摘要:

Attempts to characterize the breakdown product formed during the anaerobic degradation of the gamma isomer of benzene hexachloride (γ-BHC, C6H6Cl6) by theClostridiumsp. were made. Analysis by gas chromatography and thin-layer chromatography indicated that the degradation product of γ-BHC and α-BHC differed from γ-pentachlorocyclohexene (C6H5Cl5), a direct product of dehydrochlorination of γ-BHC. The ability of the bacterium to convert DDT to DDD by reductive dechlorination suggested that a similar mechanism might degrade γ-BHC to γ-pentachlorocyclohexane (C6H7Cl5). Potassium nitrate inhibited the bacterial degradation of γ-BHC whereas potassium sulfate and potassium chloride enhanced it.

ISSN:0008-4166    

DOI:10.1139/m69-245

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

In confirmation of earlier studies of Evans and Perkins, we have found that mice given a single intraperitoneal injection of pertussis vaccine developed a significant resistance to intracerebral challenge with live pertussis organisms as early as 1 day, or even 6 hours, after vaccination, although this early immunity was weaker than that present 14–21 days after vaccination. Cyclophosphamide, given to mice close to the time of vaccination and in doses just below the toxic level, suppressed both the early and late immunity, but with the latter the suppression was less complete. We suggest that the early resistance to challenge is probably a true immune response and not an interference reaction as postulated by Evans and Perkins.Cyclophosphamide also reduced the passive protective activity, in mice, of rabbit hyperimmune antipertussis serum. This suggests that the process by which thepassively immunizedmouse overcomes intracerebral challenge with virulent pertussis involves antibody plus some cyclophosphamide-sensitive agent normally present in the mouse.

ISSN:0008-4166    

DOI:10.1139/m69-246

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Fifteen strains of bacteria capable of degrading rutin anaerobically were isolated from bovine rumen contents and identified by morphological and biochemical evidence as strains ofButyrivibriosp. Three cultures from a laboratory collection of 53 strains of rumen bacteria also used rutin anaerobically. Two,Butyrivibrio fibrisolvensD1 andSelenomonas ruminantiumGA192, cleaved the glycosidic bond of rutin and fermented the sugar but did not degrade the insoluble aglycone produced; the third strain,Peptostreptococcussp. B178, degraded the substrate to soluble products.Butyrivibriosp. C3degraded rutin, quercitrin, and naringin to water-soluble products, showing that the organism cleaved the heterocyclic ring of these compounds.Butyrivibriosp. C3fermented the sugar moiety of hesperidin but did not cleave the heterocyclic ring. It did not attack quercetin, taxifolin, protocatechuic acid, or phloroglucinol. In a medium containing rumen fluid,Butyrivibriosp. C3degraded rutin more than twice as fast as it did in a medium containing enzymatic casein hydrolyzate, volatile fatty acids, yeast extract, and hemin in place of rumen fluid.The observations reported in this paper are believed to represent the first recorded demonstration of degradation of the heterocyclic ring structure of rutin and other bioflavonoids in pure cultures of anaerobic bacteria.

ISSN:0008-4166    

DOI:10.1139/m69-247

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The distribution of cellulase activity in the solid and liquid fractions of rumen contents collected from a fistulated steer was studied. The specific activity of cellulase in the clear supernatant of rumen fluid and in the sonicated cells suspended from the liquid fraction was 0 and 0.75 × 10−3 units/mg protein respectively against carboxymethylcellulose (CMC). On the other hand, the specific activity of the fraction obtained by ultrasonic disruption of organisms released from the solid portion of rumen contents by gentle agitation was 0.22 × 10−3, 0.19 × 10−3, and 1.10 × 10−3 units/mg protein against solka floc, avicel, and CMC respectively. Addition of autoclaved rumen fluid to the assay system resulted in a decrease in the rate of production of reducing sugars, indicating the presence of inhibitors. The cellulase exhibited a maximum activity at pH 5.5. The addition of cobalt chloride andL-cysteine resulted in an increase in cellulase activity whereas the addition of urea,D-gluconic acid lactone, sodium sulfide, and ferric chloride was inhibitory.In cellulose enrichment cultures obtained from 10−8dilution of rumen liquor, the specific activity of cellulase in the supernatant was always less than in the fraction obtained by sonic disruption of cells attached to the filter paper. The results are discussed in relation to the localization of cellulases in rumen microorganisms.

