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Li X, Dreher TW, Li R. An overview of diversity, occurrence, genetics and toxin production of bloom-forming Dolichospermum (Anabaena) species. Harmful Algae 2016; 54:54-68. [PMID: 28073482 DOI: 10.1016/j.hal.2015.10.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 10/19/2015] [Accepted: 10/24/2015] [Indexed: 05/12/2023]
Abstract
The new genus name Dolichospermum, for most of the planktonic former members of the genus Anabaena, is one of the most ubiquitous bloom-forming cyanobacterial genera. Its dominance and persistence have increased in recent years, due to eutrophication from anthropogenic activities and global climate change. Blooms of Dolichospermum species, with their production of secondary metabolites that commonly include toxins, present a worldwide threat to environmental and public health. In this review, recent advances of the genus Dolichospermum are summarized, including taxonomy, genetics, bloom occurrence, and production of toxin and taste-and-odor compounds. The recent and continuing acquisition of genome sequences is ushering in new methods for monitoring and understanding the factors regulating bloom dynamics.
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Affiliation(s)
- Xiaochuang Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Theo W Dreher
- Department of Microbiology, Oregon State University, Corvallis, OR, USA; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR, USA
| | - Renhui Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China.
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2
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Louati I, Pascault N, Debroas D, Bernard C, Humbert JF, Leloup J. Structural Diversity of Bacterial Communities Associated with Bloom-Forming Freshwater Cyanobacteria Differs According to the Cyanobacterial Genus. PLoS One 2015; 10:e0140614. [PMID: 26579722 PMCID: PMC4651346 DOI: 10.1371/journal.pone.0140614] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/27/2015] [Indexed: 12/21/2022] Open
Abstract
The factors and processes driving cyanobacterial blooms in eutrophic freshwater ecosystems have been extensively studied in the past decade. A growing number of these studies concern the direct or indirect interactions between cyanobacteria and heterotrophic bacteria. The presence of bacteria that are directly attached or immediately adjacent to cyanobacterial cells suggests that intense nutrient exchanges occur between these microorganisms. In order to determine if there is a specific association between cyanobacteria and bacteria, we compared the bacterial community composition during two cyanobacteria blooms of Anabaena (filamentous and N2-fixing) and Microcystis (colonial and non-N2 fixing) that occurred successively within the same lake. Using high-throughput sequencing, we revealed a clear distinction between associated and free-living communities and between cyanobacterial genera. The interactions between cyanobacteria and bacteria appeared to be based on dissolved organic matter degradation and on N recycling, both for N2-fixing and non N2-fixing cyanobacteria. Thus, the genus and potentially the species of cyanobacteria and its metabolic capacities appeared to select for the bacterial community in the phycosphere.
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Affiliation(s)
- Imen Louati
- iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France
| | - Noémie Pascault
- iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France
| | - Didier Debroas
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Clermont Université Blaise Pascal, Aubière, France
| | - Cécile Bernard
- MCAM MNHN, UMR CNRS 7245, Muséum National d’Histoire Naturelle, Sorbonne Universités, Paris, France
| | | | - Julie Leloup
- iEES-PARIS, UMR 7618 (UPMC-CNRS-INRA-IRD-UPEC-Paris Diderot), UPMC, Paris, France
- * E-mail:
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3
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Beversdorf LJ, Chaston SD, Miller TR, McMahon KD. Microcystin mcyA and mcyE Gene Abundances Are Not Appropriate Indicators of Microcystin Concentrations in Lakes. PLoS One 2015; 10:e0125353. [PMID: 25945933 PMCID: PMC4422731 DOI: 10.1371/journal.pone.0125353] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 03/11/2015] [Indexed: 11/19/2022] Open
Abstract
Cyanobacterial harmful algal blooms (cyanoHABs) are a primary source of water quality degradation in eutrophic lakes. The occurrence of cyanoHABs is ubiquitous and expected to increase with current climate and land use change scenarios. However, it is currently unknown what environmental parameters are important for indicating the presence of cyanoHAB toxins making them difficult to predict or even monitor on time-scales relevant to protecting public health. Using qPCR, we aimed to quantify genes within the microcystin operon (mcy) to determine which cyanobacterial taxa, and what percentage of the total cyanobacterial community, were responsible for microcystin production in four eutrophic lakes. We targeted Microcystis-16S, mcyA, and Microcystis, Planktothrix, and Anabaena-specific mcyE genes. We also measured microcystins and several biological, chemical, and physical parameters--such as temperature, lake stability, nutrients, pigments and cyanobacterial community composition (CCC)--to search for possible correlations to gene copy abundance and MC production. All four lakes contained Microcystis-mcyE genes and high percentages of toxic Microcystis, suggesting Microcystis was the dominant microcystin producer. However, all genes were highly variable temporally, and in few cases, correlated with increased temperature and nutrients as the summer progressed. Interestingly, toxin gene abundances (and biomass indicators) were anti-correlated with microcystin in all lakes except the largest lake, Lake Mendota. Similarly, gene abundance and microcystins differentially correlated to CCC in all lakes. Thus, we conclude that the presence of microcystin genes are not a useful tool for eliciting an ecological role for toxins in the environment, nor are microcystin genes (e.g. DNA) a good indicator of toxins in the environment.
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Affiliation(s)
- Lucas J. Beversdorf
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin, 53706, United States of America
| | - Sheena D. Chaston
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin, 53706, United States of America
| | - Todd R. Miller
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin, 53706, United States of America
| | - Katherine D. McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin, 53706, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin, 53706, United States of America
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Shishido TK, Humisto A, Jokela J, Liu L, Wahlsten M, Tamrakar A, Fewer DP, Permi P, Andreote APD, Fiore MF, Sivonen K. Antifungal compounds from cyanobacteria. Mar Drugs 2015; 13:2124-40. [PMID: 25871291 PMCID: PMC4413203 DOI: 10.3390/md13042124] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 12/05/2022] Open
Abstract
Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.
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Affiliation(s)
- Tânia K Shishido
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Anu Humisto
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Jouni Jokela
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Liwei Liu
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Matti Wahlsten
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Anisha Tamrakar
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - David P Fewer
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Perttu Permi
- Program in Structural Biology and Biophysics, Institute of Biotechnology/Nuclear Magnetic Resonance Laboratory, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Ana P D Andreote
- Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil.
| | - Marli F Fiore
- Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil.
| | - Kaarina Sivonen
- Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, FI-00014, Helsinki, Finland.
