scholarly journals Effects of Inorganic Nitrogen Sources on the Production of PP-V [(10Z)-12-carboxyl-monascorubramine] and the Expression of the Nitrate Assimilation Gene Cluster byPenicilliumsp. AZ

2012 ◽  
Vol 76 (1) ◽  
pp. 120-124 ◽  
Author(s):  
Teppei ARAI ◽  
Sara UMEMURA ◽  
Tamaki OTA ◽  
Jun OGIHARA ◽  
Jun KATO ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Inorganic Nitrogen ◽  
Nitrate Assimilation ◽  
Nitrogen Sources

scholarly journals A recently evolved diflavin-containing monomeric nitrate reductase is responsible for highly efficient bacterial nitrate assimilation

2020 ◽  
Vol 295 (15) ◽  
pp. 5051-5066 ◽  
Author(s):  
Wei Tan ◽  
Tian-Hua Liao ◽  
Jin Wang ◽  
Yu Ye ◽  
Yu-Chen Wei ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Biochemical Characterization ◽  
Catalytic Domain ◽  
Inorganic Nitrogen ◽  
Nitrate Assimilation ◽  
Nitrogen Sources ◽  
Electron Transfer Mechanism ◽  
Cofactor Binding ◽  
Environmental Mycobacteria

Nitrate is one of the major inorganic nitrogen sources for microbes. Many bacterial and archaeal lineages have the capacity to express assimilatory nitrate reductase (NAS), which catalyzes the rate-limiting reduction of nitrate to nitrite. Although a nitrate assimilatory pathway in mycobacteria has been proposed and validated physiologically and genetically, the putative NAS enzyme has yet to be identified. Here, we report the characterization of a novel NAS encoded by Mycolicibacterium smegmatis Msmeg_4206, designated NasN, which differs from the canonical NASs in its structure, electron transfer mechanism, enzymatic properties, and phylogenetic distribution. Using sequence analysis and biochemical characterization, we found that NasN is an NADPH-dependent, diflavin-containing monomeric enzyme composed of a canonical molybdopterin cofactor-binding catalytic domain and an FMN–FAD/NAD-binding, electron-receiving/transferring domain, making it unique among all previously reported hetero-oligomeric NASs. Genetic studies revealed that NasN is essential for aerobic M. smegmatis growth on nitrate as the sole nitrogen source and that the global transcriptional regulator GlnR regulates nasN expression. Moreover, unlike the NADH-dependent heterodimeric NAS enzyme, NasN efficiently supports bacterial growth under nitrate-limiting conditions, likely due to its significantly greater catalytic activity and oxygen tolerance. Results from a phylogenetic analysis suggested that the nasN gene is more recently evolved than those encoding other NASs and that its distribution is limited mainly to Actinobacteria and Proteobacteria. We observed that among mycobacterial species, most fast-growing environmental mycobacteria carry nasN, but that it is largely lacking in slow-growing pathogenic mycobacteria because of multiple independent genomic deletion events along their evolution.

scholarly journals Reticulate evolution in eukaryotes: origin and evolution of the nitrate assimilation pathway

2018 ◽  
Author(s):  
Eduard Ocaña-Pallarès ◽  
Sebastián R. Najle ◽  
Claudio Scazzocchio ◽  
Iñaki Ruiz-Trillo
Keyword(s):  
Nitrate Reductase ◽  
Gene Fusion ◽  
Evolutionary History ◽  
Transcriptional Control ◽  
Genetic Material ◽  
Nitrate Assimilation ◽  
Nitrogen Sources ◽  
Reticulate Evolution ◽  
Origin And Evolution ◽  
Ideal Object

