摘要:

The structure ofVibrio marinusstrain PS-207 was studied by both phase and electron microscopy. It was found to possess a trilaminar plasma membrane and cell wall. Membrane-bounded subunits containing DNA-like material were found dispersed throughout the cytoplasm. Giant round forms or "macrospheres" were observed in all growth stages. The size, shape, and construction of the "macrospheres" showed some variation, but could not be related to culture age. Studies of cell division inV.marinusstrain PS-207 indicate the primary mechanism to be a synthesis and centripetal deposition of plasma membrane with a concomitant or subsequent synthesis and centripetal deposition of cross wall material.

ISSN:0008-4166    

DOI:10.1139/m70-174

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Strain 929 mouse fibroblast L cells demonstrated an increased rate of endogenous and exogenous respiration when infected by the 6BC strain of the psittacosis organism. The respiratory quotient (R.Q.) values for infected cultures were about 1.0. Studies involving the use of 2,4-DNPand reduced phosphate suggested that the accelerated respiration was a result of increased oxidative phosphorylation. Infection was accompanied by a decline in host cell ATP levels with a concomitant increase in the ADP levels. A reduction in tissue culture medium phosphate resulted in a reduced yield of psittacosis organisms from infected cells and lower cellular levels of ATP. These results are discussed in relation to an energy parasite hypothesis.

ISSN:0008-4166    

DOI:10.1139/m70-175

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Osmiophilic bodies appear in parts of the colonial growth ofErysiphe graminisDC. f. sp.hordeiEm Marchal culture CR3 growing on the susceptible commercial Keystone variety of barley. They are readily observed by the light and electron microscope after osmium tetroxide staining and are abundant in conidiophores, conidia, and mycelium except in haustorial mother cells, in which they are usually absent. The metabolism of haustorial mother cells is distinct and the fine structure of adjoining cells is frequently different. Osmiophilic bodies are absent from the growing hyphal tip, but gradually increase in number and size further back in the terminal cell. Electron micrographs show that they are intracytoplasmic, intravacuolar, and up to 1 μ in diameter. When the colony is washed with acetone or alcohol rather than with aqueous buffer, after glutaraldehyde fixation, before osmium tetroxide fixation, the osmiophilic bodies are removed, indicating that they are lipids. Fat stains, Sudan black B, and Sudan IV stain these bodies. Perhaps the water needs of the germinating conidium are met in part by the oxidation of fats.

ISSN:0008-4166    

DOI:10.1139/m70-176

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Spores ofC.botulinum33A were irradiated at pH 2, 3, 4, 5, 6, and 7 to 0.6, 0.7, and 0.9 Mrad cobalt-60. Temperatures were controlled at −196 °C to 0 °C in distinct intervals. The survival data presented a complex wave-like pattern which appeared to be influenced by pH, temperature, and dose of radiation. Three typical survival patterns could be recognized. Pattern A (at −190 °C) showed peaks of high survival at pH 4 and 7 and low survival at pH 2 and 6. Pattern B (at −50, −40, and −30 °C) showed peaks of high survival at pH 3 and 6 and low survival at pH 2, 4–5, and 7.0. Pattern C (at 0 °C) was similar to pattern A but had generally higher peaks and deeper troughs. Between the temperatures showing typical A, B, and C patterns, the survival profiles indicated various degrees of transition from A to B or from B to C.The effect of pH appears to be related to its influence on yield of radicals in water such as, for example, ∙OH, which may result in highly lethal conditions within the region of low spore survival, and extinction of ∙OH by reaction with H∙ at the peaks of spore sur

ISSN:0008-4166    

DOI:10.1139/m70-177

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Minimum numbers of yeasts isolated from the Saskatchewan River in the summers of 1964 and 1965 ranged from 400 to 500 cells/liter upstream from the city of Saskatoon, to 4600 cells/liter immediately downstream. In the summer of 1968, a period of extremely low water, the counts were 150 cells/liter upstream from the city and 30 000 cells/liter downstream.Proton magnetic resonance spectra of the mannose-containing polysaccharides from representative cultures of the different species isolated were used as an aid in classification. Most of the species were asporogenous, and included representatives of the generaCandida,Trichosporon,Rhodotorula,Torulopsis, andCryptococcus. Some species ofPichia,Saccharomyces, andDebaryomyceswere isolated. The yeasts were mostly introduced into the river with the effluent from the Saskatoon sewage system.

