Degradation of pyrene byRhodococcus sp. UW1

Abstract

A Rhodococcus species, designated strain UW1, was isolated from contaminated soil using conventional enrichment and isolation techniques. The isolate was able to use pyrene as sole source of carbon and energy; it mineralized 72% of the pyrene within 2 weeks. During growth a metabolite was detected in the culture fluid and further characterized by UV-and mass spectrometry. There is evidence that this metabolite resulted from a recyclization of the direct recta-ringfission product of pyrene after dihydroxylation in either the 1,2-or 4,5-position. At pH 7.0 and 30°C Rhodococcus sp. UWI showed a maximum degradation rate of 0.08 mg pyrene/ml per day, while growing with a doubling time of 30 h. The activity of the initial dioxygenase system was characterized by measuring the oxygen-consumption rates of pyrene-induced resting cells, the maxima of which occurred at pH 7.2 and 45°C. Rhodococcus sp. UW1 could also use phenanthrene, anthracene, fluoranthene and chrysene as sole sources of carbon and energy, whereas naphthalene, dibenzofuran, fluorene and dibenzothiophene were only co-metabolized.

Potential for remediation of water repellent soils by inoculation with wax-degrading bacteria in south-western Australia

“…were successful in reducing water repellency in soil. These organisms are known for their ability to metabolise a wide range of organic compounds as sole carbon sources for energy and growth (Williams et al, 1989;Walter et al, 1991). Furthermore, measurements of surface tension in the growth medium of these bacteria indicated that all of them produced biosurfactants (Roper, 2004).…”

Bioremediation of naphthalene in water by Sphingomonas paucimobilis using new biodegradable surfactants based on poly (ɛ-caprolactone)

“…The species involved include Rhodococcus sp. (Walter et al, 1991), Burkholderia cepacia (Juhasz et al, 1997), Pseudomonas (Juhasz et al, 1996;Johnsen et al, 2005), Stenotrophomonas maltophilia (Boonchan et al, 1998), Mycobacterium sp. (Bouchez et al, 1995), Alcaligenes denitrificans (Weissenfels et al, 1990), and Sphingomonas paucimobilis (Mueller et al, 1990;Ye et al, 1996).…”

Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils

“…To date, growth on pyrene has been observed in some species of Rhodococcus (Walter et al 1991;Bouchez et al 1997) and strains of Burkholderia cepacia (Juhasz et al 1997); additionally, cometabolism of pyrene has been observed in Pseudomonas saccharophila (Chen and Aitken 1999). However, the ability to grow on high-molecular-weight PAH substrates may be most widespread in the genus Mycobacterium, where this result has been reported for several different species and strains (Heitkamp et al 1988b;Churchill et al 1999;Schneider et al 1996;Boldrin et al 1993;Bastiaens et al 2000;Vila et al 2001).…”

“…Growth on PAH containing four fused aromatic rings (e.g. chrysene, fluoranthene, pyrene, benz[a]anthracene) is somewhat more rare, although organisms are known which can utilize each of these as growth substrates (Heitkamp et al 1988a & b;Churchill et al 1999;Schneider et al 1996;Mueller et al 1990;Boldrin et al 1993;Bastiaens et al 2000, Walter et al 1991, Bouchez et al 1997, Juhasz et al 1997Caldini et al 1995;Weissenfels et al 1991;Vila et al 2001). Currently, very few bacteria have been reported to be capable of growth using solely PAH with five Appendix -14 or more benzene rings (Juhasz et al 1997), although some cases have been reported in which bacteria co-metabolize five-ring PAHs during growth on simpler substrates (Chen and Aitken 1999;Schneider et al 1996).…”