Further Studies on the Bacteriological Reduction of Nitrite in Fish During Spoilage

1949 ◽  
Vol 7c (9) ◽  
pp. 536-544 ◽  
Author(s):  
W. J. Dyer ◽  
C. H. Castell
Keyword(s):  
Bacterial Growth ◽  
Nitrite Reduction ◽  
Neutral Solution ◽  
Oxide Reduction ◽  
Nitrite Concentration ◽  
Acid Media ◽  
Trimethylamine Oxide

The reduction of added nitrite in stored cod fillets is due to bacterial agencies. There are two mechanisms of nitrite reduction, the first inhibiting bacterial growth in acid media, and the second inhibiting trimethylamine oxide reduction in neutral solution. The effect of several levels of nitrite concentration on spoilage in fillets stored at 3 °C. as measured organoleptically and by spoilage tests was determined.

Bacterial Reduction of Sodium Nitrite and Formation of Trimethylamine in Fish

1949 ◽  
Vol 7c (8) ◽  
pp. 461-470 ◽  
Author(s):  
W. J. Dyer
Keyword(s):  
Sodium Nitrite ◽  
Nitrate Reduction ◽  
Oxide Reduction ◽  
Bacterial Reduction ◽  
Rapid Reduction ◽  
Surface Ph ◽  
Trimethylamine Oxide

Bacteria reduce sodium nitrite in stored cod fillets. Rapid reduction of trimethylamine oxide is inhibited by the nitrite in the concentrations used, up to 700 p.p.m., trimethylamine formation occurring only after the nitrite is reduced to about 50 p.p.m. This results in an increased keeping time in fillets treated with nitrite. The surface pH remains acid until the rapid trimethylamine formation takes place.Nitrate alone, more slowly in the presence of nitrite, is rapidly reduced to nitrite and beyond. The trimethylamine oxide reduction is not affected by the nitrate reduction, the former being usually reduced before the nitrate.

scholarly journals Nitrous oxide (N<sub>2</sub>O) production in axenic <i>Chlorella vulgaris</i> cultures: evidence, putative pathways, and potential environmental impacts

2013 ◽  
Vol 10 (6) ◽  
pp. 9739-9763 ◽  
Author(s):  
B. Guieysse ◽  
M. Plouviez ◽  
M. Coilhac ◽  
L. Cazali
Keyword(s):  
Nitrous Oxide ◽  
Life Cycle Analysis ◽  
No Reduction ◽  
Genomic Analysis ◽  
Nitrite Reduction ◽  
Nitrite Accumulation ◽  
N2o Emissions ◽  
Nitrite Concentration ◽  
N2o Formation ◽  
Nr Activity

Abstract. Using antibiotic assays and genomic analysis, this study demonstrates nitrous oxide (N2O) is generated from axenic C. vulgaris cultures. In batch assays, this production is magnified under conditions favoring intracellular nitrite accumulation, but repressed when nitrate reductase (NR) activity is inhibited. These observations suggest N2O formation in C. vulgaris might proceed via NR-mediated nitrite reduction into nitric oxide (NO) acting as N2O precursor via a pathway similar to N2O formation in bacterial denitrifiers, although NO reduction to N2O under oxia remains unproven in plant cells. Alternatively, NR may reduce nitrite to nitroxyl (HNO), the latter being known to dimerize to N2O under oxia. Regardless of the precursor considered, an NR-mediated nitrite reduction pathway provides a unifying explanation for correlations reported between N2O emissions from algae-based ecosystems and NR activity, nitrate concentration, nitrite concentration, and photosynthesis repression. Moreover, these results indicate microalgae-mediated N2O formation might significantly contribute to N2O emissions in algae-based ecosystems. These findings have profound implications for the life cycle analysis of algae biotechnologies and our understanding of the global biogeochemical nitrogen cycle.

Trimethylamine oxide reduction by Salmonella

1974 ◽  
Vol 20 (12) ◽  
pp. 1745-1748 ◽  
Author(s):  
Kyung Eun Kim ◽  
George W. Chang
Keyword(s):  
Nitrate Reductase ◽  
Mutant Strain ◽  
Anaerobic Growth ◽  
Oxide Reduction ◽  
Trimethylamine Oxide ◽  
Fish Spoilage ◽  
Common Components

Trimethylamine oxide (TMAO) allows the anaerobic growth of Salmonella on glycerol and is thereby reduced to trimethylamine, a volatile indicator of fish spoilage. A mutant strain, TA1530, is unable to reduce either TMAO or nitrate; this suggests that the TMAO and nitrate reductase systems have common components.

