Isolation and Characterization of a New Generalized Transducing Bacteriophage Different from Pl in Escherichia coli

A new generalized transducing bacteriophage in the Escherichia coli system was isolated and characterized. This phage, designated D108, makes clear plaques on E. coli K-10, K-12, K-12(P1kc), K-12(D6), B/r, C, and 15 T(-), and Shigella dysenteriae. The plaque of phage D108 is larger in size than that of phage P1kc. Electron-microscopic observation revealed that phages D108 and P1kc are morphologically different from each other, suggesting that phage D108 belongs to a phage group different from phage P1. The fact that all of the 10 markers tested were transduced by phage D108 indicates that this phage is a generalized transducing phage in the E. coli system. The transduction frequency by phage D108 of chromosomal markers and of a drug resistance factor (R factor) ranged from 2 x 10(-6) to 3 x 10(-8) and 3 x 10(-9) to 6 x 10(-10) per phage, respectively. The cotransduction frequency of the thr and leu markers was 2.8% for phage P1kc and 1.5% for phage D108. The CM and TC markers (chloramphenicol-resistant and tetracycline-resistant markers, respectively) of the R factor were not cotransduced by phage D108, but the markers were generally cotransduced by phage P1kc. The results suggest that the transducing particle of phage D108 contains a smaller amount of host deoxyribonucleic acid than does phage P1kc.     

New Generalized Transducing Bacteriophage in Echerichia coli

A new generalized transducing bacteriophage similar to P1 was isolated from Salmonella oranienburg.     

Isolation and Characterization of Transducing Bacteriophage BP1 for Bacterium anitratum (Achromobacter sp.)

A small transducing phage has been isolated against a strain of Bacterium anitratum. The particle has a head dimension of 450 A and a tail approximately 200 A long. The latent period is 16 min and the average burst size is 98. The intact particle has an absorption maximum and minimum at 260 and 237 mmu, respectively. The sedimentation coefficient (S(20)) is 460. The phage contains double-stranded DNA with an S degrees (20,w) of 32.8. Molecular weight estimates of the deoxyribonucleic acid ranged from 2.33 x 10(7) to 2.66 x 10(7) based on sedimentation velocity studies. The percentage guanine plus cytosine compositions of the deoxyribonucleic acid, determined by melting temperature and cesium chloride equilibrium centrifugation, were 40.7 and 42.0, respectively.     

Isolation and Characterization of φ80 Transducing Bacteriophage for a Ribonucleic Acid Polymerase Gene

A new method for isolating specialized transducing phages is described. It was used to isolate a group of phi80 transducing phages which carry various bacterial markers from the metB region of the Escherichia coli chromosome. Some of the phages selected for transduction of the supA36 marker were also shown to carry rif, a locus known to specify the beta subunit of ribonucleic acid polymerase. Expression of the prophage rif(r) gene in lysogens was demonstrated by its ability to confer rifampin resistance on part of the cellular ribonucleic acid polymerase pool.     

Transducing Bacteriophage for Bacillus cereus

A phage, designated CP-51, that carries out generalized transduction in Bacillus cereus 569 was isolated from soil. All auxotrophic mutants tested, those requiring tryptophan, histidine, leucine, isoleucine, methionine, or phenylalanine, were transduced to prototrophy. The phage was extremely unstable when stored at 2 to 4 C, but stability was enhanced by storage at higher temperatures. The optimal temperature of those tested for maintenance of plaque-forming units was 15 C.     

Genome Sequence of a New Streptomyces coelicolor Generalized Transducing Bacteriophage, ?CAM

Streptomyces coelicolor is a model system for the study of Streptomyces, a genus of bacteria responsible for the production of many clinically important antibiotics. Here we report the genome sequence of ϕCAM, a new S. coelicolor generalized transducing bacteriophage, isolated from a soil sample originating from Lincolnshire, United Kingdom. Many open reading frames within ϕCAM shared high levels of similarity to a prophage from Salinispora tropica and a putative prophage in Streptomyces sp. strain C.     

