摘要:

Immunoconglutinin is an antibody against fixed complement which appears in the serum of an animal after a strong antigenic stimulation. Using alexinated sheep red blood cells as antigen, various reactions between rabbit immunoconglutinin and complement were examined. It was shown that immunoconglutinin acted as an antibody to bring about the binding of horse, rabbit, and guinea pig complement. In the presence of hemolytic complement, immunoconglutinin had hemolysin activity.Immunoconglutinin was specifically absorbed from immune serum by using the antibody and complement present in the serum, thus demonstrating that immunoconglutinin can react with autologous complement.Rabbit sera containing heterostimulated immunoconglutinin showed an increased and prolonged bactericidal effect. It is suggested that the function of immunoconglutinin is to enhance the normal activities of complement.

ISSN:0008-4166    

DOI:10.1139/m69-176

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Cell walls ofSaccharomyces fragilisgrown in two different media were prepared by mechanical disruption, and their chemical composition was studied. A high carbohydrate content (75–80%) was found in these walls. Glucose and mannose were represented in a ratio 1:1 in both cases; cell walls also contained a small amount of glucosamine. Sixteen common amino acids were detected inS.fragiliswall hydrolysates. One unidentified ninhydrin-positive component was present when the organism was grown in Hansen medium. A low percentage of lipid was found in both walls. The significance of all these data is discussed in the light of the difficulties encountered in the preparation and purification of walls.

ISSN:0008-4166    

DOI:10.1139/m69-177

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The influence of temperature on the pathways of glucose catabolism inPseudomonas fluorescenshas been investigated using the radiorespirometry method. When grown in continuous culture with limiting concentrations of glucose, the organism metabolized 86% of the glucose via the Entner–Doudoroff pathway at 30, 20, and 8 C. The remaining glucose, 14%, was metabolized via the hexose monophosphate pathway. When the organism was grown on non-limiting concentrations of glucose at 8 C, a major shift in pathways of glucose catabolism was observed. Fifty-seven percent of the glucose was degraded via the hexose monophosphate pathway and only 43% via the Entner–Doudoroff pathway. A change in temperature altered the pathways of glucose catabolism by regulating the growth limiting concentration of glucose rather than by directly affecting the respective enzyme activities of the pathways.

ISSN:0008-4166    

DOI:10.1139/m69-178

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Streptomycin at a dose causing decrease of growth ofBacillus subtilisstrain B3greatly affected the use of phosphorus compounds from the medium during the exponential phase of growth of the organism. Streptomycin also interfered with the accumulation of phosphate esters in the cells ofB.subtilis. The accumulation of phosphate esters like fructose-6-phosphate, fructose-1,6-diphosphate, triose phosphates, phosphoglyceric acid, and phosphopyruvic acid was consistently lower in the streptomycin-treated culture throughout the entire period of cellular growth.

ISSN:0008-4166    

DOI:10.1139/m69-179

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The biochemical mechanism of action of viomycin onR.melilotiinvolved an inhibition of protein synthesis. Adenine and amino acid incorporation into total nucleic acid and cell wall respectively was relatively unaffected. The antibiotic increased the level of14C in the intracellular pool and "nucleic acids" fraction of cells fed14C-amino acids but caused no cellular lysis. Mono- and di-valent cations protected cells from growth inhibition by viomycin.A viomycin-resistant mutant was similar to its sensitive parent in rate of uptake of glucose and glutamic acid by both growing and resting cells and in the rate of leakage when preloaded cells were suspended in buffered saline. Viomycin resistance did not appear to be episome-mediated or involve an extracellular degradative enzyme. The ability of TES buffer to eliminate viomycin resistance, coupled with the sensitivity to viomycin of cell-free protein-synthesizing systems derived from both sensitive and resistant cells indicates that resistance is probably the result of a selective reduction in antibiotic permeability.