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Pereira AL, Vasconcelos V. Classification and phylogeny of the cyanobiont Anabaena azollae Strasburger: an answered question? Int J Syst Evol Microbiol 2014; 64:1830-1840. [PMID: 24737795 DOI: 10.1099/ijs.0.059238-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The symbiosis Azolla-Anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. The cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). The classification and phylogeny of the cyanobiont is very controversial: from its morphology, it has been named Nostoc azollae, Anabaena azollae, Anabaena variabilis status azollae and recently Trichormus azollae, but, from its 16S rRNA gene sequence, it has been assigned to Nostoc and/or Anabaena, and from its phycocyanin gene sequence, it has been assigned as non-Nostoc and non-Anabaena. The literature also points to a possible co-evolution between the cyanobiont and the Azolla host, since dendrograms and phylogenetic trees of fatty acids, short tandemly repeated repetitive (STRR) analysis and restriction fragment length polymorphism (RFLP) analysis of nif genes and the 16S rRNA gene give a two-cluster association that matches the two-section ranking of the host (Azolla). Another controversy surrounds the possible existence of more than one genus or more than one species strain. The use of freshly isolated or cultured cyanobionts is an additional problem, since their morphology and protein profiles are different. This review gives an overview of how morphological, chemical and genetic analyses influence the classification and phylogeny of the cyanobiont and future research.
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Affiliation(s)
- Ana L Pereira
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal
| | - Vitor Vasconcelos
- Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal
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Hautala H, Lamminmäki U, Spoof L, Nybom S, Meriluoto J, Vehniäinen M. Quantitative PCR detection and improved sample preparation of microcystin-producing Anabaena, Microcystis and Planktothrix. Ecotoxicol Environ Saf 2013; 87:49-56. [PMID: 23122919 DOI: 10.1016/j.ecoenv.2012.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 09/24/2012] [Accepted: 10/10/2012] [Indexed: 06/01/2023]
Abstract
Blooms of toxic cyanobacteria, associated with illness and mortality in humans and animals, are becoming increasingly common worldwide. The safe use of surface waters for drinking water production and recreation necessitates assessment of toxigenic cyanobacteria. We have developed simple and reliable sample preparation and qPCR methods to detect microcystin-producing strains of three major bloom-forming genera, Anabaena, Microcystis and Planktothrix. The mcyB second thiolation motif, previously not recognized as a potential target for qPCR, was used as a basis for primer and genus-specific probe design. Assay specificity and sensitivity was confirmed with cultured cyanobacterial strains and the effect of different sample preparation methods on quantification was investigated. Sample filtration and cell lysis reduced assay time and resulted in more efficient amplification compared to DNA extraction. Positive correlation (p<0.005) between mcyB copy numbers and microcystin concentrations was observed in environmental samples. The results encourage the use of qPCR in water risk management.
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Affiliation(s)
- Henna Hautala
- Department of Biotechnology, University of Turku, Tykistökatu 6A, 6th floor, FI-20520 Turku, Finland.
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Kang HS, Sturdy M, Krunic A, Kim H, Shen Q, Swanson SM, Orjala J. Minutissamides E-L, antiproliferative cyclic lipodecapeptides from the cultured freshwater cyanobacterium cf. Anabaena sp. Bioorg Med Chem 2012; 20:6134-43. [PMID: 22980217 DOI: 10.1016/j.bmc.2012.08.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 11/16/2022]
Abstract
The extract of UIC 10035, a strain obtained from a sample collected near the town of Homestead, South Florida, showed antiproliferative activity against MDA-MB-435 cells. Bioassay-guided fractionation led to the isolation of a series of cyclic lipodecapeptides, named minutissamides E-L (1-8). The planar structures were determined by analysis of HRESIMS, tandem MS, and 1D and 2D NMR data, and the stereoconfigurations were assigned by LC-MS analysis of the Marfey's derivatives after acid hydrolysis. Minutissamides E-L (1-8) exhibited antiproliferative activity against MDA-MB-435 cells with IC(50) values ranging between 1 and 10 μM. The structures of minutissamides E-L (1-8) were closely related with those of the previously reported lipopeptides, puwainaphycins A-E and minutissamides A-D, characterized by the presence of a lipophilic β-amino acid and three non-standard amino acids NMeAsn, OMeThr and Dhb (α,β-dehydro-α-aminobutyric acid). The strain UIC 10035 was designated as cf. Anabaena sp. on the basis of morphological and 16S rRNA gene sequence analyses.
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Affiliation(s)
- Hahk-Soo Kang
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60612, USA
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8
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Abstract
Cyanobacterial mass occurrences are widespread and often contain hepatotoxic, i.e. microcystin- and nodularin-producing, species. Nowadays, detection of microcystin (mcy) and nodularin synthetase (nda) genes is widely used for the recognition of toxic cyanobacterial strains in environmental water samples. Chip assay presented here combines ligation detection reaction and hybridization on a universal microarray to detect and identify the mcyE/ndaF genes of five cyanobacterial genera specifically and sensitively. Thus, one chip assay can reveal the co-occurrence of several hepatotoxin producers. The presented quantitative real-time PCR method is used for the detection of either microcystin-producing Anabaena or Microcystis. Determination of the mcyE-gene copy numbers allows the identification of the dominant producer genus in the sample.
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Affiliation(s)
- Anne Rantala-Ylinen
- Division of Microbiology, Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
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Głowacka J, Szefel-Markowska M, Waleron M, Łojkowska E, Waleron K. Detection and identification of potentially toxic cyanobacteria in Polish water bodies. Acta Biochim Pol 2011; 58:321-333. [PMID: 21750783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 01/19/2011] [Accepted: 07/01/2011] [Indexed: 05/31/2023]
Abstract
The main goal of this study was to determine the distribution of potentially toxic cyanobacteria in 39 selected Polish water bodies. From the water bodies with blooms and also from those in which blooms were not visible 87 samples were investigated. For the first time samples from ponds localized in villages with high agricultural activities were included. Lakes for which microcystin concentrations had been determined before were included as a reference for the research. The detection of cyanobacteria was conducted by microscopic observation as well as by PCR amplification of the rpoC1 gene fragment. Cyanobacteria were present in 75 out of 87 samples. The presence of potentially toxic cyanobacteria was detected by amplification of the mcyB and mcyE genes, which are involved in the biosynthesis of microcystins. Both genes were detected in 7 out of 9 blooms investigated. In the case of samples collected from water bodies in which blooms were not observed, the mcyB and mcyE genes were detected in 20 out of 36. In order to identify the cyanobacteria occurring in selected reservoirs, 16S plus ITS clone libraries were constructed. The method allowed distinguishing 18 different genotypes. After sequence analysis, cyanobacteria belonging to genera Microcystis, Planktothrix, Anabaena, Pseudanabaena, Synechocystis, Synechococcus and Woronichinia were identified. Results confirmed the usefulness of the rpoC1 and mcy genes for monitoring water bodies and detection of potentially toxic cyanobacteria. Application of molecular markers allowed detecting potentially toxic cyanobacteria before the bloom was visible. This is the first comprehensive study concerning cyanobacteria present in different types of Polish water bodies performed using molecular markers.
