摘要:

An examination has been made of the effect which temperature of solubilization has upon the subsequent migration in SDS–polyacrylamide gel electrophoresis of proteins from the cell envelopes ofEscherichia coliK12 andNeisseria siccaATCC 9913. Conventional electrophoresis in tubes revealed substantial differences in the staining patterns of gels, depending upon whether the envelope samples were solubilized at 37 °C or 100 °C; in the case ofN.siccaat least 6 of 13 discernible bands displayed heat-modifiable behavior. The relationship of the bands produced by each of the two temperatures was investigated by a two-dimensional electrophoresis procedure, in which a sample was solubilized at 37 °C and run in a usual cylindrical gel; the entire gel was then resolubilized at 100 °C, and laid along an acrylamide slab for electrophoresis in the second dimension.It was found that "free endotoxin" of both organisms examined contained the same major proteins as the total envelope fraction, and that these free endotoxin proteins showed the same heat-modifiable properties as when present in total envelopes.

ISSN:0008-4166    

DOI:10.1139/m76-011

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Multicelled conidia ofStemphylium sarcinaeformegerminate in water forming several germ tubes. Individual cells within conidia are connected by pores which are plugged in ungerminated conidia and open in germinated ones. During germination, vacuoles enlarge, endoplasmic reticulum profiles increase in number, and mitochondria change from spherical to elongate. The germ tube wall is laid down at the site of emergence from the conidium. Shortly after germination, a septum with a central pore forms where the germ tube emerged. The germ tube wall is surrounded by a fibrillar sheath. Lipid bodies are closely associated with vacuoles during germination. The ultrastructural location of lipid was found by extraction of conidia with lipid solvents. Total lipid decreases from 14.4% of the dry weight of ungerminated conidia to 13.4% of the dry weight of conidia germinated for 10 h. No qualitative changes occurred in the major lipid classes of conidia during germination. The activities of lipase and acid phosphatase were detected in ungerminated and germinated conidia.

ISSN:0008-4166    

DOI:10.1139/m76-012

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

An electron microscopic study of the morphology ofHerpesvirus macaca, a serologically distinct infectious agent isolated from the leukocytes of rhesus monkeys, was performed. WI-38 fibroblast monolayers were infected with the virus and examined 18 days later. The morphology ofHerpesvirus macacawas, in general, typical of the herpesvirus group. Enveloped virus particles observed via negative-stain technique had a diameter of 145–155 nm. An inner capsid composed of hexagonal capsomeres had a diameter of 100–110 nm and surrounded a central core. While enveloped forms appeared to be present within the nuclei of infected cells, they were not found in the cytoplasm except within vacuolar structures. Associated changes were found in the morphology of infected cells, including intracytoplasmic myelin figures.

ISSN:0008-4166    

DOI:10.1139/m76-013

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Incubation of 4′-chloro-4-biphenylol with a mushroom tyrosinase preparation gave the catechol, 4′-chIoro-3,4-biphenyldiol as the sole in vitro metabolite. This compound was identical with the major rat urinary metabolite of 4′-chloro-4-biphenylol and thus confirms the structure assigned to the metabolite. This result also demonstrates a possible degradation pathway of hydroxylated chlorobiphenyls which are themselves the major metabolic degradation products of polychlorinated biphenyls.

ISSN:0008-4166    

DOI:10.1139/m76-014

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Cooling and warming rates affect bacterial survival profoundly with all bacteria tested (Azotobacter chroococcum,Klebsiella aerogenes,Salmonella typhimurium,Pseudomonas aeruginosa,Streptococcus faecalis) behaving similarly. Most bacteria were sensitive to salt on freezing and thawing. Viabilities of population frozen and thawed in saline were always less (by at least 20%) than comparable ones frozen in water alone. Under these conditions,S.faecaliswas resistant to the presence of sodium chloride; viabilities of populations frozen in the presence or absence of sodium chloride were always less than 5% different. The implications of these results in light of the organisms' shape, Gram stain, and respiration are discussed.

ISSN:0008-4166    

DOI:10.1139/m76-015

出版商:NRC Research Press    

年代:1976

数据来源: NRC

摘要:

Activities of enzymes which mediate the oxidation of thiosulfate to sulfate and the assimilation of sulfate to sulfide were assayed in various cell-free fractions ofThiobacillus ferrooxidansgrown autotrophically on either ferrous iron or thiosulfate or heterotrophically on glucose. There was no activity of the thiosulfate-oxidizing enzyme in extracts of bacteria grown with ferrous iron. Comparable activities for ATP-sulfurylase (EC 2.7.7.4), ADP-sulfurylase (EC 2.7.7.5), and adenylate kinase (EC 2.7.4.3) were found in the bacteria grown autotrophically with either Fe2+or S2O32−or heterotrophically with glucose.

ISSN:0008-4166    

DOI:10.1139/m76-016

出版商:NRC Research Press    

年代:1976

数据来源: NRC