Action of Nitrates and Nitrites on Bacteria

1944 ◽  
Vol 6c (3) ◽  
pp. 233-242 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Culture Medium ◽  
Fish Muscle ◽  
Experimental Conditions ◽  
Acid Ph ◽  
Fish Spoilage ◽  
Spoilage Bacteria

The amount of NaNO2 formed by reduction of NaNO3 by growing heterotrophic fish spoilage bacteria depended largely on the pH of the culture medium used. Thus NaNO2 formation was strongly inhibited in media controlled at acid pH, but amounts as high as 6,950 p.p.m. were formed when the pH was permitted to rise unchecked. NaNO3, in presence or absence of 200 p.p.m. of NaNO2, had either a very trivial effect, or no effect, on the growth of fish spoilage bacteria in broth medium or fish muscle, and it was either not, or but feebly, reduced in fish muscle under the experimental conditions.

Chemical Inhibition of Growth of Fish Spoilage Bacteria

1944 ◽  
Vol 6c (3) ◽  
pp. 257-266 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Fish Muscle ◽  
Ethyl Formate ◽  
Ethylene Dichloride ◽  
Sodium Chlorite ◽  
Inhibition Of Growth ◽  
Fish Spoilage ◽  
Spoilage Bacteria ◽  
Pure Cultures ◽  
Chloramine T ◽  
Chemical Inhibition

Inhibition of the growth of fish spoilage bacteria in naturally contaminated fish muscle, and in some instances of pure cultures of such organisms cultivated on laboratory media, by penicillic acid, 4-methoxy-2:5 toluquinone, methyl formate, ethyl formate, ethylene oxide, propylene oxide, methyl ether, ethyl ether, chloroform, ethylene dichloride, ethyl chloride, 1:4 dioxane, Chloramine B, Chloramine T, a mixture of isomeric glycerol formais, sodium chlorite, sodium benzoate, sodium nitrite, and one patent fish preservative was investigated. The results are discussed and are summarized in detail.

Development of embryonic rat eyes in organ culture

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 407-414
Author(s):  
R. Christy Armstrong ◽  
Joel J. Elias
Keyword(s):  
Organ Culture ◽  
Culture Medium ◽  
Folic Acid Deficiency ◽  
Experimental Conditions ◽  
Acid Deficiency ◽  
Series Of Experiments ◽  
Development In Vitro ◽  
Ocular System

Abnormalities of the ocular system which appear in organ culture in Waymouth's medium with freshly added glutamine (Armstrong & Elias, 1968) resemble those caused by transitory pteryolglutamic acid (PGA or folic acid) deficiency in vivo (Armstrong & Monie, 1966). The configurations of such malformations as lens herniations, retinal diverticula, and rosette-like formations of the retina are remarkably similar in both cases. The experiments reported in this paper were undertaken in an effort to understand the mechanisms involved in the production of similar abnormalities by two very different experimental conditions: the addition of glutamine in vitro and the transitory deficiency of PGA in vivo. One series of experiments involved the effects of manipulation of the PGA and glutamine content of the culture medium on eye development in vitro. Parallel studies on PGA-deficiency in vivo were undertaken in conjunction with organ-culture experiments in order to compare the effects on abnormal eye morphogenesis.

Preparation of a bilayer edible film incorporated with lysozyme and its effect on fish spoilage bacteria

2020 ◽  
Vol 40 (5) ◽  
Author(s):  
Qiuying Li ◽  
Jinxiu Xu ◽  
Dongdong Zhang ◽  
Keli Zhong ◽  
Tong Sun ◽  
...  
Keyword(s):  
Edible Film ◽  
Fish Spoilage ◽  
Spoilage Bacteria

scholarly journals Dynamics of leukotriene C production by macrophages.

1980 ◽  
Vol 152 (5) ◽  
pp. 1236-1247 ◽  
Author(s):  
C A Rouzer ◽  
W A Scott ◽  
A L Hamill ◽  
Z A Cohn
Keyword(s):  
Time Course ◽  
Culture Medium ◽  
Peritoneal Macrophages ◽  
Experimental Conditions ◽  
Silicic Acid Chromatography ◽  
Pg Release ◽  
Antigen Antibody ◽  
Mouse Peritoneal Macrophages ◽  
Hydroxyeicosatetraenoic Acids

A method for the radiochemical assay of LTC production by mouse peritoneal macrophages in vitro is presented. The method involves labeling macrophages in culture with [5,6,8,9,11,12,14,15-3H]20:4 followed by stimulation of arachidonic acid (20:4) release under the experimental conditions desired. Radiolabeled leukotriene C (LTC) is recovered from the culture medium by extraction and silicic acid chromatography in 40% yield with full retention of biological activity. Because this LTC is radiochemically pure, the quantity of LTC release may be estimated from the amount of radioactivity in the sample. Use of the radioassay to study parameters affecting LTC synthesis by macrophages indicated that the time course of LTC synthesis and its relationship to the dose of a phagocytic stimulus (zymosan) were very similar to those of prostaglandin (PG) release. LTC release was also similar to that of PG in that lower levels of both metabolites were produced by Corynebacterium parvum-elicited macrophages than by resident cells. Finally, LTC release was stimulated in response to a challenge with antigen-antibody complexes, but lower maximal levels were attained than those with zymosan. The data presented here are consistent with the hypothesis that challenge of macrophages with a phagocytic stimulus leads to the release of 20:4 by an inducible phospholipase. Cyclooxygenase and lipoxygenase then compete for the released 20:4, leading to the production of PG, hydroxyeicosatetraenoic acids, and LTC.

