Urease of<i>Corynebacterium glutamicum</i>: organization of corresponding genes and investigation of activity

Nolden, Lars; Beckers, Gabriele; Möckel, Bettina; Pfefferle, Walter; Nampoothiri, K. Madhavan; Krämer, Reinhard; Burkovski, Andreas

doi:10.1111/j.1574-6968.2000.tb09248.x

Cited by 29 publications

(10 citation statements)

References 17 publications

(16 reference statements)

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“…Interestingly, urease transcript abundance in R. albus 8 is not predicated on the presence of urea in the medium. Urease activity induction without urea was also observed in Corynebacterium glutamicum upon nitrogen starvation and in Klebsiella pneumonia under nitrogen-limited conditions (38,39). This urease activity may demonstrate that R. albus 8 expresses urease to acquire urea as an alternative nitrogen source when the ammonia concentration in the medium is limited.…”

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confidence: 72%

Nitrogen Utilization and Metabolism in Ruminococcus albus 8

Kim

Henriksen

Cann

et al. 2014

Appl Environ Microbiol

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The model rumen Firmicutes organism Ruminococcus albus 8 was grown using ammonia, urea, or peptides as the sole nitrogen source; growth was not observed with amino acids as the sole nitrogen source. Growth of R. albus 8 on ammonia and urea showed the same growth rate (0.08 h ؊1 ) and similar maximum cell densities (for ammonia, the optical density at 600 nm [OD 600 ] was 1.01; and for urea, the OD 600 was 0.99); however, growth on peptides resulted in a nearly identical growth rate (0.09 h ؊1 ) and a lower maximum cell density (OD 600 ‫؍‬ 0.58). To identify differences in gene expression and enzyme activities, the transcript abundances of 10 different genes involved in nitrogen metabolism and specific enzyme activities were analyzed by harvesting mRNA and crude protein from cells at the mid-and late exponential phases of growth on the different N sources. Transcript abundances and enzyme activities varied according to nitrogen source, ammonia concentration, and growth phase. Growth of R. albus 8 on ammonia and urea was similar, with the only observed difference being an increase in urease transcript abundance and enzyme activity in urea-grown cultures. Growth of R. albus 8 on peptides showed a different nitrogen metabolism pattern, with higher gene transcript abundance levels of gdhA, glnA, gltB, amtB, glnK, and ureC, as well as higher activities of glutamate dehydrogenase and urease. These results demonstrate that ammonia, urea, and peptides can all serve as nitrogen sources for R. albus and that nitrogen metabolism genes and enzyme activities of R. albus 8 are regulated by nitrogen source and the level of ammonia in the growth medium.A mmonia is the major end product of digestion of dietary protein and nonprotein nitrogen (urea and amino acids), as well as the major source of nitrogen for protein synthesis by ruminal bacteria (1-3). Results over a wide range of feed and N intakes demonstrate that 60 to 80% of bacterial N is derived from ammonia as a precursor (4). Since 14% of cell dry mass is nitrogen, bacterial protein synthesis and growth are greatly affected by the efficiency of ammonia assimilation. Despite its importance and central role as an intermediate in the degradation as well as assimilation of dietary nitrogen by intestinal bacteria, our understanding of the mechanism of ammonia assimilation in ruminal bacteria is superficial.Enzymes for assimilation of ammonia are widely conserved across the bacterial domain, with differences in distribution and transcriptional regulation influenced by environmental niche. Glutamate dehydrogenase (GDH), glutamine synthetase (GS), and glutamate synthase (GOGAT) are the three major types of enzymes that regulate the intracellular pool of nitrogen by controlling ammonia assimilation (5). GDH plays a significant role in the metabolism of nitrogen in many organisms by assimilating ammonia through the conversion of 2-oxoglutarate to glutamate. In the enteric proteobacteria, such as Escherichia coli and Salmonella, GDH is the primary nitrogen assimilation pathway when ...

