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H W Ackermann

Publications and source records attributed to H W Ackermann.

At least 55 records · Page 3Linked to original sources
PubMed1979

DNA base composition, nature of intracellular DNA, morphology, and classification of bacteriophages infecting Micrococcus luteus.

Ten bacteriophages infecting Micrococcus luteus have been characterized. All phages contain double-stranded DNA, of 64.3--73.5 mol% guanine plus cytosine (GC). The DNA of phage N7 has the highest GC content reported for any bacterial virus. No unusual bases have been found. The intracellular replicating DNAs of six phages are covalently closed circular molecules. All 10 phages have isometric, probably icosahedral, heads and long, flexible, noncontractile tails and can be sorted into two morphological groups based on size and presence or absence of a collar. Host-range studies indicate six host-range groups.

Bacteriophages↗
PubMed1979

Characterization of two Salmonella newport bacteriophages.

Salmonella newport phages 16--19 and 7--11 have very long heads and are members of two rare and so far little-known phage groups. Both produce various morphological aberrations. Preparations of phage 7--11 contain numerous polyheads and about 0.4% short heads belonging to nine size classes. In addition, one giant phage particle was observed. The head of phage 7--11 seems to be an icosahedron which became elongated by adding successive rows of subunits. Phages 16--19 and 7--11 have buoyant densities in CsCl of 1.43 and 1.48 g/mL and particle weights of 103 and 204 x 10(6) respectively. Both viruses contain double-stranded DNA, internal proteins, and sugars. Phage 16--19 contains 46.5% DNA of 35 x 10(6) molecular weight, and glucose. Phage 7--11 contains 47.5% DNA of 108 x 10(6) molecular weight, and mannose. Base compositions of phage and S. newport DNAs were determined from buoyant densities, melting point, and acid hydrolysis. Phage 16--19 contains 5.4% 5-methylcytosine.

Base Composition↗
PubMed1978

Partial characterization of a cubic Bacillus phage.

Partial characterization of a cubic Bacillus phage. Can. J. Microbiol. 24: 986--993. Phage Bam35 is an icosahedron of about 63 nm in diameter. It has a double capsid with spikes at the vertices, and a tail which seems to appear upon nucleic acid ejection. The phage contains DNA and, probably, lipids which seem to be located in the inner coat. The phage is Bacillus-specific, UV- and lipase-resistant, and sensitive to heat, chloroform, and ether. The latent period is 50 min and the burst size is 39. Page Bam35 belongs to a new virus group which includes a phage of B. anthracis and four phages of gram-negative bacteria harboring drug-resistance plasmids.

Bacillus thuringiensis↗
PubMed1978

[Phage-like particles produced by Clostridium tetani].

Two C. tetani strains used for toxin production spontaneously produce two varieties of phage-like particles with isometric heads. Type A has a contractile tail, whereas type B shows a non-contractile tail with a long, wavy tail fiber. No relationship between the presence of these particles and the amount of toxin produced was found.

Bacteriophages↗
PubMed1978

[The classification of Agrobacterium and Rhizobium phages (author's transl)].

All phages studied are tailed, belong to six morphological groups, and are classified by morphological and serological properties and by physico-chemical parameters of the virion and its nucleic acid. Four species of Agrobacterium and 12 species of Rhizobium phages are described, and their relationship with enterobacteria phages discussed. They include 68 viruses, whereas 60 poorly known phages have not been classified.

Bacteriophages↗
PubMed1978

[Study of lysogeny in Bacillus thuringiensis and B. cereus].

Forty-eight strains of Bacillus thuringiensis and 12 strains of B. cereus were treated with ultraviolet light and mitomycin C. The former agent was the more effective inducer. Bacillus thuringiensis produces at least seven different phage particles with long, non-contractile tails. The frequencies of lysogeny and polylysogeny are 83 and 25% respectively. Morphologically defective phages occur in 25% of strains, whereas five of them produce low molecular-weight bacteriocins. One strain of B. cereus harbors "killer-particles." There is no apparent correlation between the presence of phage-like particles, phage senstivity, and serotypes, biotypes, or the origin of B. thuringiensis strains.

Bacillus cereus↗
PubMed1976

Structural aberrations in group A Staphylococcus bacteriophages.

Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular smooth polyheads; (iii) heads and polyheads with wavy outlines; (iv) mottled heads and polyheads; (v) abnormally long and short tails; and (vi) "double capsids" connected by a small bridge. Some of these structures are rare, or have not yet been reported. The frequency os specific aberrant particles varied from one phage to another. Length distribution of smooth irregular polyheads and of abnormal tails indicated that these structures assemble at random from protein synthesized in excess. These phages represent an interesting model for genetic and morphogentic studies.

Capsid↗
PubMed1976

[Classification of tailed enterobacteria phages].

Tailed phages of enterobacteria are classified by morphological and serological properties and by physico-chemical parameters of the virion and its nuecleic acid. Twenty-four species are described; they include 250 phages belonging to seven morphological groups. Type species are proposed. About 120 poorly known phages have not been classified. A case of phage evolution, the reliability of data and the value of taxonomical criteria are discussed.

Bacteriophage Typing↗
PubMed1975

A large new Streptococcus bacteriophage.

Phage VD13 possesses a large, elongated head and a long, non-contractile tail. It is active on group D streptococci and contains double-stranded DNA. The phage produces several rare kinds of head malformations, notably polymorphic mottled structures and giant heads which probably contain DNA.

Bacteriophages↗
PubMed1975

Classification of the bacteriophages of Gram-positive cocci: Micrococcus, Staphylococcus, and Streptococcus.

Micrococcus, Staphylococcus, and Streptococcus phages are classified by morphology, serological properties and physical and chemical parameters of the virion and its nucleic acid. Fourteen species are defined; they include 75 tailed phages belonging to 6 morphological groups. Type species are proposed. Three species seem to have phylogenetic relationships with Bacillus phages.

Bacteriophage Typing↗
PubMed1974

Unusual bacteriophages in Salmonella newport.

Six phages were isolated from sewage and from a lysogenic strain. Three of them, belonging to a new morphological group, had contractile tails and elongated heads with axial ratios of 2.4:1. Two phages, possessing short tails and very long heads with axial ratios of 3.5:1, were new isolates of an extremely rare group. Phages of both groups formed polyheads of various sizes and shapes. The last phage, 61 nm in diameter, seemed to have a tail-like appendage. All phages had double-stranded DNA, were active on enterobacteria only, and differed in their host range. The first five phages seemed to be Salmonella specific.

Acridines↗