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 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.

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.

scholarly journals Aerobic Degradation of 2,4,6-Trinitrotoluene byEnterobacter cloacae PB2 and by Pentaerythritol Tetranitrate Reductase

1998 ◽  
Vol 64 (8) ◽  
pp. 2864-2868 ◽  
Author(s):  
Christopher E. French ◽  
Stephen Nicklin ◽  
Neil C. Bruce
Keyword(s):  
Nitrogen Source ◽  
Nitrogen Sources ◽  
Enterobacter Cloacae ◽  
Aerobic Degradation ◽  
Pentaerythritol Tetranitrate ◽  
Sole Nitrogen Source ◽  
Aerobic Growth ◽  
Nitrate Esters ◽  
Glycerol Trinitrate ◽  
Petn Reductase

ABSTRACT Enterobacter cloacae PB2 was originally isolated on the basis of its ability to utilize nitrate esters, such as pentaerythritol tetranitrate (PETN) and glycerol trinitrate, as the sole nitrogen source for growth. The enzyme responsible is an NADPH-dependent reductase designated PETN reductase. E. cloacae PB2 was found to be capable of slow aerobic growth with 2,4,6-trinitrotoluene (TNT) as the sole nitrogen source. Dinitrotoluenes were not produced and could not be used as nitrogen sources. Purified PETN reductase was found to reduce TNT to its hydride-Meisenheimer complex, which was further reduced to the dihydride-Meisenheimer complex. Purified PETN reductase and recombinant Escherichia coli expressing PETN reductase were able to liberate nitrogen as nitrite from TNT. The ability to remove nitrogen from TNT suggests that PB2 or recombinant organisms expressing PETN reductase may be useful for bioremediation of TNT-contaminated soil and water.

Hydroxylamines as One-Atom Nitrogen Sources for Metal-Catalyzed Cycloadditions

Synthesis ◽  
2021 ◽  
Author(s):  
Xinjun Luan ◽  
Jingxun Yu
Keyword(s):  
Transition Metal ◽  
Nitrogen Source ◽  
Nucleophilic Reagent ◽  
Nitrogen Sources ◽  
Short Review ◽  
Indole Derivatives ◽  
Electrophilic Amination ◽  
Intramolecular Cycloaddition ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

AbstractTransition-metal-catalyzed C–N bond formation is one of the most important pathways to synthesize N-heterocycles. Hydroxylamines can be transformed into a nucleophilic reagent to react with a carbon cation or coordinate with a transition metal; it can also become an electrophilic nitrogen source to react with arenes, alkenes, and alkynes. In this short review, the progress made on transition-metal-catalyzed cycloadditions with hydroxylamines as a nitrogen source is summarized.1 Introduction2 Cycloaddition To Form Aziridine Derivatives2.1 Intramolecular Cycloaddition To Form Aziridine Derivatives2.2 Intermolecular Cycloaddition To Form Aziridine Derivatives3 Cycloaddition To Form Indole Derivatives4 Cycloaddition To Form Other N-Heterocycles4.1 Aza-Heck-Type Amination Reactions4.2 Nitrene Insertion Amination Reactions4.3 Intramolecular Nucleophilic and Electrophilic Amination Reactions5 Conclusion and Outlook

PRODUCTION OF CYTASES ACTIVE ON BARLEY GUM BY BACTERIA OF THE GENUS BACILLUS

1953 ◽  
Vol 31 (1) ◽  
pp. 28-32 ◽  
Author(s):  
A. C. Blackwood
Keyword(s):  
Bacillus Subtilis ◽  
Enzymatic Activity ◽  
Nitrogen Source ◽  
Freeze Drying ◽  
Shake Flask ◽  
Sole Nitrogen Source ◽  
Genus Bacillus ◽  
Original Activity ◽  
Bacterial Cultures ◽  
Bacillus Genus

One hundred and fourteen bacterial cultures representing most of the species in the Bacillus genus were tested for the production of extracellular barley gum cytase. Assays were made on shake-flask cultures grown on a medium containing glucose and yeast extract. Although all the organisms had some enzymatic activity, certain strains of Bacillus subtilis gave the best yields of cytase. On a medium with asparagine as the sole nitrogen source even higher yields were obtained. The crude cytase preparations were stable and after freeze-drying most of the original activity remained.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

scholarly journals Varied Diazotrophies, Morphologies, and Toxicities of Genetically Similar Isolates of Cylindrospermopsis raciborskii(Nostocales, Cyanophyceae) from Northern Australia

