Light and Electron Microscopic Studies of Escherichia Coli-Coliphage Interactions Iii

Abstract

The first two articles of this series (Beutner et al., 1953; Mudd et al., 1953) contain descriptions of the light microscopic cytology and electron microscopy of T2 bacteriophage infection of Escherichia coli, strain B, with particular emphasis on the changes occurring in the chromatinic material, and with the intracellular appearance of possible phage precursors and apparently mature phage progeny. In this paper we show that the cytoplasmic organelles, the mitochondria, in contrast with the nuclei, maintain their integrity throughout the latent period of infection. MATERIALS AND METHODS Escherichia coli, strain B, and phages T2r+ and T2r were used throughout. The phage suspensions, media, basic techniques, and microscopic equipment have been described elsewhere (Beutner et al., 1953; Mudd et al., 1953). In addition, experiments were performed utilizing 2,3,5-triphenyltetrazolium chlorides as an indicator of reduction (Brodie and Gots, 1951, 1952; Kun, 1951; Shelton and Schneider, 1952). The reduction of 2,3,5-triphenyltetrazolium chloride was followed by mixing 3 ml aliquots of deepgrown (unaerated) log phase broth4 cultures of E. coli and 1 ml of a distilled water solution of I This work has been aided by a grant from the United States Atomic Energy Commission, AEC Contract no. AT(30-1)-1342. Aid was also received from the Theresa F. Felsen Memorial Fund.

LOCALIZATION OF THE SUCCINIC DEHYDROGENASE SYSTEM IN ESCHERICHIA COLI USING COMBINED TECHNIQUES OF CYTOCHEMISTRY AND ELECTRON MICROSCOPY

“…Results of such studies have shown that oxidative enzymes are associated with the cell Membran fraction (1) which contains both cell wall and plasma membrane fragments. Early work (2)(3)(4)(5) involved visual localization of enzyme sites with the use of tctrazolium salts which became reduced to colored formazans. More recently combined techniques of histochcmistry and electron microscopy have been applied to the specific structural localization of respiratory enzyme sites in bacteria (6)(7)(8).…”

CYTOCHEMICAL LOCALIZATION OF DEHYDROGENASE AND DIAPHORASE ACTIVITY IN BACILLUS MEGATERIUM

“…cytoplasmic membranes) (19). The relationship of the formazan pattern observed to a stripe-like localization of reduced triphenyl-tetrazolium or tellurite occurring in several bacterial species (20,21) remains to be determined. There is a strong possibility that the site of oxidative activity in B. megaterium as demonstrated in this paper may be associated with intracytoplasmic membrane systems which have been described recently in various Actinomycetales and eubacteria (4.…”