摘要:

The abilities of Transgrow (TG), Thayer-Martin (TM), and New York City (NYC) solid media to maintain the viability of 12 strains ofNeisseria meningitidisunder various controlled conditions were assessed. The effects of charcoal impregnation of swabs, temperature, and an enriched CO2, atmosphere were examined with holding for up to 21 days. Recovery from samples held at 35 °C was, in almost all instances, greater than at 22 or 4 °C. A strong requirement for added CO2was demonstrated, especially at lower temperatures. No positive effect could be attributed to the use of charcoal-impregnated swabs. NYC and TM media were the best overall, with the former permitting recovery from more than 75% of all samples held on slants for 20 days at 4 °C in an atmosphere of 5% CO2in air. Freezing, with holding on dry ice, was a useful alternative to the use of growth-supporting media. This latter method eliminated the requirement for an enriched CO2atmosphere.

ISSN:0008-4166    

DOI:10.1139/m79-019

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

A strain of the acellular slime mouldPhysarum polycephalumdegraded lipopolysaccharides (LPS) from a variety of bacteria. The anticomplementary (AC) activity of LPS was greatly reduced, as was the content of lauric, myristic, and palmitic acids, and the ability to sensitize erythrocytes to agglutination by antibody. These results indicate thatPhysarumhas enzymes which reduce the lipid A moiety of LPS. In contrast. 2-keto-3-deoxy-D-manno-actanoic acid (KDO), immunodominant sugars, and β-hydroxymyristic acid were scarcely affected. Both supernates and plasmodial extracts ofPhysarumhad LPS-degradative activity and were able to attack both purified LPS and LPS in killed bacteria.

ISSN:0008-4166    

DOI:10.1139/m79-020

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The naphthalenones asparvenone and its 6-O-methyl ether are produced byAspergillus parvulusduring vegetative growth in batch-mode, shaken cultures in a glucose–glycine–salts medium. The secondary metabolites first appear around the time when hyphae of developing spores begin to make contact with each other, i.e. at a very early stage of culture development. Resuspension in new medium of mycelium that is producing the naphthalenones fails to inhibit production. WhenA.parvulusis grown in parallel on a glucose–glycine–salts medium and on a glucose–malt–peptone medium, the naphthalenones appear first in the richer medium despite the fact that biomass proliferation is relatively unrestricted in that medium. Radiolabelled [1-14C]-acetate is taken up quickly by the fungus (k = 0.09 min−1) and is incorporated effectively into the naphthalenones.

ISSN:0008-4166    

DOI:10.1139/m79-021

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

An antigen (ZAB) common toNeisseria gonorrhoeaewas prepared by stepwise elution of a crude gonococcal antigen (ZA) from columns of diethylaminoethyl cellulose employing 0.02 Mphosphate buffers, pH 7.6, containing increasing concentrations of sodium chloride. Rats immunized with ZAB produced reaginic (IgE) antibody which cross-reacted with ZA prepared from eight gonococcal strains by the passive cutaneous anaphylaxis (PCA) test. Heatingof the sera at 56 °C for 4 h destroyed the PCA activity. The PCA activity of the anti-ZAB rat serum was removed after absorption with ZAB antigen or with rabbit anti-rat IgE but not after absorption with gonococcal lipopolysaccharide or with heat-killed or formalinized gonococci. Treatment of ZAB with trypsin or heating at 100 °C for 30 min destroyed or reduced the antigenic activity respectively. Further purification of ZAB by filtration through Sephadex G-100 gave a preparation (ZAB2) which contained the common antigen as shown by the cross-reactivity of anti-ZAB2rat serum with seven strains ofN.gonorrhoeae. Fraction ZAB2contained material which had a molecular weight less than 13 700 and was associated with the presence of material absorbing at 260 nm. The results of this study indicate that a low molecular weight antigen, which appears to be protein in nature and associated with nucleic acid, is common to the gonococcus and is the main antigenic component inducing reaginic (IgE) antibody in the rat.

ISSN:0008-4166    

DOI:10.1139/m79-022

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Sixty fungal isolates, 34 obtained by a static enrichment technique from soils of northern Canadian oil-producing areas and 26 from culture collections, were screened for their ability to grow onn-tetradecane, toluene, naphthalene, and seven crude oils of varying composition. Forty cultures, including 28 soil isolates, were capable of growth on one or more crude oils. The genera most frequently isolated from soils were those producing abundant small condida, e.g.PenicilliumandVerticilliumspp. Oil-degrading strains ofBeauveria bassiana,Mortieriellasp.,Phomasp.,Scolecobasidium obovatum, andTolypocladium inflatumwere also isolated. Qualitative and quantitative differences were noted among the capacities of different crude oils to sustain the growth of individual fungal isolates. Data are presented which show that ability to grow on a puren-alkane is not a good indicator of ability to grow on crude oil. Degradation of Rainbow Lake crude oil by individual isolates was demonstrated by gravimetric and gas-chromatographic techniques. The problems involved in determining the response and the potential of fungi to degrade oil spilled in the environment are discussed.

