Bacterial chlorine

Somewhat ironically, the Eschenmoser-Claisen rearrangement was not employed in Woodward s and Eschenmoser s synthesis of Vitamin 8,2, for which it was initially developed [79]. However, the reaction figured prominently in Mulzer s approach toward the molecule (cf. Scheme 7.5) [15] and has found extensive applications in Montforfs studies on bacterial chlorines [80-82]. For instance, in a synthesis of heme dl, a twofold Eschenmoser-Claisen rearrangement was used to convert porphyrin 102 into chlorin 103, setting the quaternary stereocenters of the target (Scheme 7.35) [83]. 

Resistance to antimicrobial agents is of concern as it is well known that bacterial resistance to antibiotics can develop. Many bacteria already derive some nonspecific resistance to biocides through morphological features such as thek cell wall. Bacterial populations present as part of a biofilm have achieved additional resistance owkig to the more complex and thicker nature of the biofilm. A system contaminated with a biofilm population can requke several orders of magnitude more chlorine to achieve control than unassociated bacteria of the same species. A second type of resistance is attributed to chemical deactivation of the biocide. This deactivation resistance to the strong oxidising biocides probably will not occur (27). 

Chlorine Dioxide. Like ozone, chlorine dioxide [10049-04-4] is a powerflil oxidant. It is usually generated as used. It has been used for disinfecting drinking water and bleaching paper pulp. Its effectiveness in killing microorganisms is well documented (305,306), and it has received recent study as a gas to sterilize medical devices. It requites 50% rh or higher to be effective. Bacterial cells had a D-value of 2.6 min and spores of 24 min (307). 

Two approaches that have been investigated recently for disinfection are mixtures of bromine and chlorine, and mixtures containing bromide or iodide salts. Some evidence exists that mixtures of bromine and chlorine have superior germicidal properties than either halogen alone. It is believed that the increased bacterial activity of these mixtures can be attributed to the attacks by bromine on sites other than those affected by chlorine. The oxidation of bromide or iodide salts can be used to prepare interhalogen compounds or the hypollalous acid in accordance with the following reaction ... 

Neilson AH, A-S Allard, P-A Hynning, M Remberger, L Landner (1983) Bacterial methylation of chlorinated phenols and guiaiacols formation of veratroles from gnaiacols and high molecular weight chlorinated lignin. Appl Environ Microbiol 45 774-7S3. 

Higson FK, DD Focht (1990) Bacterial degradation of ring-chlorinated acetophenones. Appl Environ Microbiol 56 3678-3685. 

Furukawa K, N Tomizuka, A Kamibayashi (1979) Effect of chlorine substitution on the bacterial metabolism of various polychlorinated biphenyls. Appl Environ Microbiol 38 301-310. 

Haddock ID, JR Horton, DT Gibson (1995) Dihydroxylation and dechlorination of chlorinated biphenyls by purified biphenyl 2,3-dioxygenase from Pseudomonas sp. strain LB400. J Bacterial 111 20-26. 

Haugland RA, DJ Schlemm, RP Lyons, PR Sferra, AM Chakrabarty (1990) Degradation of the chlorinated phenoxyacetate herbicides 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid by pure and mixed bacterial cultures. Appl Environ Microbiol 56 1357-1362. 

An anaerobic bacterial enrichment cnltnre was used to examine the dechlorination of 2,3,4,5-tetrachlorobiphenyl that prodnced 2,3,5-trichlorobiphenyl exclusively. Although there was no alteration in the valnes of 5 C, compound-specific analysis of Arochlor 1268 showed that there was a trend for decreasing C abundance with increasing content of chlorine. This is consistent with dechlorination of the congeners with more chlorine substituents. 

Haggblom M (1990) Mechanisms of bacterial degradation and transformation of chlorinated monoaromatic compounds. J Basic Microbiol 30 115-141. 

Combined Chlorine-Aldehyde Treatment A combined chlorine-aldehyde treatment that has two stages, that is, chlorination and subsequent biocide application, has been suggested. Short-residence-time shock doses of glutaraldehyde have been applied after chlorination [1180]. It has been established that a primary chlorination in overall bacterial control is useful. 

Hydrochloric acid in combination with chlorine dioxide can be used as a treatment fluid in water-injection wells that get impaired by the deposition of solid residues [332,333]. The treatment seems to be more effective than the conventional acidizing system when the plugging material contains iron sulfide and bacterial agents because of the strongly oxidative power of chlorine dioxide. Mixtures of chlorine dioxide, lactic acid, and other organic acids [1172,1173] also have been described. 

M. Knickrehm, E. Caballero, P. Romualdo, and J. Sandidge. Use of chlorine dioxide in a secondary recovery process to inhibit bacterial fouling and corrosion. In Proceedings Volume. NACE Corrosion 87 (San Francisco, CA, 3/9-3/13), 1987. 

Irritating to eyes and nose. Not Ideal for bacterial disinfection. Can result in chlorine loss. Satisfactory Ideal range Satisfactory Irritating to eyes and nose. More chlorine needed -for disinfection. 

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