摘要:

Competitive adsorption studies indicated that reovirus type 3 and coliphage T1 did not share common adsorption sites on kaolinite and montmorillonite. Compounds in the minimal essential medium (e.g., fetal bovine serum, amino acids) in which the reovirus was maintained blocked adsorption of coliphage T1 to kaolinite and partially to montmorillonite in synthetic estuarine water, but they had no effect on coliphage adsorption to montmorillonite in distilled water or on the adsorption of the reovirus to either clay. The blockage of positively charged sites on kaolinite or montmorillonite by treatment of the clays with sodium metaphosphate or with the supernatants from montmorillonite or kaolinite, respectively, had no effect on adsorption of the reovirus. These data indicate that there was a specificity in adsorption sites for mixed populations of reovirus type 3 and coliphage T1 and emphasize the importance of using more than one type of virus, especially in combination, to predict virus behavior (e.g., adsorption, loss of infectivity) in soils and sediments containing clay minerals.

ISSN:0008-4166    

DOI:10.1139/m85-011

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

The highly susceptible inbred C3H/HeNMTV mice were vaccinated with fragments derived from sonicatedSalmonella typhimuriumand then infected with the pathogen. All of the vaccinated mice survived an otherwise rapidly fatal challenge of 105organisms, i.e., >103× mean lethal dose (LD50). The vaccine also protected two-thirds of the mice infected with 106bacteria and extended the survival time of the remainder in their fatal disease. Histopathological findings showed that, like the control mice, the vaccinated and infected mice developed abscesses with infiltration of polymorphonuclear leukocytes in the organs of the reticuloendothelial system during the early stage of the infection. However, unlike the primary lesions in the control mice, the lesions of the vaccinated mice tended to be discrete and self-limiting. They began to transform into granulomas after the first week of infection. Recovery and regeneration of tissues were evident 3 weeks after the infection.

ISSN:0008-4166    

DOI:10.1139/m85-012

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Following testicular infection of rabbits withTreponema pallidum, different antibodies become detectable initially at the time of healing. Experiments were performed to determine a functional role for these antibodies. Rabbits were sacrificed after 4–8 days. Treponemal numbers steadily increased for 10–12 days. Thereafter, host defenses were sufficiently stimulated to begin clearing the organisms. Antibodies in serum and antibodies localized at the site of infection were quantitated using radioimmunoassay and enzyme-linked immunosorbent assay (ELISA) techniques. Anti-treponemal lgG was detected as early as day 4. Quantities of antibody correspondingly increased with time following infection.Treponema pallidumwas harvested 7 and 14 days postinfection and tested for surface antibodies. With increasing days postinfection, more antibody was found on the organisms. Two functional properties of these antibodies were shown. Sera from 24 of 45 rabbits infected for 14 days immobilizedT.pallidumin the presence of complement and 14-day sera blocked the attachment ofT.pallidumto tissue culture cells. We suggest that antibody-mediated, complement-dependent immobilization ofT.pallidumand blockage of attachment are at least partially responsible for healing of testicular lesions.

ISSN:0008-4166    

DOI:10.1139/m85-013

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Culture media selective forAgrobacteriumwere inoculated with dilutions of soil and crown gall tumor suspensions. Colonies on the selective media were replica plated on a medium with octopine or nopaline. More than 500 isolates were recovered, about 10% of which were confirmed as octopine-utilizing, fluorescent pseudomonads. These strains, together with four other strains ofPseudomonasthat had been isolated in a previous study, were characterized for species identity, for utilization of various carbon sources, and for capacity to grow with various opines and amino acids as the sole carbon and nitrogen source. The capacities for octopine and nopaline utilization were generally dissociated, which is similar to the situation found inAgrobacterium. However, most of the octopine-utilizing strains ofPseudomonasshowed markedly different growth kinetics in octopine and octopinic acid, two compounds that, in theAgrobacteriumsystem, have been classified into the same opine family. Generally, poor octopinic acid utilization was not correlated with poor ornithine utilization.

