Patterns of Cell Division, DNA Base Compositions, and Fine Structures of Some Radiation-Resistant Vegetative Bacteria Found in Food

Authors

S. W. Sanders, University of Nebraska-Lincoln
R. Burt Maxcy, University of Nebraska-Lincoln

Date of this Version

1-1979

Comments

Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Jan. 1979, p. 159-168.

Abstract

Representative highly radiation-resistant Moraxella-Acinetobacter (M-A), Pseudomonas radiora, Micrococcus radiodurans, and Micrococcus radiophilus exhibited a wide variety of division systems and cell wall characteristics. However, the most resistant M-A possessed unusually thick cell walls, indicating a possible role of the cell wall in radiation resistance in the M-A. Thick septation was present in most of the bacteria studied, but was absent in P. radiora, thus excluding this as a necessity for high resistance. Reliable determination of the number of division planes of the M-A for use as a taxonomic criterion was achieved by the direct observation of dividing cells. The highly resistant M-A were found to divide in multiple planes and had base compositions of 54.0 to 57.5%, unlike typical Moraxella and/or Acinetobacter species. The taxonomic position of most highly resistant bacteria remains unclear.