Phenethyl Alcohol as a Suppressor of theEnvAPhenotype Associated with theenvAGene inEscherichia coliK-12

Normark, Staffan

doi:10.1128/jb.108.1.51-58.1971

Cited by 18 publications

(23 citation statements)

References 28 publications

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“…Cleavage of the mucopolymer septum occurred during the in-vagination of the outer wall layers (9). This mutant resembles the envA mutants of E. coli recently described by Normark (15,16). Despite drastic morphological alteration, both the serpentine mutant (53S) and the septate mutant (FM10) grow at the same rate as the parent organism.…”

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confidence: 59%

Cell Division Mutations in the Blue-Green Bacterium Agmenellum quadruplicatum Strain BG1: a Comparison of the Cell Wall

1972

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The peptidoglycan from two types of filamentous cell division mutants of Agmenellum quadruplicatum strain BG1 has been compared to that of the parent organism. Small variations in the total peptidoglycan composition on a dry-weight basis were found in the mutants. The reduced level of peptidoglycan in the serpentine mutant is consistent with a general decrease in the ratio of surface area to volume as compared to the parent organism. The increased peptidoglycan content in the septate mutant confirms previous ultrastructural observations of the greatly enlarged peptidoglycan septum between adjacent cells. A comparison of peptidoglycan composition and cross-linking in the two types of filamentous mutants of A. quadruplicatum and in drug-induced phenocopies suggests that structural alterations of the peptidoglycan are not involved in the apparent impairments of cellular division. Furthermore, data concerning the relative susceptibilities of the parent and mutants to antibiotics indicate that neither mutant exhibits a gross alteration of permeability. 614

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confidence: 59%

Cell Division Mutations in the Blue-Green Bacterium Agmenellum quadruplicatum Strain BG1: a Comparison of the Cell Wall

1972

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“…The experiments reported here as well as those of the accompanying paper (17) suggest an intimate relationship between nucleic acid biosynthesis and penetration of drugs through the outer layers of the envelope. When DNA synthesis was inhibited by nalidixic acid (7), or when RNA as well as protein synthesis were inhibited by amino acid starvation (11), the envA mutant D22 showed a decreased uptake of GV (Table 1, Fig.…”

Section: Discussionsupporting

confidence: 68%

“…The nature of the coupling mechanism is unclear, but it may operate through variations in the pool size of nucleotides (6,8). Lipid changes are found in the cell envelope of strains containing envA (17). Thus it is possible that, during starvation of strain D22, inhibition of lipid biosynthesis results in a rearrangement of lipids in the outer layers of the cell 49 VOL.…”

Section: Discussionmentioning

confidence: 99%

Nature of the Penetration Barrier inEscherichia coliK-12: Effect of Macromolecular Inhibition on Penetrability in Strains Containing theenvAGene

Normark

Westling

1971

J Bacteriol

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The envA mutation in Escherichia coli K-12, which maps at 1.5 min, was previously shown to mediate sensitivity to gentian violet as well as to several antibiotics. Moreover, strains containing the envA gene were recently found to be lysed by lysozyme in the absence of ethylenediaminetetraacetate. It is here reported that the envA mutation mediates an increased uptake of gentian violet. The uptake of the dye was markedly affected by growth with different antibiotics interfering with macromolecular synthesis. Amino acid starvation of a strain containing envA with a stringent control of ribonucleic acid (RNA) synthesis resulted in a decreased uptake of gentian violet. However, no decrease in dye uptake was found during starvation in an envA transductant with a relaxed control of RNA synthesis. Inhibition of deoxyribonucleic acid (DNA) synthesis by nalidixic acid decreased the uptake of gentian violet of envA cells and, in addition, rendered the cells insensitive to the lytic action of lysozyme. Chloramphenicol treatment increased penetrability in wild-type and starved envA cells. In most instances, this effect of chloramphenicol was prevented by selectively interfering with DNA or RNA synthesis. A coordinate regulation of nucleic acid synthesis and penetrability is suggested.Gentian violet (GV) and other basic dyes have a high affinity for nucleic acids (9, 25). Resistance and sensitivity to GV and other basic dyes have been attributed to a number of genes located close to the marker for lactose utilization (13,14,22). In a report by Nakamura (13), it was also concluded that resistant strains had a lower capacity to bind basic dyes. However, Kushner and Khan (10) found that proflavinesensitive and -resistant strains bound the same amount of the dye and that binding of proflavine was a passive process. A release of bound dye caused the increased tolerance of the resistant cells.It was previously found that the envA mutation increased sensitivity to GV as well as to several antibiotics and that it mediated an unspecific increase in permeability through the outer layers of the cell envelope (16). It is reported here that sensitivity to GV is correlated to an increased uptake of the dye. The uptake of GV was markedly decreased during amino acid starvation in envA strains with stringent but not with relaxed ribonucleic acid (RNA) control. Treatment with antibiotics affecting macromolecular synthesis markedly affected uptake of GV and the response to lysozyme in both wild-type and envA strains. 45 MATERIALS AND METHODSOrganisms. Strain D21 of Escherichia coli K-12 was described by Boman et al. (3). Strain D22 is an ethyl methane sulfonate-induced mutant from strain D2 1 (19). The altered gene envA at 1.5 min on the chromosomal map mediates chain formation and an increased penetrability to antibacterial agents (16). The isogenic transductant pair E64-113 (wild type) and E64-120 (envA) and the spontaneous revertant D22S1 were described by Normark (16). Strain CP791 is an envA transductant of the rel strain CP79 (5).Med...

