摘要:

Pycnidiophora dispersaClum was isolated from jute and found to be a strong decomposer of this fiber, but not of pure cellulose. The effect of certain carbohydrates, nitrogen compounds, trace elements, and accessory growth factors as well as pH and temperature on the growth and perithecia formation of this fungus was studied. None of the carbohydrates tested gave appreciable growth or perithecia formation in liquid medium, but an initial low concentration of each produced both when tested on solid medium. Of the nitrogen compounds tested only peptone had any effect, which was probably caused by impurities. Pure vitamins and trace elements induced neither growth nor fruiting. Malt extract, yeast extract, and the culture filtrate of anActinomycessp. all stimulated growth and fruiting. The filtrate factor and malt extract factor were found to be insoluble in organic solvents, heat-resistant, and adsorbed by charcoal.

ISSN:0008-4166    

DOI:10.1139/m65-102

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Multiplication of bacteria grown in three different physical systems: basal liquid medium, medium plus agar in the sol state, and medium plus agar in the gel state, all at 39.94 ± 0.05 °C, revealed that the growth of organisms is strongly influenced by their microphysical environment. Not only was the final number of bacteria affected but their morphology was also changed. It is suggested that these effects may be due in part to a quasi-crystalline structure of the water around agar in the gel state which reduces the fluidity of the water, the distribution of the bacteria, and the mobility of nutrient ions.

ISSN:0008-4166    

DOI:10.1139/m65-103

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

In cultures ofPenicillium urticaeBainier, two successive physiological phases are distinguished. In the first, or trophophase, mycelial N, P, RNA, and —SH and the utilization of acetate for synthesis reach maximum values while glucose oxidation, mainly by the hexose monophosphate pathway, is most rapid. In the second, or idiophase, assimilation of N and P is reduced, RNA and —SH levels are lower, glucose is oxidized more slowly and mainly by glycolysis, fatty acids or mannitol accumulate, and special phenolic metabolites derived from 6-methyl-salicylic acid appear. The phase transition occurs sharply, with a minimum of respiratory activity and of acetate utilization; thereafter the pattern of secondary metabolism is established in a stepwise manner. The observations are interpreted in terms of sequential enzyme induction initiated by metabolic dislocation, and the generalized applications of such an hypothesis are considered.

ISSN:0008-4166    

DOI:10.1139/m65-104

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Spores of the insect pathogenBacillus popilliaeDutky have been formed in vitro from vegetative cultures. The procedure results reproducibly in 0.1 to 0.3% spore formation in cells of colonies grown on a solid medium under strictly denned conditions. Sporulation requires a selected strain of the organism, NRRL B-2309S, a relatively large and specific concentration of certain yeast extracts, a specific type of agar, the complete absence of glucose, the presence of acetate, and a pH within the range 7.2 to 7.5. Spore formation occurs slowly during 2- to 4-week incubation periods in surface colonies present in limited numbers on agar plates. Some of the spores formed in this manner survive heating for 15 minutes at 80 °C, and vegetative cultures derived from such spores are pathogenic via injection for larvae of the Japanese beetle,Popillia japonicaNewman.

ISSN:0008-4166    

DOI:10.1139/m65-105

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Plant tissue cultures of cauliflower and lettuce were successfully established on semisolid White"s medium supplemented with coconut milk (20%) and naphthaleneacetic acid (5 p.p.m.). On this medium the tissues exhibited vigorous proliferative growth with no tendency for organogenesis. Ethanol–ether extracts of the stale medium of these tissues yielded an alcohol-insoluble fraction that was highly and consistently inhibitory forStaphylococcus aureusbut variable in antimicrobial activity againstMycobacterium phlei. The results suggest that in view of the progress in mass tissue culturing of plant cells in vitro, the use of cultured plant tissues should be explored for the production of antimicrobial principles of medical interest.

ISSN:0008-4166    

DOI:10.1139/m65-106

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Sedimented solids, obtained as a slurry after the aerobic fermentation of thin stillage, were subjected to anaerobic decomposition in stirred culture. The solids were added gradually in increasing increments to anaerobic sludge from a sewage disposal plant for purposes of acclimatization. The fermentation resulted in the generation of large volumes of gas with a methane content of 70% and a reduction in chemical oxygen demand of approximately 65%. Gas production was somewhat inferior to that obtained during anaerobic decomposition of "raw" thin stillage solids.

ISSN:0008-4166    

DOI:10.1139/m65-107

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Growth ofBacillus subtilisstrain 168 for short periods of time in the presence of proflavine or actinomycin D produces chaining and, because transformation to prototrophy is scored by plating on minimal medium, the presence of cells in chains could interfere with accurate scoring of transformants. A procedure using absorbancy measurements has been developed to permit scoring of transformation in cell populations containing aberrant cell forms (chains). The initial presence of minute quantities ofL-tryptophan in the medium did not influence the frequency of transformation but did shorten the lag period required for growth of the transformed cells in the liquid medium. The results establish that the presence of cells in chains does interfere with evaluation of transformation as scored by the plate count procedure.A decrease in transformation frequency was observed with either proflavine or actinomycin D, indicating that both compounds inhibit the transformation ofB.subtilisstrain 168 from auxotrophy to prototrophy. Addition of proflavine or actinomycin D after the recipient cells had been incubated with donor deoxyribonucleic acid also inhibited transformation, suggesting that the chemicals have an intracellular site of action.

ISSN:0008-4166    

DOI:10.1139/m65-108

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Spheroplasts were produced in five strains of rapid-growing non-virulent mycobacteria in a variety of media. Optimal spheroplast production occurred after 8–10 days of incubation in the presence of glycine and lysozyme, but in no culture was there complete formation of spheroplasts. While the pattern of spheroplast induction appeared to be specific for each strain and to be highly reproducible, the mechanism of the induction process is unknown.

ISSN:0008-4166    

DOI:10.1139/m65-109

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Production of competence-provoking factor and transformation of a group H streptococcus were achieved in the absence of serum or albumin in media sterilized by filtration through Millipore filters.No significant transformation was found when the medium was heated more than 40–50 minutes at 115°−117 °C. This suggests that the medium contained a heat-labile factor necessary for transformation. The factor was found in yeast extract, one of the ingredients of the medium.Addition of serum to heated medium allowed production of the competence-provoking factor and of transformation. Serum albumin, claimed to be an adequate substitute for serum, was less active in this respect. It is concluded that serum contains, in addition to albumin, another factor enhancing transformation.

ISSN:0008-4166    

DOI:10.1139/m65-110

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The competence-provoking factor produced by the highly transformable group H streptococcus, strain Challis, was used to provoke efficient transformability in the poorly transformable group H streptococcus, strain Wicky. Transformations to streptomycin resistance were carried out with C14-labelled DNA which was extracted from bacteria fed with thymidine-2-C14.When cultures of strain Wicky were grown in Difco brain–heart infusion broth, supplemented with serum, and treated with competence factor and deoxyribonucleic acid, 25 to 40% of viable units were transformed while no transformation occurred without the factor. At the same time, the incorporation of C14into cells treated with competence factor was higher than incorporation of C14into untreated cells.Crude preparations of the competence factor had a retarding effect on growth of the streptococcus, irrespective of whether DNA was added.

ISSN:0008-4166    

DOI:10.1139/m65-111

出版商:NRC Research Press    

年代:1965

数据来源: NRC