ISSN:0008-4166    

DOI:10.1139/m85-014

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

An endo-cellulase, two β-glucosidases, and two 1,3-β-glucanases fromPhytophthora infestanswere partially purified from the culture filtrate and their biochemical properties determined. The molecular weights were estimated by chromatography on Sephacryl S-200 and were 21 000 (endo-cellulase), 160 000 – 230 000 and 32 000 (β-glucosidases I and II), 160 000 – 230 000 and 21 000 (β-glucanases I and II). The optimal pH of the endocellulase was 6.0. The other enzymes showed the following optimal pH and temperature values: β-glucosidase 1,5.5 and 48 °C; β-glucosidase II, 5.25 and 30 °C; 1,3-β-glucanase 1, 7.0and40 °C; and 1,3-β-glucanase II, 4.5 and 45 °C. The β-glucosidase II was unstable above 30 °C, while the other enzymes remained stable to 43 °C. The β-glucosidase I did not show Michaelis–Menten kinetics forp-nitrophenyl-glucopyranoside (pNPG) and gentiobiose as substrates. The extrapolatedKmvalue forpNPG was 1.1 mmol/L and theKmvalue for cellobiose was 280 mmol/L. TheKmvalues of the β-glucosidase II were 34 mmol/L forpNPG, 340 mmol/L for cellobiose, and 42 mmol/L for gentiobiose. Finally, theKmvalue of the 1,3-β-glucanase II for laminarin was 0.29 g/L. The isoelectric point of the enzymes were 3.2 (endo-cellulase), 3.3 (β-glucosidase I), 4.7 (β-glucosidase II), and 3.4 (the two 1,3-β-glucanases). At 10 mmol/L, Cu2+inhibited the β-glucosidase I by 90%, and the β-glucosidase II by about 50%. The 1,3-(3-glucanase II was inhibited 75% by Mn2+and 35% by Cu2+.

ISSN:0008-4166    

DOI:10.1139/m85-015

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

The toxicity of copper to the marine bacteriumVibrio alginolyticuswas examined. Experiments were conducted with both aerobic and anaerobic cultures. Calorimetric and radiochemical techniques were used to examine the effect of copper on heat production, respiration, and carbon assimilation by the cultures. Plate counts were used to determine the number of viable cells present. Copper was more toxic to the bacterium in anaerobic culture (mean toxic concentration (TC50) = 2.1 μM)) than in aerobic culture (TC50 = 6.4 μM). Both cytotoxic and cytostatic effects were observed. The cytotoxic effect was not significantly different under aerobic and anaerobic conditions. The cytostatic effect, observed only in anaerobic culture, resulted in a decrease in the rate of metabolism of the surviving cells. The magnitude of the cytostatic and cytotoxic effects were dependent on the copper concentration, exhibiting saturation at higher concentrations. Organic chelators EDTA and nitrilotriacetic acid protected the anaerobic cultures from the copper, indicating that Cu–organic complexes are not toxic to the organism.

ISSN:0008-4166    

DOI:10.1139/m85-016

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Contrary to previous reports, cultures ofPhanerochaete chrysosporiumagitated on a gyrotory shaker degraded synthetic lignin to CO2approximately as rapidly and extensively as static cultures. Agitated cultures also degraded the lignin in aspen wood to CO2and water-soluble products as well as static cultures, if the wood particles became enmeshed in the mycelium. An atmosphere of oxygen stimulated lignin degradation, compared with air, in both agitated and static cultures. The mycelia in agitated cultures with ligninolytic activity formed single, large pellets.

ISSN:0008-4166    

DOI:10.1139/m85-017

出版商:NRC Research Press    

年代:1985

数据来源: NRC

ISSN:0008-4166    

DOI:10.1139/m85-018

出版商:NRC Research Press    

年代:1985

数据来源: NRC