Growth and Cultivation of the Unusual Generalized Transducing Bacillus Bacteriophage SP-15

Additional properties of SP-15, a generalized transducing bacteriophage notable for the ability to transfer an unusually large fragment of deoxyribonucleic acid (DNA) to Bacillus subtilis and B. licheniformis, are presented together with improved methods that enhance its utility. Simple means have been found to provide the rigid control over moisture that is necessary for the assay of plaque-forming units (PFU). Reproducible procedures for propagating transducing phage, which depend upon an appropriate mixing of PFU with uninfected bacteria, have replaced less reliable methods that utilized infected spores. Transduction of B. subtilis W-23 increased linearly when MgSO(4) in recipient cell-SP-15 mixtures was increased from 0.005 to 0.03 m. Methods have been developed that protect SP-15 from the damaging effects of CsCl and of osmotic shock subsequent to dilution. Evidence that the PFU and transducing particles of lysates decay at the same slow rate during extended storage suggests that the decay is a result of damage to protein rather than to DNA. One-step growth experiments, in which SP-15 was propagated on B. subtilis W-23-S(r)/1 mg, indicated a latent period of 100 min, a rise period of 60 min, and a burst size of 25 to 34 PFU per infected cell. These findings suggest explanations for some of the technical difficulties SP-15 has presented.     

Isolation and Characterization of a Bacteriophage for Vibrio fetus

Bacteriophages were isolated from 22 of 38 strains of Vibrio fetus by an enrichment process, utilizing the donor and host strains growing together in fluid thioglycollate medium. One phage, V-45, isolated by the conventional lawn-spot method, was characterized by stability in broth, growth kinetics, and morphology. It was sensitive to rapid thermal inactivation, chloroform, and pH values above 6.5. Calcium was required for phage replication and stability in broth. Magnesium provided the best protection against thermal inactivation at 50 C in the pH range of 6.5 to 7.5. The minimum latent period was 135 min, rise time was 75 min, and average burst size was 35 plaque-forming units per infected cell. Phage V-45 resembled Bradley's morphological group B, having a long tail without contractile sheath. Dimensions were: head, about 50 nm; tail, about 7 by 240 nm; and tail lumen, 2 to 3 nm.     

Isolation and Characterization of a Bacteriophage for Thiobacillus novellus

A DNA-containing bacteriophage for Thiobacillus novellus has been isolated from sewage and purified by ammonium sulfate precipitation, differential centrifugation, and cesium chloride equilibrium centrifugation. The buoyant density of this phage in CsCl is 1.51 g/cm(3). Electron microscopy studies have revealed a polyhedral head about 60 nm in diameter and a tail surrounded by a number of fine filaments. It has an adsorption rate constant of 1.1 x 10(-9) ml/min, a latent period of 45 min, and an average burst size of 150. The mole guanine and cytosine content in its DNA has been estimated to be 57 to 58%. Five structural proteins with molecular weights of 62,000, 42,500, 30,500, 17,750, and 13,500 have been detected by polyacrylamide gel electrophoresis techniques.     

Isolation and Characterization of a Bacteriophage of Arthrobacter globiformis

A bacteriophage which reproduces on Arthrobacter globiformis ATCC 8010 was isolated from soil. This bacteriophage, designated phiAG8010, propagates either in soft agar or broth cultures of the host. Because of a slow adsorption rate, neither the latent period nor burst size was determined. The mature virion belongs to Bradley's group B and exhibits a hexagonal head measuring 69 nm (length) by 60 nm (width) attached to a sheathless tail 120 nm long. The buoyant density of the mature virion is 1.534 g/cm(3). The mature virion contains double-stranded DNA with a buoyant density of 1.722 g/cm(3) (equivalent to 63.3% G + C). Of 14 strains (representing 13 species) of Arthrobacter examined, including A. globiformis ATCC 4336, only A. globiformis ATCC 8010 supported replication of phiAG8010.     

