scholarly journals Substrate Specificities and Availability of Fucosyltransferase and β-Carotene Hydroxylase for Myxol 2′-Fucoside Synthesis in Anabaena sp. Strain PCC 7120 Compared with Synechocystis sp. Strain PCC 6803

2008 ◽  
Vol 190 (20) ◽  
pp. 6726-6733 ◽  
Author(s):  
Mari Mochimaru ◽  
Hajime Masukawa ◽  
Takashi Maoka ◽  
Hatem E. Mohamed ◽  
Wim F. J. Vermaas ◽  
...  
Keyword(s):  
High Performance ◽  
Carotenoid Biosynthesis ◽  
Biosynthetic Pathways ◽  
Wild Type ◽  
Substrate Specificities ◽  
Field Desorption Mass Spectrometry ◽  
Anabaena Sp ◽  
Pcc 7120 ◽  
Β Carotene ◽  
Pcc 6803

ABSTRACT To elucidate the biosynthetic pathways of carotenoids, especially myxol 2′-glycosides, in cyanobacteria, Anabaena sp. strain PCC 7120 (also known as Nostoc sp. strain PCC 7120) and Synechocystis sp. strain PCC 6803 deletion mutants lacking selected proposed carotenoid biosynthesis enzymes and GDP-fucose synthase (WcaG), which is required for myxol 2′-fucoside production, were analyzed. The carotenoids in these mutants were identified using high-performance liquid chromatography, field desorption mass spectrometry, and 1H nuclear magnetic resonance. The wcaG (all4826) deletion mutant of Anabaena sp. strain PCC 7120 produced myxol 2′-rhamnoside and 4-ketomyxol 2′-rhamnoside as polar carotenoids instead of the myxol 2′-fucoside and 4-ketomyxol 2′-fucoside produced by the wild type. Deletion of the corresponding gene in Synechocystis sp. strain PCC 6803 (sll1213; 79% amino acid sequence identity with the Anabaena sp. strain PCC 7120 gene product) produced free myxol instead of the myxol 2′-dimethyl-fucoside produced by the wild type. Free myxol might correspond to the unknown component observed previously in the same mutant (H. E. Mohamed, A. M. L. van de Meene, R. W. Roberson, and W. F. J. Vermaas, J. Bacteriol. 187:6883-6892, 2005). These results indicate that in Anabaena sp. strain PCC 7120, but not in Synechocystis sp. strain PCC 6803, rhamnose can be substituted for fucose in myxol glycoside. The β-carotene hydroxylase orthologue (CrtR, Alr4009) of Anabaena sp. strain PCC 7120 catalyzed the transformation of deoxymyxol and deoxymyxol 2′-fucoside to myxol and myxol 2′-fucoside, respectively, but not the β-carotene-to-zeaxanthin reaction, whereas CrtR from Synechocystis sp. strain PCC 6803 catalyzed both reactions. Thus, the substrate specificities or substrate availabilities of both fucosyltransferase and CrtR were different in these species. The biosynthetic pathways of carotenoids in Anabaena sp. strain PCC 7120 are discussed.

scholarly journals Increased Production of Zeaxanthin and Other Pigments by Application of Genetic Engineering Techniques toSynechocystis sp. Strain PCC 6803

2000 ◽  
Vol 66 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Delphine Lagarde ◽  
Laurent Beuf ◽  
Wim Vermaas
Keyword(s):  
Mutant Strain ◽  
Fold Increase ◽  
Carotenoid Biosynthesis ◽  
Carotenoid Content ◽  
Wild Type ◽  
Gene Encoding ◽  
Genes Encoding ◽  
In The Wild ◽  
Β Carotene ◽  
Pcc 6803

ABSTRACT The psbAII locus was used as an integration platform to overexpress genes involved in carotenoid biosynthesis inSynechocystis sp. strain PCC 6803 under the control of the strong psbAII promoter. The sequences of the genes encoding the yeast isopentenyl diphosphate isomerase (ipi) and theSynechocystis β-carotene hydroxylase (crtR) and the linked Synechocystis genes coding for phytoene desaturase and phytoene synthase (crtP andcrtB, respectively) were introduced intoSynechocystis, replacing the psbAII coding sequence. Expression of ipi, crtR, andcrtP and crtB led to a large increase in the corresponding transcript levels in the mutant strains, showing that the psbAII promoter can be used to drive transcription and to overexpress various genes in Synechocystis. Overexpression of crtP and crtB led to a 50% increase in the myxoxanthophyll and zeaxanthin contents in the mutant strain, whereas the β-carotene and echinenone contents remained unchanged. Overexpression of crtR induced a 2.5-fold increase in zeaxanthin accumulation in the corresponding overexpressing mutant compared to that in the wild-type strain. In this mutant strain, zeaxanthin becomes the major pigment (more than half the total amount of carotenoid) and the β-carotene and echinenone amounts are reduced by a factor of 2. However, overexpression of ipi did not result in a change in the carotenoid content of the mutant. To further alter the carotenoid content of Synechocystis, the crtOgene, encoding β-carotene ketolase, which converts β-carotene to echinenone, was disrupted in the wild type and in the overexpressing strains so that they no longer produced echinenone. In this way, by a combination of overexpression and deletion of particular genes, the carotenoid content of cyanobacteria can be altered significantly.

