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Biomedical subjects

F E Young

Publications and source records attributed to F E Young.

At least 145 records · Page 8Linked to original sources
PubMed1970

Genetic analysis in Bacillus pumilus by PBSI-mediated transduction.

Bacteriophage PBS1 mediates generalized transduction in Bacillus pumilus NRRL B-3275 (BpB1). Transduction frequencies for single auxotrophic markers are of the order of 10(-4) transductants per plaque-forming unit in crude phage lysates. The characteristics of PBS1 propagated on BpB1 and the properties of the system of transduction are similar to those reported for PBS1 propagated on Bacillus subtilis. By transduction, eight amino acid auxotrophic markers in BpB1 have been oriented into two linkage groups. One group contains the auxotrophic markers arginine A, leucine, and phenylalanine, and the other group contains the markers lysine, serine, tryptophan, isoleucine-valine, and isoleucine. The nature and relative order of the markers within each linkage group suggest that the arrangement of genes in these areas of the chromosome of BpB1 is similar to the arrangement of phenotypically comparable genes in two linkage groups (defined by PBS1 transduction) in B. subtilis. However, transduction of any of the above cited markers in BpB1 to prototrophy with PBS1 propagated on B. subtilis 168 could not be demonstrated. In addition to BpB1, seven other strains of B. pumilus can be infected with PBS1. Transduction has been demonstrated in three of these strains.

Amino Acids↗
PubMed1970

Isolation of L-forms of Bacillus subtilis which grow in liquid medium.

L-forms of Bacillus subtilis can be isolated by treatment of the parent strain sequentially with N-methyl-N'-nitro-N-nitrosoguanidine and lysozyme and selection of the surviving protoplasts on semisolid medium containing 2,000 units of penicillin per ml. Some of these clones can be adapted to grow in liquid cultures containing 1.2 m NaCl. This method will aid in the isolation of cell wall mutants which require hypertonic medium for growth.

Bacillus subtilis↗
PubMed1969

Identification of Bacillus subtilis NRRL B-3275 as a strain of Bacillus pumilus.

The physiological and biochemical properties of a species of Bacillus previously identified as B. subtilis NRRL B-3275 (B-3275) were compared with those of seven strains of B. pumilus and five strains of B. subtilis. The biotin requirement of B-3275, its inability to hydrolyze starch, and its failure to reduce nitrate indicate that the organism is more closely related to the B. pumilus strains than to those of B. subtilis. Hybridization of deoxyribonucleic acid (DNA) from B-3275 with that of the strains of B. pumilus showed a binding efficiency (compared with the homologous reaction) of 58 to 99%, depending on the strain. Hybridization with the DNA from any of the strains of B. subtilis did not exceed 24%. DNA from B-3275 was unable to transform two amino acid auxotrophic markers to prototrophy in a highly competent strain of B. subtilis 168. We conclude that B-3275 is a strain of B. pumilus which we designate as B. pumilus NRRL B-3275.

Amino Acids↗
PubMed1969

Chromosomal location of genes regulating resistance to bacteriophage in Bacillus subtilis.

Many of the viruses which infect Bacillus subtilis require glucosylated polyglycerol teichoic acid for adsorption. These mutants can be divided into three classes on the basis of enzymatic defects and growth on galactose-minimal medium. Transduction with phage PBS1 reveals that two of these, gtaA and gtaB, are linked to hisA1, whereas the gtaC locus is linked to argC. Analysis by deoxyribonucleic acid-mediated transformation indicates that these loci exist in a cluster between the hisA1 and argC4 loci. Anomalies in mapping in the group II region of the chromosome exist. The basis of these anomalies is discussed.

Adsorption↗
PubMed1969

Binding of rabbit gamma globulin by competent Bacillus subtilis cultures.

Deoxyribonucleic acid (DNA)-mediated transformation of Bacillus subtilis can be inhibited by antibodies which specifically interact with single-stranded DNA. This inhibition occurs at a time when the transformation reaction is insensitive to deoxyribonuclease. Studies with radioactive proteins revealed that the maximal binding of gamma globulin occurs immediately preceding the development of maximal competence in the population. Other proteins, such as deoxyribonuclease cytochrome c and serum albumin also adsorb to the surface of the cell. After treatment with lysozyme, 67% of the radioactive gamma globulin remains associated with the cytoplasmic membrane. These findings suggest that the DNA is complexed in a deoxyribonuclease-insensitive form to the surface of the cell and is converted to a single-stranded state prior to transport past the membrane and integration into the chromosome.

Animals↗
PubMed1967

Cell walls of group D streptococci. II. Chemical studies on the type 1 antigen purified from the autolytic digest of cell walls.

Autolysis of group D, type I cell walls by an indigenous autolytic enzyme results in the solubilization of the type I antigen. The antigen was purified from the autolytic digest by diethylaminoethyl cellulose chromatography. Chemical analysis of the purified type 1 antigen revealed glucose, glucosamine, galactosamine, rhamnose, ribitol, phosphorus, and residual peptoglycan components. This analysis suggested that the type I antigen is a heteropolymer which may contain a ribitol teichoic acid. The antigen purified by the procedure outlined here is higher in phosphorus content, lower in peptidoglycan, and more reactive serologically than the antigen prepared by methods previously described.

Alanine↗
PubMed1966

Fractionation and partial characterization of the products of autolysis of cell walls of Bacillus subtilis.

Young, Frank E. (Western Reserve University, Cleveland, Ohio). Fractionation and partial characterization of the products of autolysis of cell walls of Bacillus subtilis. J. Bacteriol. 92:839-846. 1966.-Autolysis of the cell wall of Bacillus subtilis by an indigenous autolytic enzyme results in solubilization of 90% of the cell wall. The solubilized cell wall (supernatant fraction) was fractionated by the combination of ion-exchange chromatography on diethylaminoethyl cellulose and gel filtration on Sephadex G-25 into polysaccharides (composed of N-acyl glucosamine and N-acyl muramic acid), mucopeptides, peptides, and teichoic acid. The chemical composition of the products of autolysis confirms the proposed mechanism of autolysis and establishes the autolytic enzyme as an N-acyl muramyl-l-alanine amidase. The heteropolymers in the cell wall are linked by peptide bridges. Two peptides which account for 70% of the peptides of the cell wall have a molar ratio of 1.0:0.9:1.3 for diaminopimelic acid, glutamic acid, and alanine, respectively. Other minor peptides contain diaminopimelic acid, glutamic acid, and alanine in molar ratios of 1.0:0.9:1.5, 1.0:0.5:1.0, and 1.0:1.5:1.7, respectively. The procedures employed in this study should be applicable to the fractionation of heteropolymers in cell walls of other gram-positive organisms and thereby aid in the study of the structure of antigenic determinants and endotoxins.

Bacillus subtilis↗