Chloroform degradation

Jahng D, TK Wood (1994) Trichloroethylene and chloroform degradation by a recombinant pseudomonad expresssing soluble methane monooxygenase from Methylosinus trichosporium OB3b. Appl Environ Microbiol 60 2473-2482. 

Because aqueous chloroform degradation is clearly mostly the result of electron capture, it might be expected that deoxygenation would increase the rate. However, deoxygenated solutions show reduced destruction efficiency [14]. Therefore, a mechanism has been suggested wherein CHC12 [product of Eq. (27)] is attacked by oxygen ... 

Degradation of carbon tetrachloride by photochemical, x-ray, or ultrasonic energy produces the trichloromethyl free radical which on dimeri2ation gives hexachloroethane. Chloroform under strong x-ray irradiation also gives the trichloromethyl radical intermediate and hexachloroethane as final product. 

Timberlake and Bridle (1971) and later Wrolstad and Durst (1998) compared the acetone-chloroform method of extraction to acidified methanol and, depending on the material used, the anthocyanin recoveries were comparable or up to 30% higher with the use of acetone. This procedure proved efficient for a wide range of anthocyanin-rich plants to achieve high recoveries with minimal degradation. - ... 

Methane, butane, and chloroform. Cells of Methylosinus trichosporium grown with methane and of Pseudomonas butanovora md My cobacterium vaccae grown with butane were able to partially degrade chloroform (Hamamura et al. 1997). Again this may be the result of the induction of monooxygenase activity. 

Traps with Bio-Sep beads amended with [ Cg]-benzene and [ C]-toluene were used to assess biodegradation in an aquifer (Geyer et al. 2005). Beads were lyophilized after exposure, lipids were extracted with chloroform-methanol, and the fatty acids and values analyzed. High enrichment of was observed in several fatty acids, which showed that the label from the substrates had been incorporated. In addition, there were differences in the abundance of the fatty acids in beads amended with benzene or toluene that suggested the existence of different microbial degradative populations. 

A number of haloalkanes including dichloromethane, chloroform, 1,1-dichloroethane and 1,2-dichloroethane may be degraded by the soluble MMO system of Methylosinus trichosporium (Oldenhuis et al. 1989). 

The degradation of tetrachloromethane by Pseudomonas stutzeri strain KC involves hydrolysis to CO2 by a mechanism involving the natnrally prodnced pyridine-2,6-dithiocarboxylic acid (Lewis et al. 2001) details have already been discnssed in Chapter 7, Part 3. This organism was nsed in field evaluation at a site at which the indigenons flora was ineffective, and acetate was used as electron donor (Dybas et al. 2002). One novel featnre was inocnlation at a series of wells perpendicnlar to the established flow of the gronndwater plnme. Effective removal of tetrachloromethane was snstained over a period of 4 years, and transient levels of chloroform and H2S disappeared after redncing the concentration of acetate. 

The quantity R is proportional to the number of chain scissions per original macromolecule. For both PBS and PHS, for all solvents studied (1,4-dioxane, acetonitrile, chloroform, tetrahydrofuran, toluene and 2-butanone) the scattered light intensity decreases after irradiation. The amount of degradation R° for the same polysulfone is higher for solvents with larger yield of radicals. R° is larger for PHS than for PBS in the case of the solvents 1,4-dioxane and acetonitrile, which have the highest yield of radicals ... 

The nucleophilic substitution on poly(vinyl chloroformate) with phenol under phase transfer catalysis conditions has been studied. The 13c-NMR spectra of partly modified polymers have been examined in detail in the region of the tertiary carbon atoms of the main chain. The results have shown that the substitution reaction proceeds without degradation of the polymer and selectively with the chloroformate functions belonging to the different triads, isotactic sequences being the most reactive ones. 

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