Biohydrogen production by Anabaena sp. PCC 7120 wild-type and mutants under different conditions: Light, nickel, propane, carbon dioxide and nitrogen

2011 ◽  
Vol 35 (10) ◽  
pp. 4426-4434 ◽  
Author(s):  
Ana Evangelista Marques ◽  
Ana Teresa Barbosa ◽  
Joana Jotta ◽  
Manuel Caldeira Coelho ◽  
Paula Tamagnini ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Biohydrogen Production ◽  
Wild Type ◽  
Anabaena Sp ◽  
Pcc 7120

scholarly journals A TRAP Transporter for Pyruvate and Other Monocarboxylate 2-Oxoacids in the Cyanobacterium Anabaena sp. Strain PCC 7120

2010 ◽  
Vol 192 (22) ◽  
pp. 6089-6092 ◽  
Author(s):  
Rafael Pernil ◽  
Antonia Herrero ◽  
Enrique Flores
Keyword(s):  
Open Reading Frames ◽  
Wild Type ◽  
Cyanobacterium Anabaena ◽  
Anabaena Sp ◽  
Significant Uptake ◽  
Pcc 7120 ◽  
Reading Frames ◽  
T System

ABSTRACT In the cyanobacterium Anabaena sp. strain PCC 7120, open reading frames (ORFs) alr3026, alr3027, and all3028 encode a tripartite ATP-independent periplasmic transporter (TRAP-T). Wild-type filaments showed significant uptake of [14C]pyruvate, which was impaired in the alr3027 and all3028 mutants and was inhibited by several monocarboxylate 2-oxoacids, identifying this TRAP-T system as a pyruvate/monocarboxylate 2-oxoacid transporter.

scholarly journals hetL Overexpression Stimulates Heterocyst Formation in Anabaena sp. Strain PCC 7120

2002 ◽  
Vol 184 (24) ◽  
pp. 6873-6881 ◽  
Author(s):  
Duan Liu ◽  
James W. Golden
Keyword(s):  
Null Mutant ◽  
Wild Type ◽  
Heterologous Promoter ◽  
Repeat Proteins ◽  
Overexpression Strain ◽  
In The Wild ◽  
Anabaena Sp ◽  
Pcc 7120 ◽  
Diazotrophic Growth ◽  
Heterocyst Development

ABSTRACT The cyanobacterium Anabaena sp. strain PCC 7120 forms single heterocysts about every 10 to 15 vegetative cells along filaments. PatS is thought to be a peptide intercellular signal made by developing heterocysts that prevents neighboring cells from differentiating. Overexpression of the patS gene suppresses heterocyst formation. The hetL gene (all3740) was isolated in a genetic screen to identify genes involved in PatS signaling. Extracopy hetL allowed heterocyst formation in a patS overexpression strain. hetL overexpression from a heterologous promoter in wild-type Anabaena PCC 7120 induced multiple-contiguous heterocysts (Mch) in nitrate-containing medium. The predicted HetL protein is composed almost entirely of pentapeptide repeats with a consensus of A(D/N)L*X, where * is a polar amino acid. Thirty Anabaena PCC 7120 genes contain this repeat motif. A synthetic pentapeptide corresponding to the last 5 amino acids of PatS, which suppresses heterocyst formation in the wild type, did not suppress heterocyst formation in a hetL overexpression strain, indicating that HetL overexpression is affecting heterocyst regulation downstream of PatS production. The transcription regulator NtcA is required for the initiation of heterocyst formation. hetL overexpression allowed the initiation of heterocyst development in an ntcA-null mutant, but differentiation was incomplete. hetR and hetC mutations that block heterocyst development are epistatic to hetL overexpression. A hetL-null mutant showed normal heterocyst development and diazotrophic growth, which could indicate that it is not normally involved in regulating development, that it normally plays a nonessential accessory role, or perhaps that its loss is compensated by cross talk or redundancy with other pentapeptide repeat proteins.

scholarly journals ThetrpEGene Negatively Regulates Differentiation of Heterocysts at the Level of Induction in Anabaena sp. Strain PCC 7120