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Affiliation(s)
- Joanna Głowacka
- Department of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, Poland
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Hussain A, Krischke M, Roitsch T, Hasnain S. Rapid determination of cytokinins and auxin in cyanobacteria. Curr Microbiol 2010; 61:361-9. [PMID: 20339849 DOI: 10.1007/s00284-010-9620-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 03/10/2010] [Indexed: 11/27/2022]
Abstract
Five cyanobacterial strains, Anabaena sp. Ck1, Oscillatoria sp. Ck2, Phormidium sp. Ck3, Chroococcidiopsis sp. Ck4, and Synechosystis sp. Ck5 were selected for their positive cytokinins-like activity using cucumber cotyledon bioassay and GUS assay in Arabidopsis ARR5::GUS. Classical cucumber cotyledon bioassay was modified for direct screening of cyanobacteria avoiding need for extraction and purification. Cytokinins from cyanobacteria were absorbed onto filter paper which was then assayed for cytokinins-like activity. A rapid chromatographic method was developed for the simultaneous determination of cytokinins and indole-3-acetic acid (IAA). Cyanobacterial biomass (50-100 mg) and cell-free culture filtrate were extracted in Bieleski buffer and purified by solid-phase extraction. The extract was used to determine phytohormones by ultra performance liquid chromatography and electrospray ionization-tandem mass spectrometry in positive and negative modes, respectively, with multiple reactions monitoring. Stable isotope-labeled cytokinins and IAA standards were added in the samples to follow recovery of the compounds and method validation. Five cytokinins determined in the selected strains were Zeatin (cis and trans isomers), Zeatin riboside, Dihydrozeatin riboside, and zeatin-o-glucoside. The strains were shown to accumulate as well as release the phytohormones.
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Affiliation(s)
- Anwar Hussain
- Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
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Mihali TK, Kellmann R, Neilan BA. Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5. BMC Biochem 2009; 10:8. [PMID: 19331657 PMCID: PMC2679770 DOI: 10.1186/1471-2091-10-8] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 03/30/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs) are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for such an unusual phylogenetic distribution of this shared uncommon metabolic pathway, include a polyphyletic origin, an involvement of symbiotic bacteria, and horizontal gene transfer. RESULTS We describe the identification, annotation and bioinformatic characterisation of the putative paralytic shellfish toxin biosynthesis clusters in an Australian isolate of Anabaena circinalis and an American isolate of Aphanizomenon sp., both members of the Nostocales. These putative PST gene clusters span approximately 28 kb and contain genes coding for the biosynthesis and export of the toxin. A putative insertion/excision site in the Australian Anabaena circinalis AWQC131C was identified, and the organization and evolution of the gene clusters are discussed. A biosynthetic pathway leading to the formation of saxitoxin and its analogues in these organisms is proposed. CONCLUSION The PST biosynthesis gene cluster presents a mosaic structure, whereby genes have apparently transposed in segments of varying size, resulting in different gene arrangements in all three sxt clusters sequenced so far. The gene cluster organizational structure and sequence similarity seems to reflect the phylogeny of the producer organisms, indicating that the gene clusters have an ancient origin, or that their lateral transfer was also an ancient event. The knowledge we gain from the characterisation of the PST biosynthesis gene clusters, including the identity and sequence of the genes involved in the biosynthesis, may also afford the identification of these gene clusters in dinoflagellates, the cause of human mortalities and significant financial loss to the tourism and shellfish industries.
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Affiliation(s)
- Troco K Mihali
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Ralf Kellmann
- Department of Molecular Biology, University of Bergen, P.O. Box 7803, 5020 Bergen, Norway
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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Aldea MR, Mella-Herrera RA, Golden JW. Sigma factor genes sigC, sigE, and sigG are upregulated in heterocysts of the cyanobacterium Anabaena sp. strain PCC 7120. J Bacteriol 2007; 189:8392-6. [PMID: 17873052 PMCID: PMC2168693 DOI: 10.1128/jb.00821-07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We used gfp transcriptional fusions to investigate the regulation of eight sigma factor genes during heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120. Reporter strains containing gfp fusions with the upstream regions of sigB2, sigD, sigI, and sigJ did not show developmental regulation. Time-lapse microscopy of sigC, sigE, and sigG reporter strains showed increased green fluorescent protein fluorescence in differentiating cells at 4 h, 16 h, and 9 h, respectively, after nitrogen step down.
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Affiliation(s)
- M Ramona Aldea
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX 77843-3258, USA
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Halinen K, Jokela J, Fewer DP, Wahlsten M, Sivonen K. Direct evidence for production of microcystins by Anabaena strains from the Baltic Sea. Appl Environ Microbiol 2007; 73:6543-50. [PMID: 17766456 PMCID: PMC2075070 DOI: 10.1128/aem.01377-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anabaena is a filamentous, N(2)-fixing, and morphologically diverse genus of cyanobacteria found in freshwater and brackish water environments worldwide. It contributes to the formation of toxic blooms in freshwater bodies through the production of a range of hepatotoxins or neurotoxins. In the Baltic Sea, Anabaena spp. form late summer blooms, together with Nodularia spumigena and Aphanizomenon flos-aquae. It has been long suspected that Baltic Sea Anabaena may produce microcystins. The presence of microcystins has been reported for the coastal regions of the Baltic proper, and a recent report also indicated the presence of the toxin in the open Gulf of Finland. However, at present there is no direct evidence linking Baltic Sea Anabaena spp. to microcystin production. Here we report on the isolation of microcystin-producing strains of the genus Anabaena in the open Gulf of Finland. The dominant microcystin variants produced by these strains included the highly toxic MCYST-LR as well as [d-Asp(3)]MCYST-LR, [d-Asp(3)]MCYST-HtyR, MCYST-HtyR, [d-Asp(3),Dha(7)]MCYST-HtyR, and [Dha(7)]MCYST-HtyR variants. Toxic strains were isolated from the coastal Gulf of Finland as well as from the easternmost open-sea sampling station, where there were lower salinities than at other stations. This result suggests that lower salinity may favor microcystin-producing Anabaena strains. Furthermore, we sequenced 16S rRNA genes and found evidence for pronounced genetic heterogeneity of the microcystin-producing Anabaena strains. Future studies should take into account the potential presence of microcystin-producing Anabaena sp. in the Gulf of Finland.
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Affiliation(s)
- Katrianna Halinen
- Department of Applied Chemistry and Microbiology, P.O. Box 56, Viikki Biocenter (Viikinkaari 9), FIN-00014 University of Helsinki, Finland.
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Moslavac S, Nicolaisen K, Mirus O, Al Dehni F, Pernil R, Flores E, Maldener I, Schleiff E. A TolC-like protein is required for heterocyst development in Anabaena sp. strain PCC 7120. J Bacteriol 2007; 189:7887-95. [PMID: 17720784 PMCID: PMC2168721 DOI: 10.1128/jb.00750-07] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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 beta-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).
