual signal fraction [55],... 

Jacques MA and Morris CE. 1995. Bacterial population dynamics and decay on leaves of different ages of ready-to-use broad leaved endive. Int J Food Sci Technol 30 221-236. 

Let us consider sulfate reduction by bacterial activity at the expense of decaying solid organic matter. Berner suggests the simplified equation... 

Anaerobic digestion, like pyrolysis, occurs in the absence of air. But, the decomposition is caused by bacterial action rather than high temperatures. This process takes place in most biological materials, but it is accelerated by warm, wet and airless conditions. It occurs naturally in decaying vegetation in ponds, producing the type of marsh gas that can catch fire. 

Preservatives (LD, DW, ADW, HC, FC) Guards against product aging by decay, discoloration, oxidation, and bacterial attack Ability to decrease water availability Butylated hydroxytoluene Ethylene diamine Glutaraldehyde 0.05-0.2% 0.05-0.2%... 

Bacterial attack is an early stage in the degradation of wood exposed in wet or moist conditions. Bacteria can be the dominant form of attack when fungal decay is suppressed by a wood-preserving treatment. Bacteria can attack the cell wall of wood by tunnelling, cavitation or erosion mechanisms (Eaton and Hale, 1993). 

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