AbstractGenes and genomes can evolve through interchanging genetic material, this leading to reticular evolutionary patterns. However, the importance of reticulate evolution in eukaryotes, and in particular of horizontal gene transfer (HGT), remains controversial. Given that metabolic pathways with taxonomically-patchy distributions can be indicative of HGT events, the eukaryotic nitrate assimilation pathway is an ideal object of investigation, as previous results revealed a patchy distribution and suggested one crucial HGT event. We studied the evolution of this pathway through both multi-scale bioinformatic and experimental approaches. Our taxon-rich genomic screening shows this pathway to be present in more lineages than previously proposed and that nitrate assimilation is restricted to autotrophs and to distinct osmotrophic groups. Our phylogenies show a pervasive role of HGT, with three bacterial transfers contributing to the pathway origin, and at least seven well-supported transfers between eukaryotes. Our results, based on a larger dataset, differ from the previously proposed transfer of a nitrate assimilation cluster from Oomycota (Stramenopiles) to Dikarya (Fungi, Opisthokonta). We propose a complex HGT path involving at least two cluster transfers between Stramenopiles and Opisthokonta. We also found that gene fusion played an essential role in this evolutionary history, underlying the origin of the canonical eukaryotic nitrate reductase, and of a novel nitrate reductase in Ichthyosporea (Opisthokonta). We show that the ichthyosporean pathway, including this novel nitrate reductase, is physiologically active and transcriptionally co-regulated, responding to different nitrogen sources; similarly to distant eukaryotes with independent HGT-acquisitions of the pathway. This indicates that this pattern of transcriptional control evolved convergently in eukaryotes, favoring the proper integration of the pathway in the metabolic landscape. Our results highlight the importance of reticulate evolution in eukaryotes, by showing the crucial contribution of HGT and gene fusion in the evolutionary history of the nitrate assimilation pathway.

Characterization and expression analysis of a gene cluster for nitrate assimilation from the yeastArxula adeninivorans

Yeast ◽  
2006 ◽  
Vol 26 (2) ◽  
pp. 83-93 ◽  
Author(s):  
Erik Böer ◽  
Anja Schröter ◽  
Rüdiger Bode ◽  
Michael Piontek ◽  
Gotthard Kunze
Keyword(s):  
Gene Cluster ◽  
Expression Analysis ◽  
Nitrate Assimilation

Comparison of Organic and Inorganic Nitrogen Sources for Rice 1

1987 ◽  
Vol 79 (5) ◽  
pp. 937-943 ◽  
Author(s):  
M. P. Westcott ◽  
D. S. Mikkelsen
Keyword(s):  
Inorganic Nitrogen ◽  
Nitrogen Sources

scholarly journals Medium Optimization for Spore Production of a Straw-Cellulose Degrading Actinomyces Strain under Solid-State Fermentation Using Response Surface Method

2020 ◽  
Vol 12 (21) ◽  
pp. 8893
Author(s):  
Huanran Liu ◽  
Dan Zhang ◽  
Xia Zhang ◽  
Chuanzhi Zhou ◽  
Pei Zhou ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Spore Production ◽  
Steepest Ascent ◽  
Medium Components ◽  
Burman Design ◽  
Plackett Burman Design ◽  
Central Composite

The strains capable of degrading cellulose have attracted much interest because of their applications in straw resource utilization in solid-state fermentation (SSF). However, achieving high spore production in SSF is rarely reported. The production of spores from Streptomyces griseorubens JSD-1 was investigated in shaker-flask cultivation in this study. The optimal carbon, organic nitrogen and inorganic nitrogen sources were sucrose, yeast extract and urea, respectively. Plackett–Burman design (PBD) was adopted to determine the key medium components, and the concentration levels of three components (urea, NaCl, MgSO4·7H2O) were optimized with the steepest ascent path and central composite design (CCD), achieving 1.72 × 109 CFU/g of spore production. Under the optimal conditions (urea 2.718% w/v, NaCl 0.0697% w/v, MgSO4·7H2O 0.06956% w/v), the practical value of spore production was 1.69 × 109 CFU/g. The determination coefficient (R2) was 0.9498, which ensures an adequate credibility of the model.

scholarly journals Inactivation of gltB Abolishes Expression of the Assimilatory Nitrate Reductase Gene (nasB) in Pseudomonas putida KT2442

2000 ◽  
Vol 182 (12) ◽  
pp. 3368-3376 ◽  
Author(s):  
Leo Eberl ◽  
Aldo Ammendola ◽  
Michael H. Rothballer ◽  
Michael Givskov ◽  
Claus Sternberg ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Pseudomonas Putida ◽  
Nitrogen Starvation ◽  
Nitrate Assimilation ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Nucleotide Sequence Analysis ◽  
Nitrate Reductase Gene ◽  
Physiological Characterization ◽  
Reductase Gene

