Nitroaromatic compounds serve as nitrogen source for Desulfovibrio sp. (B strain)

1993 ◽  
Vol 39 (4) ◽  
pp. 430-433 ◽  
Author(s):  
R. Boopathy ◽  
C. F. Kulpa
Keyword(s):  
Nitrogen Source ◽  
Aromatic Ring ◽  
Culture System ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Sole Source ◽  
Nitroaromatic Compounds ◽  
Sole Nitrogen Source ◽  
Sulfate Reducing ◽  
Soil And Water

A sulfate-reducing bacterium, Desulfovibrio sp. (B strain), isolated from a continuous anaerobic digester, used various nitroaromatic compounds such as 2,4-dinitrophenol, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as sole nitrogen sources for growth and also used these compounds as electron acceptors in the absence of sulfate in the culture medium. More than 60% of the nitroaromatics were transformed within 6 days of incubation. The organism also used aniline as sole nitrogen source, but not as an electron acceptor. Desulfovibrio sp. (B strain) did not use nitroaromatics as sole source of carbon and energy. The nitro groups in the aromatic ring were reduced and reductively deaminated to ammonia, which was used as nitrogen source, leaving the aromatic ring intact. Even though this organism did not degrade the nitroaromatics completely, it may be useful in degrading nitroaromatics in contaminated soil and water containing other aromatic degraders in a syntrophic culture system under anaerobic conditions.Key words: anaerobic process, biotransformation, nitroaromatics, aniline, Desulfovibrio sp.

Metabolism of trinitrobenzene by a Pseudomonas consortium

1994 ◽  
Vol 40 (9) ◽  
pp. 787-790 ◽  
Author(s):  
Ramaraj Boopathy ◽  
John Manning ◽  
Carlo Montemagno ◽  
Kris Rimkus
Keyword(s):  
Nitrogen Source ◽  
Culture System ◽  
Culture Medium ◽  
Sole Source ◽  
Bacterial Consortium ◽  
Ammonia Concentration ◽  
Amino Compound ◽  
Nitroaromatic Compound ◽  
Degrading Bacteria ◽  
Soil And Water

The metabolism of trinitrobenzene by a Pseudomonas consortium was studied. The Pseudomonas consortium used trinitrobenzene as a sole source of nitrogen, but not as a sole source of carbon. Trinitrobenzene was metabolized within 60 h of incubation. The main intermediates produced were dinitroaniline, 1,5-dinitrobenzene, nitroaniline, 5-nitrobenzene, and ammonia. The ammonia concentration in the culture medium increased during the course of incubation. Nearly stoichiometric amounts of 1,5-dinitrobenzene and 5-nitrobenzene were produced by the consortium. During trinitrobenzene metabolism by this bacterial consortium, the trinitrobenzene was first reduced to an amino compound, dinitroaniline. This intermediate was reductively deaminated with the release of ammonia into the culture medium and production of 1,5-dinitrobenzene. By the same mechanism, 1,5-dinitrobenzene was further converted to 5-nitrobenzene, which was not metabolized further, even after 60 days of incubation. This pathway is believed to be novel in that an aerobic bacterial consortium uses the nitroaromatic compound as its nitrogen source but leaves the ring intact. The bacterial consortium studied could be used in a syntrophic culture system with other 5-nitrobenzene-degrading bacteria to remove trinitrobenzene completely from soil and water at contaminated sites.Key words: trinitrobenzene, aniline, nitrobenzene, biodegradation, transformation.

scholarly journals Mutants affecting histidine utilization inAspergillus nidulans

1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Carbon Source ◽  
Nitrogen Sources ◽  
Limiting Factor ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Exogenous Substrate ◽  
Growth Properties ◽  
Type Strains

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.

scholarly journals Production characteristics of the diatom Cylindrotheca closterium (Ehrenb.) Reimann et Lewin grown in an intensive culture at various nitrogen sources in the medium

2019 ◽  
Vol 4 (1) ◽  
pp. 33-44 ◽  
Author(s):  
S. N. Zheleznova
Keyword(s):  
Stationary Phase ◽  
Nitrogen Source ◽  
Nutrient Medium ◽  
Maximum Yield ◽  
Nitrogen Sources ◽  
Dry Weight ◽  
Sole Source ◽  
Active Growth ◽  
Cylindrotheca Closterium ◽  
Production Characteristics

