摘要:

Streplomyces caeruleushas been shown to produce a hitherto unknown antibiotic to which the name caerulomycin has been given. This was first obtained from a fresh isolate (PRL 1687), and subsequently, after the strain had been identified, from an authentic culture ofS.caeruleus. It was extracted from culture filtrates with ether and purified as a colorless crystalline amphoteric substance, C12H11O2N3, which inhibited the growth of some filamentous fungi and yeasts and had weak activity against certain bacteria.

ISSN:0008-4166    

DOI:10.1139/m59-039

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A comparison was made of the growth factor requirements and growth factor synthesizing capacity of bacteria from control soil, rhizosphere, and rhizoplane of wheat. Organisms for which growth factors were essential were proportionately much less abundant at or near the root than in more distant soil; this is ascribed chiefly to lower percentages of forms requiring thiamine, biotin, and vitamin B12. At the rhizoplane proportions of bacteria requiring growth factors were as low as, or lower than, in the rhizosphere. Bacteria capable of synthesizing growth-promoting substances were proportionately much more numerous in the root zone than in control soil. Somewhat greater capacity was shown by rhizoplane than by rhizosphere isolates. Fungi characteristic of the rhizoplane showed the highest capacity for vitamin production.The occurrence of growth-promoting substances at or near the root is attributable chiefly to microbial synthesis rather than to root excretion. This is the reverse of the situation believed to exist respecting amino acids. The preferential stimulation of growth factor synthesizing organisms is regarded as an indirect effect of plant growth—a reflection of the direct stimulation of amino acid requiring forms, a group with pronounced capacity for vitamin synthesis.

ISSN:0008-4166    

DOI:10.1139/m59-040

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The identity of theStreptomyceswhich produces the new crystalline antibiotic, caerulomycin, was determined. The distinctive characteristics of the culture are: produces a blue-to-red indicator pigment; requires a neutral or alkaline reaction for growth; bears oblong to cylindrical spores in straight and flexuous chains; is not chromogenic on peptone media but produces hydrogen sulphide on iron-peptone agar; and does not grow on unbuffered potato or carrot plugs, Difco litmus milk, ASA agar, or Pridham and Gottlieb's synthetic agar medium. The culture readily utilizes glucose, fructose, galactose, mannitol, sucrose, xylose, starch, and maltose but does not utilize, or utilizes to a limited extent, mannose, i-inositol, adonitol, lactose, ribose, raffinose, and cellulose.A direct comparison with authentic cultures ofStreptomyces coelicolorandStreptomyces caeruleusproved the unknown to be qualitatively indistinguishable only from the latter. A literature survey did not reveal other species resembling the unknown, which was therefore concluded to be a member ofStreptomyces caeruleusBaldacci.The original description ofS.caeruleusis amended and some characteristics of the culture grown under reproducible conditions are reported.

ISSN:0008-4166    

DOI:10.1139/m59-041

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

An organism which answers the published descriptions ofHaemobartonella muriswas isolated from Sprague-Dawley rats. The rats had either been splenectomized or were under other forms of stress. The organism was grown in a serum–tryptone medium which had been used successfully in the cultivation ofBartonella bacilliformis. The cultivated organism was infective for non-carrier Sprague-Dawley rats under different forms of stress; Wistar rats were not carriers and infections could not be induced.The effects of protein intake and tumors on the development of infection are also discussed. Rats fed a diet of 12% casein while carrying Flexner-Jobling tumors were more susceptible to infection than were those on diets of 0, 6, or 18% casein. Neither diets alone nor tumors alone placed sufficient stress on the animals for the development of symptoms.

ISSN:0008-4166    

DOI:10.1139/m59-042

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Five strains of motile, alpha hemolytic streptococci were isolated during a systematic study of 820 oropharyngeal specimens for group D streptococci. The motile streptococci contain the Lancefield group D somatic polysaccharide. Photomicrographs record the presence of flagella in stained preparations. It appears both practical and expedient to classify these motile group D streptococci as another variety ofStreptococcus faecalis.

ISSN:0008-4166    

DOI:10.1139/m59-043

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Penicillium lilacinumwas grown on a high sugar–salts medium favorable for fat formation. Thiamin hydrochloride was added to 5-day-old cultures at three different concentrations, namely, 0.25, 2.5, and 5.0 mg/l. Sugar uptake, growth, and fat formation were followed after addition of vitamin for a period of 9 days. Sugar uptake was enhanced by the lowest and suppressed by the two higher vitamin concentrations. At higher concentrations, there was an early inhibition of dry weight increase, but by the end of the experiment, the weight of the high thiamin cultures equalled that of the controls. The effect of thiamin on fat formation was dependent on both the concentration and period of incubation. By the end of the incubation period, the low thiamin concentration had promoted fat formation, the high concentration had suppressed it, while the medium concentration was ineffective.

ISSN:0008-4166    

DOI:10.1139/m59-044

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

An aerobic, motile, Gram-negative bacterium of uncertain taxonomy has been isolated from soil by the enrichment method. This bacterium utilizesDL-1-amino-2-propanol as its sole source of carbon, nitrogen, and energy for growth in mineral media. The oxidation of the aminopropanol by resting cells is complete in the presence of 2,4-dinitrophenol. Lactic acid and a number of two and three carbon substrates are oxidized with molecular oxygen by resting cells and serve as adequate substrates for the growth of the bacterium, in the presence of ammonium chloride. The amino acids alanine and aspartic acid were found to be suitable growth substrates while serine, 3-amino-1-propanol, isopropylamine, and mono- and di-methylaminoethanol did not suffice. The results of this investigation are discussed with reference to a possible cycle of vitamin B12synthesis and degradation in the soil.

ISSN:0008-4166    

DOI:10.1139/m59-045

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

D-Amino acids have been found to induce protoplast-like forms (crescents) inAlcaligenes fecalisstrain LB. This induction is similar in most respects to that by penicillin with the exception of the effects produced in tryptone.D-Amino acids appear to act synergistically with penicillin. The amino acid composition of cell walls ofD-amino acid and penicillin-induced crescents as well as of normal cells has been examined by column chromatography. The main difference between normal and crescent cell walls consists of a reduction in the amount of the basic peptide unit of the phenol-insoluble fraction. These results are discussed in relation to the induction of protoplast-like forms.

ISSN:0008-4166    

DOI:10.1139/m59-046

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The ability of exogenousD-methionine to prevent the incorporation of exogenousL-methionine into the protein ofAlcaligenes fecalishas been studied.D-Methionine has been found to competitively inhibit the ability of the cell to concentrate mediumL-methionine with an efficiency of about 14:1. It does not inhibit the incorporation of endogenous methionine into cell protein.D-Methionine is replaceably concentrated by the cell and is able to specifically displaceL-methionine previously concentrated by the cell. The significance of these findings for the mechanism of concentration of amino acids by bacteria is discussed.

ISSN:0008-4166    

DOI:10.1139/m59-047

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

By means of physical and chemical procedures seven antigenic fractions have been isolated fromTrichinella spiralislarvae, as determined by complement fixation. Some evidence is presented to indicate that at least some of the isolated fractions are antigenically distinct and that antibodies inTrichinella-infestedrabbit develop at different times for different fractions. Importance of using a properly selected antigen in serodiagnosis of trichinosis is discussed.

ISSN:0008-4166    

DOI:10.1139/m59-048

出版商:NRC Research Press    

年代:1959

数据来源: NRC