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L L Campbell

Publications and source records attributed to L L Campbell.

At least 19 recordsLinked to original sources
PubMed1982

Cytochrome c3 from the sulfate-reducing anaerobe Desulfovibrio africanus Benghazi: antigenic properties.

Antisera were prepared against cytochromes c3 from Desulfovibrio africanus, D. vulgaris, and D. salexigens. Cross-reactions were observed between antisera to D. vulgaris and D. africanus cytochromes and heterologous cytochromes c3. A weak cross-reaction with antisera against both D. vulgaris and D. africanus cytochromes and the acid form of the D. salexigens cytochrome was seen; the basic form did not react.

Cross Reactions↗
PubMed1979

Cytochrome c3 from the sulfate-reducing anaerobe Desulfovibrio africanus Benghazi: purification and properties.

Cytochrome c3 was purified from Desulfovibrio africanus Benghazi by extraction with alkaline deoxyribonuclease, fractionation with ammonium sulfate, batch elution from carboxymethyl Sephadex followed by chromatography on the same resin, and gel filtration on Sephadex G-75. The preparation was judge homogeneous by a variety of criteria. The molecular weight was determined in an analytical ultracentrifuge, and values between 14,400 and 15,490 were obtained, depending upon the presumed value of partial specific volume. Gel filtration on a calibrated column of Sephadex G-75 gave a value of 14,900 daltons. The amino acid composition was very similar to that observed for the cytochrome from other species of Desulfovibrio, with the exception of increased levels of ThR and PhE. S-Carboxymethylation of the protein before and after heme removal by HgCl2 demonstrated eight Cys molecules involved in heme binding or four heme sites per molecule. Titration with sodium dithionite under N2 gave an electrochemical potential (E' 0) of -276 mV relative to the normal hydrogen electrode. Electrochemical titration of the cytochrome gave a Nernst plot with two linear regions with E' 0 values of -0.376 and -0.534 V. The spectra produced at various potentials exhibited shifts in isosbestic points upon reduction, suggesting changes in conformation during the reaction.

Amino Acids↗
PubMed1978

alpha-amylase from five strains of Bacillus amyloliquefaciens: evidence for identical primary structures.

The alpha-amylases from five strains of Bacillus amyloliquefaciens were compared to determine whether differences in primary structure are responsible for variations in catalytic properties previously reported among the enzymes. Amino acid analysis established virtually identical compositions for the proteins. Reaction with dimethylaminoaphthylene sulfonylchloride indicated the amino-terminal amino acid of each amylase to be valine. Carboxyl termini of the enzymes have been determined by digestion with carboxypeptidase A. The resulting kinetic data indicate tyrosine as the carboxyl terminus and leucine as the penultimate residue for all five proteins. Isoelectric focusing of the enzymes yielded isoelectric points in the pH range of 5.09 to 5.18. Tryptic digests of the enzymes chromatographed on a cation-exchange column showed identical elution patterns. It is concluded that the primary structure of the amylase from the five strains is identical or exhibits only conservative substitutions.

Amino Acids↗
PubMed1977

Growth of desulfovibrio in lactate or ethanol media low in sulfate in association with H2-utilizing methanogenic bacteria.

In the analysis of an ethanol-CO(2) enrichment of bacteria from an anaerobic sewage digestor, a strain tentatively identified as Desulfovibrio vulgaris and an H(2)-utilizing methanogen resembling Methanobacterium formicicum were isolated, and they were shown to represent a synergistic association of two bacterial species similar to that previously found between S organism and Methanobacterium strain MOH isolated from Methanobacillus omelianskii. In lowsulfate media, the desulfovibrio produced acetate and H(2) from ethanol and acetate, H(2), and, presumably, CO(2) from lactate; but growth was slight and little of the energy source was catabolized unless the organism was combined with an H(2)-utilizing methanogenic bacterium. The type strains of D. vulgaris and Desulfovibrio desulfuricans carried out the same type of synergistic growth with methanogens. In mixtures of desulfovibrio and strain MOH growing on ethanol, lactate, or pyruvate, diminution of methane produced was stoichiometric with the moles of sulfate added, and the desulfovibrios grew better with sulfate addition. The energetics of the synergistic associations and of the competition between the methanogenic system and sulfate-reducing system as sinks for electrons generated in the oxidation of organic materials such as ethanol, lactate, and acetate are discussed. It is suggested that lack of availability of H(2) for growth of methanogens is a major factor in suppression of methanogenesis by sulfate in natural ecosystems. The results with these known mixtures of bacteria suggest that hydrogenase-forming, sulfate-reducing bacteria could be active in some methanogenic ecosystems that are low in sulfate.

