摘要:

The assimilation of14C-bicarbonate under controlled conditions was examined in midlog-phase mycelium grown on dextrose as sole carbon source. Sustained assimilation depended on the presence of exogenous nitrogen and carbon sources. When these were provided, assimilation rates of 20–30 μmoles/hour per 100 mg dry weight were maintained for at least 4 hours. After the second hour, almost all of the assimilated bicarbonate-C entered the 80% ethanol-insoluble fraction. Amino acids, especially aspartic and glutamic, were the main destination of assimilated bicarbonate-C; nucleic acids and acids of the tricarboxylic acid cycle accounted for smaller amounts of this carbon. The apparentKmfor overall assimilation was 1.4 – 2.2 × 10−4 Mwith respect to bicarbonate.Assimilation was inhibited by inhibitors of protein synthesis, especially actidione andp-fluorophenylalanine. Evidence was obtained for regulation of assimilation by its end products, and also by the carbon source on which the mycelium was grown. It is concluded that assimilation of bicarbonate or CO2has an anaplerotic function during protein synthesis in this organism.

ISSN:0008-4166    

DOI:10.1139/m69-070

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A simple prefilter pad – membrane filter combination method is described for the detection and quantitation of low concentrations of virus in natural waters. The data obtained indicate that in surface water experimentally contaminated with poliovirus type 1 (Mahoney strain), more than 50% of the initial virus dose is recovered. The method is practical, efficient, and can be used in field studies. It was clearly demonstrated that the prefilter pad (AP25), when used by itself will adsorb viruses. A certain concentration of electrolytes (200 p.p.m. Ca2+) is necessary in water to prevent the loss of virus in filtrate when filtering is done through the membrane filter.

ISSN:0008-4166    

DOI:10.1139/m69-071

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Upon addition of either iron or manganese to a purified agar medium, the level of prodigiosin per unit protein inSerratia marcescensincreased over that in cultures containing no added Fe3+or Mn2+. Addition of manganese in the presence or absence of added iron was generally correlated with increased prodigiosin per unit protein. Iron added in the absence of supplemental manganese was correlated with increasing prodigiosin levels. However, increasing the iron concentration in the presence of all levels of added manganese resulted in decreased prodigiosin production. Prodigiosin per unit protein as a function of culture age showed a definite increase up to the stationary phase of growth. Additions of Fe3+or Mn2+or both resulted in cells which contained both free hydroxylysine and free ethanolamine, and lower levels of all other ninhydrin-reactive compounds than were found in cells to which neither of these cations was added.

ISSN:0008-4166    

DOI:10.1139/m69-072

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Quantitative studies were carried out on the bacterial populations of two associated littoral marine algae,Polysiphonia lanosaandAscophyllum nodosum, and of the environmental seawater. Samplings conducted twice monthly from May to September, 1964, showed that numbers of bacteria onP.lanosaand in the seawater remained relatively constant while those onA.nodosumdecreased in mid-summer, after an apparent spring maximum, and then gradually increased.Pure cultures of 25 isolates of frequent occurrence were studied and identified to the genus level. There was a preponderance of members of the generaVibrioandFlavobacter(eight of each genus). Three members of theEscherichiagroup, two ofPseudomonas, and one belonging to each of the generaSarcina,Staphylococcus, andAchromobacter(orAlkaligenes), as well as a pink yeast (Rhodotorula), made up the rest of the isolates.The optimum temperature for growth of most of the isolates was around 21 °C. Five of the isolates failed to grow at 30 °C. Twenty did not grow at 37 °C; of the five organisms which grew at 37 °C, growth was feeble in every case but one.Studies on the gross nutritional requirements of the marine organisms showed that 22 of the 25 isolates required a supplement of amino acids in the growth medium. Two were able to grow on basal medium; one isolate grew only in a medium supplemented with growth factors in addition to amino acids.The above findings are briefly discussed with special reference to the association between the two algae.