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“…Phenethylalcohol (PEA) partially reverses the separation lesion of such mutants as E . coli env A (NORMARK 1971). Accordingly the effect of PEA (at 0.1%) was tested on the morphology of strain 4a grown at 25 "C in YEMM.…”

Section: E F F E C T Of P H E N E T H Y L a L C O H O L O N T H E D Imentioning

confidence: 99%

An alteration in outer membrane permeability associated with a division lesion in a strain of Salmonella typhimurium

Ahmed

Rowbury

1978

J of Basic Microbiology

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Salmonella typhimurium strain 4a is a temperature sensitive mutant with defects in both septation and separation. The separation lesion was reversed by phenethylalcohol but this agent failed to allow septation or growth a t restrictive temperature. Organisms of strain 4a grown a t 42 "C were, unlike the parental strain, resistant to lysis by lysozyme plus EDTA and lipopolysaccheride was poorly extracted by EDTA from cultures of strain 4a grown a t 42 "C. Such cultures may, therefore, be resistant to lysis with lysozyme plus EDTA not because the murein is altered but because the EDTA fails to permeabjlize the outer membrane to lysozyme. I n confirmation of this, murein isolated from strain 4a after growth at 42 "C showed the same sensitivity to lysozyme as murein from the parental strain. In spite of the altered envelope properties of strain 4a after growth a t 42 "C, no major changes in protein or phospholipid composition have so far been demonstrated.Salntonella typhimurium strain 4a is a temperature sensitive division mutant. Previous studies showed that organisms of this strain grown a t 25 "C in minimal medium (MM) + histidine or in broth were of similar size and morphology to those of the parent strain. With strain 4a, however, temperature shifts'to 39 "C or above in these media caused almost immediate and complete division inhibition ; increase in cell mass continued and long filaments resulted (AHMED and ROWBURY 1971a). These filaments were non-septated.A second division abnormality is manifested by strain 4a a t 25 "C in yeast-extract minimal medium (YEMM). I n this medium a t 25 "C organisms grow mainly as long chains; separation is evidently aberrant (AHMED et al. 1973). Studies of ts+ revertants of strain 4a and of phenotypic reversion of the strain with sucrose are in accord with the septation and separation alterations being consequences of a single mutation (AHMED and I~OWBURY 1974). Because strain 4a showed a separation lesion under certain conditions, we tested the effect of phenethylalcohol (PEA) on its division behaviour; NORMARK (1971) showed that PEA partially reversed the chaining which occurs with Escherichia coli envA during exponential growth. The results described here establish that PEA also reverses the separation defect of strain 4a but has no effect on the inhibition of septation which occurs a t 39 "C or above.It has been suggested that PEA acts primarily on the cell membrane (SILVER and WENDT 1907) ; for example, a t high levels, protoplasts and spheroplasts are lysed by PEA. If PEA does act primarily on the membrane then its ability to correct the separation defect of strain 4a may indicate a membrane alteration in the mutant. In view of this, we have examined strain 4a for altered membrane properties and changes in membrane composition after growth a t restrictive temperature. The outer membrane of strain 4a appears to have altered permeability properties after growth a t 42 "C and EDTA failed to extract normal amounts of lipopolysaccharide from the outer membrane. No major chang...

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Phenethyl Alcohol as a Suppressor of theEnvAPhenotype Associated with theenvAGene inEscherichia coliK-12

Cited by 18 publications

References 28 publications

Cell Division Mutations in the Blue-Green Bacterium Agmenellum quadruplicatum Strain BG1: a Comparison of the Cell Wall

Cell Division Mutations in the Blue-Green Bacterium Agmenellum quadruplicatum Strain BG1: a Comparison of the Cell Wall

Nature of the Penetration Barrier inEscherichia coliK-12: Effect of Macromolecular Inhibition on Penetrability in Strains Containing theenvAGene

An alteration in outer membrane permeability associated with a division lesion in a strain of Salmonella typhimurium

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