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Affiliation(s)
- Suncana Moslavac
- LMU, Department of Biology I, VW-Research Group, Menzinger Str. 67, 80638 München, Germany
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15
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Wolk CP, Fan Q, Zhou R, Huang G, Lechno-Yossef S, Kuritz T, Wojciuch E. Paired cloning vectors for complementation of mutations in the cyanobacterium Anabaena sp. strain PCC 7120. Arch Microbiol 2007; 188:551-63. [PMID: 17639350 DOI: 10.1007/s00203-007-0276-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 06/11/2007] [Accepted: 06/16/2007] [Indexed: 11/26/2022]
Abstract
The clones generated in a sequencing project represent a resource for subsequent analysis of the organism whose genome has been sequenced. We describe an interrelated group of cloning vectors that either integrate into the genome or replicate, and that enhance the utility, for developmental and other studies, of the clones used to determine the genomic sequence of the cyanobacterium, Anabaena sp. strain PCC 7120. One integrating vector is a mobilizable BAC vector that was used both to generate bridging clones and to complement transposon mutations. Upon addition of a cassette that permits mobilization and selection, pUC-based sequencing clones can also integrate into the genome and thereupon complement transposon mutations. The replicating vectors are based on cyanobacterial plasmid pDU1, whose sequence we report, and on broad-host-range plasmid RSF1010. The RSF1010- and pDU1-based vectors provide the opportunity to express different genes from either cell-type-specific or -generalist promoters, simultaneously from different plasmids in the same cyanobacterial cells. We show that pDU1 ORF4 and its upstream region play an essential role in the replication and copy number of pDU1, and that ORFs alr2887 and alr3546 (hetF A) of Anabaena sp. are required specifically for fixation of dinitrogen under oxic conditions.
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Affiliation(s)
- C Peter Wolk
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824-1312, USA.
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16
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Hotto AM, Satchwell MF, Boyer GL. Molecular characterization of potential microcystin-producing cyanobacteria in Lake Ontario embayments and nearshore waters. Appl Environ Microbiol 2007; 73:4570-8. [PMID: 17526791 PMCID: PMC1932839 DOI: 10.1128/aem.00318-07] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distribution and genotypic variation of potential microcystin (MC) producers along the southern and eastern shores of Lake Ontario in 2001 and 2003 were examined using a suite of PCR primers. Cyanobacterial, Microcystis sp., and Microcystis-specific toxin primer sets identified shoreline distribution of cyanobacterial DNA (in 97% of the stations) and MC synthetase genes (in 50% of the stations). Sequence analysis of a partial mcyA amplicon targeting Microcystis, Anabaena, and Planktothrix species indicated that the Microcystis sp. genotype was the dominant MC genotype present and revealed a novel Microcystis-like sequence containing a 6-bp insert. Analysis of the same samples with genus-specific mcyE primers confirmed that the Microcystis sp. genotype was the dominant potential MC producer. Genotype compositions within embayments were relatively homogenous compared to those for shoreline and tributary samples. MC concentrations along the shoreline exhibited both temporal and spatial differences as evidenced by the protein phosphatase inhibition assay, at times exceeding the World Health Organization guideline value for drinking water of 1.0 microg MC-LReq liter(-1). MC genotypes are widespread along the New York State shoreline of Lake Ontario, appear to originate nearshore, and can be carried through the lake via wind and surface water current patterns.
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Affiliation(s)
- A M Hotto
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA
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17
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Narikawa R, Zikihara K, Okajima K, Ochiai Y, Katayama M, Shichida Y, Tokutomi S, Ikeuchi M. Three putative photosensory light, oxygen or voltage (LOV) domains with distinct biochemical properties from the filamentous cyanobacterium Anabaena sp. PCC 7120. Photochem Photobiol 2007; 82:1627-33. [PMID: 16922605 DOI: 10.1562/2006-05-02-ra-888] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Light, oxygen or voltage (LOV) domains function as blue-light sensors in the phototropin family of photoreceptors found in plants, algae and bacteria. We detected putative LOV domains (Alr3170-LOV, All2875-LOV and Alr1229-LOV) in the genome of a filamentous cyanobacterium, Anabaena sp. PCC 7120. These cyanobacterial LOV domains are closely clustered with the known LOV domains. Alr3170-LOV and A112875-LOV carry the conserved cysteine residue unique to the photoactive LOV, whereas Alr1229-LOV does not. We expressed these three LOV domains in Escherichia coli and purified them. In fact, Alr3170-LOV and A112875-LOV that are conserved in Nostoc punctiforme, a related species, bound flavin mononucleotide and showed spectral changes unique to known LOV domains on illumination with blue light. Alr3170-LOV was completely photoreduced and dark reversion was slow, whereas A112875-LOV was slowly photoreduced and dark reversion was rapid. For comparison, AvA112875-LOV in a closely related A. variabilis was also studied as a homolog of A112875-LOV. Finally, we observed that Alr1229-LOV that is not conserved in N. punctiforme showed no flavin binding.
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Affiliation(s)
- Rei Narikawa
- Department of Life Sciences (Biology), Graduate School of Art and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan
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18
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Bennett JP, Whittingham JL, Brzozowski AM, Leonard PM, Grogan G. Structural characterization of a beta-diketone hydrolase from the cyanobacterium Anabaena sp. PCC 7120 in native and product-bound forms, a coenzyme A-independent member of the crotonase suprafamily. Biochemistry 2007; 46:137-44. [PMID: 17198383 DOI: 10.1021/bi061900g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gene alr4455 from the well-studied cyanobacterium Anabaena sp. PCC 7120 encodes a crotonase orthologue that displays beta-diketone hydrolase activity. Anabaena beta-diketone hydrolase (ABDH), in common with 6-oxocamphor hydrolase (OCH) from Rhodococcus sp. NCIMB 9784, catalyzes the desymmetrization of bicyclo[2.2.2]octane-2,6-dione to yield [(S)-3-oxocyclohexyl]acetic acid, a reaction unusual among the crotonase superfamily as the substrate is not an acyl-CoA thioester. The structure of ABDH has been determined to a resolution of 1.5 A in both native and ligand-bound forms. ABDH forms a hexamer similar to OCH and features one active site per enzyme monomer. The arrangement of side chains in the active site indicates that while the catalytic chemistry may be conserved in OCH orthologues, the structural determinants of substrate specificity are different. In the active site of ligand-bound forms that had been cocrystallized with the bicyclic diketone substrate bicyclo[2.2.2]octane-2,6-dione was found the product of the asymmetric enzymatic retro-Claisen reaction [(S)-3-oxocyclohexyl]acetic acid. The structures of ABDH in both native and ligand-bound forms reveal further details about structural variation and modes of coenzyme A-independent activity within the crotonases and provide further evidence of a wider suprafamily of enzymes that have recruited the crotonase fold for the catalysis of reactions other than those regularly attributed to canonical superfamily members.