ISSN:0008-4166    

DOI:10.1139/m70-178

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The effect of aflatoxin B1on induced and constitutive enzyme synthesis was examined in strains ofBacillus cereus(NRRL B-569, NRRL B-3537) andBacillus licheniformis(NRRL B-3560, NRRL B-3540). Although B1partially blocked penicillinase elaboration inB.cereusafter incubation with the toxin, the level of B1-mediated reduction in total protein synthesis was similar to the diminished production of penicillinase. Comparative studies on the effects of aflatoxin B1and actinomycin D on enzyme synthesis and growth inB.licheniformisdemonstrated that actinomycin D exerted a differential inhibitory effect on induction of penicillinase and α-glucosidase, whereas levels of reduction of enzyme production initiated by aflatoxin resembled toxin-mediated growth inhibition. Thus, the mode of action of aflatoxin B1is not exclusively analogous to that of actinomycin D inB.licheniformis. However, induced-penicillinase production inB.licheniformiswas enhanced by relatively low levels of both actinomycin D and aflatoxin B1.

ISSN:0008-4166    

DOI:10.1139/m70-179

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A comparative study has been made of the production of tetanus toxin according to two different methods: growth of the tetanus bacillus in jars, and growth in bottles. An important difference has been noted in the characteristics of the growth ofPlectridium tetaniwhen using one or the other of the two methods studied; in particular, the titer of the toxin produced in jars is much greater than that produced in bottles. Moreover, it has been noticed that the liberation into the surrounding medium of the toxin synthesized inside the bacterial cells during logarithmic growth is favored by a lysis of the cells which becomes manifest after 4–5 days of growth. This lysis occurs when the pH value of the culture reaches 7.5–7.6.

ISSN:0008-4166    

DOI:10.1139/m70-180

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Amines produced by 31 strains of theClostridium bifermentansandC.sordelliigroups were compared by examining trifluoroaceticanhydride derivatives of basic chloroform extracts from spent cultural medium by gas–liquid chromatography (g.l.c.). All of the urease-positive strains (16) exhibited an amine profile consistent with that ofC.sordellii. On the other hand, 12 of 15 urease-negative strains produced amine g.l.c. patterns like that ofC.bifermentans, and three strains produced amine patterns identical with that ofC.sordellii. The carbohydrate composition of some of the strains was determined by g.l.c. of trimethylsilyl derivatives of acid-digested formamide extracts of whole cells. Two of the three urease-negative strains with amine profiles likeC.sordelliihad a carbohydrate composition similar to that ofC.sordellii, and the other strain had a carbohydrate profile more like that ofC.bifermentans. One known strain ofC.bifermentanshad a carbohydrate profile with characteristics of bothC.bifermentansandC.sordellii. The results of this study point out the variability of urease production byC.sordelliiand the value of gas chromatography in differentiating this organism fromC.bifermentans.

ISSN:0008-4166    

DOI:10.1139/m70-181

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The effect of sodium azide and antimycin on the production of psittacosis organisms from L cells was studied. In both cases it was found that a reduction of cellular adenosine triphosphate (ATP) brought about by the inhibitor was accompanied by a reduction in the yield of psittacosis organisms. The same observations were made when Eagles minimum essential medium (MEM) glucose was reduced to a less than optimal concentration. These results are discussed in relation to an energy parasite concept.

ISSN:0008-4166    

DOI:10.1139/m70-182

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A study of the factors influencing the development of an interferon-induced antiviral state indicated that the induction phase of the interferon "uptake" system was dependent on interferon concentration and exposure time of cells to interferon. The same parameters were found to affect the development of antiviral activity when a greater concentration of interferon was applied to cells which had been induced. Low pH was found to affect, adversely, the development of an antiviral state in cells exposed to interferon. This effect was at the induction rather than the uptake level of interferon action.

ISSN:0008-4166    

DOI:10.1139/m70-183

出版商:NRC Research Press    

年代:1970

数据来源: NRC