Isolation and Characterization of a Temperate Bacteriophage Specific for Rhodopseudomonas spheroides

The isolation of a temperature phage specific for the photosynthetic bacterium Rhodopseudomonas spheroides is reported. This phage, Rphi-1, establishes a state of lysogeny and can be induced from the prophage state by exposure to mitomycin C or UV irradiation. Mutants of Rphi-1 which grow on a standard laboratory strain (2.4.1) of Rhodopseudomonas spheroides were isolated. Although the original Rphi-1 isolated was chloroform sensitive, the mutant which plates on strain 2.4.1 is chloroform resistant. Rphi-1 does not grow on closely related bacteria, such as Rhodopseudomonas palustris or Rhodopseudomonas capsulata. Rphi-1 mutants forms plaques with the same efficiency whether the plates are incubated under aerobic conditions in the dark or under anaerobic conditions in the light (phototropic conditions).     

Isolation of a Specialized Lambda Transducing Bacteriophage Carrying the Beta Subunit Gene for Escherichia coli Ribonucleic Acid Polymerase

A heat-inducible lysis-defective lambda prophage has been integrated directly into the E. coli chromosome at a site (bfe) very closely linked to the ribonucleic acid polymerase mutation rif(d), a dominant rifampin resistance allele. This unusual lysogen has facilitated the isolation of specialized transducing phages conferring rifampin resistance to sensitive cells, and carrying at least the beta subunit gene of RNA polymerase in intact form.     

一株裂解性低温假单胞菌噬菌体的分离及特性研究

从明永冰川低温土壤中分离、纯化获得一株低温假单胞菌噬菌体PFV1,并对其生物学特性(噬菌体基因组限制性酶切片段长度多态性、衣壳蛋白组分分析及生理特征)进行了初步研究。基于16S rRNA基因测序分析结果,将宿主菌初步鉴定为荧光假单胞菌菌株。噬菌体PFV1为球形,直径约50 nm。PFV1在4℃时具有侵染活性,4~25℃范围内均可形成噬菌。对氯仿具有一定的敏感性,具有热不稳定性,基因组为双链DNA,大小约38 kb。     

Isolation and Sequencing of a Temperate Transducing Phage for Pasteurella multocida

A temperate bacteriophage (F108) has been isolated through mitomycin C induction of a Pasteurella multocida serogroup A strain. F108 has a typical morphology of the family Myoviridae, presenting a hexagonal head and a long contractile tail. F108 is able to infect all P. multocida serogroup A strains tested but not those belonging to other serotypes. Bacteriophage F108, the first P. multocida phage sequenced so far, presents a 30,505-bp double-stranded DNA genome with cohesive ends (CTTCCTCCCC cos site). The F108 genome shows the highest homology with those of Haemophilus influenzae HP1 and HP2 phages. Furthermore, an F108 prophage attachment site in the P. multocida chromosome has been established to be inside a gene encoding tRNA^Leu. By using several chromosomal markers that are spread along the P. multocida chromosome, it has been demonstrated that F108 is able to perform generalized transduction. This fact, together with the absence of pathogenic genes in the F108 genome, makes this bacteriophage a valuable tool for P. multocida genetic manipulation.     

Isolation and Characterization of a Bacteriophage Tail-Like Bacteriocin from a Strain of Rhizobium

