摘要:

During 6-day exposures of cells ofSaccharomyces cerevisiaeto acetate sporulation medium, the content of free amino acids declined to approximately one-third of that of vegetative cells, but proline was exceptional in that it increased conspicuously in amount. The content of combined amino acids also diminished to about one-third, ammonia was evolved, and amino acids (not including proline) passed out of the cells into the medium. When dihydroxyacetone replaced acetate in the sporulation medium, the results were similar except that the decline in content of free and combined amino acids was much greater, more ammonia was evolved, and only very small amounts of amino acids could be detected in the medium. Transfer of sporulated cells to growth medium led to an increase in the pool of free amino acids, except for proline, which declined in amount.In two other species ofSaccharomycesthe free proline content also increased on exposure to sporulation medium, but inSchizosaccharomyces pombeandTorulopsis famatano such increase was observed.

ISSN:0008-4166    

DOI:10.1139/m64-082

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

WhenMicrococcus violagabriellaewas grown in the presence of 0.01 Mcresol, it elaborated a brown pigment which diffused readily into the medium. This pigment was purified and compared with the normal, red, insoluble iron-containing pigment of this organism, as well as the brown pigments, which have been designated as bacterial melanins, isolated from two melanogenic strains ofPseudomonas aeruginosa. The pigment from the inhibitedM.violagabriellaeresembled those from theP.aeruginosastrains, and melanins of other forms, with regard to absorption spectra, reduction of ammoniacal AgNO3, and susceptibility to bleaching by H2O2. Unlike thePseudomonasstrains,M.violagabriellaerequired iron for pigmentation, although iron was not incorporated into the pigment, but lacked the ability to produce pigment from either tyrosine or dihydroxyphenylalanine. As a result, theMicrococcuspigment is considered to be an alternate end product of normal pigment synthesis rather than a melanin, and the inhibition by cresol is validated as a tool for the study of normal pigment biosynthesis inM.violagabriellae.

ISSN:0008-4166    

DOI:10.1139/m64-083

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Airborne yeasts were trapped on agar surfaces of Petri plates at fruit and vegetable sites in the Niagara region during four growing seasons and occasionally in winter. Yeast isolates were screened for several characteristics and potential usefulness in the wine industry. Airborne fungi outnumbered yeasts about 20:1. The majority of yeasts (75%) belonged to the Cryptococcaceae, mainlyTorulopsis,Cryptococcus, andKloeckera. Ascigerous yeasts (25%) were trapped less frequently.Saccharomycesspp. were obtained mostly at or after fruit harvests, at other times rarely. Of 968 isolates screened, 71 were of potential commercial value for wine or other beverage production.

ISSN:0008-4166    

DOI:10.1139/m64-084

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A method has been developed for the quantitative analysis of sugars and polyols accumulated in the mycelium of fungi. The constituents of the neutral, water-soluble material extracted from the cells with hot water were separated as their borate complexes on a column of strongly basic anion exchange resin. Alternate fractions were analyzed for sugars and the rest for polyols. The separation of polyols on a sulphonic acid type of cation exchange resin was also examined.Cultures of two strains ofClaviceps purpureagrown on a variety of nutrient media always stored trehalose and mannitol in the mycelium. The accumulation of other carbohydrates depended upon the medium in which the fungus was grown and the strain used.

ISSN:0008-4166    

DOI:10.1139/m64-085

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Production of the red insoluble pigment byMicrococcus violagabriellaewas studied. Pigmentation was found to require oxygen and high levels of iron and to be stimulated by tryptophan alone among the amino acids. The pigment was isolated, purified, and analyzed chemically and spectrophotometrically. It was found to be similar to pulcherrimin fromCandida pulcherrima. Immunological cross reactivity and analysis of derivatives confirmed the similarity between the bacterial and yeast pigments. From these data it is postulated that the pigment is an iron chelate of pulcherriminic acid with an associated low molecular weight peptide moiety with glycine as the sole N-terminal amino acid. The pigment appears to differ from that ofC.pulcherrimasolely with respect to this peptide and in the mode of aggregation of the molecule.

ISSN:0008-4166    

DOI:10.1139/m64-086

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Soils incubated with C14-labelled acetate for 6 to 9 hours showed that 22–30% of the acetate was oxidized to CO2. Fractionation of the soil revealed that the radioactivity of the remaining substrate was widely distributed in various fractions. Greatest activity was noted in the acid hydrolyzable humin fraction (50%) with lesser amounts (5–10%) being recovered in the fulvic acid and alcohol extract. Hymatomelanic acid, α-humus, and β-humus contained only traces of activity.Ion-exchange separation of the acid hydrolysate of the humin fraction indicated that a considerable portion of the activity was associated with an unidentified compound which had certain characteristics of itaconic acid. Radioactivity was also found to be present in the 15 amino acids identified.