The Surface Concept in Measurement of Fish Spoilage

1942 ◽  
Vol 6a (1) ◽  
pp. 53-62 ◽  
Author(s):  
A. J. Wood ◽  
G. J. Sigurdsson ◽  
W. J. Dyer
Keyword(s):  
Human Consumption ◽  
Plate Method ◽  
Fish Products ◽  
Surface Ph ◽  
Contact Plate ◽  
Fish Spoilage ◽  
Spoilage Bacteria ◽  
Composite Samples ◽  
Surface Changes

The contact plate method as used for cod muscle has revealed that the major changes rendering fish unfit for human consumption can be attributed almost entirely to surface pollution of the fish with spoilage bacteria. This is confirmed by three chemical tests, trimethylamine, tyrosine, and surface pH. The relative rates of increase in all three are much greater at the surface than in the interior of cod and haddock fillets. The more rapid surface changes are taken as evidence that tests for spoilage in fish products should be based on samples from the surface of the products and not from composite samples.

Electrochemical Study of Mannitol Oxidation at Nickel Oxide Electrode

2003 ◽  
Vol 68 (9) ◽  
pp. 1636-1646
Author(s):  
Domenica Tonelli ◽  
Barbara Ballarin ◽  
Mario Berrettoni ◽  
Marcello Trevisani
Keyword(s):  
Nickel Oxide ◽  
Culture Medium ◽  
Electrochemical Reaction ◽  
Oxide Electrode ◽  
Experimental Conditions ◽  
Liquid Culture Medium ◽  
Viable Cells ◽  
Nickel Oxide Electrode ◽  
Kinetics Of ◽  
Overall Kinetics

The electrocatalytic oxidation of mannitol at a nickel oxide electrode was investigated. The experimental conditions for determining mannitol concentrations have been optimised taking into account the involved electrochemistry. Unlike what previously reported in the literature, our findings lead to the conclusion that both the electrochemical reaction involving the Ni(II)/Ni(III) couple and the chemical reaction between mannitol and Ni(III) are effective in determining the overall kinetics of the electrocatalytic process. The calibration line for mannitol was linear up to 20.0 mmol l-1. Mannitol determination with the nickel oxide electrode was performed in a liquid culture medium selective for Staphylococcus aureus in order to make an indirect calibration of bacterial viable cells, but the results were not satisfactory.

scholarly journals The Relation of the Composition of the Culture Medium to the Formation of Endospores by Aerobic Bacilli

1932 ◽  
Vol 32 (4) ◽  
pp. 535-543 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Inorganic Salt ◽  
Synthetic Medium ◽  
Ammonium Phosphate ◽  
Spore Formation ◽  
Experimental Conditions ◽  
Nitrogenous Compounds ◽  
Low Concentrations ◽  
High Concentrations

1. Spore formation in eight typical members of the genusBacillushas been studied.2. Three of these strains, including one species ofB. anthracis, have been found to be practically asporogenous under the experimental conditions. In general the following statements hold good for the sporogenous races studied.3. Spore formation is almost, or entirely, inhibited by cultivation on media rich in amino acids, such as tryptic digests of casein or meat. Similar inhibition results following cultivation on a medium containing reasonably high concentrations of a mixture of amino acids and asparagine.4. When such media are suitably diluted with standard inorganic salt solutions the percentage of spores formed is greatly increased, and frequently at least 99 per cent. of spores are formed if the dilution is sufficiently high.5. When simple nitrogenous compounds such as amino acids are added to a dilute casein digest medium in which sporulation is almost complete, a definite decrease in the percentage of spores present is observed. Asparagine, which is probably readily assimilated, apparently completely hinders spore formation in most cases. Other amino acids do not exert so pronounced an effect, and ammonium phosphate does not appreciably inhibit the formation of spores.6. The fact that the addition of glycine suppresses growth markedly when it is added to a dilute casein digest medium, but does not appreciably hinder sporulation, suggests that the formation of spores is not due to any toxic effect of added compounds, or compounds already present in the medium.7. Sporulation is almost complete in a “synthetic” medium in which low concentrations of ammonium phosphate and sucrose represent the sources of nitrogen and carbon, respectively. However, frequent transfers in such a medium may inhibit spore formation partially or entirely in certain instances. This effect probably depends upon the enhanced ability of the culture in question to utilise sucrose as a source of carbon when cultivated constantly in its presence.8. It is concluded, from the above data, that endospore formation in aerobic bacilli bears an inverse relationship to the amount of available nutrient material present in the culture medium.I am indebted to Prof. Sir F. G. Hopkins and Miss M. Stephenson for their constant encouragement during the progress of this work. My thanks are due to Mr Pirie of this Department who kindly furnished me with several of the amino acids employed, and to Dr Miles of the Department of Pathology for his kindness in supplying me with certain of the cultures.

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