Bacterial strain 16-3 spontaneously produces a bacteriocin which inhibits the growth of closely related strain 16-2. Both strains were newly isolated from root nodules of lupines and probably belong to the species Rhizobium lupini. Production of infectious progeny of newly isolated virulent phage 16-2-4 in strain 16-2 is inhibited completely if complexes are bacteriocin-treated during the first half of the latent period. Treatment begun during the second half leads to premature lysis of complexes and inactivates only those progeny phages which were not yet fully matured at the moment of the particle-induced lysis. Examination by electron microscope of the bacteriocin enrichment revealed the presence of particles 123 nm in length which resemble the tails of T-even bacteriophages. Since the particles sediment together with the bactericidal activity in the sucrose gradient and adsorb specifically to bacteriocin-sensitive cells, it is concluded that they are identical with the bactericidal agent. The particles are not found attached to phage heads and cannot self-propagate; they are regarded as incomplete and are named INCO particles. INCO particles consist of a core enveloped by a contractile sheath. One end of the sheath is connected to a baseplate to which six fibers, each 32 nm in length, are attached. These connect the baseplate of an adsorbing particle to the cell surface. Since INCo cores are probably empty, it is concluded that specific adsorption of the particles to the bacterial surface is sufficient to inactive sensitive cells irreversibly.     

Isolation and Characterization of Bacteriophage T4 Base Plates

A method for isolating bacteriophage T4 base plates from lysates of Escherichia coli B cells infected with the ts mutant in gene 19, ts B31 has been developed. By electrophoresis in polyacrylamide gel with sodium dodecyl sulfate the base plates have been shown to contain five to seven protein components with molecular weights of 36,000, 53,000, 66,000, 81,000, 87,000, and probably about 100,000. Electron microscope studies have demonstrated that base plates may occur in two structural states: in the form of hexagons or stars. Star rays and short fibrils are not radial or elongated and are turned sideways at an angle to the radius. Base plates do not complement in vitro with free tail cores isolated after disintegration of particles of the wild-type bacteriophage.     

Isolation and Characterization of a Bacteriophage Lytic for Desulfovibrio salexigens, a Salt-Requiring, Sulfate-Reducing Bacterium

A bacteriophage that lysed Desulfovibrio salexigens cells was isolated from marine sediments and preliminarily characterized by electron microscopy and electrophoretic analysis of structural proteins and genomic nucleic acid. The bacteriophage had an icosahedral head and a long flexible tail, and the buoyant density of the bacteriophage particles was 1.468 g/ml in cesium chloride. The particles consisted of a double-stranded DNA molecule about 33 kilobase pairs long and at least 11 structural proteins.     

Buoyant Density Analysis of Staphylococcal Bacteriophage 80 Transducing Particles

Densities of pase, tet, and ol transducing particles were indistinguishable, and about 0.002 g x cm(-3) less dense than the plaque-forming units (PFU). The densities of the PFU and nov transducing particles were indistinguishable, the PFU having a density of 1.507 g x cm(-3).     

Isolation of a Bacteriophage for Bdellovibrio bacteriovorus

A phage infective for Bdellovibrio bacteriovorus was isolated. Electron microscopy revealed that it is tail-less, has a hexagonal appearance and two distinct capsomere layers, and is 60 to 70 nm in size. The nucleic acid appears to be single-stranded deoxyribonucleic acid. This is the first report of the isolation of a phage infective for B. bacteriovorus.     

Bacteriophages of Rhodopseudomonas spheroides: Isolation and Characterization of a Rhodopseudomonas spheroides Bacteriophage

A DNA-containing bacteriophage, designated RS1, infecting Rhodopseudomonas spheroides 2.4.1, has been isolated from sewage. The buoyant density of RS1 in CsCl equilibrium centrifugation is 1.50 g/cm(3), and the buoyant density of RS1 DNA is 1.706. The phage possesses a polyhedral head, approximately 65 nm in diameter, and a tail 60 nm long. When grown on aerobic cells, RS1 has a latent period of 120 min and an average burst size of 20. When grown on anaerobic cells, RS1 has a latent period of 150 min, and a burst size similar to that observed during aerobic infection. The adsorption rate constant of RS1 to aerobic cells is 1.2 x 10(-9) ml/min, and 0.58 x 10(-9) ml/min to anaerobic cells. Adsorption of RS1 to R. spheroides requires the presence of divalent cations.