摘要:

Aspergillus flavusproduces an inducible esterase that hydrolyzes the depside, 2-(3′,4′-dihydroxybenzoyloxy)-4,6-dihydroxybenzoic acid. The activity of this enzyme may be followed by measurement of the rate of production of protocatechnic acid, which reacts with alkaline potassium ferricyanide to give a product with an absorption maximum at 540 mμ. Synthesis of the esterase is induced when the organism is grown on rutin, robinin, hyperosid, kaempferol, rhamnetin, myricetin, quercetin, and fisetin, but not when grown on apigenin, galangin, glucose, naringenin, morin, rhamnose, robinetin, or taxifolin. The esterase has been partially purified and separated from the rutinase and quercetinase enzymes. The esterase is most active at pH 4.5. Eighty percent of the activity remained after holding the enzyme for 10 minutes at 60 °C. The enzyme readily attacked the depside linkages in tannic acid but did not hydrolyze common ester substrates such as ethyl butyrate.

ISSN:0008-4166    

DOI:10.1139/m63-087

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Chalcomycin, a new, slightly water-soluble, organic-solvent-soluble, neutral antibiotic containing only carbon, hydrogen, and oxygen was obtained from filtrates of two new strains ofStreptomyces bikiniensis. A paper-disk agar-diffusion assay, which employsSarcina luteaPCI 1001 W as the test organism, has been developed. The sensitivity range of the assay is 1–10 μg chalcomycin/ml. Shaken flask fermentations in a medium containing glucose, yeast hydrolyzate, and meat peptone have produced titers of 200 μg/ml. Chalcomycin is primarily active againstStaphylococcus aureus, including isolates resistant to various antibiotics, andStreptococcus pyogenes. In experimental mouse infections with various mouse-virulent strains ofS.aureus, a single dose of chalcomycin gave oral ED50values of 13 to 53 mg/kg and subcutaneous values of 8 to 47 mg/kg. AgainstS.pyogenes, oral and subcutaneous administration of a single dose gave ED50values of 88 and 55 mg/kg, respectively. Chalcomycin was well tolerated by mice, rats, dogs, and monkeys.

ISSN:0008-4166    

DOI:10.1139/m63-088

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

An open-type continuous-flow culture apparatus is described, with a working capacity of 500 ml culture. The glass culture vessel, of novel design, permits strict chemostat operation, and has the additional advantages of preventing wall growth, of operating without need for antifoam addition, and of growing filamentous microorganisms without plugging the apparatus. The agitation and mixing produce completely homogenous conditions in the culture; consequently representative sampling and product removal are obtained. Species of anaerobic and aerobic bacteria, yeasts, and micro- and macro-fungi have been grown in the apparatus, in runs which exceeded 4 months" duration. The apparatus is simple to use, reliable in operation, and suitable for wide laboratory use with non-pathogenic organisms.

ISSN:0008-4166    

DOI:10.1139/m63-089

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The growth response of a lecithin-deficient strain ofNeurospora crassato equimolar supplements of either choline or glycerophosphorylcholine is essentially the same. This is in contrast to the negligible stimulatory effect of phos-phorylcholine on growth of the same organism. The results of enzymatic and growth-response studies withNeurosporasuggest that glycerophosphorylcholine is available to the organism without prior hydrolysis by enzymes released into the culture medium.

ISSN:0008-4166    

DOI:10.1139/m63-090

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Certain preparations of alpha hemolysin induced dissolution of rabbit and sheep erythrocytes and hydrolyzed casein. Components which were independently hemolytic and proteolytic were separated by the following sequence of procedures: precipitation with zinc acetate and ethyl alcohol at approximately −5 °C and pH 4.0, ion exchange chromatography with carboxymethylcellulose, and zone electrophoresis with granules of potato starch. The comparative lytic activity of the hemolytic component against erythrocytes of the rabbit and of the sheep was 19:1. No separation could be effected between these two hemolytic properties.

ISSN:0008-4166    

DOI:10.1139/m63-091

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The utilization of starch, dextrin, inulin, and glycogen byA.clavatusDesmazieres,A.sclerotiorumHuber,A.indicusMehrotra and Agnihotri, andA.allahabadiiMehrotra and Agnihotri was studied through circular paper chromatography. These polysaccharides were evidently assimilated through transglycosidation. It was noticed that these fungi, during the process of utilization of these polysaccharides, produced some additional oligosaccharides some of which could not be identified.All four molds showed better growth on starch, dextrin, and glycogen than on glucose (final hydrolytic product of these polysaccharides); however, these organisms showed better growth on fructose than on inulin.

ISSN:0008-4166    

DOI:10.1139/m63-092

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Neutralization tests using antisera for 4 of 16Agrobacterium radiobacterphages indicated that all 16 phages belonged to one serological group. Within the group the phages were differentiated by the neutralization velocity constants, theK-values. Occasionally the antisera inactivated heterologous phages more rapidly than the homologous phages. With some systems the reactions were not of the first order throughout the course of neutralization. This anomaly in the kinetics was not due to hereditary antigenic inhomogeneity in the phage population, as indicated by curves obtained with the parent phage and with isolates which resisted neutralization. Adaptation of the phages to a heterologous host lowered the originalK-values with homologous antisera without a change in the host range. None of the four antisera neutralized any of five phages ofAgrobacterium tumefaciens, collectively lysing 16 strains ofA.radiobacter, including homologous hosts of the phages used in the immunizations.

ISSN:0008-4166    

DOI:10.1139/m63-093

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Analysis of hydrocyanic acid contents of the roots of six sorghum strains revealed the concentration to be high in the seedling, and that it reduced with age. Hydrocyanic acid was also present in the roots of ratoon plants but in lower concentrations than in seed plants of the same strain. Rhizosphere effects on the microbial populations at different stages of plant growth were observed and the effect varied with the strain and age of plant. The rhizosphere:soil (R:S) ratio for bacteria ranged from 1 to 25, for fungi 1 to 17, and for actinomycetes 1 to 6. The rhizosphere effect continued in the ratoon plants in all strains, though to a lesser extent than in seed plants. Statistical analysis of the data for correlation between hydrocyanic acid concentration in roots and the population of rhizosphere microorganisms did not indicate any uniform effect in all the sorghum strains.

ISSN:0008-4166    

DOI:10.1139/m63-094

出版商:NRC Research Press    

年代:1963

数据来源: NRC

ISSN:0008-4166    

DOI:10.1139/m63-095

出版商:NRC Research Press    

年代:1963

数据来源: NRC

ISSN:0008-4166    

DOI:10.1139/m63-096

出版商:NRC Research Press    

年代:1963

数据来源: NRC