ISSN:0008-4166    

DOI:10.1139/m69-180

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Sodium fluoride (0.48 mM) completely inhibited intracellular polyglucose synthesis by resting cells ofStreptococcus salivariusincubated anaerobically with glucose. Inhibition was complete if fluoride was preincubated with the cells before the addition of the substrate or if added during active synthesis. However, the degradation of the intracellular material in the absence of exogenous glucose continued at an appreciable rate at 15 times this NaF concentration. The degree of fluoride inhibition of both polyglucose degradation and synthesis was increased as the pH of the reaction mixture decreased. The rate and quantity of the intracellular polysaccharide synthesized during subsequent incubations with glucose in the absence of NaF was not reduced significantly by preincubating the cells with NaF up to 2.4 mM. However, both parameters were reduced by prior exposure to 4.8 mMNaF.Fluoride-resistant cells, obtained either by stepwise selection or by ultraviolet-induced mutation, synthesized polyglucose in the presence of 2.4 mMNaF at rates and amounts only slightly less than those of control cells incubated in buffer free of this inhibitor. Furthermore, the ability of resistant cells to synthesize polyglucose in the presence of high NaF levels was retained despite growth for 300 generations in medium free of sodium fluoride. The ultraviolet-induced strains synthesized polyglucose at greater rates and amounts than the stepwise selected cells, suggesting that they differ in the nature of their resistance.

ISSN:0008-4166    

DOI:10.1139/m69-181

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Low concentrations of sodium fluoride inhibited use of exogenous glucose by washed cells of the homofermentative oral microbeStreptococcus salivariuswhether added before or after the substrate. Complete inhibition of exogenous glucose metabolism was achieved by NaF concentrations above 0.96 mM. Inhibition of glucose uptake caused an immediate reduction in the lactic acid formed as a result of metabolism, although the percentage conversion of glucose to lactic acid was not altered by fluoride at levels below 0.24 mM. Above this concentration, short periods of non-stoichiometric lactate formation were observed but continued incubation in the presence of fluoride always resulted in the production of normal quantities of lactic acid. Fluoride inhibition of glucose metabolism was pH-dependent with complete inhibition by 0.12 mMNaF occurring at pH values below 6.0. Sufficient fluoride was absorbed by cells at fluoride concentrations above 1.2 mMin a 30-minute period to reduce significantly subsequent glycolytic activity by the cells in medium free of the inhibitor.Mutants resistant to 2.4 mMNaF were shown to degrade glucose in the presence of 2.4 and 4.8 mMNaF at rates 74–46% of that of the control cells grown in the absence of this inhibitor. Growth of these resistant cells for 300 generations in medium free of fluoride stimulated the rate of glucose metabolism in the presence of 2.4 mMNaF, but exposure to 4.8 mMNaF reduced the rate of activity to 30% of that of the same cells incubated at 2.4 mMNaF. Comparison of the fluoride sensitivity of exogenous glucose metabolism and of endogenous polyglucose degradation have indicated that the prime site of fluoride action in these cells was at some point before glucose-6-P formation, possibly involved with the glucose transport process, the phosphorylation of glucose by hexokinase or an associated reaction. This conclusion was confirmed in recent experiments which demonstrated that the addition of low concentrations of fluoride to cells incubated with glucose resulted in an immediate reduction in the intracellular level of glucose-6-P.

ISSN:0008-4166    

DOI:10.1139/m69-182

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Soluble cytoplasmic fractions and washed cell wall fragments fromStreptomycesspecies cultures were compared as immunizing antigens for preparation of antisera. The anti cell wall serum gave fewer cross reactions between species, and thereby appears to be the better reagent for use in evaluation of serological relationships.

ISSN:0008-4166    

DOI:10.1139/m69-183

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Inactivation rates of PS-192 phage ofAgrobacterium radiobacterwith specific antisera homologous to phage PR-1001 deviated from a first-order reaction. In an investigation of this phenomenon, several hypotheses were tested, including effect of the animal, hereditary resistance to neutralization, exhaustion of antiserum potency, combining of antibody with phage in such a way as to render neutralization-resistant complexes, a non-specific effect of the complement, and a non-immune serum factor. None of these hypotheses, however, could be corroborated experimentally. Preliminary investigation of the cationic environment showed that mono- and di-valent cations exert considerable effect on the course of neutralization of the bacteriophages studied.

ISSN:0008-4166    

DOI:10.1139/m69-184

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Escherichia coli(ATCC No. 8739) can use a variety of alkyl and aminoalkylphosphonic acids as a source of phosphorus during growth. Chloromethylphosphonate, phenylphosphonate, hydroxymethylphosphonate, and 2-aminoethylphosphonate will act as a source of phosphorus during growth in the absence of inorganic phosphate. No growth occurs when methylene diphosphonic acid is substituted for inorganic phosphate. Cleavage of the carbon to phosphorus bond of these aromatic and substituted alkyl phosphonic acids during growth is indicated by these growth studies.

ISSN:0008-4166    

DOI:10.1139/m69-185

出版商:NRC Research Press    

年代:1969

数据来源: NRC