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Affiliation(s)
- Joseph P Bennett
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK
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19
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Prasanna R, Kumar R, Sood A, Prasanna BM, Singh PK. Morphological, physiochemical and molecular characterization of Anabaena strains. Microbiol Res 2005; 161:187-202. [PMID: 16765835 DOI: 10.1016/j.micres.2005.08.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2005] [Indexed: 10/25/2022]
Abstract
A set of 30 Anabaena strains, isolated from diverse geographical regions of India, were characterized using morphological and physiochemical attributes as well as molecular marker profiles. Significant differences were observed among the Anabaena strains with regard to the shape and size of trichomes and individual cells within a filament, besides qualitative and quantitative aspects of phycobiliprotein accumulation and activities of enzymes involved in nitrogen metabolism. Analyses of molecular polymorphisms in a selected set of 13 Anabaena strains, using primers based on repetitive sequences in the genome, led to unambiguous differentiation of the strains as well as understanding of their genetic relationships. Informative morphological, physio-chemical and molecular characters have been identified that could aid in differentiation and utilization of Anabaena strains as bioinoculants or as sources of pigments.
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Affiliation(s)
- Radha Prasanna
- Centre for Conservation and Utilization of Blue-Green Algae, Indian Agricultural Research Institute, IARI, New Delhi 110012, India.
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20
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Torres S, Fjetland CR, Lammers PJ. Alkane-induced expression, substrate binding profile, and immunolocalization of a cytochrome P450 encoded on the nifD excision element of Anabaena 7120. BMC Microbiol 2005; 5:16. [PMID: 15790415 PMCID: PMC1079853 DOI: 10.1186/1471-2180-5-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Accepted: 03/24/2005] [Indexed: 11/29/2022] Open
Abstract
Background Alkanes have been hypothesized to act as universal inducers of bacterial cytochrome P450 gene expression. We tested this hypothesis on an unusual P450 gene (cyp110) found on a conserved 11 kilobase episomal DNA element of unknown function found in filamentous cyanobacteria. We also monitored the binding of potential substrates to the P450 protein and explored the distribution of P450 protein in vegetative cells and nitrogen-fixing heterocysts using immuno-electron microscopy. Results Hexadecane treatments resulted in a two-fold increase in mRNA, and a four-fold increase in P450 protein levels relative to control cultures. Hexane, octane and dodecane were toxic and induced substantial changes in membrane morphology. Long-chain saturated and unsaturated fatty acids were shown to bind the CYP110 protein using a spectroscopic spin-shift assay, but alkanes did not bind. CYP110 protein was detected in vegetative cells but not in differentiated heterocysts where nitrogen fixation occurs. Conclusion Hexadecane treatment was an effective inducer of CYP110 expression in cyanobacteria. Based on substrate binding profiles and amino acid sequence similarities it is hypothesized that CYP110 is a fatty acid ω-hydroxylase in photosynthetic cells. CYP110 was found associated with membrane fractions unlike other soluble microbial P450 proteins, and in this regard CYP110 more closely resembles eukarytotic P450s. Substrate stablization is an unlikely mechanism for alkane induction because alkanes did not bind to purified CYP110 protein.
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Affiliation(s)
- Sergio Torres
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM, USA
| | - Conrad R Fjetland
- University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, TX, USA
| | - Peter J Lammers
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM, USA
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21
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Li R, Watanabe MM. Fatty Acid Composition of Planktonic Species of Anabaena (Cyanobacteria) with Coiled Trichomes Exhibited a Significant Taxonomic Value. Curr Microbiol 2004; 49:376-80. [PMID: 15486714 DOI: 10.1007/s00284-004-4380-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 06/11/2004] [Indexed: 11/26/2022]
Abstract
Twenty-six axenic strains of planktonic Anabaena with coiled trichomes belonging to 13 species were investigated by analyzing the pattern and content of their fatty acid composition, and by comparing their fatty acid composition with their morphological properties. In general, the planktonic Anabaena with coiled trichomes contained 14:0, 16:0, 16:1(cis-), 18:0, 18:1, 18:2, and 18:3(alpha) as their major fatty acid component, and were classified as Type 2 according to the Kenyon-Murata System. The Type 2 was further divided into two subtypes: Type 2A with 16:2 and 16:3, and Type 2B without 16:2 and 16:3. Among these Anabaena strains with coiled form, A. oumiana (NIES-73 and Ana Kas1) and A. eucompacta (Ana Chiba) contained Type 2B fatty acid composition, and other strains contained Type 2A. Among the strains with the latter type, A. circinalis (Ana Da) and A. curva (Ana Ao) had low levels of 18:3(alpha). Most Anabaena strains with coiled trichomes showed a strong correlation between morphological characteristics and fatty acid composition.
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Affiliation(s)
- Renhui Li
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0035, Japan.
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22
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Pomati F, Burns BP, Neilan BA. Identification of an Na(+)-dependent transporter associated with saxitoxin-producing strains of the cyanobacterium Anabaena circinalis. Appl Environ Microbiol 2004; 70:4711-9. [PMID: 15294806 PMCID: PMC492425 DOI: 10.1128/aem.70.8.4711-4719.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Blooms of the freshwater cyanobacterium Anabaena circinalis are recognized as an important health risk worldwide due to the production of a range of toxins such as saxitoxin (STX) and its derivatives. In this study we used HIP1 octameric-palindrome repeated-sequence PCR to compare the genomic structure of phylogenetically similar Australian isolates of A. circinalis. STX-producing and nontoxic cyanobacterial strains showed different HIP1 (highly iterated octameric palindrome 1) DNA patterns, and characteristic interrepeat amplicons for each group were identified. Suppression subtractive hybridization (SSH) was performed using HIP1 PCR-generated libraries to further identify toxic-strain-specific genes. An STX-producing strain and a nontoxic strain of A. circinalis were chosen as testers in two distinct experiments. The two categories of SSH putative tester-specific sequences were characterized by different families of encoded proteins that may be representative of the differences in metabolism between STX-producing and nontoxic A. circinalis strains. DNA-microarray hybridization and genomic screening revealed a toxic-strain-specific HIP1 fragment coding for a putative Na(+)-dependent transporter. Analysis of this gene demonstrated analogy to the mrpF gene of Bacillus subtilis, whose encoded protein is involved in Na(+)-specific pH homeostasis. The application of this gene as a molecular probe in laboratory and environmental screening for STX-producing A. circinalis strains was demonstrated. The possible role of this putative Na(+)-dependent transporter in the toxic cyanobacterial phenotype is also discussed, in light of recent physiological studies of STX-producing cyanobacteria.