ISSN:0008-4166    

DOI:10.1139/m64-087

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

The gamma irradiation resistant mutants ofEscherichia coliwere indole negative. They did not produce mucoid or slime material in Endo"s agar. A marked variation was noted in the rates of growth of the resistant mutants under shaking and stationary conditions of culture. The mode and rate of utilization of specific carbohydrate substrates by a strain highly resistant to gamma irradiation (12γ) differed from that of the parent (P) strain. The 12γ resting cell suspensions exhibited no respiration on lactose, but substantial activity on glucose and succinic acid. The DNA and RNA contents per parent and 12γ cell were the same. The possible sites of inactivation are discussed.

ISSN:0008-4166    

DOI:10.1139/m64-088

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Three species of bacterium-feeding nematodes,Caenorhabditis briggsae,Rhabditis oxycerca, andPanagrellussp. were lysed by two out of three soil isolates of myxobacters in liquid and agar medium.Aphelenchus avenue, a fungus-feeding nematode andHeterodera trifolii, a cyst-forming plant parasite, were unaffected by the myxobacters. Lysis of the nematodes was also shown spectrophotometrically by the decrease in optical density of a nematode homogenate following addition of an enzyme concentrate from a cell-free fluid culture of one of the myxobacters, and by the increase in trichloracetic acid soluble tyrosine residues in the mixture after 15–20 minutes incubation. The enzyme concentrate could be separated into a "lytic" fraction that dissolved the nematodes and a "proteolytic" fraction that did not.

ISSN:0008-4166    

DOI:10.1139/m64-089

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Cultures ofStreptomycessp. 3022awere grown in the presence of C14-labelled substrates and incorporation of radioactivity into chloramphenicol measured.D-Glucose, labelled in carbons 1 or 2 or uniformly, was an efficient precursor of thep-nitrophenylserinol moiety and of the phenylpropanoid amino acids of the mycelium. The distribution of label in the ring and side-chain carbon atoms ofp-nitrophenylserinol and cellular phenylalanine from experiments in which glucose-1-C14, glucose-2-C14, and glycine-2-C14were fed provided evidence that the two phenylpropanoid systems had a common biosynthetic origin. The results were also consistent with their formation via the shikimic acid – prephenic acid route. Uniformly C14-labelled shikimic acid, though poorly utilized by this organism, was incorporated selectively into both the aromatic portion of chloramphenicol and the aromatic amino acids in the mycelium.L-Phenylalanine-U-C14,L-phenylalanine-carboxyl-C14,L-tyrosine-carboxyl-C14,DL-p-hydroxyphenylserine-2-C14, and acetate-2-C14were poor precursors of thep-nitrophenylserinol moiety. Since phenylalanine and tyrosine were incorporated into the mycelium the biosynthetic route to the phenylpropanoid portion of chloramphenicol evidently does not pass through either of these amino acids but branches at an earlier step.

ISSN:0008-4166    

DOI:10.1139/m64-090

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

After ultraviolet light irradiation, strain 6464 ofBacillus cereuslysed, resulting in the release of toxin, phospholipase, and mature phage particles. Small amounts of toxin and phospholipase produced by non-induced cultures were correlated with the infrequent spontaneous release of bacteriophage. Stationary incubation following ultraviolet induction results in a greater yield of toxin and phospholipase than post irradiation incubation on a shaker. Postirradiation incubation at temperatures below 37° either reduced (30°) or prevented (26°) toxin and phospholipase production. A clone was obtained which was sensitive to the phage from the parent strain and was presumably no longer lysogenic for it. This cured strain still exhibited ultraviolet-induced optical density decline accompanied by release of toxin and phospholipase. Mitomycin C would induce strain 6464 and the cured strain derived from it and both released toxin and phospholipase during mitomycin C induced lysis. The induced lysis of the cured strain could be prevented by postinduction treatment with inhibitors of synthesis of protein (chloramphenicol), RNA (actinomycin D), or DNA (5-fluorouracil deoxyriboside).

ISSN:0008-4166    

DOI:10.1139/m64-091

出版商:NRC Research Press    

年代:1964

数据来源: NRC