摘要:

In the commercial production of rennet extract, calves' stomachs are soaked in brine tanks held at a low temperature. Unless special precautions are taken, a heavy scum forms on these tanks. Salt tolerant yeasts of the genusDebaryomyces, which grow well at low temperatures, are chiefly responsible for this scum from whichD.tyrocola, originally isolated from cheese, andD.Guilliermondi, originally isolated from sausages, were isolated. Attempts to isolate these species from the contents of a calf's stomach, salted calves' stomachs, dried calves' stomachs, and soil were unsuccessful. These species did not grow in a medium containing 20% sodium chloride, nor in one in which the pH had been lowered to 2.0.

ISSN:1923-4287    

DOI:10.1139/cjr42c-005

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

The nitrates in pot cultures of gray wooded soil were generally affected by the various amendments as follows: increased by applications of neutral or acid subsurface peat and not depressed by neutral or acid surface peat; increased by ammonium phosphate alone and in combination with the surface and subsurface peats, and by ammonium sulphate in combination with the subsurface peats, but slightly depressed by triple superphosphate in combination with the subsurface peats.The wheat crop yields in pot cultures of gray wooded soil were generally affected by the various amendments as follows: increased somewhat by peat alone, and especially by subsurface peat; increased substantially by ammonium phosphate alone, but increased to a greater extent in all three series by a combination of ammonium phosphate and subsurface peat; increased substantially by ammonium sulphate and subsurface peat, but not by triple superphosphate and peat.The plate counts of bacteria in treated cultures of gray wooded soil increased for two to four months, and then decreased. The ammonium phosphate plus subsurface peat treatment gave the highest counts, the ammonium phosphate plus surface peat the second highest, and the ammonium sulphate plus subsurface peat the third highest. The differences between the effects of triple superphosphate plus subsurface peat, ammonium phosphate, surface peat, and subsurface peat, were small. The control gave only a small increase during the course of the experiment.The ratio method showed that there are very large numbers of bacteria in gray wooded soil. Instead of ranging from about 500,000 to about 8,000,000 per gm. of soil as with the plate count method, the numbers varied from about 200,000,000 to 2,000,000,000. The numbers reached a maximum after three months' incubation. The ammonium phosphate plus subsurface peat treatment again gave the highest average number, and the succeeding order was also about the same as in the case of the plate counts.When mixed with gray wooded soil, surface peat, though highly carbonaceous, did not cause any significant decrease in nitrate at first, and produced some increase later. Straw caused some decrease at first, but the later recovery counterbalanced this loss. Cotton caused a decrease to practically none for about three months, and even when combined with ammonium phosphate caused some decrease. Ammonium phosphate alone and in combination with straw and surface peat produced large increases in nitrate. In a duplicate experiment with black soil the trends were similar, but the nitrate was not reduced to the same extent by straw and cotton, and when ammonium phosphate was added with the organic matter, nitrate was not reduced by peat, straw, or cotton.

ISSN:1923-4287    

DOI:10.1139/cjr42c-006

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

Cuttings of feed grasses less than 7 in. high, taken from the same field and given the same treatment, were found to vary considerably in carotene content. Factors that were found to contribute to these variations were: the amount of sunshine and rain prior to each cutting, the height of the cutting, and the manner of storage. Higher carotene content was found when the cuttings were taken following periods of increased daily sunshine particularly if these periods were preceded by rain. Cuttings less than 7 in. high contained larger amounts of carotene than did 12 in. cuttings. Storing the ground, dehydrated feed grasses in 100-lb. paper-lined burlap sacks at 35° F. during the summer months reduced the average loss in carotene content to 7.5%.

ISSN:1923-4287    

DOI:10.1139/cjr42c-007

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

Two species of osmophilic yeasts, previously described but not named, have been designated respectivelyZygosaccharomyces nectarophilusLochhead and Farrell andZygosaccharomyces rugosusLochhead and Farrell.

ISSN:1923-4287    

DOI:10.1139/cjr42c-008

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

The mycelium ofNeurospora tetraspermareadily conducts an electric current. During the time an electric current of about 5 μa. is allowed to pass through cultures ofN.tetraspermaorGelasinospora tetrasperma, mycelial growth ceases almost entirely, but afterwards the fungi grow normally again and show no ill effects. Electric currents of the order of 1 or 10 μa. running in either direction through two fused strains ofN.tetraspermado not alter the normal direction of nuclear migration from one strain to the other.

ISSN:1923-4287    

DOI:10.1139/cjr42c-009

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

An ultra-violet spectrographic method has been developed for estimating the amount of sodium lignosulphonate present in solutions. The method has been applied to the measurement of lignosulphonate losses in liquid media after fungous growth and the results are compared with those obtained under similar conditions by the β-naphthylamine precipitation method. The spectrographic method gave slightly lower values but was free from certain errors present in the chemical method. The results confirmed previous observations that fungi are capable of decomposing lignosulphonates.

ISSN:1923-4287    

DOI:10.1139/cjr42c-010

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

About 160 Chinese spring wheats and a number of Chinese winter wheats were tested in the seedling stage in the greenhouse to determine their reaction to eight physiologic races of stem rust (Puccinia graminis Tritici) and to four physiologic races of leaf rust (Puccinia triticina). The spring wheats were also subjected, in the field, to epidemics of stem rust and leaf rust in which a large number of physiologic races of each rust were employed. The wheats were classified as one or another of the following species:Triticum vulgare,T.compactum,T.durum, andT.turgidum.By means of these tests, it has been demonstrated that the Chinese wheats are rather highly susceptible to the physiologic races of stem rust prevalent in North America. Many of the wheats showed, however, considerable resistance to leaf rust in both the greenhouse and the field tests. Varieties resistant to leaf rust were present in all of the four above-mentioned species.Seventy-five lines of Canadian spring wheat derived from a cross between Renown Selection, which is resistant to stem rust and moderately resistant to leaf rust, and Garnet, which in North America is resistant to stripe rust (Puccinia glumarum), were tested in the seedling stage in the greenhouse for their reaction to stripe rust. Two physiologic races (race 6 and race 13) were used in these tests. The same lines were subjected to rust epidemics in the field to determine their resistance to stem rust and leaf rust. Several of these lines were found to possess resistance to all three rusts. These lines may prove valuable breeding material in case it is desired to develop by breeding methods Chinese varieties resistant to all three of these rusts.

ISSN:1923-4287    

DOI:10.1139/cjr42c-011

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

Full length Norway spruce cuttings, with and without a heel of old wood, were collected from the lower part of the tree at semimonthly intervals from July to October and were propagated in several media in outside frames.Plain cuttings generally rooted better than cuttings with a heel of old wood, as judged by percentage rooted and the number and lengths of root. Heels, however, for'summer collections favoured survival and rooting in sand, and root length in sand–peat. In several experiments involving early spring collections propagated in sand, the presence or absence of heels had little effect on the responses of the cuttings.A late October collection involved six types of plain cuttings taken from the lower part of the tree and propagated in two different sand–peat media. In sedge peat medium there was little difference in the rooting of second order terminal, second order large lateral, second order small lateral, or third order lateral cuttings, the average rooting being 90%. Third order lateral cuttings showed an inferior development of new growth. The percentage of first order terminal cuttings rooted was 67%; these had markedly superior new growth development; when shortened, only 32% of such cuttings rooted. Irregular differences between the types of cutting occurred in the inferior sphagnum peat medium.

ISSN:1923-4287    

DOI:10.1139/cjr42c-012

出版商:NRC Research Press    

年代:1942

数据来源: NRC