摘要:

Organic nitrogen sources were more readily utilized than inorganic nitrogen sources by three strains ofClaviceps purpurea. Glucose, fructose, mannose, cellobiose, and sucrose were readily utilized, but not xylose, ribose, mannitol, maltose, starch, powdered cellulose, carboxymethyl cellulose, or methyl cellulose. Carbon dioxide was required for initiation of growth. An exogenous supply of biotin was required for growth in a medium containing glucose, ammonium succinate, and minerals. This requirement could be nearly replaced by equimolar amounts of biotinL-sulphoxide and biocytin. Desthiobiotin slightly replaced biotin but homobiotin, norbiotin, oleate, aspartate, pimelate, and Tween 80 were inactive. Oleate and aspartate stimulated early growth.

ISSN:0008-4166    

DOI:10.1139/m57-001

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Whole cells or the cell walls of 22 species representing 11 genera of Gram-negative bacteria were exposed to lysozyme using a modified Nakamura technique. The cell walls of all organisms contain the lysozyme substrate in differing amounts (twoBrucellaspp.,Proteus vulgarisX-19, andVibrio choleraeChicago are possible exceptions) when evaluated spectrophotometrically and with the electron microscope. Using the latter technique, the sequence of events during bacteriolysis with lysozyme was observed. After exposure to lysozyme in saline, with the modified Nakamura technique and the phase microscope, cells were observed to either swell or shrink depending on the pH of the menstruum. This phenomenon apparently involves reversible hydration of cell proteins with concomitant changes in light transmission.

ISSN:0008-4166    

DOI:10.1139/m57-002

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Nakamura conditions are helpful in demonstrating the presence of the lysozyme substrate in Gram-negative bacteria because: (1) the low pH (3.5) pretreatment uncovers or releases the substrate from a "bound" state within the cell wall for lysozyme digestion; (2) the addition of alkali (to pH 10.0 or above) allows for increased hydration and dispersion of the cell proteins once the lysozyme substrate has been removed. Increased hydration and dispersion alter the index of refraction of bacterial suspensions so that it is near the index of water, and clearing of the suspensions results. Irrespective of the acids and/or alkalies used, little difference was noted in their effect on clearing. The need for caution in attributing lack of clearing in bacterial suspensions to inactivation or inhibition of autolytic enzyme systems is discussed.

ISSN:0008-4166    

DOI:10.1139/m57-003

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

A relatively high proportion of the indigenous bacteria of a field soil (27.1%, corresponding to 14.1 millions/g.) required one or more vitamins for growth. The vitamins found to be essential, either alone or with others, were, in order of frequency, thiamine, biotin, vitamin B12, pantothenic acid, folic acid, nicotinic acid, and riboflavin. In all, 16 different 'patterns' were noted for vitamin requirements, the number of vitamins needed by individual strains ranging from one to five. The findings point to the soil as an important habitat of vitamin-requiring bacteria, many of which show potentiality as assay organisms. Their occurrence in the numbers found indicates that growth-factors should receive equal emphasis with antibiotics in problems involving the microbial equilibrium in soil and interrelationships between the normal soil microflora, soil-borne disease organisms, and growing plants.

ISSN:0008-4166    

DOI:10.1139/m57-004

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The Feulgen stain was applied to the macro yeast cells, derived fromSaccharomyces cerevisiae, and Feulgen-positive areas were readily located. Staining could not be observed within the central vacuole and could be found at only one point outside of the vacuole. This point was considered as being the location of the yeast cell nucleus.

ISSN:0008-4166    

DOI:10.1139/m57-005

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The hemolytic activity of α-toxin ofMicrococcus pyogenesvar.aureushas been shown to be maximal at pH 6.8–7.0 in phosphate-buffered saline. Within the limits of 25 to 75% hemolysis there is a linear relationship between lysin concentration and extent of hemolysis after incubation for 15 minutes. Citrate and glucose have been shown to inhibit hemolysis by α-toxin. The manner in which the factors studied affect determination of α-toxin activity by a direct hemolysis procedure is discussed.

ISSN:0008-4166    

DOI:10.1139/m57-006

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Stationary cultures ofClaviceps purpurea(Fr.) Tul. grown 50 days on a liquid medium containing mannitol, ammonium succinate, and salts produced small amounts of ergot alkaloids.Ergometrine, ergometrinine, ergotamine, ergotaminine, ergocornine, ergocorninine, ergocryptine, agroclavine, and penniclavine were identified by paper chromatography of culture extracts. The selection of strains, the composition of the medium, and the length of the incubation period appeared to be important factors influencing the production of alkaloids.

ISSN:0008-4166    

DOI:10.1139/m57-007

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

1,4-Dimefhyl-7-isopropyl-bicyclo-decapentane (BD.I) has been shown to ameliorate the course of experimental tuberculosis of guinea pigs. Further experiments demonstrate that tuberculin reactions in BD.I treated animals, whether normal or immunized, were markedly milder than in similar but untreated groups of animals. Tuberculous lesions in BD.I treated normal and immunized guinea pigs were less severe when compared with untreated animals as seen at autopsy 6, 8, and 12 weeks after virulent superinfection. It seems that the drug does not interfere with the immune principle. Partial desensitization and the therapeutic effects are attributed to stimulation of the cellular defense apparatus.

ISSN:0008-4166    

DOI:10.1139/m57-008

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Twenty-two of 30 representative soil bacteria having simple nutritional requirements, in that they showed maximum development in a medium of inorganic salts and sugar, were found to be able to synthesize a variety of amino acids, though in no single case were more than four ninhydrin-positive substances found. The culture filtrates permitted the growth of amino-acid-requiring bacteria to the extent that they contained the specific amino acid or acids required by strains of the latter group. The findings point to an associative action between these nutritional groups of soil organisms and suggest that the preferential stimulation in the rhizosphere of bacteria requiring amino acids may be ascribed in part to the ability of the other group of bacteria, which are numerically increased in the rhizosphere, to synthesize amino acids.

ISSN:0008-4166    

DOI:10.1139/m57-009

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Sporulation and growth of a bakers' yeast isolate were compared in 0.05 to 1% glucose, fructose, mannose, galactose, and dihydroxyacetone. Maximum yields of asci in glucose, fructose, and mannose were observed at 0.05% with a marked decline in increasing concentrations. Maximum yields of three- and four-spored asci were found at 0.1%. Galactose differed from the other hexoses in that the decline in ascus yields at higher concentrations was relatively small. The addition of 0.05% acetate increased the number of spores per ascus in the lowest concentrations of hexose. Cells grown in galactose were somewhat longer than glucose-grown cells, but not when 10−1Mphosphate, 3.3 × 10−3Marsenate, or 0.033% glucose were added to the growth medium. They also formed fewer spores per ascus than glucose-grown cells. Yields of asci in dihydroxyacetone were comparable to those observed in hexose, but growth in this compound was extremely slow. No sporulation or growth was observed inDL-glyceraldehyde,DL-glyceric acid, or glycerol.

ISSN:0008-4166    

DOI:10.1139/m57-010

出版商:NRC Research Press    

年代:1957

数据来源: NRC