摘要:

A methanol-utilizing organism identified as a strain ofPseudomonas methanicawas isolated. Methanol oxidation by extracts of the organism was shown to involve peroxidative oxidation of the alcohol to formaldehyde. A diphosphopyridine nucleotide dependent aldehyde dehydrogenase, specific for formaldehyde and requiring glutathione for activity, was demonstrated.

ISSN:0008-4166    

DOI:10.1139/m60-001

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

The solid content of several halophilic bacteria was estimated by immersion refractometry. Values for extreme halophiles ranged from 28 to 32%, and for moderate halophiles from 31 to 45%. The solid content of these organisms changed with variation in the salt content of the environment. It is thought that these differences are the result of changes in the water content of the cell. Spheres (spheroplasts) had a slightly lower solid content than the parent rods. Nuclear and other inclusion bodies, mostly of lower refractive index than the cytoplasm, were noted.

ISSN:0008-4166    

DOI:10.1139/m60-002

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

Tricholoma nudum, when grown on media containing sucrose, hydrolyzes this sugar and utilizes the glucose preferentially. Eighty to 85% of the fructose remains in the medium at the completion of glucose utilization. If the fermentation is stopped at this point the mycelium can be separated from the broth and the fructose recovered in crystalline form or as a syrup.

ISSN:0008-4166    

DOI:10.1139/m60-003

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

By the use of a simple device employing a source of U.V. light,Euglenacell suspensions were subjected to simultaneous mutagenic irradiation and selection against the ability to swim. Among the survivors, mutants with impaired motility predominated.

ISSN:0008-4166    

DOI:10.1139/m60-004

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

AStreptomycessp. (PRL 1642) was grown on a complex medium containing eitherDL-valine-1-C14,D-valine-1-C14, orL-valine-1-C14. The antibiotic isolated from the culture was identified as valinomycin and hydrolyzcd to giveL-valine,D-valine,D-α-hydroxyisovaleric acid, andL-lactic acid.L-Valine-1-C14in the medium was incorporated to an equal extent into theD-valyl andL-valyl portions of the antibiotic, to a lesser extent into theD-α-hydroxyisuvaleryl portion, and not at all into the lactyl portion. The C14was present only in the carboxyl groups of the labelled hydrolytic products of the antibiotic.D-Valine-1-C14in the medium was incorporated to only a slight extent into the antibiotic and mycelium.

ISSN:0008-4166    

DOI:10.1139/m60-005

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

Fifty-three strains of nonpigmented Gram-negative rods which failed to produce acid in Kligler's iron agar were studied. Detailed examination revealed that many strains had been incorrectly identified asAlcaligenes. Sixteen strains were identified asPseudomonas aeruginosa, and it was concluded that important identifying characteristics of this species are: (1) acid production from glucose, arabinose, and xylose, but not from lactose; (2) the ability to liquefy gelatin; (3) good motility and production of gaseous nitrogen in a motility–nitrate medium; and (4) a positive gluconate test. Thirty-seven strains appeared to be members of the genusAchromobacterand all produced acid from one or more carbohydrates. These strains were divided into three groups on the basis of (1) activity on gelatin, (2) nitrate reduction, and (3) motility. Some strains resembledPseudomonas aeruginosain such characteristics as reduction of nitrate to molecular nitrogen and oxidation of gluconate to 2-ketogluconate, but differed in that they neither liquefied gelatin nor peptonized and reduced litmus milk. More important, they had peritrichous flagella.

ISSN:0008-4166    

DOI:10.1139/m60-006

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

Forty strains of Gram-negative rods which resembledAlcaligenesin failing to attack carbohydrates were studied. Twenty-four strains had lophotrichous flagella, three were monotrichous, three were either lophotrichous or monotrichous, six were peritrichous, and four were nonflagellated. Strains were grouped by their action on gelatin and nitrate, and by motility. Most lophotrichous and monotrichous organisms liquefied gelatin, reduced nitrate, or did both, whereas most peritrichous and nonflagellated rods failed to do either.Serological studies indicated antigenic heterogeneity, but some strains in the more homogeneous physiological groups were related, mainly through flagellar antigens. Three phages were obtained without induction but only one of these was lytic for a single heterologous strain. Inducible substances resembling bacteriocines were elaborated by several strains, and the activity was confined primarily to homogeneous physiological and serological groups. Some lophotrichous strains closely resembled but were not identical with the genusLophomonas. The validity of the genusAlcaligenesis questioned, since few isolates resemble the original description (peritrichous flagella) and these could be included in the genusAchromobacter.

ISSN:0008-4166    

DOI:10.1139/m60-007

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

The indeterminate-growing synnema ofIsaria cretaceaarises from the vegetative mat when it is grown on No. IS-M synthetic medium. Synnemata development is not dependent upon the particular carbon or nitrogen source, or on the concentration of carbon, nitrogen, or phosphate of this medium. Development does require more exogenous biotin and thiamine than is required for maximal vegetative mat growth. Sucrose is a specific inhibitor of synnemata development and when it replaces the glucose of the medium the mat grows more profusely, the pH drops further, and synnemata do not appear. Addition of indoleacetic acid, which inhibits endogenous respiration ofI.cretacca, to the sucrose medium retards vegetative mat growth (primary vegetative growth) and initiates synnemata growth (secondary vegetative growth). Addition of calcium carbonate or phosphate buffer also results in the development of synnemata but does not retard vegetative mat growth. It was concluded that the synnema is the product of the change of the center of growth from the hyphal tips of the vegetative mat to the hyphal tips of privileged vertical hyphae. Efficient translocation and a potentiality for indeterminate growth would seem to be requirements for synnemata morphogenesis. Secondary growth ordinarily follows primary growth but the sequence can be interrupted if an exogenous nutrient favors either continued primary growth or rapid staling of the medium. The data suggested that the synnema was synthesized from endogenous nutrients and this conclusion was supported by the observation that synnemata readily developed from washed mycelium that had been placed in a nutrient-free moist chamber.

ISSN:0008-4166    

DOI:10.1139/m60-008

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

An electron microscopic study of thin sections of the tuberculate spores ofHistoplasma capsulatumis presented in which details of structure of the cytoplasm, cell border, and protruding tubercles as well as structural changes associated with growth and maturation of the spore are revealed. On the basis of the observations made on the fine structure, the mode of formation of the tubercles is considered.

ISSN:0008-4166    

DOI:10.1139/m60-009

出版商:NRC Research Press    

年代:1960

数据来源: NRC

摘要:

The effect on air-borne cells of single chemical compounds added to a bacterial suspension prior to atomization has been studied. It has been found that some amino acids, long chain protein degredates, some sugars and polyhydroxycyclohexanes can enhance the survival of air-borne cells. The ability of a compound to preserve viability during periods of desiccation has been found to be connected with the presence of an amino and/or secondary alcohol group. For maximal protection these groups need to be substituted onto a six-membered ring nucleus. The hydroxyl group has been found toxic if present on a benzene ring, but protective on a pyrimidine ring. Inositol was found to afford a large measure of stability to the air-borne cells and its stabilizing ability could be destroyed by urea and guanidine. It is suggested that compounds enhance survival by replacing water molecules in protein structure during desiccation through hydrogen bonding and so preserve the natural structure of the cellular proteins. Peaks in death rates at intermediate relative humidity levels have been found to be due to the presence of the added compounds.

ISSN:0008-4166    

DOI:10.1139/m60-010

出版商:NRC Research Press    

年代:1960

数据来源: NRC