2001 ◽  
Vol 67 (4) ◽  
pp. 1839-1845 ◽  
Author(s):  
Martin L. Saker ◽  
Brett A. Neilan
Keyword(s):  
Nitrogen Source ◽  
Growth Rates ◽  
Vegetative Cell ◽  
Nitrogen Sources ◽  
Water Bodies ◽  
Cylindrospermopsis Raciborskii ◽  
Rrna Gene ◽  
Northern Australia ◽  
Fixed Nitrogen ◽  
Freeze Dried

ABSTRACT The potentially toxic freshwater cyanobacteriumCylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. This paper investigates the effects of different nitrogen sources (NO3 −, NH4 +, and omission of a fixed form of nitrogen) on the growth rates, morphologies, and cylindrospermopsin (CYL) concentrations (expressed as a percentage of the freeze-dried weight) of seven C. raciborskii isolates obtained from a range of water bodies in northern Australia and grown in batch culture. In general, growth rates were lowest in the absence of a fixed-nitrogen source and highest with NH4 + as the nitrogen source. Conversely, the highest concentrations of CYL were recorded in cultures grown in the absence of a fixed-nitrogen source and the lowest were found in cultures supplied with NH4 +. Cultures supplied with NO3 − were intermediate with respect to both CYL concentration and growth rate. Different nitrogen sources resulted in significant differences in the morphology of C. raciborskii trichomes. Most notable were the loss of heterocysts and the tapering of end cells in cultures supplied with NH4 + and the statistically significant increase in vegetative cell length (nitrogen depleted < NO3 − < NH4 +). The morphological changes induced by different nitrogen sources were consistent for all isolates, despite measurable differences in vegetative-cell and heterocyst dimensions among isolates. Such induced morphological variation has implications forCylindrospermopsis taxonomy, given that distinctions between species are based on minor and overlapping differences in cell lengths and widths. The close phylogenetic association among all seven isolates was confirmed by the high level (>99.8%) of similarity of their 16S rRNA gene sequences. Another genetic technique, analysis of the HIP1 octameric-palindrome repeated sequence, showed greater heterogeneity among the isolates and appears to be a useful method for distinguishing among isolates of C. raciborskii.

scholarly journals Monomethylamine as a Nitrogen Source for a Nonmethylotrophic Bacterium, Agrobacterium tumefaciens

2010 ◽  
Vol 76 (12) ◽  
pp. 4102-4104 ◽  
Author(s):  
Yin Chen ◽  
Kathryn L. McAleer ◽  
J. Colin Murrell
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Nitrogen Source ◽  
Key Enzymes ◽  
Genes Encoding

ABSTRACT Monomethylamine can be used by nonmethylotrophs as a sole nitrogen source but not as a carbon source; however, little is known about the genes and enzymes involved. The γ-glutamylmethylamide/N-methylglutamate pathway for monomethylamine utilization by methylotrophs has recently been resolved. We have identified genes encoding key enzymes of this pathway in nonmethylotrophs (e.g., Agrobacterium tumefaciens) and demonstrated that this pathway is also involved in the utilization of monomethylamine as a nitrogen source by nonmethylotrophs.

Iron compounds in the heart-body of the terebellid polychaete Neoamphitrite figulus

1965 ◽  
Vol 45 (2) ◽  
pp. 341-351 ◽  
Author(s):  
R. Phillips Dales
Keyword(s):  
Metabolic Activity ◽  
Iron Compounds ◽  
Iron Protein ◽  
Different Ages ◽  
Different Seasons ◽  
Haem Iron ◽  
By Products

The heart-body contains haematins derived from by-products of haem synthesis. It also contains a non-haem iron protein and a flavin. Study of the relative amounts of these substances in worms of different ages and at different seasons suggests that the flavin plays some part in the metabolic activity of the organ and that the haematins accumulate throughout life. No evidence was found for the heart-body participating in any excretory activity or in haemoglobin breakdown.

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