摘要:

Sugar composition and serological specificity of the lipopolysaccharides (LPS) purified from 16Erwinia carotovorastrains in six different serogroups were determined. All the LPS preparations contained 2-keto-3-deoxyoctonoic acid, glucosamine, heptose, and glucose, and most contained galactose. Either rhamnose or fucose was present in LPS from 12 of the strains, and the presence or absence of these deoxy sugars was consistent for all strains within a serogroup. LPS from two strains contained mannose. One unidentified sugar was present in all LPS preparations, but six other unidentified sugars varied in different LPS preparations. All LPS preparations reacted in an enzyme-linked, immunosorbent assay (ELISA) with antisera produced against whole cells of a type strain in the same serogroup as the strain from which the LPS was extracted. Several cross-reactions among strains that previously were observed in immunodiffusion tests with whole-cell preparations were also observed in ELISA with purified LPS. Some of the LPS preparations also reacted in immunodiffusion with a precipitin line of identity with whole-cell preparations. The results indicate thatE.carotovoraserogroups probably are based on the LPS 0-antigen.

ISSN:0008-4166    

DOI:10.1139/m85-110

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Concanavalin A causes visible agglutination of trefoil rhizobia in a direct agglutination assay at 10−6 M. Trefoil chemotactin does not cause agglutination at similar concentrations. The bacteria are attracted by chemotactin at concentrations below 10−7 M. Lectins that cause rhizobial agglutination do not serve as chemoattractants at these concentrations. A filter agglutination assay showed agglutination of the bacteria by concanavalin A at concentrations of 10−8to 10−10 M. Chemotactin gives no agglutination in this assay at any concentration tested. Hence, the response of the bacteria to chemotactin probably is not due to agglutination.

ISSN:0008-4166    

DOI:10.1139/m85-111

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Cell walls, isolated from seven pathogenic species ofCandida, were lipid extracted and fractionated by treatment with ethylenediamine or enzymatically hydrolyzed using chitinase and laminarinase. Two different chitinase preparations were used, one fromStreptomycessp. which had some β-1,3-glucanase activity, and another fromSerratia marcescenswhich did not have glucanase activity. Laminarinase was a commercial preparation. The monosaccharide constituents of whole cell walls and the fractions derived from them were determined qualitatively and quantitatively by gas–liquid chromatography of the products of a mild acid hydrolysis and by the phenol – sulfuric acid assay of the products of a stronger acid hydrolysis. The monomeric constituents of the enzymatic hydrolyses were analyzed using gas–liquid chromatography. Approximately 50% of all walls was soluble in ethylenediamine. Glucose and mannose were the only monosaccharides found in all of the fractions derived from ethylenediamine extraction examined. Similarities among the strains, based upon relative amounts of glucose and mannose, were more apparent than differences, but statistical analyses of the data revealed a general trend of decreasing similarity in the following order,C.albicansandC.stellatoidea,C.tropicalisandC.parapsilosis, andC.pseudotropicalis,C.guilliermondii, andC.krusei. In the enzymatic assays, mannose and glucose were released by laminarinase, whereas glucose andN-acetyl-D-glucosamine orN-acetyl-D-glucosamine alone were released by the chitinases. These assays supported the trend in relationships cited above, with the data being somewhat more definitive.

ISSN:0008-4166    

DOI:10.1139/m85-112

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

A study was conducted to determine the incidence of fecal coliforms, fecal streptococci,Aeromonas hydrophilia, andSalmonellaspp. in the waste discharges of seven sewage treatment plants, four fruit and vegetable canneries, a meat packing plant, a poultry processing plant, and a potato processing plant located along the Cornwallis River in Nova Scotia, Canada. Surface water samples were also collected from 13 locations in the river to assess the impact of these waste discharges on the receiving water quality. The results showed that the final effluents from most of the sewage treatment and processing plants were of very poor bacteriological quality, with the number of indicator bacteria comparable with those found in raw sewage. Salmonellae were isolated from the effluents of the meat and poultry plants and five of the seven sewage treatment plants surveyed. No salmonellae were detected in the effluents of the fruit and vegetable canneries. The impact of the discharge of untreated municipal and food processing wastes on the Cornwallis River water quality was evidenced by the recovery from river water of fiveSalmonellaserotypes, and the high fecal coliform counts which exceeded recommended limit for bathing and shellfish harvesting.

ISSN:0008-4166    

DOI:10.1139/m85-113

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

During shadowing, a "cap" of metal develops on small particles. This cap increases, apparent particle width (measured normal to the shadowing direction) by an extent which cannot be predetermined. The extent of this increase in particle size (here defined as the "cap,"X) is estimated in the present method by using opposite (180° sample rotation) bidirectional shadowing. It is argued that the bidirectional cap is the sum of the two unidirectional caps, and therefore thatX = 2A− (B + C), whereAis the mean bidirectionally shadowed particle size, andBandCare the two mean unidirectionally shadowed particle sizes. As a validation of the method, the mean diameter of air-dried ferritin was estimated and the results appear to confirm the hypothesis (mean diameter by present method, 10.7 ± 0.2 nm; mean diameter by previous methods, 10.89 nm).

