scholarly journals Nitrogen Availability Affects the Metabolic Profile in Cyanobacteria

Metabolites ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 867
Author(s):  
Kosuke Inabe ◽  
Ayaka Miichi ◽  
Mami Matsuda ◽  
Takanobu Yoshida ◽  
Yuichi Kato ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nitrogen Assimilation ◽  
Nitrogen Availability ◽  
Nitrogen Sources ◽  
Tca Cycle ◽  
Metabolome Analysis ◽  
Rate Analysis ◽  
Genetic Responses ◽  
Synechocystis Sp ◽  
Pcc 6803

Nitrogen is essential for the biosynthesis of various molecules in cells, such as amino acids and nucleotides, as well as several types of lipids and sugars. Cyanobacteria can assimilate several forms of nitrogen, including nitrate, ammonium, and urea, and the physiological and genetic responses to these nitrogen sources have been studied previously. However, the metabolic changes in cyanobacteria caused by different nitrogen sources have not yet been characterized. This study aimed to elucidate the influence of nitrate and ammonium on the metabolic profiles of the cyanobacterium Synechocystis sp. strain PCC 6803. When supplemented with NaNO3 or NH4Cl as the nitrogen source, Synechocystis sp. PCC 6803 grew faster in NH4Cl medium than in NaNO3 medium. Metabolome analysis indicated that some metabolites in the CBB cycle, glycolysis, and TCA cycle, and amino acids were more abundant when grown in NH4Cl medium than NaNO3 medium. 15N turnover rate analysis revealed that the nitrogen assimilation rate in NH4Cl medium was higher than in NaNO3 medium. These results indicate that the mechanism of nitrogen assimilation in the GS-GOGAT cycle differs between NaNO3 and NH4Cl. We conclude that the amounts and biosynthetic rate of cyanobacterial metabolites varies depending on the type of nitrogen.

scholarly journals Biochemical elucidation of citrate accumulation in Synechocystis sp. PCC 6803 via kinetic analysis of aconitase

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maki Nishii ◽  
Shoki Ito ◽  
Noriaki Katayama ◽  
Takashi Osanai
Keyword(s):  
Kinetic Analysis ◽  
Chemical Equilibrium ◽  
Isocitrate Dehydrogenase ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Unicellular Cyanobacterium ◽  
Citrate Accumulation ◽  
Kinetics Of ◽  
Synechocystis Sp ◽  
Pcc 6803

AbstractA unicellular cyanobacterium Synechocystis sp. PCC 6803 possesses a unique tricarboxylic acid (TCA) cycle, wherein the intracellular citrate levels are approximately 1.5–10 times higher than the levels of other TCA cycle metabolite. Aconitase catalyses the reversible isomerisation of citrate and isocitrate. Herein, we biochemically analysed Synechocystis sp. PCC 6803 aconitase (SyAcnB), using citrate and isocitrate as the substrates. We observed that the activity of SyAcnB for citrate was highest at pH 7.7 and 45 °C and for isocitrate at pH 8.0 and 53 °C. The Km value of SyAcnB for citrate was higher than that for isocitrate under the same conditions. The Km value of SyAcnB for isocitrate was 3.6-fold higher than the reported Km values of isocitrate dehydrogenase for isocitrate. Therefore, we suggest that citrate accumulation depends on the enzyme kinetics of SyAcnB, and 2-oxoglutarate production depends on the chemical equilibrium in this cyanobacterium.

scholarly journals Unconventional biochemical regulation of the oxidative pentose phosphate pathway in the model cyanobacterium Synechocystis sp. PCC 6803

2020 ◽  
Vol 477 (7) ◽  
pp. 1309-1321
Author(s):  
Shoki Ito ◽  
Takashi Osanai
Keyword(s):  
Tca Cycle ◽  
Pentose Phosphate ◽  
Succinic Semialdehyde ◽  
Synechocystis 6803 ◽  
Succinic Semialdehyde Dehydrogenase ◽  
Metabolite Production ◽  
Semialdehyde Dehydrogenase ◽  
Biochemical Regulation ◽  
Synechocystis Sp ◽  
Pcc 6803

