Adenosine Triphosphate Content in Lactobacillus casei and the Blender-resistant Phage-Cell Complex-forming Ability of Cells on Infection with PL-1 Phage

Abstract

SUMMARYThe intracellular ATP content of Lactobacillus casei ATCC 27o92 grown in a glucose-containing medium was almost constant (2 to 3/zg/mg dry wt. cells) through the early to middle stage of logarithmic phase, but it was lowered to less than o. I #g/mg after cessation of growth owing to the exhaustion of available glucose. All the cells in the early stage of stationary phase were still viable and thus considered to be in a starved state. When such starved cells were infected with PL-~ phages in a tris-maleate buffer of pH 6.0, the process of forming blender-resistant phagecell complexes signifying the complete injection of phage genomes into the cells was much inhibited. There was a good correlation between the ATP content of cells and the extent of the formation of blender-resistant phage-cell complexes and the correlation coefficient between them was 0"89 + o'o9 at the 95 % confidence limit. On the other hand, the process of forming both the phage-adsorbed cells and the anti-phage serum-resistant phage-cell complexes were not affected by the ATP content of cells. Feeding of glucose to such starved cell cultures caused the ceils to restore both the ATP content and the ability to form blender-resistant phage-ceil complexes. Such restoration was also observed when the starved cells collected by centrifugation were incubated in a glucose-containing medium. The significance of the intracellular level of high energy compounds such as ATP for the mechanism of the injection of phage genomes into the cells is discussed.

Lactococcal Bacteriophages Require a Host Cell Wall Carbohydrate and a Plasma Membrane Protein for Adsorption and Ejection of DNA

“…If the mechanism of phage DNA translocation across the plasma membrane is to be accurately reproduced in vitro, the ejected phage DNA should traverse the membrane. However, the DNA translocation step is known to require the proton motive force in intact cells (15,40), and without it, the DNA is only partially released from the phage capsule. Moreover, in vitro interactions between coliphages and their receptors in the absence of the proton motive force result in ejection of phage DNA free into the medium (5,27,28,41).…”

Phage adsorption and lytic propagation in Lactobacillus plantarum: Could host cell starvation affect them?

“…In this regard, the energy requirement to carry out some stages of the lytic cycle (DNA injection) was previously studied in lactic acid bacteria. Specifically, the presence of intracellular high-energy compounds was demonstrated to be indispensable for penetration of phage PL-1 genome into the bacterial host cell ( L. casei ) [ 14 , 15 , 21 , 25 ]. In addition, phage PL-1 adsorbed on starved cells but the DNA injection into the host cell was inhibited due to the absence of an active cell metabolism (decrease of intracellular ATP content, inhibition of protein synthesis).…”

“…Much research related to inhibition of phage development when cell starvation conditions are induced was carried out mainly on Escherichia coli [ 12 , 13 ]. Regarding LAB, the available information is only focused on the influence of bacterial metabolism (studied using starved cells) on some stages of the infective cycle (phage adsorption/DNA injection) in Lactobacillus casei [ 14 , 15 ].…”

Genetics and Biotechnology of Lactic Acid Bacteria

“…Yakokura (1977) suggested that the receptor for phage J-l involved both cell wall L-rhamnose and cytoplasmic membrane Dgalactosamine of Lb. While adsorption of phage PL-l occurred normally in the absence of Ca++, this cation was shown to be essential for phage DNA penetration as was A TP (Watanabe and Takesue, 1972;Watanabe et al, 1979). For Lb.…”