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Affiliation(s)
- Francesco Pomati
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
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23
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Abstract
A PCR-based positive hybridization (PPH) method was developed to explore toxic-specific genes in common between toxigenic strains of Anabaena circinalis, a cyanobacterium able to produce saxitoxin (STX). The PPH technique is based on the same principles of suppression subtractive hybridization (SSH), although with the former no driver DNA is required and two tester genomic DNAs are hybridized at high stringency. The aim was to obtain genes associated with cyanobacterial STX production. The genetic diversity within phylogenetically similar strains of A.circinalis was investigated by comparing the results of the standard SSH protocol to the PPH approach by DNA-microarray analysis. SSH allowed the recovery of DNA libraries that were mainly specific for each of the two STX-producing strains used. Several candidate sequences were found by PPH to be in common between both the STX-producing testers. The PPH technique performed using unsubtracted genomic libraries proved to be a powerful tool to identify DNA sequences possibly transferred laterally between two cyanobacterial strains that may be candidate(s) in STX biosynthesis. The approach presented in this study represents a novel and valid tool to study the genetic basis for secondary metabolite production in microorganisms.
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Affiliation(s)
- Francesco Pomati
- Cyanobacteria and Astrobiology Research Laboratory, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
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24
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Abstract
In this study, fatty-acid content and patterns were analyzed in order to distinguish Nostoc flagelliforme, an edible terrestrial cyanobacterium, from other Nostoc species and representatives typical of its close neighbors (genera Anabaena, Microcystis, and Synechococcus). According to the Kenyon-Murata classification system, all the Nostoc species were assigned to Group II due to the presence of C18:2n3 and C18:3n3, and the absence of C18:3n6. Hierarchical cluster analysis was also employed to separate N. flagelliforme and other Nostoc species or strains. A dendrogram calculation of all fatty-acid components manifested phenetic characteristics, showing that the degree of relatedness of two strains of N. flagelliforme aggregated them within a small subgroup. Another dendrogram, calculated from seven comprehensive parameters (including ratios of different fatty-acid categories, degree of fatty-acid unsaturation, etc.), also clearly delimited the minute difference in fatty-acid profiles between the tested organisms. Our results suggest that profiling fatty acids could be a useful approach in the taxonomic or phylogenetic study of the genus Nostoc and might serve as a valuable supplement to the current morphology-based classification system.
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Affiliation(s)
- Xue-Jun Liu
- Department of Botany, University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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25
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Hisbergues M, Christiansen G, Rouhiainen L, Sivonen K, Börner T. PCR-based identification of microcystin-producing genotypes of different cyanobacterial genera. Arch Microbiol 2003; 180:402-10. [PMID: 14551674 DOI: 10.1007/s00203-003-0605-9] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Revised: 08/29/2003] [Accepted: 09/09/2003] [Indexed: 10/26/2022]
Abstract
Microcystins are harmful hepatotoxins produced by many, but not all strains of the cyanobacterial genera Anabaena, Microcystis, Anabaena, Planktothrix, and Nostoc. Waterbodies have to be monitored for the mass development of toxic cyanobacteria; however, because of the close genetic relationship of microcystin-producing and non-producing strains within a genus, identification of microcystin-producers by morphological criteria is not possible. The genomes of microcystin-producing cells contain mcy genes coding for the microcystin synthetase complex. Based on the sequence information of mcy genes from Microcystis and Planktothrix, a primer pair for PCR amplification of a mcyA gene fragment was designed. PCR with this primer pair is a powerful means to identify microcystin-producing strains of the genera Anabaena, Microcystis, and Planktothrix. Moreover, subsequent RFLP analysis of the PCR products generated genus-specific fragments and allowed the genus of the toxin producer to be identified. The assay can be used with DNA from field samples.
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Affiliation(s)
- Michael Hisbergues
- Department of Biology, Humboldt University, Chausseestrasse 117, 10115 Berlin, Germany
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26
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Tsygankov AA, Fedorov AS, Kosourov SN, Rao KK. Hydrogen production by cyanobacteria in an automated outdoor photobioreactor under aerobic conditions. Biotechnol Bioeng 2002; 80:777-83. [PMID: 12402323 DOI: 10.1002/bit.10431] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The possibility of hydrogen production by a hydrogenase impaired mutant strain of Anabaena variabilis in outdoor culture was studied. A computer-controlled rooftop (outdoor) tubular photobioreactor (4.35 L) was assembled. H(2) production rates by A. variabilis PK84 grown in CO(2) + air in the photobioreactor were measured together with other parameters such as temperature, irradiance, pH, dry biomass weight, and pO(2), and Chl a concentrations during summer months of 1998 and 1999. Efficiencies of light energy bioconversion to H(2) energy and energy accumulated in biomass were calculated. The influence of irradiance, temperature, and mode of cultivation on H(2) production and efficiency of light energy bioconversion were evaluated. The culture produced up to 1.1 L H(2) day(-1) PhBR(-1). The efficiency of light energy to H(2) energy bioconversion on some days was 0.094%. However, the conditions for maximum H(2) photoproduction and for maximum efficiency of light energy to H(2) energy bioconversion were not the same. A. variabilis PK84 could produce hydrogen for prolonged periods (up to 40 days) without injection of fresh inoculum. During this period photobioreactor produced 24.5 L of H(2). Possibilities for increasing the efficiency of light energy conversion are discussed.
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Affiliation(s)
- A A Tsygankov
- Institute of Basic Biological Problems RAS, Pushchino, Moscow Region, 142290, Russia
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27
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Abstract
We exploit a property of microalgae-that of their ability to autofluoresce when exposed to epifluorescence illumination-to tackle the problem of detecting and analysing microalgae in sediment samples containing complex scenes. We have added fluorescence excitation to the hardware portion of our microalgae image processing system. We quantitatively measured 120 characteristics of each object detected through fluorescence excitation, and used an optimized subset of these characteristics for later automated analysis and species classification. All specimens used for training and testing our system came from natural populations found in Lake Biwa, Japan. Without the use of fluorescence excitation, automated analysis of images containing algae specimens in sediment is near impossible. We also used fluorescence imaging to target microalgae in water samples containing large numbers of obtrusive nontargeted objects, which would otherwise slow processing speed and decrease species analysis and classification accuracy. Object drift problems associated with the necessity to use both a fluorescence and greyscale image of each microscope scene were solved using techniques such as template matching and a novel form of automated seeded region growing (SRG). Our system proved to be not only user-friendly, but also highly accurate in classifying two major genera of microalgae found in Lake Biwa-the cyanobacteria Anabaena spp. and Microcystis spp. Classification accuracy was measured to be over 97%.
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Affiliation(s)
- Ross F Walker
- Lake Biwa Research Institute, 1-10 Uchidehama, Otsu, Shiga 520-0806, Japan.