Metabolite production from carbon dioxide using sugar catabolism in cyanobacteria has been in the spotlight recently. Synechocystis sp. PCC 6803 (Synechocystis 6803) is the most studied cyanobacterium for metabolite production. Previous in vivo analyses revealed that the oxidative pentose phosphate (OPP) pathway is at the core of sugar catabolism in Synechocystis 6803. However, the biochemical regulation of the OPP pathway enzymes in Synechocystis 6803 remains unknown. Therefore, we characterized a key enzyme of the OPP pathway, glucose-6-phosphate dehydrogenase (G6PDH), and related enzymes from Synechocystis 6803. Synechocystis 6803 G6PDH was inhibited by citrate in the oxidative tricarboxylic acid (TCA) cycle. Citrate has not been reported as an inhibitor of G6PDH before. Similarly, 6-phosphogluconate dehydrogenase, the other enzyme from Synechocystis 6803 that catalyzes the NADPH-generating reaction in the OPP pathway, was inhibited by citrate. To understand the physiological significance of this inhibition, we characterized succinic semialdehyde dehydrogenase (SSADH) from Synechocystis 6803 (SySSADH), which catalyzes one of the NAD(P)H generating reactions in the oxidative TCA cycle. Similar to isocitrate dehydrogenase from Synechocystis 6803, SySSADH specifically catalyzed the NADPH-generating reaction and was not inhibited by citrate. The activity of SySSADH was lower than that of other bacterial SSADHs. Previous and this studies revealed that unlike the OPP pathway, the oxidative TCA cycle is a pathway with low efficiency in NADPH generation in Synechocystis 6803. It has, thus, been suggested that to avoid NADPH overproduction, the OPP pathway dehydrogenase activity is repressed when the flow of the oxidative TCA cycle increases in Synechocystis 6803.

scholarly journals Metabolic engineering of Synechocystis sp. PCC 6803 for the production of aromatic amino acids and derived phenylpropanoids

2020 ◽  
Vol 57 ◽  
pp. 129-139 ◽  
Author(s):  
Laura Furelos Brey ◽  
Artur J. Włodarczyk ◽  
Jens F. Bang Thøfner ◽  
Meike Burow ◽  
Christoph Crocoll ◽  
...  
Keyword(s):  
Amino Acids ◽  
Metabolic Engineering ◽  
Aromatic Amino Acids ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Proteomic and cellular views of Arthrospira sp. PCC 8005 adaptation to nitrogen depletion

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1224-1236 ◽  
Author(s):  
Frédéric Deschoenmaeker ◽  
Raphaël Facchini ◽  
Baptiste Leroy ◽  
Hanène Badri ◽  
C.-C. Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nitrogen Availability ◽  
Glycogen Synthesis ◽  
Nitrogen Sources ◽  
Survival Strategies ◽  
Nitrogen Deprivation ◽  
Label Free ◽  
Nitrogen Depletion ◽  
Term Survival ◽  
Cellular Analysis

Cyanobacteria are photosynthetic prokaryotes that play a crucial role in the Earth’s nitrogen and carbon cycles. Nitrogen availability is one of the most important factors in cyanobacterial growth. Interestingly, filamentous non-diazotrophic cyanobacteria, such as Arthrospira sp. PCC 8005, have developed survival strategies that enable them to adapt to nitrogen deprivation. Metabolic studies recently demonstrated a substantial synthesis and accumulation of glycogen derived from amino acids during nitrogen starvation. Nevertheless, the regulatory mechanism of this adaptation is poorly understood. To the best of our knowledge, this study is the first proteomic and cellular analysis of Arthrospira sp. PCC 8005 under nitrogen depletion. Label-free differential proteomic analysis indicated the global carbon and nitrogen reprogramming of the cells during nitrogen depletion as characterized by an upregulation of glycogen synthesis and the use of endogenous nitrogen sources. The degradation of proteins and cyanophycin provided endogenous nitrogen when exogenous nitrogen was limited. Moreover, formamides, cyanates and urea were also potential endogenous nitrogen sources. The transporters of some amino acids and alternative nitrogen sources such as ammonium permease 1 were induced under nitrogen depletion. Intriguingly, although Arthrospira is a non-diazotrophic cyanobacterium, we observed the upregulation of HetR and HglK proteins, which are involved in heterocyst differentiation. Moreover, after a long period without nitrate, only a few highly fluorescent cells in each trichome were observed, and they might be involved in the long-term survival mechanism of this non-diazotrophic cyanobacterium under nitrogen deprivation.

scholarly journals Current knowledge and recent advances in understanding metabolism of the model cyanobacterium Synechocystis sp. PCC 6803

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Lauren A. Mills ◽  
Alistair J. McCormick ◽  
David J. Lea-Smith
Keyword(s):  
Amino Acids ◽  
Heterotrophic Bacteria ◽  
Membrane Lipids ◽  
Current Knowledge ◽  
Oxygenic Photosynthesis ◽  
Photosynthetic Organisms ◽  
Physiological Processes ◽  
Synechocystis Sp ◽  
Pcc 6803

