Soil degradation microorganisms

If PAH-degrading microorganisms use broad-specificity enzymes or common pathways to transform multiple PAHs, then inducers for the metabolism of one PAH substrate might co-induce the transformation of a range of PAHs. Preliminary evidence indicated that the transformation of naphthalene, phenanthrene, fluoranthene, and pyrene by Pseudomonas saccharophila P15 was stimulated by salicylate [132], a known inducer of naphthalene metabolism in pseudomonads [43]. However, Chen and Aitken [181] reported in more detail the inducing effects of salicylate on the transformation of various HMW PAHs by Pseudomonas saccharophila P15 isolated from contaminated soil, including... 

Incubations of heptachlor with a mixed culture of soil microorganisms for 12 weeks showed conversion of heptachlor to chlordene, 1-exohydroxychlordene, heptachlor epoxide, and chlordene epoxide. A mixed culture of soil microorganisms, obtained from a sandy loamy soil, degraded heptachlor epoxide to the less toxic 1-exohydroxychlordene. Conversion was about 1% per week during the 12-week test period (Miles et al. 1971). 

Microorganisms isolated from a loamy sand soil degraded lindane and some of the metabolites identified were pentachlorobenzene, 1,2,4,5-tetrachlorobenzene, 1,2,3,5-tetrachlorobenzene, y-PCCH, y-TCCH and p-3,4,5,6-tetrachloro-l-cyclohexane (p-TCCH) (Tu, 1976). y-PCCH was also reported as a metabolite of lindane in an Ontario soil that was pretreated with jo,//-DDT, dieldrin, lindane, and heptachlor (Yule et ah, 1967). The reported half-life in soil is 266 d (Jury et al., 1987). 

Lee, A. EPTC (5-ethyl lV,lV-dipropylthiocarbamate)-degrading microorganisms isolated from a soil previously exposed to EPTC, Soil Biol Blochem., 16 529-531, 1984. 

The effect of PCDDs, PCDFs, and PCDDs on CP-degrading microorganisms in soil has not been systematically studied. These compounds do not biodegrade and do not seem to inhibit CP bioremediation (Valo Salkinoja-Salonen, 1986 McBain et al., 1995). The treatment of soils contaminated simultaneously with PAHs and chlorinated dimeric compounds by white-rot fungi could be potentially advantageous since the peroxidase enzymes oxidize all these chemicals (e.g. Valli et al., 1992 Gold et al., 1994 Lamar Glaser, 1994). 

Triazine biodegradation in soil is dependent on a number of factors, most importantly the presence, population, and activity of triazine-degrading microorganisms. Therefore, factors that affect soil microbial populations and activity... 

Several pure cultures isolated from soils degraded nitrophenols (EPA 1985). As in the case of water, adaptation of soil to 4-nitrophenol was a prerequisite for biodegradation the presence of a critical number of degrader microorganisms was necessary for the initiation of biodegradation However, unlike in natural water, the mineralization of low concentrations of 4-nitrophenol proceeds with little or no initial acclimation period (Scow et al. 1986). Addition of specific nutrients from pristine aquifer also resulted in more rapid adaptation (Aelion et al. 1987 Swindoll et al. 1988), and the rate of biodegradation was concentration-dependent (Scow et al. 1986). The biodegradation of... 

Soil. Degraded predominantly by microorganisms to 4-chloro-2-methyl phenol, followed by ring hydroxylation at the 6-position and ring opening. DTJ0 (aerobic) 3-13 days... 

Soil degradation G = 10.5 d by microorganisms isolated from soil or waste water at 30°C (Kurane et al. 1977) G = 10-50 d via volatilization subject to plant uptake from soil (Ryan et al. 1988) ... 

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