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28
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Gugger M, Lyra C, Henriksen P, Couté A, Humbert JF, Sivonen K. Phylogenetic comparison of the cyanobacterial genera Anabaena and Aphanizomenon. Int J Syst Evol Microbiol 2002; 52:1867-80. [PMID: 12361299 DOI: 10.1099/00207713-52-5-1867] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Morphological analysis and sequencing of the 165 rRNA gene, the spacer region of the ribosomal operon (ITS1) and the rbcLX (RubisCO) region was performed on 26 Anabaena strains and 14 Aphanizomenon strains isolated from several lakes in Denmark, Finland and France. Based on their morphology, Anabaena strains differed from strains of Aphanizomenon: the vegetative cells, heterocysts and akinetes were significantly wider in Anabaena than in Aphanizomenon. Phylogenetic trees based on the 16S rDNA, ITS1 and rbcLX regions showed that the planktic Anabaena strains were not distinguishable from Aphanizomenon strains. The results of the clustering of Anabaena and Aphanizomenon strains based on 16S rDNA sequences showed that these two genera are not monophyletic. Sequence analysis of the 16S rDNA, ITS1-S and rbcLX regions of the planktic Anabaena strains showed that this genus is heterogeneous. In all methods, Anabaena strains that produced different toxic compounds (e.g. anatoxin-a, microcystin and an unknown neurotoxin) were clustered separately from each other but were grouped either with non-toxic Anabaena and/or Aphanizomenon strains. Our data suggest that the planktic Anabaena and Aphanizomenon isolates belong to the same genus, regardless of their morphological differences. Thus, a taxonomic revision of the two genera is required.
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Affiliation(s)
- Muriel Gugger
- Department of Applied Chemistry and Microbiology, Biocenter Viikki, Helsinki University, Finland
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29
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Henson BJ, Watson LE, Barnum SR. Molecular differentiation of the heterocystous cyanobacteria, Nostoc and Anabaena, based on complete NifD sequences. Curr Microbiol 2002; 45:161-4. [PMID: 12177735 DOI: 10.1007/s00284-001-0111-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The segregation of Nostoc and Anabaena into separate genera has been debated for some time. The nitrogen fixation gene nifD was completely sequenced from representatives of these genera and analyzed phylogenetically, by using the representatives of other genera of the heterocystous cyanobacteria as outgroups. We were clearly able to differentiate between Nostoc and Anabaena in all analyses used. Our data suggest that Nostoc and Anabaena should remain as separate genera.
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Affiliation(s)
- Brian J Henson
- Department of Botany, Miami University, Oxford, OH 45056, USA
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30
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Gugger M, Lyra C, Suominen I, Tsitko I, Humbert JF, Salkinoja-Salonen MS, Sivonen K. Cellular fatty acids as chemotaxonomic markers of the genera Anabaena, Aphanizomenon, Microcystis, Nostoc and Planktothrix (cyanobacteria). Int J Syst Evol Microbiol 2002; 52:1007-1015. [PMID: 12054217 DOI: 10.1099/00207713-52-3-1007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cellular fatty acid content of 22 cyanobacterial strains belonging to the genera Anabaena, Aphanizomenon, Calothrix, Cylindrospermum, Nostoc, Microcystis and Planktothrix were analysed. The identities of the major peaks were confirmed by MS. Correspondence analysis of the data revealed three distinct groups formed by the Microcystis strains, the Nostoc/Planktothrix strains and the Anabaena/Aphanizomenon/Cylindrospermum strains. The Calothrix strain did not cluster with the other heterocystous cyanobacteria, supporting its morphological classification separate from the Nostocaceae family. The presence of large amounts of the fatty acids 18:30omega6,9,12c and 18:0 iso distinguished the Microcystis strains from the other cyanobacteria studied. The high content of 16:1omega7c grouped the Nostoc strains with the Planktothrix strains. A free-living strain of Nostoc contained 16:1omegao5c and 16: 1omega7c (about 1: 1), separating it from the symbiotic Nostoc strain and the Planktothrix strains. the strains of Anabaena, Aphanizomenon and Cylindrospermum grouped tightly and were characterized by the presence of 16:1omega9c and 16:0 anteiso fatty acids. Correspondence analysis of Anabaena, Aphanizomenon and Cylindrospermum showed that all hepatotoxic Anabaena strains grouped together, whereas the non-toxic and neurotoxic Anabaena strains grouped with the non-toxic Aphanizomenon strains.
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Abstract
Fifty axenic strains of planktonic Anabaena, including 24 strains of the straight form and 26 strains of the coiled form, were examined for their DNA base composition (GC content). The taxonomic value of their GC content at species level was evaluated by comparing their morphological, physiological and biochemical properties. The DNA base composition determined for all fifty strains ranged from 35.9 to 56.4 mol% GC. The straight-form strains were in the range of 35.9-56.4 mol% GC, while coiled forms were in the range of 38.1-50.3 mol% GC. In general, strains assigned to the same species showed similar DNA base composition. However, of three strains of A. affinis Lemmermann that were separated into two categories, two had 40.6-40.9 mol% GC, and the third strain 45.6 mol% GC. It is noteworthy that the DNA base composition of the newly established species A. eucompacta Li et Watanabe was 45.5 mol% GC, which differed from 39.5 mol% GC of the morphologically close species, A. compacta (Nygarrd) Hickel.
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Affiliation(s)
- Ren Hui Li
- National Institute for Environmental Studies, Tsukuba 305-0035, Japan.
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Subhashini R, Kumar K, Kannaiyan S. Biodiversity of Anabaena azollae isolates from different Azolla cultures. Indian J Exp Biol 2000; 38:1168-71. [PMID: 11395965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The random amplified polymorphic DNA (RAPD) profile of A. azollae strains isolated from four different Azolla cultures was studied by using different primers. The objective of this study was to determine whether polymerase chain reaction (PCR) with different primers could differentiate the isolated A. azollae strains from one another. The primers amplified specific sequences of the isolates and generated fingerprinting pattern characteristic of each isolate. Clear polymorphism was noticed among all the strains which depends on the primer sequence.
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Affiliation(s)
- R Subhashini
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore 641 003, India
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Beltran EC, Neilan BA. Geographical segregation of the neurotoxin-producing cyanobacterium Anabaena circinalis. Appl Environ Microbiol 2000; 66:4468-74. [PMID: 11010900 PMCID: PMC92326 DOI: 10.1128/aem.66.10.4468-4474.2000] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2000] [Accepted: 06/14/2000] [Indexed: 11/20/2022] Open
Abstract
Blooms of the cyanobacterium Anabaena circinalis are a major worldwide problem due to their production of a range of toxins, in particular the neurotoxins anatoxin-a and paralytic shellfish poisons (PSPs). Although there is a worldwide distribution of A. circinalis, there is a geographical segregation of neurotoxin production. American and European isolates of A. circinalis produce only anatoxin-a, while Australian isolates exclusively produce PSPs. The reason for this geographical segregation of neurotoxin production by A. circinalis is unknown. The phylogenetic structure of A. circinalis was determined by analyzing 16S rRNA gene sequences. A. circinalis was found to form a monophyletic group of international distribution. However, the PSP- and non-PSP-producing A. circinalis formed two distinct 16S rRNA gene clusters. A molecular probe was designed, allowing the identification of A. circinalis from cultured and uncultured environmental samples. In addition, probes targeting the predominantly PSP-producing or non-PSP-producing clusters were designed for the characterization of A. circinalis isolates as potential PSP producers.
