摘要:

Water samples taken at monthly intervals from three sites in the mouth of the Patuxent River in the Chesapeake Bay were cultured for bdellovibrios lytic toVibrio parahaemolyticusand for total viable bacterial counts. The number of bdellovibrios recovered decreased from the spring months (April, May, June (AMJ)) until very few were detected during the winter months (January, February, March (JFM)), which also coincided with the lowest water temperatures. During the AMJ season there was a significant increase as compared with the JFM season in the number of bdellovibrios for all sites. The highest number of bdellovibrios was recovered during each season from the shoreline water sample, with one exception. The seasonal variation in the number of bdellovibrios was observed to correlate statistically with the water temperature.

ISSN:0008-4166    

DOI:10.1139/m82-011

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

A marine oil-degrading population grown at 8 °C showed a selective sensitivity regarding utilization of compounds in Prudhoe Bay oil in the presence of the dispersant Corexit 9527. The response was dependent on the nitrogen and phosphate levels of the medium and on the concentration of dispersant used. In the presence of a nitrogen–phosphate solution and a Corexit 9527 – crude oil substrate, degradation of then-alkanes of the saturate fraction was temporarily retarded in proportion to the concentration of Corexit 9527 present. This retardation was overcome with extended incubation time. In the absence of nitrogen–phosphate supplementation, the effect of Corexit 9527 was pronounced, retardingn-alkane degradation even with extended incubation time. Corexit 9527 had less effect on the degradation of the aromatic fraction and may indeed be stimulatory in the case of select compounds. The development and testing of dispersants containing nitrogen and phosphate is recommended.

ISSN:0008-4166    

DOI:10.1139/m82-012

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The rate of recovery of herpes simplex virus (HSV) from human trigeminal ganglia explant monolayers is affected by two factors: (1) time elapsed from the death of an individual to the establishment of in vitro culture of ganglia and (2) surface area onto which ganglia are explanted. Spontaneous reactivation of HSV from human trigeminal ganglia can be maximized when ganglia are obtained within 12 h of death and explanted onto a surface area of 250 cm2. Viruses isolated by explantation of human trigeminal ganglia were found to be uniformly HSV type 1 by restriction enzyme analysis.

ISSN:0008-4166    

DOI:10.1139/m82-013

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Complex medium is rendered alkaline by the growth of marine pseudomonad D71, and in such a medium spinae are produced towards the end of log phase when the pH has increased over 7.5. Spinae production is unaffected by changes in oxygen tension and illumination but controlled by interactions of pH, salt concentration, and temperature. Under optimal laboratory conditions for growth a culture is partially spined but it becomes increasingly spined as growth temperature or pH is increased or ionic concentration decreased. By contrast, flagella are produced at low temperatures and pH, suggesting that spinae function in an opposite sense to flagella accommodating the bacterium to its environment. The conditions controlling spinae production are discussed in the context of possible spina function.

ISSN:0008-4166    

DOI:10.1139/m82-014

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Strains ofAcremonium roseumandChaetomium globosumwere tested for their ability to attack the protein components of wool by culturing the fungi in basal medium containing wool and monitoring changes in pH and soluble protein levels occurring in the medium. Net increases in soluble protein and pH were detected in the cultures ofA.roseum,C.globosum, and the positive control,Trichophyton mentagrophytes. To test for keratin denaturation by sulfite production (sulfitolysis), human hairs were exposed to the fungi in culture. Overgrown hairs were stained by the tetrazonium method, a test specific for compounds produced by sulfitolysis. Isolates ofTrichophyton tonsurans,T.rubrum,T.terrestre,Microsporum cookei, and nondermatophytic saprotrophic fungi were also tested for sulfitolysis. Positive results for sulfitolysis were obtained withT.mentagrophytes,T.tonsurans,T.rubrum,T.terrestre, andM.cookei;A.roseum,C.globosum, and the remaining species were negative.

ISSN:0008-4166    

DOI:10.1139/m82-015

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

DNA of lambda and seven related phages was digested with restriction endonuclease,EcoRI. Seven different fragment patterns were observed, only two of the eight phages showing identical profiles. Restriction enzyme fragment analysis is thus shown to be a sensitive tool for the differentiation of biologically indistinguishable phages.

ISSN:0008-4166    

DOI:10.1139/m82-016

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

The endo-β-1, 4-glucanase (carboxymethylcellulase) activity in cell extracts prepared fromBacteroides succinogenesS85 was almost unaffected by prolonged incubation at 39 °C in the presence of merthiolate, a sulfhydryl inhibitor. The β-1, 4-glucosidase (cellobiase) activity, however, was rapidly inactivated by the same treatment. The cellobiase was also inactivated by exposure to air, but was stabilized by dithiothreitol in a nitrogen atmosphere. These results suggest that the cellobiase required reduced sulfhydryl groups for activity.

ISSN:0008-4166    

DOI:10.1139/m82-017

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

AnAlcaligenessp. isolated from soil and shown to be an active heterotrophic nitrifier was found to be highly tolerant of hydroxylamine. Growth of this organism occurred in medium containing as much as 235 mg NH2OH-N∙L−1. Joint culturing of theAlcaligenessp. andNitrobacter agilisin medium containing 18 mg NH2OH-N∙L−1resulted in the eventual synthesis of nitrite and nitrate. However,N.agiliscultured separately in the presence of hydroxylamine at concentrations as low as 5 mg NH2OH-N∙L−1was subsequently unable to convert nitrite to ni

ISSN:0008-4166    

DOI:10.1139/m82-018

出版商:NRC Research Press    

年代:1982

数据来源: NRC

摘要:

Strains of halophilic rods, presumably halobacteria, produce substances that inhibit the growth of other halobacteria but not halococci or moderate halophiles. The spectrum of action of these substances, called "halocins," was determined on 39 halobacteria or presumed halobacteria. The properties of halocin H4, produced by strain R-4, were studied usingHalobacterium halobiumas an indicator organism. Halocin H4 is adsorbed by the indicator organism and causes both death and lysis. It is a high molecular weight substance(s), destroyed by heat or exposure to low salt concentrations or treatment with a protease. Experiments are presented to show that it is not a virus.

ISSN:0008-4166    

DOI:10.1139/m82-019

出版商:NRC Research Press    

年代:1982

数据来源: NRC