The diatom Cylindrotheca closterium (Ehrenberg) Reimann et Levin is characterized by high productivity (up to 1.5 g·l-1·day-1) and the ability to accumulate a valuable carotenoid fucoxanthin (up to 2 % of dry weight). In the development of biotechnology based on microalgae, the key issue is the creation of concentrated nutrient medium. Nitrogen is one of the most important components in the nutrient medium that significantly affects the production characteristics of all microalgae. The aim of this study is to compare the production characteristics of C. closterium in an intensive storage culture using different forms of nitrogen in the medium. In the first experiment, nitrate and sodium nitrite, urea, and nitrogen in the form of ammonium were used as a source of nitrogen. The amount of nitrates, nitrites, ammonium, and urea in the medium was calculated from the nitrogen content of the RS nutrient medium, with a nitrogen to phosphorus ratio of 15 : 1. In the second experiment, amino acids were used as a nitrogen source – arginine, asparagine, cysteine. The possibility of using the microalgae C. closterium for the growth of various organic sources of nitrogen (urea, cysteine, asparagine) was shown. Productive characteristics in the intensive storage culture of C. closterium using urea, cysteine, and asparagine as the sole source of nitrogen in the RS nutrient medium were determined. It is shown that when urea was used, the productivity reached its maximum values and amounted to 1.5 g·l-1·day-1. Thus, the expediency of using urea in the medium for obtaining the maximum yield of biomass was shown. The use of cysteine in the stationary phase of growth to achieve a long stationary phase with minimal concentrations of the nitrogen source in the nutrient medium is also advisable. It was found that C. closterium was able to grow and vegetate at sufficiently high concentrations of nitrite, and the addition of nitrogen in ammonium form to the nutrient medium during the active growth of C. closterium led to inhibition of all metabolic processes and to the death of the culture.

scholarly journals CMO1 encodes a putative choline monooxygenase and is required for the utilization of choline as the sole nitrogen source in the yeast Scheffersomyces stipitis (syn. Pichia stipitis)

Microbiology ◽  
2014 ◽  
Vol 160 (5) ◽  
pp. 929-940 ◽  
Author(s):  
Tomas Linder
Keyword(s):  
Nitrogen Source ◽  
Nitrogen Sources ◽  
Pichia Stipitis ◽  
Sole Nitrogen Source ◽  
Scheffersomyces Stipitis ◽  
Gene Encoding ◽  
Iron Protein ◽  
Choline Monooxygenase ◽  
Haem Iron ◽  
Eukaryotic Genomes

Sixteen yeasts with sequenced genomes belonging to the ascomycete subphyla Saccharomycotina and Taphrinomycotina were assayed for their ability to utilize a variety of primary, secondary, tertiary and quartenary aliphatic amines as nitrogen sources. The results support a previously proposed pathway of quaternary amine catabolism whereby glycine betaine is first converted into choline, which is then cleaved to release trimethylamine, followed by stepwise demethylation of trimethylamine to release free ammonia. There were only a few instances of utilization of N-methylated glycine species (sarcosine and N,N-dimethylglycine), which suggests that this pathway is not intact in any of the species tested. The ability to utilize choline as a sole nitrogen source correlated strongly with the presence of a putative Rieske non-haem iron protein homologous to bacterial ring-hydroxylating oxygenases and plant choline monooxygenases. Deletion of the gene encoding the Rieske non-haem iron protein in the yeast Scheffersomyces stipitis abolished its ability to utilize choline as the sole nitrogen source, but did not affect its ability to use methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, ethanolamine or glycine as nitrogen sources. The gene was named CMO1 for putative choline monooxygenase 1. A bioinformatic survey of eukaryotic genomes showed that CMO1 homologues are found throughout the eukaryotic domain.

scholarly journals The Regulator of the Yeast Proline Utilization Pathway Is Differentially Phosphorylated in Response to the Quality of the Nitrogen Source

2000 ◽  
Vol 20 (3) ◽  
pp. 892-899 ◽  
Author(s):  
Hoching L. Huang ◽  
Marjorie C. Brandriss
Keyword(s):  
Nitrogen Source ◽  
Target Genes ◽  
Nitrogen Sources ◽  
Sole Source ◽  
Wild Type ◽  
Mutant Proteins ◽  
Phosphatase Treatment ◽  
Proline Utilization ◽  
Utilization Pathway