ISSN:0008-4166    

DOI:10.1139/m79-023

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Numbers of germinableCylindrocladium crotalariaemicrosclerotia (assayed at 26 °C) decreased progressively over 4 weeks when naturally infested soils were incubated at 6 °C. Lower numbers of germinable microsclerotia were obtained from a soil incubated at −3 than at 5 °C, while no germinable microsclerotia were found for soils incubated at −10 °C. Significantly, when soils incubated at −10 or at 6 °C for 4 weeks were transferred to 26 °C for 4 weeks, the low-temperature effect was partially reversed. Incubation of naturally infested soils under field conditions from October to February indicated that a similar low-temperature induced phenomenon exists in nature.Germinability of axenic laboratory-grown microsclerotia ofC.crotalariae,C.floridanum, andC.scopariumincubated 4 weeks at 6 °C ranged from 0 to 91% (mean = 38%) of the initial germinability. Partial recovery of laboratory-grown microsclerotia from the low-temperature effect, by incubation at 26 °C, was demonstrated. Conductivity measurements of solutions bathing microsclerotia incubated at 6 °C were higher than those incubated at 26 °C for 4 weeks and indicated that chilling injury may account, in part, for decreased germinability of microsclerotia.

ISSN:0008-4166    

DOI:10.1139/m79-024

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The toxin-induced chlorosis caused byPseudomonas coronafaciensis influenced by irradiance. Three levels of irradiance caused differences in symptom expression but did not affect the rate of increase or final population of viable cells ofP.coronafaciensin rye leaves. Distinct and faint halo blight symptoms appeared in 3–4 days in full light (1425 μ W cm−2), and 58% shade (598 μ W cm−2) respectively. No symptoms or only faint symptoms appeared after 7 days at 86% shade (202 μ W cm−2). When plants kept in 58 and 86% shade were moved to full light 5 days after inoculation, lesion size and chlorosis increased rapidly during the next 2 days. On the 7th day after inoculation, the size of lesions from the 58 and 86% shade treatments exceeded those in full light by 2.5 and 5 times, respectively. A chlorosis index based on lesion size and chlorophyll loss within lesions also reflected this trend although chlorophyll loss was greater in lesions in full light for 7 days. Conditions of low irradiance such as that caused by overcast weather and (or) a dense leaf canopy followed by bright sunshine can cause greater losses from halo blight than a continuous period of high irradiance. Sympton expression may be masked by low irradiance but increase of inoculum is not impaired. Although increased light enhances chlorosis, toxin diffusion or production may be reduced.

ISSN:0008-4166    

DOI:10.1139/m79-025

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The nitrogen source available toDiplodia maydisin vivo is reported to affect the severity of stalk rot in maize. Nitrate and (or) ammonium salts were tested for their effect on the type of nitrogen metabolism found inDiplodia maydisin vitro. The level of glutamate dehydrogenase remained essentially constant on either nitrogen salt but nitrate reductase was induced by growth on nitrate salts and was not extractable on ammonium salts. Properties of nitrate reductase reported here are similar to those reported for the higher plant andNeurospora crassaenzymes. The relationship of nitrogen metabolism inDiplodia maydistoZea maysL. stalk rot is discussed.

ISSN:0008-4166    

DOI:10.1139/m79-026

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Production of mycotoxins byChaetomiumspp. and related fungi on rice culture was examined by a combination of cytotoxicity tests using HeLa cells and thin-layer chromatography. Three species,C.mollipilium,C.rectum, andC.subuffine, as well asC.cochliodesandC.globosum, were proved to produce chaetoglobosins. From cultures of four strains ofChaetomiumsp., assigned toC.thielavioideum, and one strain ofFarrowiasp., chaetocin, sterigmatocystin, andO-methylsterigmatocystin were isolated. Morphological characteristics of the producers of sterigmatocystins are described.

ISSN:0008-4166    

DOI:10.1139/m79-027

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The fate ofBacillus sphaericusstrain SSII-1 cells ingested byCulex pipiens quinquefasciatus(=C.pipiens fatigans,C.fatigans,C.quinquefasciatusof authors; Diptera: Culicidae) larvae and the cytological events preceding death of the host were observed using electron microscopy.Bacillus sphaericuscells were digested rapidly in the anterior and central midgut. The outer cell wall layer and cytoplasmic ground substance disappeared soon after ingestion. Cytolysosomes became prominent in midgut cells as these cells gradually separated from one another. All bacteria, includingB.sphaericus, were confined within the peritrophic membrane until after death of the host. Digestion by the larval host is confirmed as a possible mechanism for release ofB.sphaericustoxin from the bacterial cells.

ISSN:0008-4166    

DOI:10.1139/m79-028

出版商:NRC Research Press    

年代:1979

数据来源: NRC