摘要:

Metabolites formed by the equivalent of 230 to 3000 cells of severalClostridiumspecies were detected by use of a gas chromatograph fitted with an electron capture detector. A variety of organic acids, alcohols, and ketones were produced by growing cultures of the 10 species tested. Compounds excreted by 300 to 3000 cells of 12 strains ofClostridium perfringenswere detected, and both common and dissimilar metabolites were formed by these strains. The sensitivity for detecting sixClostridiumspecies increased up to several thousandfold when chlorophenoxyacetates were added to the medium, the increase being most marked with 2,4-di- and 2,4,5-trichlorophenoxyacetates. The results show that cometabolism is useful in increasing the sensitivity and speed of detection ofClostridiumspecies.

ISSN:0008-4166    

DOI:10.1139/m72-232

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Respiration rates were measured and respiratory quotients (RQ) were calculated for sexually reproducing and nonreproducing cultures ofGlomerella magna. Oxygen uptake per unit of extractable protein by reproducing cultures was fairly constant until day 7 when it increased markedly as the sexual structures were being differentiated. Oxygen uptake by nonreproducing cultures was highest on days 2, 3, and 4 while initiation of sexual reproduction by exposure to light was still possible. RQ values of reproducing cultures were constant at about 0.85, while the nonreproductive cultures reached a maximum of 1 by day 4 and then declined with culture age to 0.47. The isozymes of peroxidase ando-diphenol oxidase were similar in reproducing and nonreproducing cultures. One "tyrosinase" band and one "laccase" (p-diphenol oxidase) band were observed with tyrosine andp-phenylenediamine as the substrates. Isozymes of peroxidase or diphenol oxidase exhibited different substrate specificities.

ISSN:0008-4166    

DOI:10.1139/m72-233

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Staphylococcus aureusandPseudomonas aeruginosaare often found in succession or in association in infections. To study experimentally their interactions, we have used systems of growth or survival of mixed cultures of both species in vitro in a semisynthetic medium and in vivo in the peritoneal cavity of mice. Conditions for maximum growth in vitro of both species in mixed cultures are about similar to those in pure culture when the pH is maintained between 6.0 and 7.3. The inhibition ofS.aureusgrowth by some antimetabolites or antibiotics, e.g., 5-methyltryptophan andD-cycloserine, is antagonized in mixed cultures.Staphylococcuscoagulase, DNase, and alpha toxin were present either in mixed cultures or after mixing pure culture supernatants of both species, butP.aeruginosaslime was not observed in these conditions. In vivo, the survival ofS.aureusseemed greater in mixed infections withP.aeruginosathan in those withS.aureusalone. In our systems,S.aureusmay have benefited from the presence ofP.aeruginosawhereas the reverse was not observed. These observations on interbacterial ecology could help to explain the importance and the behavior of some species at the initiation of pyogenic infections, either their interactions or their selection.

ISSN:0008-4166    

DOI:10.1139/m72-234

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

A strain ofPenicillium lilacinum, isolated from soil, produced pustulanase, β-(1 → 3)-glucanase, (EC. 3.2.1.6) and cellulase (EC.3.2.1.4) when cultivated on a medium containing pustulan as the sole source of carbon. If pustulan was replaced by ketopustulan, the production of pustulanase was stimulated about 10-fold although the amount of stimulation was dependent on the degree of oxidation of pustulan. β-(1 → 3)-Glucanase production was stimulated slightly by ketopustulan; however, the degree of oxidation did not affect significantly the yield of this enzyme. Cellulase production was either unaffected by the oxidized polymer, or at higher degrees of oxidation, decreased. Tween 80 stimulated the production of the three enzymes in media containing ketopustulan with a low degree of oxidation but was inhibitory to pustulanase and cellulase production in media containing ketopustulan with a high degree of oxidation. A combination of gel filtration and isoelectric focusing revealed that each enzyme activity was attributable to at least two proteins.

ISSN:0008-4166    

DOI:10.1139/m72-235

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Bacteriolytic activity and its relationship to the level of immunoglobulins, complement, lysozyme, and transferrin was measured in 20 pairs and bactericidal activity in 6 pairs of maternal and cord serum.Escherichia coliLilly, an organism easily lysed by normal human serum and four other Gram-negative bacteria were used.Cord sera invariably had lower bacteriolytic and bactericidal activity than their corresponding maternal sera. No statistically significant relationship between these activities and the level of immunoglobulins, complement, lysozyme, or transferrin was detected. A higher level of lysozyme was unable to compensate for the lower levels of other factors in the cord sera.

ISSN:0008-4166    

DOI:10.1139/m72-236

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Many tree seedlings for reforestation are now being produced in small discreet containers. On these seedlings, losses and stunting from root pathogens occur widely and unpredictably. Some myxobacteria of the groupCytophagawhich produce powerful extracellular proteolytic and chitinolytic enzymes were introduced into fumigated or non-fumigated peat before or after sowing seeds of four species of conifer. They actively colonized the rhizosphere of the developing seedlings without affecting seedling development. In subsequent inoculation tests with pathogenic fungi, there was significantly less mortality, chlorosis, and stunting, than in checks without myxobacteria.

ISSN:0008-4166    

DOI:10.1139/m72-237

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Two avirulent clones ofAgrobacterium tumefacienswhich appeared spontaneously during culture are indistinguishable from the parental strains from which they were derived with respect to either sensitivity to the bacteriophages tested or the production of phages during growth. One attenuated clone, isolated after treatment of the virulent B6 strain with proflavin is able to induce limited proliferations in infected tissues that do not progress into visible tumors. These proliferations do not respond to exogenous auxin. Tumors appearing in decapitated pea seedlings inoculated with the attenuated clone after infection by virulent bacteria are larger than those of seedlings inoculated only with virulent bacteria. When introduced into tissues before virulent bacteria, attenuated bacteria inhibit tumor formation. Like the parental strain, the attenuated clone is lysogenic for phages inducible by ultraviolet irradiation and also by conditions within host tissues.

ISSN:0008-4166    

DOI:10.1139/m72-238

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The phospholipid fraction of the yeastH.wingeiwas studied by a combination of DEAE-cellulose column chromatography and thin-layer chromatography. Phosphatidyl choline, phosphatidyl serine, and phosphatidyl ethanolamine were identified. The absence of phosphoinositide was noted. An unknown acidic phospholipid accounts for less than 1% of the total phosphorus. A cerebroside or cerebroside-like compound was provisionally identified.

ISSN:0008-4166    

DOI:10.1139/m72-239

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The lipids from conidia ofAspergillus nigerwere extracted and identified. The polar lipid content was higher (54.3%) than the neutral lipid fraction (45.7%). The major fatty acids present were C16:0, C18:0, C18:1, and C18:2. The amount of unsaturation in total fatty acids (62%) was higher than the unsaturation in the polar lipids (35%). Freeze-etched replicas of dormant conidia revealed the presence of lipid bodies.

ISSN:0008-4166    

DOI:10.1139/m72-240

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The intestinal microflora of two distinct populations of glaucous-winged gulls (Larus glaucescens) was examined both qualitatively and quantitatively. The constant presence ofEscherichia colitype I,Clostridium perfringens, andStreptococcus faecaliswas demonstrated. The number of microorganisms of these normal indicators of fecal pollution of water was sufficiently great to suggest that more attention must be given to the contamination of water supplies by this bird.

ISSN:0008-4166    

DOI:10.1139/m72-241

出版商:NRC Research Press    

年代:1972

数据来源: NRC