1. Assessment of the biodegradation potential of psychrotrophic microorganisms.
- Author
-
Whyte LG, Greer CW, and Inniss WE
- Subjects
- Arthrobacter genetics, Arthrobacter metabolism, Bacterial Proteins biosynthesis, Bacterial Proteins genetics, Base Sequence, Biodegradation, Environmental, Canada, Catechol 2,3-Dioxygenase, Cytochrome P-450 CYP4A, Cytochrome P-450 Enzyme System biosynthesis, Cytochrome P-450 Enzyme System genetics, DNA Primers, Flavobacterium genetics, Flavobacterium metabolism, Mixed Function Oxygenases biosynthesis, Mixed Function Oxygenases genetics, Molecular Sequence Data, Multienzyme Complexes biosynthesis, Multienzyme Complexes genetics, Oxygenases biosynthesis, Oxygenases genetics, Polymerase Chain Reaction, Pseudomonas genetics, Pseudomonas metabolism, Rhodococcus genetics, Rhodococcus metabolism, Bacteria genetics, Bacteria metabolism, Dioxygenases, Environmental Pollution, Genes, Bacterial, Naphthalenes metabolism, Toluene metabolism
- Abstract
Bioremediation of polluted temperate and cold temperature environments may require the activity of psychrotrophic bacteria, because their low temperature growth range parallels the ambient temperatures encountered in these environments. In the present study, 135 psychrotrophic microorganisms isolated from a variety of ecosystems in Canada were examined for their ability to mineralize 14C-labelled toluene, naphthalene, dodecane, hexadecane, 2-chlorobiphenyl, and pentachlorophenol. A number of the psychrotrophic strains mineralized toluene, naphthalene, dodecane, and hexadecane. None of the psychrotrophs were capable of mineralizing 2-chlorobiphenyl or pentachlorophenol. Those strains demonstrating mineralization activity were subsequently screened by the polymerase chain reaction (PCR) and Southern hybridization of PCR products for the presence of catabolic genes (alkB, ndoB, todCl, and xylE) involved in known bacterial biodegradative pathways for these compounds. Some of the psychrotrophs able to mineralize toluene and naphthalene possessed catabolic genes that hybridized to xylE or todCl, and ndoB, respectively. The alkB PCR fragments obtained from the strains that mineralized dodecane and hexadecane did not hybridize to an alkB gene probe derived from Pseudomonas oleovorans. Psychrotrophic strain Q15, identified as a Rhodococcus sp., also mineralized the C28 n-paraffin octacosane. A gene probe constructed from the "alkB" PCR fragment from strain Q15 did hybridize with the alkB PCR fragments from most of the psychrotrophic alkane biodegraders, indicating that the alkB primers may be amplifying another gene(s), perhaps with low homology to P. oleovorans alkB, which may be involved in the biodegradation of both short chain (dodecane) and longer chain alkanes (hexadecane, octacosane). All of the psychrotrophic biodegradative isolates examined were capable of mineralization activity at both 23 and 5 degrees C, indicating their potential for low temperature bioremediation of petroleum hydrocarbon contaminated sites.
- Published
- 1996
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