2014 ◽  
Vol 197 (2) ◽  
pp. 362-370 ◽  
Author(s):  
Patrick Videau ◽  
Loralyn M. Cozy ◽  
Jasmine E. Young ◽  
Blake Ushijima ◽  
Reid T. Oshiro ◽  
...  
Keyword(s):  
Repeat Sequence ◽  
Mutant Phenotype ◽  
Wild Type ◽  
Content Type ◽  
Type Pattern ◽  
In The Wild ◽  
Anabaena Sp ◽  
Pcc 7120

Levels of 2-oxoglutarate (2-OG) reflect nitrogen status in many bacteria. In heterocystous cyanobacteria, a spike in the 2-OG level occurs shortly after the removal of combined nitrogen from cultures and is an integral part of the induction of heterocyst differentiation. In this work, deletion of one of the two annotatedtrpEgenes inAnabaenasp. strain PCC 7120 resulted in a spike in the 2-OG level and subsequent differentiation of a wild-type pattern of heterocysts when filaments of the mutant were transferred from growth on ammonia to growth on nitrate. In contrast, 2-OG levels were unaffected in the wild type, which did not differentiate under the same conditions. An inverted-repeat sequence located upstream oftrpEbound a central regulator of differentiation, HetR,in vitroand was necessary for HetR-dependent transcription of a reporter fusion and complementation of the mutant phenotypein vivo. Functional complementation of the mutant phenotype with the addition of tryptophan suggested that levels of tryptophan, rather than the demonstrated anthranilate synthase activity of TrpE, mediated the developmental response of the wild type to nitrate. A model is presented for the observed increase in 2-OG in thetrpEmutant.

Control of light-dependent keto carotenoid biosynthesis in Nostoc 7120 by the transcription factor NtcA

2016 ◽  
Vol 71 (9-10) ◽  
pp. 303-311 ◽  
Author(s):  
Gerhard Sandmann ◽  
Jürgen Mautz ◽  
Jürgen Breitenbach
Keyword(s):  
Transcription Factor ◽  
Redox State ◽  
Photosynthetic Electron Transport ◽  
Carotenoid Biosynthesis ◽  
High Light ◽  
Light Conditions ◽  
Promoter Regions ◽  
Carotenogenic Genes ◽  
Pcc 7120 ◽  
Β Carotene

Abstract In Nostoc PCC 7120, two different ketolases, CrtW and CrtO are involved in the formation of keto carotenoids from β-carotene. In contrast to other cyanobacteria, CrtW catalyzes the formation of monoketo echinenone whereas CrtO is the only enzyme for the synthesis of diketo canthaxanthin. This is the major photo protective carotenoid in this cyanobacterium. Under high-light conditions, basic canthaxanthin formation was transcriptionally up-regulated. Upon transfer to high light, the transcript levels of all investigated carotenogenic genes including those coding for phytoene synthase, phytoene desaturase and both ketolases were increased. These transcription changes proceeded via binding of the transcription factor NtcA to the promoter regions of the carotenogenic genes. The binding was absolutely dependent on the presence of reductants and oxo-glutarate. Light-stimulated transcript formation was inhibited by DCMU. Therefore, photosynthetic electron transport is proposed as the sensor for high-light and a changing redox state as a signal for NtcA binding.

scholarly journals Biosynthesis of arsenolipids by the cyanobacterium Synechocystis sp. PCC 6803

2014 ◽  
Vol 11 (5) ◽  
pp. 506 ◽  
Author(s):  
Xi-Mei Xue ◽  
Georg Raber ◽  
Simon Foster ◽  
Song-Can Chen ◽  
Kevin A. Francesconi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mutant Strain ◽  
High Performance ◽  
Tandem Mass ◽  
Wild Type ◽  
Arsenic Compounds ◽  
Synechocystis Sp ◽  
Pcc 6803

Environmental context Arsenic biotransformation processes play a key role in the cycling of arsenic in aquatic systems. We show that a freshwater cyanobacterium can convert inorganic arsenic into arsenolipids, and the conversion efficiency depends on the arsenic concentration. The role of these novel arsenic compounds remains to be elucidated. Abstract Although methylated arsenic and arsenosugars have been verified in various freshwater organisms, lipid-soluble arsenic compounds have not been identified. Here, we report investigations with the model organism cyanobacterium Synechocystis sp. PCC 6803 wild type and ΔarsM (arsenic(III) S-adenosylmethionine methyltransferase) mutant strain, which lacks the enzymes for arsenic methylation cultured in various concentrations of arsenate (AsV). Although Synechocystis accumulated higher arsenic concentrations at the higher exposure levels, the bioaccumulation factor decreased with increasing AsV. The accumulated arsenic in the cells was partitioned into water-soluble and lipid-soluble fractions; lipid-soluble arsenic was found in Synechocystis wild type cells (3–35% of the total depending on the level of arsenic exposure), but was not detected in Synechocystis ΔarsM mutant strain showing that ArsM was required for arsenolipid biosynthesis. The arsenolipids present in Synechocystis sp. PCC 6803 were analysed by high performance liquid chromatography–inductively coupled plasma–mass spectrometry, high performance liquid chromatography–electrospray mass spectrometry, and high resolution tandem mass spectrometry. The two major arsenolipids were characterised as arsenosugar phospholipids based on their assigned molecular formulas C47H88O14AsP and C47H90O14AsP, and tandem mass spectrometric data demonstrated the presence of the phosphate arsenosugar and acylated glycerol groups.