Acetates↗
PubMed1976

Subunits of the alkaline phosphatase of Bacillus licheniformis: chemical, physicochemical, and dissociation studies.

The alkaline phosphatase (orthophosphoric monoester phosphydrolase, EC 3.1.3.1) of Bacillus licheniformis MC14 was studied in an attempt to determine the number of subunits contained in the 120,000-molecular-weight native enzyme. Two moles of arginine was liberated per mole of native enzyme by carboxypeptidases A and B in the presence of sodium dodecyl sulfate. The effect on the native enzyme of progressively lowering the solvent buffer pH was monitored by determining the molecular weight by sedimentation equilibrium analysis, the sedimentation coefficient, the frictional coefficient, and the percent alpha-helix content of the enzyme. The alkaline phosphatase dissociates into two subunits around pH 4. At pH 2.8 a further decrease in S value, but no change in molecular weight, is observed, indicating a change in conformation. The frictional coefficients and percent alpha-helix content agree with this interpretation. A subunit molecular weight of 59,000 was calculated from sodium dodecyl sulfate gels.

Alkaline Phosphatase↗
PubMed1975

Production and purification of the thermophilic bacteriophage TP-84.

A new procedure for production and purification of the thermophilic bacteriophage TP-84 in high yields is described. Cultures of Bacillus stearothermophilus strain 10, enriched with nutrients to obtain heavy growth and to prevent sporulation and maintained at a pH of 6.5, were infected with the phage in a 100-liter fermentor. Addition of magnesium chloride (0.01 M) and a temperature of 58-C were essential for maximal phage production. Phage (5 times 1011 infective particles/ml) was precipitated with polyethylene glycol (molecular weight 6,000) in the presence of sodium chloride and was further purified by cesium chloride density centrifugation.

Bacillus↗
PubMed1974

Morphological observations of Diplodia maydis on synthetic and natural substrates as revealed by scanning electron microscopy.

Mycelial and spore morphology of Diplodia maydis were investigated by using scanning electron microscopy after growth on various media and natural substrates (oat and corn kernels, and corn husks). Of several specimen preparation methods studied, Parducz fixation followed by critical-point or freeze-drying gave adequate preservation for pycnidia, mycelia, and spores. Morphological characteristics were similar in rotary and reciprocal shaker cultures and differed from that found in stationary cultures in the amount of slime-like material produced and precipitated matter on the mycelial surfaces. In general, mycelial surfaces were smooth. Large areas of coalesced material were present in all samples examined. Slime-like material produced in liquid media appeared as a finely laced net, randomly appearing throughout the mycelia with bead-like structures present along the net. A fine netting also was observed interspersed among the spores inside the pycnidia obtained from oats. Slime-like material was observed to cover the pycnidia produced on oat and corn kernels. In the latter case, the spores were less protected by the outer slime-like covering. Thickened node-like structures were observed in mycelial mats produced in modified Fries 2 medium, on potato dextrose agar plates, and on infected oats. Round and ovate thickened node-like structures were observed in mycelium produced on corn kernels. In general, node-like structures were less abundant in mycelia from naturally infected substrates. Conidia were commonly rounded to tapered and two celled, with a distinctive ridged septum at the middle. Dried spores were collapsed in a characteristic flask-like fashion.

Culture Media↗
PubMed1974

Properties of two homologous alkaline proteases from Streptomyces rectus.

