THE RADIOSENSITIVITY OF CULTURE OF ESCHERICHIA FREUNDII AS A FUNCTION OF THE ACCUMULATION OF INTRA- AND EXTRACELLULAR CITRATE PRODUCED BY ADDITION OF FLUOROACETATE TO THE CULTURE MEDIUM

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Arch. Intern. Physiol. Biochim.

OSTI ID:4680139

Liebecq, C; Osterrieth, P M

In the presence of 10/sup -4/M sodium fluoroacetate, cultures of E. freundii (strain EF 5) in a 0.5% glucose medium with an initial pH of 4.8 accumulate relatively large amounts of citric acid. Bacteria grown under these conditions are less radiosensitive than control cultures grown in the absence of fluoroacetate. However, in subsequent experiments it was possible to produce cultures that produced large quantities of citric acid without showing radioresistance. Thus there does not seem to be a correlation between citric acid concentration of the medium and radiosensitivity of the bacteria, nor can any radioprotective action be attributed to citric acid. At the pH of the medium it would have only low complexing activity. A slight but significant diminutlon of radiosensitivity was observed in cultures grown in 0.1% glucose medium at pH 6.8 in the presence of fluoroacetate. In this case, citric acid accumulates intracellularly only; its concentration reaches approximates 18 mu g/mg nitrogen as compared with 6 mu g/mg in control cultures. It is suggested that it may be the internal accumulation of citric acid that confers protection on the cells. The results may be analognus to earlier studies in mice, in which it was noted that injection of fluoroacetate (causing a considerable accumulation of citric acid in the tissues) enhanced radioresistance. (H.H.D.)

• Research Organization: Universite, Liege
• NSA Number: NSA-17-024907
• OSTI ID: 4680139
• Journal Information: Arch. Intern. Physiol. Biochim., Journal Name: Arch. Intern. Physiol. Biochim. Vol. Vol: 71
• Country of Publication: Country unknown/Code not available
• Language: French

Related Subjects

ACETATES
ACIDITY
BACTERIA
BIOLOGY AND MEDICINE
CITRIC ACID
ESCHERICHIA FREUNDII
MICE
ORGANIC FLUORINE COMPOUNDS
QUANTITY RATIO
RADIATION PROTECTION
RADIOSENSITIVITY