ABSTRACT By using mini-Tn5 transposon mutagenesis, random transcriptional fusions of promoterless bacterial luciferase,luxAB, to genes of Pseudomonas putida KT2442 were generated. Insertion mutants that responded to ammonium deficiency by induction of bioluminescence were selected. The mutant that responded most strongly was genetically analyzed and is demonstrated to bear the transposon within the assimilatory nitrate reductase gene (nasB) of P. putida KT2442. Genetic evidence as well as sequence analyses of the DNA regions flanking nasBsuggest that the genes required for nitrate assimilation are not clustered. We isolated three second-site mutants in which induction ofnasB expression was completely abolished under nitrogen-limiting conditions. Nucleotide sequence analysis of the chromosomal junctions revealed that in all three mutants the secondary transposon had inserted at different sites in the gltB gene of P. putida KT2442 encoding the major subunit of the glutamate synthase. A detailed physiological characterization of thegltB mutants revealed that they are unable to utilize a number of potential nitrogen sources, are defective in the ability to express nitrogen starvation proteins, display an aberrant cell morphology under nitrogen-limiting conditions, and are impaired in the capacity to survive prolonged nitrogen starvation periods.

EFFECTS OF NITROGEN SOURCES AND ORGANIC MATTER ON NITROGEN FIXATION AND YIELD OF SOYBEANS

1972 ◽  
Vol 52 (6) ◽  
pp. 991-996 ◽  
Author(s):  
H. S. JOHNSON ◽  
D. J. HUME
Keyword(s):  
Organic Matter ◽  
Nitrogen Fixation ◽  
Seed Yield ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Cattle Manure ◽  
Control Treatment ◽  
Available N ◽  
Corn Cobs ◽  
Ground Corn

The effects of two sources of nitrogen and ground corn cobs, applied either alone or in combination, on nitrogen fixation and seed yield of Glycine max (L.) Merr. cult Altona were investigated in an area where control plants fixed only 7.5 kg N2/ha. Treatments were: N, 280 kg N/ha as NH4NO3; organic matter (O.M.), 14 T (dry wt)/ha of ground corn cobs as an organic matter source; N + O.M.; M1; 88 T/ha of liquid cattle manure; M1 + O.M.; M2, 176 T/ha of liquid cattle manure; M2 + O.M.; and C, control. Treatment effects on nitrogen fixation, measured as acetylene reduction rates, and seed yield were related to the levels of available N supplied to the plants. Nitrogen fixation was progressively increased by treatments M1, M2 + O.M., M1 + O.M., and O.M., with the latter two fixing seven times as much nitrogen as the control. Final seed yield, however, was increased by treatments supplying the highest levels of inorganic nitrogen to plants, with N and N + O.M. producing higher yields than the control plots.

THE ISOLATION AND CHARACTERIZATION OF METHANOMONAS METHANOOXIDANS BROWN AND STRAWINSKI

1964 ◽  
Vol 10 (5) ◽  
pp. 791-799 ◽  
Author(s):  
L. R. Brown ◽  
R. J. Strawinski ◽  
C. S. McCleskey
Keyword(s):  
Formic Acid ◽  
Inorganic Nitrogen ◽  
Nitrogen Sources ◽  
Energy Sources ◽  
Resting Cells ◽  
Gram Negative ◽  
Oxidation Of Methane ◽  
Isolation And Characterization ◽  
Trapping Agent

Procedures for the isolation and characterization of Metkanomonas methanooxidans Brown and Strawinski are described. Isolates from varied sources are alike in cellular morphology, inasmuch as they form only microcolonies, and in their dependence on methane or methanol as carbon and energy sources for growth. Both organic and inorganic nitrogen sources are used. The organism is a Gram negative non-sporeforming rod, 1.5 to 3.0 μ by 1.0 μ in size, and motile by means of a single polar flagellum. In growing cultures the oxygen/methane ratio was approximately 1.1 and in resting cells 1.7. The R.Q. for methane with resting cells was 0.43. Resting cells were unable to oxidize organic compounds other than methane, methanol, formaldehyde, and formate. Formic acid was detected in test solutions after cell suspensions had metabolized methane, methanol, and formaldehyde. Using sodium sulphite as trapping agent for formaldehyde, it was found that 60 to 70% of the methane or methanol consumed was converted to formaldehyde. In the presence of iodoacetate, 70% of the methane consumed was present terminally as methanol. Thus it was shown that methanol, formaldehyde, and formic acid are sequential intermediates in the oxidation of methane by these organisms.

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