ISSN:0008-4166    

DOI:10.1139/m85-114

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Azospirillum brasilenseCd was grown in ammonium–malate mineral salts medium in batch culture and in chemostat continuous culture. It was found that poly-β-hydroxybutyrate synthesis was favored under oxygen limitation in chemostat culture and under high C/N ratios towards the end of exponential growth in batch culture. The degradation and synthesis of poly-β-hydroxybutyrate under starvation conditions occurred in a biphasic pattern and was affected by the poly-β-hydroxybutyrate content of the cells. During a 7-day incubation period in phosphate buffer, the survival and respiration rate of bacteria containing about 40% poly-β-hydroxybutyrate (dry weight) were higher than those of cells containing about 5% poly-β-hydroxybutyrate. Polymer-rich cells fixed atmospheric nitrogen in the absence of exogenous carbon and combined nitrogen. Biphasic nitrogenase activity was observed during starvation. When nitrogenase activity was high, hydroxybutyrate dehydrogenase activity was low and vice versa. Aerotactic response was higher in polymer-rich cells. In the presence of stress factors such as ultraviolet irradiation, dessication, and osmotic pressure poly-β-hydroxybutyrate-poor cells died more rapidly than poly-β-hydroxybutyrate-rich cells.

ISSN:0008-4166    

DOI:10.1139/m85-115

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

The molecular relationship between pUB110 (Kmr, 4.4 kilobases (kb)) and antibiotic-resistant plasmids from thermophilic bacilli, pTHT15 (Tcr, 4.5 kb) and pTHN1 (Kmr, 4.8 kb), were studied by blot hybridization. Extensive homology was observed between pUB110 and pTHT 15 at the region which includes the replication origin. Incompatibility studies revealed that pTHT 15 and pUB110 were slightly incompatible inBacillus subtilisbut that they were apparently compatible inB.stearothermophilus. This difference in incompatibility between pTHT15 and pUB110 in the two host cells might be due to a difference in the copy number of pTHT15 in the two organisms. From the results of blot hybridization, mode of kanamycin inactivation, and DNA sequencing, it was determined that pTHN1 encoded the identical gene for kanamycin nucleotidyl transferase as that of pUB110. All three plasmids pTHT15, pTHN1, and pUB110 shared a common DNA homology at thein vitromembrane-binding region.

ISSN:0008-4166    

DOI:10.1139/m85-116

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Different cell lipid accumulation and composition patterns were observed in the yeastsLipomyces starkeyiandCandida steatolyticaby varying the nutritive conditions. InLipomyces starkeyi303 which accumulates high levels of lipids as triglycerides, the composition of the different lipid fractions was relatively unaffected by the culture medium. In contrast, the lipid composition ofCandida steatolytica20C was strongly affected by the composition of the medium under conditions of nitrogen limitation and when starch was used as the carbon source, high levels of straight and branched hydrocarbons were observed. [Traduction de l'auteur]

ISSN:0008-4166    

DOI:10.1139/m85-117

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

Production ofD-amino-acid oxidase byTrigonopsis variabilishas been investigated using a two-stage cultivation technique. After transfer of exponentially growing cells to fresh medium, the enzyme was induced by addition ofD-amino acids to the growth medium, among whichD-methionine andD-alanine were the most effective. The simultaneous presence of theLform of amino acids ordid not affect this induction. The presence of trace metals, inorganic phosphate, and a high rate of agitation were necessary for formation of maximalD-amino-acid oxidase activity. The enzyme is not subject to glucose repression.

ISSN:0008-4166    

DOI:10.1139/m85-118

出版商:NRC Research Press    

年代:1985

数据来源: NRC

摘要:

To obtain information on the route(s) of ammonium assimilation inStreptomyces venezuelae, cell suspensions transferred to fresh medium lacking nitrogen were pulsed with [15N2]ammonium sulphate. Cells and extracellular fluids were examined by nuclear magnetic resonance and amino acid analysis to assess changes in amino acid pools and the disposition of [15N]ammonium. Following addition of [15N]ammonium, glutamate–glutamine pools of low cell density replacement cultures expanded rapidly and became progressively labelled with15N, whereas the alanine pool size increased much more slowly and became labelled with15N to a much lesser extent. These results are consistent with the assimilation of ammonium via glutamate dehydrogenase or glutamine synthetase – glutamate synthase rather than alanine dehydrogenase. Under anaerobic conditions,S.venezuelaeassimilates ammonium into alanine rather than glutamate–glutamine. Alanine dehydrogenase may thus function as a vehicle to regenerate NAD+to maintain substrate-level phosphorylation during periods of anaerobiosis.

ISSN:0008-4166    

DOI:10.1139/m85-119

出版商:NRC Research Press    

年代:1985

数据来源: NRC