Regulation of expression of theRhizopusoryzaeuricase and urease enzymes

2002 ◽  
Vol 48 (12) ◽  
pp. 1104-1108 ◽  
Author(s):  
Peter C Farley ◽  
Sugiarto Santosa
Keyword(s):  
Uric Acid ◽  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Minimal Medium ◽  
Urease Activity ◽  
Rhizopus Oryzae ◽  
Sole Nitrogen Source ◽  
Catabolic Pathway ◽  
Regulation Of Expression ◽  
Uricase Activity

The regulation of intracellular urease and uricase activities was examined in Rhizopus oryzae. Urease activity (2.4 U/mg protein) was present in R. oryzae mycelium grown in minimal medium containing NH4Cl as sole nitrogen source. This activity increased threefold under nitrogen derepression conditions, but no induction by urea was detected. Control of urease activity in R. oryzae differs from that found in Neurospora crassa but resembles the situation in Aspergillus nidulans. No uricase activity was detected in R. oryzae mycelium grown in minimal medium containing NH4Cl as sole nitrogen source. Uricase activity was increased 10- to 40-fold under derepression conditions and was induced by exogenous uric acid (60- to 78-fold). Control of the R. oryzae uricase differs from that found in N. crassa and A. nidulans. This is the first analysis of the regulation of enzymes from the purine catabolic pathway in any member of the Zygomycetes.Key words: Rhizopus oryzae, uricase, urease, nitrogen metabolism.

scholarly journals Purification of arginase from Aspergillus nidulans.

1994 ◽  
Vol 41 (4) ◽  
pp. 467-471 ◽  
Author(s):  
A Dzikowska ◽  
J P Le Caer ◽  
P Jonczyk ◽  
P Wëgleński
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Neurospora Crassa ◽  
Molecular Mass ◽  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Sole Nitrogen Source ◽  
Mass Ratio ◽  
Conserved Domains ◽  
Native Molecular Mass ◽  
High Degree

Arginase (EC 3.5.3.1) of Aspergillus nidulans, the enzyme which enables the fungus to use arginine as the sole nitrogen source was purified to homogeneity. Molecular mass of the purified arginase subunit is 40 kDa and is similar to that reported for the Neurospora crassa (38.3 kDa) and Saccharomyces cerevisiae (39 kDa) enzymes. The native molecular mass of arginase is 125 kDa. The subunit/native molecular mass ratio suggests a trimeric form of the protein. The arginase protein was cleaved and partially sequenced. Two out of the six polypeptides sequenced show a high degree of homology to conserved domains in arginases from other species.

SOME GENETIC AND PHYSIOLOGICAL CHARACTERISTICS OF UREASE-DEFECTIVE STRAINS OF NEUROSPORA CRASSA

1971 ◽  
Vol 13 (2) ◽  
pp. 256-269 ◽  
Author(s):  
Philip Haysman ◽  
H. Branch Howe Jr.
Keyword(s):  
Linkage Group ◽  
Nitrogen Source ◽  
Urease Activity ◽  
Temperature Sensitive ◽  
Sole Nitrogen Source ◽  
Group V ◽  
Group I ◽  
Mutant Strains

Fourteen mutant strains have been isolated which differ from wild type with respect to urease activity: Seven strains lack detectable activity in vivo and in vitro, B1, C21 and allele 601, D1 and allele D3, D2, and W2, and fail to grow with urea as sole nitrogen source; seven have activity in vivo and varying amounts in vitro, A7, E3, E7, R2, S3, and temperature-sensitive strains C5 and K3. Strains D1 and D3 are allelic to Kolmark's ure-1; W2, to Kolmark's ure-2. Strain D2, which is either allelic or closely linked to ure-1, complements none of the strains lacking urease activity nor three of the strains having defective activity, and may be a regulatory mutant. Strains B1, C21 and allele 601 represent two previously unreported loci in linkage group I. Only two of the seven swains having defective urease activity have been mapped, A7 and S3, and have been assigned to linkage group V. These seven strains grow readily on Vogel's medium modified by having urea as sole nitrogen source but not on W-M medium similarly modified; growth is restricted on modified Vogel's medium as well, however, if the initial concentration of nitrogen, as urea, is suitably adjusted to exceed that of phosphorus.

scholarly journals The effect of thiourea on ureide metabolism in Neurospora crassa

1973 ◽  
Vol 136 (3) ◽  
pp. 749-755 ◽  
Author(s):  
Jasti Nirmala ◽  
Killampalli Sivarama Sastry
Keyword(s):  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Inorganic Nitrogen ◽  
Wild Strain ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Selective Toxicity ◽  
In The Wild

The wild-type strain of Neurospora crassa Em 5297a can utilize allantoin as a sole nitrogen source. The pathway of allantoin utilization is via its conversion into allantoic acid and urea, followed by the breakdown of urea to ammonia. This is shown by the inability of the urease-less mutant, N. crassa 1229, to grow on allantoin as a sole nitrogen source and by the formation of allantoate and urea by pre-formed mycelia of this mutant. In the wild strain (Em 5297a) thiourea is tenfold more toxic on an allantoin medium than on an inorganic nitrogen medium; allantoin as well as urea counteract thiourea toxicity in the allantoin nitrogen medium. This selective toxicity of thiourea for the mould utilizing allantoin nitrogen does not, however, result in an impairment of allantoin uptake, allantoinase activity or the formation of urea from allantoin. The only process affected by thiourea is the synthesis of urease; urea antagonizes this effect of thiourea in N. crassa.

scholarly journals Nickel Supplements Improve Growth when Foliar Urea is the Sole Nitrogen Source for Tomato

1998 ◽  
Vol 123 (4) ◽  
pp. 556-559 ◽  
Author(s):  
Bernard A. L. Nicoulaud ◽  
Arnold J. Bloom
Keyword(s):  
Lycopersicon Esculentum ◽  
Nitrogen Source ◽  
Nutrient Solution ◽  
Urease Activity ◽  
Sole Nitrogen Source ◽  
Foliar Urea

Concentrations of up to 1.0 μm NiCl2 in a nutrient solution improved growth of tomato (Lycopersicon esculentum Mill. `T-5') seedlings that received foliar urea as their sole nitrogen source. Nickel in the nutrient solution decreased the amount of urea present in the shoots and increased the amount in the roots, although it had no significant effect upon leaf urease activity. These results indicate that a) the presence of nickel in the nutrient solution improves growth of plants receiving foliar urea and b) the effect of nickel was related more to increased urea translocation from shoot to root than to enhanced leaf urease activity.

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 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.

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 Nitrogen Source Regulates Glutamate Dehydrogenase NADP Synthesis in Neurospora crassa

1983 ◽  
Vol 154 (1) ◽  
pp. 524-528 ◽  
Author(s):  
Georgina Hernández ◽  
Ray Sánchez-Pescador ◽  
Rafael Palacios ◽  
Jaime Mora
Keyword(s):  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Glutamate Dehydrogenase
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