ABSTRACT The proline utilization pathway in Saccharomyces cerevisiae is regulated by the Put3p transcriptional activator in response to the presence of the inducer proline and the quality of the nitrogen source in the growth medium. Put3p is constitutively bound to the promoters of its target genes, PUT1 andPUT2, under all conditions studied but activates transcription to the maximum extent only in the absence of rich nitrogen sources and in the presence of proline (i.e., when proline serves as the sole source of nitrogen). Changes in target gene expression therefore occur through changes in the activity of the DNA-bound regulator. In this report, we demonstrate by phosphatase treatment of immunoprecipitates of extracts metabolically labeled with32P or 35S that Put3p is a phosphoprotein. Examination of Put3p isolated from cells grown on a variety of nitrogen sources showed that it was differentially phosphorylated as a function of the quality of the nitrogen source: the poorer the nitrogen source, the slower the gel migration of the phosphoforms. The presence of the inducer does not detectably alter the phosphorylation profile. Activator-defective and activator-constitutive Put3p mutants have been analyzed. One activator-defective mutant appears to be phosphorylated in a pattern similar to that of the wild type, thus separating its ability to be phosphorylated from its ability to activate transcription. Three activator-constitutive mutant proteins from cells grown on an ammonia-containing medium have a phosphorylation profile similar to that of the wild-type protein in cells grown on proline. These results demonstrate a correlation between the phosphorylation status of Put3p and its ability to activate its target genes and suggest that there are two signals, proline induction and quality of nitrogen source, impinging on Put3p that act synergistically for maximum expression of the proline utilization pathway.

scholarly journals Nitrogen source-dependent inhibition of yeast growth by glycine and its N-methylated derivatives

2019 ◽  
Vol 113 (3) ◽  
pp. 437-445
Author(s):  
Tomas Linder
Keyword(s):  
Growth Inhibition ◽  
Nitrogen Source ◽  
Minimal Medium ◽  
Kluyveromyces Lactis ◽  
Nitrogen Sources ◽  
Growth Efficiency ◽  
Sole Source ◽  
Yeast Growth ◽  
Glycine Species ◽  
Dependent Inhibition

Abstract The effect of nitrogen source on the inhibitory properties of glycine and its N-methylated derivatives N-methylglycine (sarcosine), N,N-dimethylglycine, N,N,N-trimethylglycine (glycine betaine) on yeast growth was investigated. On solid minimal medium, all four glycine species completely or partially inhibited growth of Kluyveromyces lactis, Komagataella pastoris, Ogataea arabinofermentans, Spathaspora passalidarum and Yamadazyma tenuis at concentrations 5–10 mM when 10 mM NH4Cl was the sole source of nitrogen. If NH4Cl was substituted by sodium L-glutamate as the sole source of nitrogen, obvious growth inhibition by glycine and its N-methylated derivatives was generally not observed in any of these species. No obvious growth inhibition by any of the glycine species at a concentration of 10 mM was observed in Cyberlindnera jadinii, Lipomyces starkeyi, Lodderomyces elongisporus, Scheffersomyces stipitis or Yarrowia lipolytica on solid minimal medium irrespective of whether the nitrogen source was NH4Cl or sodium L-glutamate. Growth inhibition assays of K. pastoris in liquid minimal medium supplemented with increasing concentrations of N,N-dimethylglycine demonstrated inhibitory effects for nine tested nitrogen sources. In most cases, N,N-dimethylglycine supplementation caused a decrease in growth efficiency that appeared to be proportional to the concentration of N,N-dimethylglycine. The biological relevance of these results is discussed.