Effect of Nitrite on Reduction of Trimethylamine Oxide in Cod Fillets

1949 ◽  
Vol 7c (7) ◽  
pp. 421-429 ◽  
Author(s):  
C. H. Castell
Keyword(s):  
Bacterial Growth ◽  
Inhibitory Action ◽  
Trimethylamine Oxide ◽  
Growth Of Bacteria

Concentrations of nitrite required to prevent or retard the formation of trimethylamine in cod fillets stored at 3 °C. are much less than those required to inhibit bacterial growth on the fish under the same conditions.This is not the result of the nitrite having a selective inhibitory action on the growth of bacteria that reduce trimethylamine oxide.

Experimental evidence for plasmid-bornenor-nirgenes inSinorhizobium melilotiJJ1c10

2004 ◽  
Vol 50 (9) ◽  
pp. 657-667 ◽  
Author(s):  
Yiu-Kwok Chan ◽  
Wayne A McCormick
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Sinorhizobium Meliloti ◽  
Nitrite Reduction ◽  
Nucleotide Sequence Analysis ◽  
Gene Products ◽  
Oxide Reduction ◽  
Accessory Gene ◽  
Genes Encoding ◽  
Denitrification Genes

In denitrification, nir and nor genes are respectively required for the sequential dissimilatory reduction of nitrite and nitric oxide to form nitrous oxide. Their location on the pSymA megaplasmid of Sinorhizobium meliloti was confirmed by Southern hybridization of its clones with specific structural gene probes for nirK and norCB. A 20-kb region of pSymA containing the nor-nir genes was delineated by nucleotide sequence analysis. These genes were linked to the nap genes encoding periplasmic proteins involved in nitrate reduction. The nor-nir-nap segment is situated within 30 kb downstream from the nos genes encoding nitrous oxide reduction, with a fix cluster intervening between nir and nos. Most of these predicted nor-nir and accessory gene products are highly homologous with those of related proteobacterial denitrifiers. Functional tests of Tn5 mutants confirmed the requirement of the nirV product and 1 unidentified protein for nitrite reduction as well as the norB-D products and another unidentified protein for nitric oxide reduction. Overall comparative analysis of the derived amino acid sequences of the S. meliloti gene products suggested a close relationship between this symbiotic N2fixer and the free-living non-N2-fixing denitrifier Pseudomonas G-179, despite differences in their genetic organization. This relationship may be due to lateral gene transfer of denitrification genes from a common donor followed by rearrangement and recombination of these genes.Key words: denitrification genes, nitric oxide reductase, nitrite reductase, Rhizobiaceae, Sinorhizobium meliloti.

scholarly journals THE BACTERIAL GROWTH INHIBITOR (LACTENIN) OF MILK

1930 ◽  
Vol 51 (2) ◽  
pp. 327-339 ◽  
Author(s):  
F. S. Jones ◽  
Henry S. Simms
Keyword(s):  
Low Temperature ◽  
Bacterial Growth ◽  
Small Volume ◽  
Growth Inhibitor ◽  
Dry Weight ◽  
Weight Basis ◽  
Neutral Solution ◽  
Inhibitory Substance ◽  
Reliable Measure ◽  
Growth Inhibitory

The bacterial growth inhibitory substance found in milk is called lactenin in this paper. It is stable for 1½ hours at pH 4 and at pH 10 and for longer periods in neutral solution. It is not associated with salts and carbohydrates and may be separated from them by dialysis. Lactenin is removed by agents which precipitate the proteins of whey. Part of these proteins may be hydrolyzed by tryptic digestion and the resulting split products, together with the salts and sugar, may then be removed by dialysis without appreciable loss of lactenic activity. This dialysis may be performed in a concentrating dialyzer, under sterile conditions and at low temperature, thus reducing the solution to small volume. The material may then be completely desiccated and kept 3 months with practically no loss of activity. The residue, on treating this dried material with salt solution, is 200 times as active as the original milk, on a dry weight basis. The size of hemolytic zones of the scarlet fever streptococcus grown on a medium containing lactenin is found to furnish a simple and reliable measure of lactenic activity.

scholarly journals Petroleum Pollution Bioremediation Using Water-Insoluble Uric Acid as the Nitrogen Source

2003 ◽  
Vol 69 (10) ◽  
pp. 6337-6339 ◽  
Author(s):  
Omry Koren ◽  
Vishnia Knezevic ◽  
Eliora Z. Ron ◽  
Eugene Rosenberg
Keyword(s):  
Uric Acid ◽  
Crude Oil ◽  
Nitrogen Source ◽  
Bacterial Growth ◽  
Open System ◽  
Open Systems ◽  
Petroleum Pollution ◽  
Acid Media ◽  
Enrichment Cultures ◽  
Pure Cultures

ABSTRACT The biodegradation of hydrocarbon pollutants in open systems is limited by the availability of a utilizable nitrogen source. This limitation can be overcome by using uric acid. Enrichment cultures grown on crude oil-uric acid media yielded mixed and pure cultures that degraded petroleum. In a simulated open system, uric acid bound to crude oil and was available for bacterial growth and petroleum biodegradation.

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