PMID- 14674583
OWN - NLM
STAT- MEDLINE
DCOM- 20040106
LR  - 20190906
IS  - 0090-4341 (Print)
IS  - 0090-4341 (Linking)
VI  - 45
IP  - 3
DP  - 2003 Oct
TI  - Energization of Comamonas testosteroni ATCC 17454 for indicating toxic effects of 
      chlorophenoxy herbicides.
PG  - 317-23
AB  - The toxicity of chlorophenoxy herbicides to a bacterium, strongly related to the 
      well-known species Delftia (formerly Comamonas) acidovorans that are able to 
      detoxify these xenobiotics, was investigated. The oxidation of n-hexanol via 
      alcohol dehydrogenases, coupled with the generation of ATP by electron transport 
      phosphorylation (ETP), was used as an indicator for energy-toxic effects on the 
      growth of Comamonas testosteroni ATCC 17454. Uncoupling--reductions in ATP 
      synthesis accompanied by increased respiration--was found to be induced by 1 mM 
      of the classic uncoupler 2,4-dinitrophenol (2,4-DNP) at pH 7.0 and 8.0. At pH 5.4 
      and 6.0, the ATP synthesis and respiration were strongly inhibited by both 
      2,4-DNP and the chlorophenoxy herbicides tested. In contrast, 5 mM of 
      2,4-dichlorophenoxyacetic acid (2,4-D) and of 2-(2,4-dichlorophenoxy)-propanoic 
      acid (2,4-DCPP) were required for detectable uncoupling effects--reduction of the 
      P/O ratios by about 30%--at pH 7.0. These chemicals may have less uncoupling 
      power because the concentration of their protonated (undissociated) forms (pKa 
      values 2.7 and 3.0) is an order of magnitude lower than that of 2,4-DNP (pKa = 
      4.0) at this pH value. Strong uncoupling accompanied by increased respiration, 
      like that induced by 1 mM 2,4-DNP, was also caused by 5 mM 
      4-(2,4-dichlorophenoxy)-butyric acid (2,4-DCPB), which correlates with its high 
      pKa value of 4.6. The order of toxicity of the chlorophenoxy herbicides (2,4-D < 
      2,4-DCPP < 2,4-DCPB) to the ETP, which correlates well with the lipophilicity of 
      their undissociated forms (log P 2.7 < 3.4 < 3.5, respectively), was confirmed by 
      measuring their capacity to inhibit the growth of Comamonas testosteroni ATCC 
      17454. The results show that energization via alcohol dehydrogenases can be used 
      as an indicator for investigating energy-toxic effects of organics on the ETP and 
      growth of chlorophenoxy herbicide-detoxifying bacteria.
FAU - Loffhagen, N
AU  - Loffhagen N
AD  - Sektion Umweltmikrobiologie, Umweltforschungszentrum Leipzig-Halle GmbH, 
      Permoserstrasse 15, D-04318 Leipzig, Germany.
FAU - Hartig, C
AU  - Hartig C
FAU - Babel, W
AU  - Babel W
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Arch Environ Contam Toxicol
JT  - Archives of environmental contamination and toxicology
JID - 0357245
RN  - 0 (Coloring Agents)
RN  - 0 (Herbicides)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - EC 1.1.1.1 (Alcohol Dehydrogenase)
RN  - Q13SKS21MN (2,4-Dinitrophenol)
SB  - IM
MH  - 2,4-Dinitrophenol/*metabolism/pharmacokinetics/toxicity
MH  - Adenosine Triphosphate/*metabolism
MH  - Alcohol Dehydrogenase/*pharmacology
MH  - Coloring Agents/*metabolism/pharmacokinetics/toxicity
MH  - Comamonas testosteroni/*enzymology
MH  - Electron Transport
MH  - Herbicides/*metabolism/pharmacokinetics/toxicity
MH  - Hydrogen-Ion Concentration
MH  - Inactivation, Metabolic
MH  - Oxidation-Reduction
MH  - Phosphorylation
EDAT- 2003/12/17 05:00
MHDA- 2004/01/07 05:00
CRDT- 2003/12/17 05:00
PHST- 2003/12/17 05:00 [pubmed]
PHST- 2004/01/07 05:00 [medline]
PHST- 2003/12/17 05:00 [entrez]
AID - 10.1007/s00244-003-2142-6 [doi]
PST - ppublish
SO  - Arch Environ Contam Toxicol. 2003 Oct;45(3):317-23. doi: 
      10.1007/s00244-003-2142-6.