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Affiliation(s)
- E C Beltran
- School of Microbiology and Immunology, The University of New South Wales, Sydney, New South Wales 2052, Australia
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Abstract
Although the cyanobacterium Anabaena circinalis occurs worldwide, Australian isolates are believed to exclusively possess the saxitoxin group neurotoxins (paralytic shellfish poisons). Identification of A. circinalis in a mixed population is complicated due to limited morphological differences between Anabaena species. Sequence analysis of the DNA-dependent RNA polymerase (rpoC1) gene from 24 Anabaena isolates, including 12 designated A. circinalis, permitted a phylogenetic analysis to be performed. In addition, an A. circinalis-specific PCR was developed and tested successfully on environmental samples.
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Affiliation(s)
- K M Fergusson
- The Cooperative Research Centre for Water Quality and Treatment, Australian Water Quality Centre, SA Water Corporation, Salisbury, South Australia 5108, Australia
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Maldener I, Fiedler G, Ernst A, Fernández-Piñas F, Wolk CP. Characterization of devA, a gene required for the maturation of proheterocysts in the cyanobacterium Anabaena sp. strain PCC 7120. J Bacteriol 1994; 176:7543-9. [PMID: 8002578 PMCID: PMC197211 DOI: 10.1128/jb.176.24.7543-7549.1994] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Mutant M7, obtained by transposon mutagenesis of the cyanobacterium Anabaena sp. strain PCC 7120, is impaired in the development of mature heterocysts. Under aerobic conditions, the mutant is unable to fix N2 because of a deficiency of at least two components of the oxygen-protective mechanisms: a hemoprotein-coupled oxidative reaction and heterocyst-specific glycolipids. DNA contiguous with the inserted transposon was recovered from the mutant and sequenced. The transposon had inserted itself within a 732-bp open reading frame designated devA. The wild-type form of devA, obtained from a lambda-EMBL3 library of Anabaena sp. DNA, had the identical sequence. Directed mutagenesis of devA in the wild-type strain showed that the phenotype of the mutant was caused by insertion of the transposon. The wild-type form of devA on a shuttle vector complemented the mutation in M7. Expression of devA by whole filaments, monitored following nitrogen stepdown by using luxAB as the reporter, increased ca. eightfold during differentiation; the increase within differentiating cells was much greater. The deduced sequence of the DevA protein shows strong similarity to the ATP-binding subunit of binding protein-dependent transport systems. The product of devA may, therefore, be a component of a periplasmic permease that is required for the transition from a proheterocyst to a mature, nitrogen-fixing heterocyst.
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Affiliation(s)
- I Maldener
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing 48824-1312
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Linden H, Misawa N, Saito T, Sandmann G. A novel carotenoid biosynthesis gene coding for zeta-carotene desaturase: functional expression, sequence and phylogenetic origin. Plant Mol Biol 1994; 24:369-379. [PMID: 8111038 DOI: 10.1007/bf00020174] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A DNA fragment which has been isolated previously from an Anabaena DNA expression library was subcloned. The corresponding protein was overexpressed in Escherichia coli. The recombinant enzyme was fully active in converting zeta-carotene into lycopene in vitro with neurosporene as an intermediate. A smaller fragment which still contained the active enzyme was sequenced. An open reading frame of 1497 bp was found coding for a protein consisting of 499 amino acids with the calculated molecular weight of 56,740. In a computer search of nucleotide sequences contained in the EMBL nucleotide sequence library, all the best-fitting comparisons were carotenoid desaturases. The highest similarity was found with the crtI phytoene desaturase genes of bacteria and the al-1 gene from Neurospora crassa. A much lower similarity was found with the pds genes coding for phytoene desaturase from cyanobacteria and higher plants. It is shown in protein similarity plots that the amino acid similarity of zeta-carotene desaturase to the latter is mainly limited to the N terminus of the polypeptides. In contrast, the protein similarity plots and a comparison of a conserved region clearly demonstrate that there is a strong relationship between zeta-carotene desaturase and the phytoene desaturases from various bacteria and fungi. Therefore we propose that the zeta-carotene desaturase gene is homologous to the crt I phytoene desaturase genes of bacteria and fungi.
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Affiliation(s)
- H Linden
- Lehrstuhl Physiologie und Biochemie der Pflanzen, Universität Konstanz, Germany
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Caudales R, Wells JM. Differentiation of free-living Anabaena and Nostoc cyanobacteria on the basis of fatty acid composition. Int J Syst Bacteriol 1992; 42:246-51. [PMID: 1581185 DOI: 10.1099/00207713-42-2-246] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera Anabaena and Nostoc were analyzed to differentiate the genera. The fatty acid compositions of 10 Anabaena strains and 10 Nostoc strains that were grown for 12 days on BG-11o medium were determined by gas-liquid chromatography-mass spectroscopy. Of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at least one of the genera). These fatty acids included (with mean percentages in the Anabaena and Nostoc strains, respectively) the saturated fatty acids 16:0 (30.55 and 23.23%) and 18:0 (0.77 and 1.27%); several unsaturated fatty acids, including 14:1 cis-7 (2.50 and 0.11%), 14:1 cis-9 (3.10 and 3.41%), a polyunsaturated 16-carbon (sites undetermined) fatty acid with an equivalent chain length of 15.30 (1.20 and 1.03%), 16:4 cis-4 (0.95 and 0.87%), 16:3 cis-6 (2.16 and 1.51%), 16:1 cis-7 (1.44 and 0.36%), 16:1 cis-9 (6.53 and 18.76%), 16:1 trans-9 (4.02 and 1.35%), 16:1 cis-11 (1.62 and 0.42%), 18:2 cis-9 (10.16 and 12.44%), 18:3 cis-9 (18.19 and 17.25%), 18:1 cis-9 (4.01 and 5.10%), and 18:1 trans-9 (0.92 and 1.94%); and the branched-chain fatty acids iso-16:0 (2.50 and 1.14%) and iso-15:1 (0.34 and 2.05%).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Caudales
- Department of Biochemistry and Microbiology, Cook College, Rutgers University, New Brunswick, New Jersey 08903-0231
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