Some physicochemical properties of two thermostable proteases from Streptomyces rectus are described. The enzymes were judged to be identical with respect to molecular weight, inactivation with serine protease inhibitors, and in primary structure by peptide analysis. Amino acid analysis indicated the enzymes had identical compositions except for their amide content. The molecular weights of the enzymes were judged to be 28,000 by sedimentation equilibrium, 26,200 by sedimentation diffusion, and 29,100 from amino acid analysis. Titration of the proteases with diisopropylfluorophosphate and phenylmethane sulfonylfuoride indicate equivalent weights of 28,500 and 32,800 g, respectively, for the proteins. The pentapeptide around the serine residue reacting with diisopropylfluorophosphate was isolated and had the composition: Asx(1), Gly(1), Thr(1), Ser(1), Met(1).

Amino Acids↗
PubMed1971

Purification and properties of a hydrogenase from Desulfovibrio vulgaris.

The soluble hydrogenase of Desulfovibrio vulgaris was purified and some of its properties are described. The molecular weight was determined for the enzyme by sedimentation equilibrium (45,400) and amino acid analysis (44,800). The hydrogenase appears to be a loosely coiled molecule or to have a high axial ratio, which is reflected in an unusually low sedimentation coefficient (2.58S) and a low diffusion coefficient (D 5.85). The molecular weight of the hydrogenase (41,000), as calculated by the Svedberg equation, was in general agreement with the sedimentation equilibrium molecular weight. Amino acid analysis revealed the presence of six halfcystine residues per mole of enzyme and a total of 417 amino acid residues. The specificity of the hydrogenase and its capacity to reduce certain low potential dyes and cytochrome c(3) was studied. Metal analysis of the hydrogenase indicated the presence of 1 mole of ferrous iron per mole of enzyme.

Absorption↗
PubMed1971

Transformation in Bacillus amyloliquefaciens.

The methodology and some of the requirements for the deoxyribonucleic acid-mediated transformation of an arginine auxotroph of Bacillus amyloliquefaciens to prototrophy are described.

Arginine↗
PubMed1971

Thiosulfate reductase of Desulfovibrio vulgaris.

The thiosulfate reductase of Desulfovibrio vulgaris has been purified and some of its properties have been determined. Only one protein component was detected when the purified enzyme was subjected to polyacrylamide gel electrophoresis at pH values of 8.9, 8.0, and 7.6. In the presence of H(2), the enzyme, when coupled to hydrogenase and with methyl viologen as an electron carrier, catalyzed the reduction of thiosulfate to hydogen sulfide. The use of specifically labeled (35)S-thiosulfate revealed that the outer sulfur atom was reduced to sulfide and the inner sulfur atom was released as sulfite. Thus, the enzyme catalyzes the reductive dismutation of thiosulfate to sulfide and sulfite. The molecular weight of the enzyme was determined by sedimentation equilibrium (16,300) and amino acid analysis (15,500). The enzyme sedimented as a single, symmetrical component with a calculated sedimentation coefficient of 2.21S. Amino acid analysis revealed the presence of two half-cystine residues per mole of enzyme and a total of 128 amino acid residues. Carbohydrate and organic phosphorus analyses revealed the presence of 9.2 moles of carbohydrate and 4.8 moles of phosphate per mole of enzyme. The substrate specificity of the enzyme was studied.

Acrylates↗
PubMed1971

Homology of ribosomal ribonucleic acid of Desulfovibrio species with Desulfovibrio vulgaris.

Three species of Desulfovibrio were found to have a high degree of ribosomal ribonucleic acid homology with Desulfovibrio vulgaris. Desulfotomaculum nigrificans, which is also a sulfate-reducing anaerobe, had only 38% ribosomal ribonucleic acid homology with D. vulgaris. The homologies of six other unrelated genera were determined and found to be lower than 50%.

Alcaligenes↗
PubMed1971

Homology of ribosomal ribonucleic acid diverse bacterial species with Escherichia coli and Bacillus stearothermophilus.

Hybridization competition experiments were used to examine the ribosomal ribonucleic acid (rRNA) homologies of 22 bacteria and 3 higher organisms with Escherichia coli and Bacillus stearothermophilus. Although little or no homology was observed with the higher organisms, the bacteria showed a wide range of homologies. Organisms whose rRNA showed closer homology to E. coli rRNA showed less rRNA homology to B. stearothermophilus rRNA and vice versa.

Animals↗