scholarly journals A TolC-Like Protein Is Required for Heterocyst Development in Anabaena sp. Strain PCC 7120

2007 ◽  
Vol 189 (21) ◽  
pp. 7887-7895 ◽  
Author(s):  
Suncana Moslavac ◽  
Kerstin Nicolaisen ◽  
Oliver Mirus ◽  
Fadi Al Dehni ◽  
Rafael Pernil ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Protein Export ◽  
Filamentous Cyanobacterium ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Anabaena Sp ◽  
Pcc 7120 ◽  
Export System ◽  
Diazotrophic Growth ◽  
Mutant Cells

ABSTRACT The filamentous cyanobacterium Anabaena sp. strain PCC 7120 forms heterocysts in a semiregular pattern when it is grown on N2 as the sole nitrogen source. The transition from vegetative cells to heterocysts requires marked metabolic and morphological changes. We show that a trimeric pore-forming outer membrane β-barrel protein belonging to the TolC family, Alr2887, is up-regulated in developing heterocysts and is essential for diazotrophic growth. Mutants defective in Alr2887 did not form the specific glycolipid layer of the heterocyst cell wall, which is necessary to protect nitrogenase from external oxygen. Comparison of the glycolipid contents of wild-type and mutant cells indicated that the protein is not involved in the synthesis of glycolipids but might instead serve as an exporter for the glycolipid moieties or enzymes involved in glycolipid attachment. We propose that Alr2887, together with an ABC transporter like DevBCA, is part of a protein export system essential for assembly of the heterocyst glycolipid layer. We designate the alr2887 gene hgdD (heterocyst glycolipid deposition protein).

scholarly journals A Negative Regulator of Carotenogenesis in Blakeslea trispora

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Wei Luo ◽  
Zunyang Gong ◽  
Na Li ◽  
Yuzheng Zhao ◽  
Huili Zhang ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Carotenoid Biosynthesis ◽  
Negative Regulator ◽  
Blakeslea Trispora ◽  
Regulation Mechanism ◽  
Null Mutant ◽  
Structural Genes ◽  
Wild Type ◽  
Β Carotene

ABSTRACT As an ideal carotenoid producer, Blakeslea trispora has gained much attention due to its large biomass and high production of β-carotene and lycopene. However, carotenogenesis regulation in B. trispora still needs to be clarified, as few investigations have been conducted at the molecular level in B. trispora. In this study, a gene homologous to carotenogenesis regulatory gene (crgA) was cloned from the mating type (−) of B. trispora, and the deduced CrgA protein was analyzed for its primary structure and domains. To clarify the crgA-mediated regulation in B. trispora, we used the strategies of gene knockout and complementation to investigate the effect of crgA expression on the phenotype of B. trispora. In contrast to the wild-type strain, the crgA null mutant (ΔcrgA) was defective in sporulation but accumulated much more β-carotene (31.2% improvement at the end) accompanied by enhanced transcription of three structural genes (hmgR, carB, and carRA) for carotenoids throughout the culture time. When the wild-type copy of crgA was complemented into the crgA null mutant, sporulation, transcription of structural genes, and carotenoid production were restored to those of the wild-type strain. A gas chromatography-mass spectrometry (GC-MS)-based metabolomic approach and multivariate statistical analyses were performed to investigate the intracellular metabolite profiles. The reduced levels of tricarboxylic acid (TCA) cycle components and some amino acids and enhanced levels of glycolysis intermediates and fatty acids indicate that more metabolic flux was driven into the mevalonate (MVA) pathway; thus, the increase of precursors and fat content contributes to the accumulation of carotenoids. IMPORTANCE The zygomycete Blakeslea trispora is an important strain for the production of carotenoids on a large scale. However, the regulation mechanism of carotenoid biosynthesis is still not well understood in this filamentous fungus. In the present study, we sought to investigate how crgA influences the expression of structural genes for carotenoids, carotenoid biosynthesis, and other anabolic phenotypes. This will lead to a better understanding of the global regulation mechanism of carotenoid biosynthesis and facilitate engineering this strain in the future for enhanced production of carotenoids.

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