Abstract Cyanobacteria are key organisms in the global ecosystem, useful models for studying metabolic and physiological processes conserved in photosynthetic organisms, and potential renewable platforms for production of chemicals. Characterizing cyanobacterial metabolism and physiology is key to understanding their role in the environment and unlocking their potential for biotechnology applications. Many aspects of cyanobacterial biology differ from heterotrophic bacteria. For example, most cyanobacteria incorporate a series of internal thylakoid membranes where both oxygenic photosynthesis and respiration occur, while CO2 fixation takes place in specialized compartments termed carboxysomes. In this review, we provide a comprehensive summary of our knowledge on cyanobacterial physiology and the pathways in Synechocystis sp. PCC 6803 (Synechocystis) involved in biosynthesis of sugar-based metabolites, amino acids, nucleotides, lipids, cofactors, vitamins, isoprenoids, pigments and cell wall components, in addition to the proteins involved in metabolite transport. While some pathways are conserved between model cyanobacteria, such as Synechocystis, and model heterotrophic bacteria like Escherichia coli, many enzymes and/or pathways involved in the biosynthesis of key metabolites in cyanobacteria have not been completely characterized. These include pathways required for biosynthesis of chorismate and membrane lipids, nucleotides, several amino acids, vitamins and cofactors, and isoprenoids such as plastoquinone, carotenoids, and tocopherols. Moreover, our understanding of photorespiration, lipopolysaccharide assembly and transport, and degradation of lipids, sucrose, most vitamins and amino acids, and haem, is incomplete. We discuss tools that may aid our understanding of cyanobacterial metabolism, notably CyanoSource, a barcoded library of targeted Synechocystis mutants, which will significantly accelerate characterization of individual proteins.

scholarly journals Inactivation of spkD, encoding a Ser/Thr kinase, affects the pool of the TCA cycle metabolites in Synechocystis sp. strain PCC 6803

Microbiology ◽  
2008 ◽  
Vol 154 (7) ◽  
pp. 2161-2167 ◽  
Author(s):  
Sophie Laurent ◽  
Jichan Jang ◽  
Annick Janicki ◽  
Cheng-Cai Zhang ◽  
Sylvie Bédu
Keyword(s):  
Tca Cycle ◽  
The Tca Cycle ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Systematic Characterization of the ADP-Ribose Pyrophosphatase Family in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2005 ◽  
Vol 187 (14) ◽  
pp. 4984-4991 ◽  
Author(s):  
Kenji Okuda ◽  
Hidenori Hayashi ◽  
Yoshitaka Nishiyama
Keyword(s):  
Amino Acids ◽  
Recombinant Proteins ◽  
Flavin Adenine Dinucleotide ◽  
Fold Increase ◽  
Evolutionary Mechanisms ◽  
Bacterial Type ◽  
Low Activity ◽  
Synechocystis Sp ◽  
Pcc 6803

ABSTRACT We have characterized four putative ADP-ribose pyrophosphatases Sll1054, Slr0920, Slr1134, and Slr1690 in the cyanobacterium Synechocystis sp. strain PCC 6803. Each of the recombinant proteins was overexpressed in Escherichia coli and purified. Sll1054 and Slr0920 hydrolyzed ADP-ribose specifically, while Slr1134 hydrolyzed not only ADP-ribose but also NADH and flavin adenine dinucleotide. By contrast, Slr1690 showed very low activity for ADP-ribose and had four substitutions of amino acids in the Nudix motif, indicating that Slr1690 is not an active ADP-ribose pyrophosphatase. However, the quadruple mutation of Slr1690, T73G/I88E/K92E/A94G, which replaced the mutated amino acids with those conserved in the Nudix motif, resulted in a significant (6.1 × 102-fold) increase in the k cat value. These results suggest that Slr1690 might have evolved from an active ADP-ribose pyrophosphatase. Functional and clustering analyses suggested that Sll1054 is a bacterial type, while the other three and Slr0787, which was characterized previously (Raffaelli et al., FEBS Lett. 444:222-226, 1999), are phylogenetically diverse types that originated from an archaeal Nudix protein via molecular evolutionary mechanisms, such as domain fusion and amino acid substitution.

scholarly journals Probing Direct Interactions between CodY and the oppD Promoter of Lactococcus lactis

2005 ◽  
Vol 187 (2) ◽  
pp. 512-521 ◽  
Author(s):  
Chris D. den Hengst ◽  
Peter Curley ◽  
Rasmus Larsen ◽  
Girbe Buist ◽  
Arjen Nauta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactococcus Lactis ◽  
Nitrogen Availability ◽  
Nitrogen Sources ◽  
Dnase I ◽  
Site Directed Mutagenesis ◽  
Upstream Region ◽  
Binding Studies ◽  
Genes Encoding

ABSTRACT CodY of Lactococcus lactis MG1363 is a transcriptional regulator that represses the expression of several genes encoding proteins of the proteolytic system. These genes include pepN, pepC, opp-pepO1, and probably prtPM, pepX, and pepDA2, since the expression of the latter three genes relative to nitrogen availability is similar to that of the former. By means of in vitro DNA binding assays and DNase I footprinting techniques, we demonstrate that L. lactis CodY interacts directly with a region upstream of the promoter of its major target known so far, the opp system. Our results indicate that multiple molecules of CodY interact with this promoter and that the amount of bound CodY molecules is affected by the presence of branched-chain amino acids and not by GTP. Addition of these amino acids strongly affects the extent of the region protected by CodY in DNase I footprints. Random and site-directed mutagenesis of the upstream region of oppD yielded variants that were derepressed in a medium with an excess of nitrogen sources. Binding studies revealed the importance of specific bases in the promoter region required for recognition by CodY.

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