Degradation of PCBs: Construction of chlorobiphenyl-utilizing bacteria by continuous amalgamated culture

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:5481928

Adams, R H

Recombinant strain Pseudomonas sp. CB15, which mineralizes 3-chlorobiphenyl, was constructed from Pseudomonas sp. HF1, which grows on 3-chlorobenzoate, and Acinetobacter sp. P6 which grows on biphenyl. The causes of the inability of the recombinant to also utilize 3,3{prime}-dichlorobiphenyl (3,3{prime} DCBP) were investigated. Incompatibility between the meta- and ortho-fission pathways during growth on 3-chlorobiphenyl was observed. The meta-fission of 2,3-dihydroxybiphenyl, (the nonchlorinated analogue of the metabolic intermediate 3-chloro-2{prime},3{prime}-dihydroxybiphenyl) was affected by substrate inhibition and was also inhibited by 3-chlorocatechol. The ortho-fission of 3-chlorocatechol followed Michaelis-Menten kinetics but the addition of 2,3-dihydroxybiphenyl inhibited the reaction. The growth rate of 3-chlorobiphenyl was increased, however, by the addition of surfactant or by mechanical fragmentation of the substrate, which resulted in complete mineralization in 2.8 days. Nevertheless, neither of these methods allowed strain CB15 to grown on 3,3{prime} DCBP. Addition of 3,3{prime} DCBP into the culture medium had no effect on the rate of 3-chlorobiphenyl mineralization, which indicates that toxic intermediates are not produced from the transformation of 3,3{prime} DCBP. The inability to grow on 3,3{prime} DCBP is more likely due to the low transformation rate, which was about one-fifth the rate of 3-chlorobiphenyl by resting cells.

• Research Organization: California Univ., Riverside, CA (United States)
• OSTI ID: 5481928
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AROMATICS
BACTERIA
BIODEGRADATION
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
CHLORINATED AROMATIC HYDROCARBONS
CONTINUOUS CULTURE
DECOMPOSITION
GROWTH
HALOGENATED AROMATIC HYDROCARBONS
METABOLISM
MICROORGANISMS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PSEUDOMONAS