ISSN:0008-4166    

DOI:10.1139/m69-073

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The biological activity of lipid extracts of five strains ofListeria monocytogeneswas studied, with special reference to their monocytosis-producing activity in mice. Two of the strains gave more active extracts than the others, and cells grown at 4 C produced more lipid with better activity than cells grown at room temperature or at 37 C. Extracts obtained from cells harvested at the various stages of log phase at 4 C all gave similar levels of monocytosis in mice. The level of monocyte response varied from animal to animal, but in general, older mice (28 to 48 weeks) responded better than young mice (9 to 15 weeks) and females gave a better response than males. These extracts also produced leucopenia in young mice, but this was less consistent and leucocytosis was more often observed in older mice. Granulocytosis and lymphopenia were commonly found in mice injected with lipid extracts ofL.monocytogenes. These changes were affected by the strain of bacteria but not by the age and sex of the test animals. The changes in blood picture normally reached a maximum 1 to 2 days after injection and returned to normal after about 5 days.

ISSN:0008-4166    

DOI:10.1139/m69-074

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Cytophagasp. (NCMB 1314) produces a factor capable of solubilizing cholinesterase from body muscle of plaice. A simple dialyzable medium supporting bacterial growth and production of the cholinesterase-solubilizing factor has been developed. The optimal conditions for extracellular production of the factor have been investigated. Either the whole culture or a cell-free preparation can be used to liberate structurally bound cholinesterase from body muscle of plaice.

ISSN:0008-4166    

DOI:10.1139/m69-075

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

An isolate ofCephalosporiumsp. (PRL 2070) and the chemical changes taking place in the culture medium during its production of the pigment cephalochromin are described.

ISSN:0008-4166    

DOI:10.1139/m69-076

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Pseudomonas aeruginosaMac 436 was found to produce simultaneously three phenazine pigments identified as pyocyanine, phenazine-1-carboxylic acid, and oxychlororaphine. Production of these pigments on various media indicated a wide variation in yields depending on the composition of the media, but satisfactory yields of all three pigments were obtained. A scheme was developed for separation and assay of the pigments from the culture liquor. Details of production, isolation, assay, and identification are given.

ISSN:0008-4166    

DOI:10.1139/m69-077

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A wild-type strain ofNeurospora crassawas inhibited 30% by 0.1 μg/ml ofL-ethionine. With 1 μg/ml the cultures failed to grow for the first 5 days of incubation and then they grew at a rate comparable to that of a control culture. However, the final weight of the inhibited cultures was less than that of the untreated cultures.L-Ethionine at 2.5 μg/ml completely inhibited growth of the cultures. The growth of a methionine-requiring strain ofN.crassawas inhibited about 90% when the ratio of ethionine to methionine was at least 10:1. Ethionine at 0.6 μg/ml inhibited the growth of a choline-requiring mutant. α-Methylmethionine and norleucine at 1 mg/ml did not inhibit growth of the wild-typeN.crassain liquid medium. S-Ethyl-cysteine inhibited growth much less than ethionine.p-Fluorophenylalanine was as effective an inhibitor as ethionine.

ISSN:0008-4166    

DOI:10.1139/m69-078

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A human fetal lung cell culture contaminant possessing most of the characteristics of that described by Girardiet al. (5) was shown to belong to theM.hyorhinis-GDL group of cytopathic mycoplasma by accessory factor neutralization test. The homotypic antiserum in this test neutralized the contaminant as well as three closely related strains while it could inhibit the growth of the contaminant only on agar. The mycoplasma could be detected in tissue cultures by the acridine orange staining technique and by direct immunofluorescence. These appeared as minute coccobacillary bodies either isolated or in clumps, predominantly extracellular in the original tissue culture but apparently intracellular in monkey kidney cell culture. A titer of 106TCID50per 0.1 ml was obtained in monkey kidney cell culture and the cytopathic effect induced in this culture was inhibited by pretreatment of the agent with 20% ether for 18 hours at 4 C, with tris buffer at pH 3 for 3 hours, or by heating at 56 C for 3 minutes. The cytopathic effect was suppressed by chlortetracycline (50 μg/ml) and neutralized with accessory factor by specific antiserum produced in rabbit up to a titer of 8192, whereas a variety of normal human and animal sera failed to do so. The source of the contaminant could not be determined.

ISSN:0008-4166    

DOI:10.1139/m69-079

出版商:NRC Research Press    

年代:1969

数据来源: NRC