Activity of sulfate-reducing bacteria in human periodontal pocket

2002 ◽  
Vol 48 (12) ◽  
pp. 1099-1103 ◽  
Author(s):  
R Boopathy ◽  
M Robichaux ◽  
D LaFont ◽  
M Howell
Keyword(s):  
Electron Acceptor ◽  
Nitrogen Sources ◽  
Sulfate Reducing Bacteria ◽  
Sole Source ◽  
Periodontal Pocket ◽  
Sulfate Reducing ◽  
Optimum Growth Temperature ◽  
Dental Tissues ◽  
Type Iv ◽  
Reducing Bacteria

Samples of subgingival dental tissues were examined for the presence of sulfate-reducing bacteria (SRB). Using enrichment cultures, SRBs were detected in 9 of 17 individuals. A pure culture of SRB was obtained from one sample collected from a patient with type IV periodontal disease. The characterization of this isolate showed that it belongs to the genus Desulfovibrio. The isolate used pyruvate, lactate, glucose, fructose, and ethanol as the sole source of carbon. However, the isolate was unable to use acetate and methanol as a carbon source, indicating it as an incomplete oxidizer unable to carry out the terminal oxidation of substrates. Apart from using sulfate as electron acceptor, the isolate also used thiosulfate and nitrate as an electron acceptor. It has the ability to use a variety of nitrogen sources, including ammonium chloride, nitrate, and glutamate. The optimum growth temperature of the isolate was 37°C and the optimum pH for growth was 6.8. The SRB isolate contained the electron carrier desulfoviridin. The numbers of SRB in the mouth are assumed to be limited by sulfate. Potential sources of sulfate in the subgingival area include free sulfate in pocket fluid and glycosaminoglycans and sulfur-containing amino acids from periodontal tissues.Key words: sulfate-reducing bacteria, periodontal pocket, Desulfovibrio, subgingival tissues, electron acceptor.

Growth of filamentous marine fungi in a continuous culture system

1976 ◽  
Vol 54 (9) ◽  
pp. 893-899 ◽  
Author(s):  
L. M. Churchland ◽  
M. McClaren
Keyword(s):  
Continuous Culture ◽  
Nitrogen Source ◽  
Batch Culture ◽  
Culture System ◽  
Organic Nitrogen ◽  
Marine Fungi ◽  
Continuous System ◽  
Nitrogen Sources ◽  
Organic Nitrogen Source ◽  
Continuous Culture System

A continuous culture system has been designed for the cultivation of certain species of marine fungi. Growth in this apparatus was compared with growth in batch culture. Growth of the three marine species tested (Zalerion maritimum, Humicola alopallonella, and Monodictys pelagica) was significantly higher in continuous culture than in batch culture.Growth of two isolates of Z. maritimum was compared on three inorganic nitrogen sources and one organic nitrogen source. Growth of the fungus in the continuous system differed both qualitatively and quantitatively from that in batch culture. Both isolates showed greater growth on the organic nitrogen source in the closed system. In the continuous system, growth was equivalent on all nitrogen sources.

Multiplication of an ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and Microsporum

Microbiology ◽  
2004 ◽  
Vol 150 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Olivier Jousson ◽  
Barbara Léchenne ◽  
Olympia Bontems ◽  
Sabrina Capoccia ◽  
Bernard Mignon ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Proteolytic Activity ◽  
Culture Medium ◽  
Pathogenic Fungi ◽  
Soy Proteins ◽  
Species Differentiation ◽  
Microsporum Canis ◽  
Sole Nitrogen Source ◽  
Ancestral Gene ◽  
Dermatophyte Species

Dermatophytes are human and animal pathogenic fungi which cause cutaneous infections and grow exclusively in the stratum corneum, nails and hair. In a culture medium containing soy proteins as sole nitrogen source a substantial proteolytic activity was secreted by Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. This proteolytic activity was 55–75 % inhibited by o-phenanthroline, attesting that metalloproteases were secreted by all three species. Using a consensus probe constructed on previously characterized genes encoding metalloproteases (MEP) of the M36 fungalysin family in Aspergillus fumigatus, Aspergillus oryzae and M. canis, a five-member MEP family was isolated from genomic libraries of T. rubrum, T. mentagrophytes and M. canis. A phylogenetic analysis of genomic and protein sequences revealed a robust tree consisting of five main clades, each of them including a MEP sequence type from each dermatophyte species. Each MEP type was remarkably conserved across species (72–97 % amino acid sequence identity). The tree topology clearly indicated that the multiplication of MEP genes in dermatophytes occurred prior to species divergence. In culture medium containing soy proteins as a sole nitrogen source secreted Meps accounted for 19–36 % of total secreted protein extracts; characterization of protein bands by proteolysis and mass spectrometry revealed that the three dermatophyte species secreted two Meps (Mep3 and Mep4) encoded by orthologous genes.

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