摘要:

Entamoeba invadensin chick embryos, incubated at 30 °C, invaded and produced changes in the liver. The embryos did not survive more than six days at 30 °C. after inoculation of the fluid medium, with or withoutE.invadens, and the inoculated amoebae did not survive the death of the embryo.

ISSN:0008-4166    

DOI:10.1139/m56-001

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A virus that lysed its homologous culture was obtained in 20 out of 29 attempts by inoculating wheat with different cultures ofXanthomonas trifolii. Each virus lysed, in addition, certain but in no case all other cultures. A composite virus-filtrate lysed all 29 cultures and 157 of 191 additional isolates obtained from various kinds of cultivated seeds. It did not lyse any of the 18 cultures ofX.translucensnor any of 17 other recognized species or subspecies.

ISSN:0008-4166    

DOI:10.1139/m56-002

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

In response to a need for an actinomycete plating medium that would effectively inhibit fungi, two substances were tested — sodium propionate and the antibiotic cycloheximide (Acti-dione). Cycloheximide proved superior to the propionate. Five micrograms of cycloheximide per ml. of agar medium greatly reduced radial growth of fungal colonies, 40 μgm. almost completely prevented fungal growth, yet even 100 μgm. showed no inhibition of any of 85 actinomycete cultures isolated from agricultural and forest soil on media free of inhibitor. The concentration selected as most suitable for routine use was 40 μgm. of cycloheximide per ml. of agar medium, added just prior to the pouring of the plates.

ISSN:0008-4166    

DOI:10.1139/m56-003

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The utilization of desoxyadenylic, desoxyguanylic, and thymidylic acid phosphorus byE.colihas been studied. Under comparable conditions phosphate is utilized from the three nucleotides at about the same rate. The rate of uptake is independent of nucleotide concentration, up to about 15 μgm. of nucleotide per ml., but markedly dependent on the inorganic phosphate concentration of the medium.E.colican split off thymidylic acid phosphorus and release it into the medium as inorganic phosphate. Phosphate taken up from thymidylic and desoxyadenylic acids is distributed uniformly over the nucleotides of bacterial RNA and of DNA. It is concluded that nucleotide phosphate is assimilated exclusively as inorganic phosphorus.

ISSN:0008-4166    

DOI:10.1139/m56-004

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A number of carbohydrates and nitrogenous adjuncts were tested for their effect on the constitutive and adaptive pentosanases produced byBacillus stibtilisandB.pumilusrespectively in a medium containing biotin, ammonium phosphate, and other mineral salts.B.subtilisproduced more enzyme with sulphite liquor than with any of the other carbohydrate sources tested. Next, in decreasing order of merit, were wheat bran, maltose, ribose, beet molasses, oat hulls, and pectin. Of the nitrogenous adjuncts tested, corn steep liquor, soybean meal, gelatin, gelysate, and ammonium lactate doubled the yield of enzyme whereas yeast extract, peptone, urea, and others were less effective. ForB.pumilusthe better carbohydrate sources, in decreasing order of merit, were wheat bran, water soluble pentosan of wheat flour, xylan, straw holo-cellulose, wheat straw, and sulphite liquor. Of the nitrogen sources, corn steep liquor was outstanding while casein, casitone, phytone, yeast extract, distillers' dried solubles, and soybean meal followed in decreasing order. A medium containing 6% wheat bran (20 mesh), 1% corn steep liquor neutralized with ammonia, 0.05% sodium chloride, and 0.05% calcium carbonate was devised for the production of pentosanase byB.pumilus. With this medium in shaken Erlenmeyer flasks, the enzyme was produced at a high rate between 12 and 40 hr.; thereafter the rate of production decreased. Maximum yields were obtained in 96 hr. A temperature of 26 °C. was more favorable for pentosanase production than higher temperatures.

ISSN:0008-4166    

DOI:10.1139/m56-005

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The bacteriophage pattern of 24 classified acid-fast microorganisms is presented and compared to that of a group of unclassified mycobacteria isolated from tuberculous patients. Of 33 unclassified acid-fast cultures studied 24 (73%) were typed satisfactorily; these comprised 93% of the cultures isolated from gastric lavage, 75% of those isolated from urine, and 29% from sputum. The majority of these fell into aMycobacterium smegmatisphage pattern.

ISSN:0008-4166    

DOI:10.1139/m56-006

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

An agar diffusion cup assay method for candidin is described. Some conditions of the assay medium affecting growth rate of the test organism and diffusion rate of candidin are presented. Critical steps of the procedure were tested statistically for significant variation and found acceptable. Both the sodium salt and Zwitterionic forms of candidin can be assayed.

ISSN:0008-4166    

DOI:10.1139/m56-007

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Fermentations of cellulose were carried out using rumen microflora. Butyric, propionic, acetic, and traces of formic acids were produced from the cellulose fermented. When peptone was present and the pH of the mash was maintained at 6.5 and the end products of fermentation were removed continuously by a dialysis ion exchange system, 84% of a 4.12% cellulose suspension was fermented in 72 hr. at 40 °C. Fermentations using rumen organisms might become a means of utilization for low forms of wood waste.

ISSN:0008-4166    

DOI:10.1139/m56-008

出版商:NRC Research Press    

年代:1956

数据来源: NRC

ISSN:0008-4166    

DOI:10.1139/m56-009

出版商:NRC Research Press    

年代:1956

数据来源: NRC