Biomaterial Database

Isolation and characterization of a bacteriophage tail-like bacteriocin from a strain of Rhizobium. 1972

W Lotz, and F Mayer

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.

UI	MeSH Term	Description	Entries
D008242	Lysogeny	The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.	Integration, Prophage,Prophage Integration,Integrations, Prophage,Prophage Integrations
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008961	Models, Structural	A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)	Model, Structural,Structural Model,Structural Models
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D005561	Formates	Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.	Formic Acids,Acids, Formic
D000085	Acetates	Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.	Acetate,Acetic Acid Esters,Acetic Acids,Acids, Acetic,Esters, Acetic Acid
D000327	Adsorption	The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.	Adsorptions
D001430	Bacteriocins	Substances elaborated by specific strains of bacteria that are lethal against other strains of the same or related species. They are protein or lipopolysaccharide-protein complexes used in taxonomy studies of bacteria.	Bacteriocin,Lantibiotic,Lantibiotics
D001435	Bacteriophages	Viruses whose hosts are bacterial cells.	Phages,Bacteriophage,Phage