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confidence: 72%

Nitrogen Utilization and Metabolism in Ruminococcus albus 8

Kim

Henriksen

Cann

et al. 2014

Appl Environ Microbiol

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“…This correlates with data obtained for C. glutamicum , which shows a urease activity of 0.9 μmol min -1 (mg protein) -1 in complex medium and a urease activity of 0.9-2.2 μmol min -1 (mg protein) -1 when ammonium is used as single nitrogen source. In this bacterium, however, urease activity is increased to 7.8 μmol min -1 (mg protein) -1 , when cells are exposed to nitrogen starvation [19,20]. Despite the fact that urease activity is not upregulated in response to starvation, M. smegmatis shows at least low urease activity and the reason for the complete growth deficiency with urea as single nitrogen source remains unclear.…”

Section: Resultsmentioning

confidence: 99%

Nitrogen starvation-induced transcriptome alterations and influence of transcription regulator mutants in Mycobacterium smegmatis

et al. 2013

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BackgroundAs other bacteria, Mycobacterium smegmatis needs adaption mechanisms to cope with changing nitrogen sources and to survive situations of nitrogen starvation. In the study presented here, transcriptome analyses were used to characterize the response of the bacterium to nitrogen starvation and to elucidate the role of specific transcriptional regulators.ResultsIn response to nitrogen deprivation, a general starvation response is induced in M. smegmatis. This includes changes in the transcription of several hundred genes encoding e.g. transport proteins, proteins involved in nitrogen metabolism and regulation, energy generation and protein turnover. The specific nitrogen-related changes at the transcriptional level depend mainly on the presence of GlnR, while the AmtR protein controls only a small number of genes.ConclusionsM. smegmatis is able to metabolize a number of different nitrogen sources and nitrogen control in M. smegmatis is similar to control mechanisms characterized in streptomycetes, while the master regulator of nitrogen control in corynebacteria, AmtR, is plays a minor role in this regulatory network.

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“…Two GS enzymes have been described in C. glutamicum : GlnA (also annotated as GlnA1, GSI) and GlnA2 (GSI). GlnA is the essential functional glutamine synthetase which is subjected to post-translational modification by the adenylyl transferase enzyme GlnE [ 42 , 43 ]. GlnA2 has been described as a non-essential enzyme which is not subjected to post-translational modifications.…”

Section: Nitrogen Metabolismmentioning

confidence: 99%

Polyamine and Ethanolamine Metabolism in Bacteria as an Important Component of Nitrogen Assimilation for Survival and Pathogenicity

Krysenko

Wohlleben

2022

Medical Sciences

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Nitrogen is an essential element required for bacterial growth. It serves as a building block for the biosynthesis of macromolecules and provides precursors for secondary metabolites. Bacteria have developed the ability to use various nitrogen sources and possess two enzyme systems for nitrogen assimilation involving glutamine synthetase/glutamate synthase and glutamate dehydrogenase. Microorganisms living in habitats with changeable availability of nutrients have developed strategies to survive under nitrogen limitation. One adaptation is the ability to acquire nitrogen from alternative sources including the polyamines putrescine, cadaverine, spermidine and spermine, as well as the monoamine ethanolamine. Bacterial polyamine and monoamine metabolism is not only important under low nitrogen availability, but it is also required to survive under high concentrations of these compounds. Such conditions can occur in diverse habitats such as soil, plant tissues and human cells. Strategies of pathogenic and non-pathogenic bacteria to survive in the presence of poly- and monoamines offer the possibility to combat pathogens by using their capability to metabolize polyamines as an antibiotic drug target. This work aims to summarize the knowledge on poly- and monoamine metabolism in bacteria and its role in nitrogen metabolism.

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Urease ofCorynebacterium glutamicum: organization of corresponding genes and investigation of activity

Cited by 29 publications

References 17 publications

Nitrogen Utilization and Metabolism in Ruminococcus albus 8

Nitrogen Utilization and Metabolism in Ruminococcus albus 8

Nitrogen starvation-induced transcriptome alterations and influence of transcription regulator mutants in Mycobacterium smegmatis

Polyamine and Ethanolamine Metabolism in Bacteria as an Important Component of Nitrogen Assimilation for Survival and Pathogenicity

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