ISSN:0008-4166    

DOI:10.1139/m69-248

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A number of yeasts, many of which were originally isolated from spoiled beer and similar sources, were tested for their ability to degrade or modify some of the components of hop extract. The yeasts could be divided into three major groups: those which caused little change in the composition of the steam-distillable components of the hop extract – yeast extract medium; those which apparently modified one or more components as determined by the shifting of a major peak on the gas–liquid chromatogram; and those which caused extensive degradation and complete disappearance of the major steam-distillable components of the hop extract medium.

ISSN:0008-4166    

DOI:10.1139/m69-249

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The germination of sclerotia ofMacrophomina phaseoliwas found to be less than 5% in soil. The germination of sclerotia on silica gel, silica gel plus soil leachate, or potato dextrose agar was found to be in excess of 90%. Germination in soil could be increased to over 50% by the addition of natural or synthetic sugar pine root exudate. The amino acid fraction of the synthetically prepared root exudate was most effective in increasing sclerotial germination.

ISSN:0008-4166    

DOI:10.1139/m69-250

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Of the 50 strains of myxobacteria (mainly cytophagas) tested most were able to solubilize autoclaved feathers but none attacked unmodified feathers. The strain studied most extensively rapidly solubilized up to 80% of the substrate leaving only the resistant shafts. In the absence of a readily assimilable energy source, such as glucose, about 70% of the protein nitrogen solubilized appeared as ammonia which the organism could not use. Glucose exhibited an amino acid sparing effect.

ISSN:0008-4166    

DOI:10.1139/m69-251

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Diverticula cells of larval, nymphal, and adultDermacentor andersoni(Stiles) ticks demonstrated a non-infective phase of 7 to 11 days after engorgement of blood containing Powassan virus. Other organs such as salivary glands, Gené's organ glands, and accessory glands supported virus multiplication. This was demonstrated by infectivity titrations and observations of fluorescent foci when the tissues were stained with Powassan virus antiserum conjugated with fluorescein isothiocyanate (FITC). Transstadial transfer of virus was observed through ecdysis of larvae to nymphs and from nymphs to adults. This occurred both after the ticks had fed on hamsters (which produced a substantial viremia) and guinea pigs (which did not become viremic). Virus was detected only in larval gut and invaded nymphal salivary glands during ecdysis. Infection localized in gut and salivary glands of engorged nymphs and adults and was not detected in adult female accessory and Gené's glands until repletion. Adult males maintained high virus titers (106.0mouse LD50per milliliter) in salivary glands only. Transovarial transfer was not detected, although infectivity was present on the surface of eggs laid by the mediation of an infected Gené's organ gland. Powassan virus was detected in salivary gland secretions, and transmission of virus to hamsters and guinea pigs was demonstrated by the bite ofD.andersoninymphs and adults which were infected by ingestion of infective blood by their antecedent larvae.

ISSN:0008-4166    

DOI:10.1139/m69-252

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Immunodiffusion and hemagglutination tests have demonstrated that antiserum against Ehrlich ascites fluid is active against tissue saline extracts and erythrocytes of the mouse, rat, guinea pig, hamster, and cat. Detailed studies have shown that cat liver extract shares a common antigen present in the Ehrlich ascites cell, normal mouse liver, and guinea pig kidney. Enzyme susceptibility and heat stability tests have indicated that the cat heterophile antigen is heat stable and protein in nature. The relationship of this new heterophile antigen with other identified heterophile antigens is discussed.

ISSN:0008-4166    

DOI:10.1139/m69-253

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The mechanism of temperature sensitivity of induced temperature-sensitive mutations was studied inParamecium aurelia, syngen 4.The catalase reaction of crude preparations was compared at various temperature ranges between wild type andtsmutant stocks. Onetsmutant out of 100 stocks showed a catalase reaction labile at 35.5 °C unlike that of the wild type as well as the othertsmutants.Genetic tests revealed that this heat-labile catalase reaction was controlled genetically and was recessive.

ISSN:0008-4166    

DOI:10.1139/m69-254

出版商:NRC Research Press    

年代:1969

数据来源: NRC