Jörg Schneider

Characterization of pGA1, a new plasmid from Corynebacterium glutamicum LP-6

A new plasmid, pGA1, has been isolated from Corynebacterium glutamicum LP-6, and its detailed restriction map has been prepared. The 4.9-kb plasmid has a G + C content of 57%. It replicates in C. glutamicum ATCC13032 and is compatible with the three other plasmids, pCC1, pBL1 and pHM1519, commonly used for vector construction for amino acid-producing corynebacteria. Fusions of pGA1 with different Escherichia coli replicons (transferred from E. coli to Corynebacterium via transformation of spheroplasts or by filter mating experiments with intact cells) are shown to be suitable as shuttle plasmids; some of them are highly stable in C. glutamicum, even when propagated without any selection pressure.

Phage typing — a useful tool in actinomycete systematics ☆

A total of 905 strains of several genera of the Actinomycetales were tested in respect to their sensitivity to genus- and species-specific actinophages. The results provided clear evidence that phage typing is a useful aid for the identification of actinomycetes. At the genus level, the specificity of actinophages has led to the correct placement of falsely identified strains, as well as to the rearrangement of genera. At the species level, however, phage typing has been less successful: only some actinophages are available so far, lysing strains (often not all) of one or a few related species (synonyms), e.g., of the genera Streptomyces and Amycolatopsis, as well as Saccharopolyspora.

Distribution of Modules among the Central Regions of the Genornes of Several Actinophages of Faenia and Saccharopolyspora

The central regions of the genomes of oFR 114, oFR113 and Mp 1, three temperate phages of the thermophilic actinomycete Faenia, are shown to differ mainly with respect to modules of about 3·5 kb, designated J-module (oFR114) and N-module (oFR113, Mp1). The distribution of J and N was observed amongst 22 phages of Faenia and Saccharopolyspora; J-module homology was found on six phage genomes, whereas homology to the N-module was detected on ten phage genomes.

Characterization of øGA1, An Inducible Phage Particle from Brevibacterium Flavum

Eighteen related strains of Arthrobacter, Brevibacterium and Corynebacterium were used as indicator strains in an attempt to isolate corynephages from a large number of soils and from waste-water samples. Although no phages capable of producing plaques were isolated, one of the indicator strains used, Brevibacterium flavum ATCC 14067, was lysogenic for the inducible phage phi GA1. This phage was not observed to form plaques on any of the strains tested. phi GA1 is of B1-morphotype with a linear double-stranded DNA genome of 48.1 kb with cohesive ends; a restriction map is presented.

Corynephage Cog, a virulent bacteriophage of Corynebacterium glutamicum, and its relationship to phi GA1, an inducible phage particle from Brevibacterium flavum.

The host range of the virulent bacteriophage Cog among several strains of amino acid-producing corynebacteria is limited to Corynebacterium glutamicum LP-6. Cog is a typical corynephage of the Siphoviridae family (B1 morphotype) with an isometric head of 52 nm and a medium length, striated tail of 190 nm. It has a linear genome of 39.7 kb with cohesive ends and 53% G + C; a restriction map is presented, including regions of DNA homology (by hybridization) with the inducible phage particle phi GA1 from Brevibacterium flavum.

Characterization of a family of temperate actinophages of Faenia rectivirgula

SUMMARY: Six temperate phages of the thermophilic actinomycete Faenia rectivirgula were characterized by restriction analysis and found to be closely related: (1) three phages (oFR113, oFR371, oFFR114) isolated from lysogenic strains, (2) a deletion-derivative of oFR113 (oFR755R) and (3) two phages (oFR747 and oFRG9) isolated from soil. oFR371 differs from oFR113 by a deletion not overlapping with that in oFR755R. The restriction maps of oFR114 and oFR113 are very similar. oFR747 and oFRG9 belong to the same family as shown by the comparison of their restriction fragment patterns.

A group of actinophages ofFaenia rectivirgula

One virulent phage from soil lysed all tested strains ofFaenia rectivirgula, whereas six others—three of them from lysogenic cultures—lysed only nonlysogenic strains. Restriction analysis showed that these six phages are closely related, although one of them is virulent and the others are temperate. Another member of this group is aStreptomyces erythraeus phage, which also lysed only the four nonlysogenic strains ofF. rectivirgula.

φSC623, a temperate actinophage of Streptomyces coelicolor Müller, and its relatives φSC347 and φSC681

Summary: Three species-specific, temperate actinophages of Streptomyces coelicolor Muller, φSC623, φSC347 and φSC681, were compared with respect to host range, virion structure, antiserum cross-inactivation, DNA-restriction pattern, DNA hybridization, and DNA base composition. The restriction map of φSC623 (57 kb) was established with eight restriction enzymes; the homologies of this phage with φSC347 and φSC681 suggested that it might be a hybrid phage composed of approximately equal parts homologous to one of the other two phages. No homology was detected between φSC623 and R4, a temperate, wide-host-range phage which can also lysogenize S. coelicolor Muller.

Distribution of homologies among the genomes of several actinophages of Faenia and Saccharopolyspora as determined by DNA hybridization.

The DNA of phi FR114, a temperate phage of the thermophilic actinomycete Faenia rectivirgula, was hybridized with the genomes of 11 different phages of Faenia and Saccharopolyspora. This revealed several regions (modules) within the phi FR114 DNA which were distributed independently among the genomes of the other phages. The genome of the lytic phage 121, originally described for Sap. erythraea, exhibited a similar modular organization. So far no functions of the possible modules are known.

Characterization of three group A klebicin plasmids: localization of their E colicin immunity genes

We have investigated the immunity to E colicins conferred by three group A klebicin plasmids. pP5a, which encodes klebicin A1-P5, like pClo-DF13, confers immunity to colicin E6 on Escherichia coli K12, whilst pP5b and pP3, which encode klebicins A2-P5 and A3-P3 respectively, both confer immunity to colicin E3. We have determined the restriction endonuclease and functional maps of the three group A klebicin plasmids. By sub-cloning and transposon mutagenesis we have investigated the relationship between the klebicin immunity and the E colicin immunity conferred by these plasmids. The colicin E6 and the klebicin A1 immunity are encoded by a single gene present on pP5a. The colicin E3 and the klebicin A2 immunity are encoded by a single gene present on pP5b. The colicin E3 and the klebicin A3 immunity are encoded by separate genes present on pP3. Recombinant pML8412, which is derived from the ColE6-CT14 plasmid and encodes colicin E6 immunity, confers klebicin A1-P5 immunity upon Klebsiella pneumoniae UNF5023. Recombinant pKC23, which is derived from the ColE3-CA38 plasmid and confers colicin E3 immunity, confers immunity to klebicin A2-P5, but not to klebicin A3-P3.