Effects of paraquat on Escherichia coli: Differences between B and K-12 strains

Journal Article · Thu Feb 01 00:00:00 EST 1990 · Journal of Bacteriology; (USA)

OSTI ID:6749524

Kitzler, J W; Minakami, H; Fridovich, I ^[1]

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1. Duke Univ. Medical Center, Durham, NC (USA)

Escherichia coli B and K-12 are equally susceptible to the bacteriostatic effects of aerobic paraquat, but they differed strikingly when the lethality of paraquat was evaluated. E. coli B suffered an apparent loss of viability when briefly exposed to paraquat, whereas E. coli K-12 did not. This difference depended on the ability of the B-strain, but not the K-12 strain, to retain internalized paraquat; the B strain was killed on aerobic tryptic soy-yeast extract plates during the incubation which preceded the counting of colonies. This difference in retention of paraquat between strains was demonstrated by delayed loss of viability, by growth inhibition, and by cyanide-resistant respiration after brief exposure to paraquat, washing, and testing in fresh medium. This difference was also shown by using ({sup 14}C)paraquat. This previously unrecognized difference between E. coli B and K-12 has been the cause of apparently contradictory reports and should lead to some reevaluation of the pertinent literature.

• OSTI ID: 6749524
• Journal Information: Journal of Bacteriology; (USA), Vol. 172:2; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ESCHERICHIA COLI
SENSITIVITY
HERBICIDES
BIOLOGICAL EFFECTS
CARBON 14 COMPOUNDS
COMPARATIVE EVALUATIONS
GROWTH
INHIBITION
RETENTION
TRACER TECHNIQUES
VIABILITY
BACTERIA
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MICROORGANISMS
PESTICIDES
550201* - Biochemistry- Tracer Techniques