WorldWideScience

Sample records for marine chroococcoid cyanobacteria

  1. Origin of marine planktonic cyanobacteria.

    Science.gov (United States)

    Sánchez-Baracaldo, Patricia

    2015-12-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya).

  2. Degradation of crude oil by marine cyanobacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Vipparty, V.; David, J.J.; Chandramohan, D.

    The marine cyanobacteria Oscillatoria salina Biswas, Plectonema terebrans Bornet et Flanhault and Aphanocapsa sp. degraded Bombay High crude oil when grown in artificial seawater nutrients as well as in plain natural seawater. Oil removals...

  3. Floating cultivation of marine cyanobacteria using coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M.; Yoshida, E.; Takeyama, H.; Matsunaga, T. [Tokyo University of Agriculture and Technology, Tokyo (Japan). Dept. of Biotetechnology

    2000-07-01

    The aim was to develop improved methodologies for bulk culturing of biotechnologically useful marine cyanobacteria in the open ocean. The viability of using coal fly ash (CFA) blocks as the support medium in a novel floating culture system for marine microalgae was investigated. The marine cyanobacterium Synechococcus sp. NKBC 040607 was found to adhere to floating CFA blocks in liquid culture medium. The marine cyanobacterium Synechococcus sp. NKBG 042902 weakly adhered to floating CFA blocks in BG-11 medium. Increasing the concentration of calcium ion in the culture medium enhanced adherence to CFA blocks.

  4. Marine cyanobacteria as sources of new biotechnological applications

    Directory of Open Access Journals (Sweden)

    Vitor Vasconcelos

    2014-06-01

    Bioactive compounds from cyanobacteria may also have allelopathic activity with potential use to control algal blooms or as antifouling in the marine environment (Leão et al., 2012, Antunes et al., 2013. We have isolated and characterized for the first time allelopathic compounds named Portoamides that act synergistically to prevent the growth of some microalgae (Leão et al., 2010. Cyanobacteria extracts can also prevent the development of some invertebrates such as sea urchins and mussels (Martins et al., 2007 and so they can be candidates to develop antifouling agents that are environmentally friendly. The potential of cyanobacteria as source of new bioactive compounds is enormous, with the advantage of being applicable in many different areas of biotechnology, with many industrial applications.

  5. Exploring Marine Cyanobacteria for Lead Compounds of Pharmaceutical Importance

    Directory of Open Access Journals (Sweden)

    Bushra Uzair

    2012-01-01

    Full Text Available The Ocean, which is called the “mother of origin of life,” is also the source of structurally unique natural products that are mainly accumulated in living organisms. Cyanobacteria are photosynthetic prokaryotes used as food by humans. They are excellent source of vitamins and proteins vital for life. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immunodeficiency syndrome (AIDS, arthritis, and so forth, while other compounds have been developed as analgesics or to treat inflammation, and so forth. They produce a large variety of bioactive compounds, including substances with anticancer and antiviral activity, UV protectants, specific inhibitors of enzymes, and potent hepatotoxins and neurotoxins. Many cyanobacteria produce compounds with potent biological activities. This paper aims to showcase the structural diversity of marine cyanobacterial secondary metabolites with a comprehensive coverage of alkaloids and other applications of cyanobacteria.

  6. Antimicrobial and Cytotoxic Assessment of Marine Cyanobacteria - Synechocystis and Synechococcus

    OpenAIRE

    Martins, Rosário F.; Ramos, Miguel F.; Herfindal, Lars; Sousa, José A.; Skærven, Kaja; Vasconcelos, Vitor M.

    2008-01-01

    Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60...

  7. Floating cultivation of marine cyanobacteria using coal fly ash.

    Science.gov (United States)

    Matsumoto, M; Yoshida, E; Takeyama, H; Matsunaga, T

    2000-01-01

    The aim of this study was to develop improved methodologies for bulk culturing of biotechnologically useful marine cyanobacteria in the open ocean. We have investigated the viability of using coal fly ash (CFA) blocks as the support medium in a novel floating culture system for marine micro-algae. The marine cyanobacterium Synechococcus sp. NKBG 040607 was found to adhere to floating CFA blocks in liquid culture medium. Maximum density of attached cells of 2.0 x 10(8) cells/cm2 was achieved using seawater. The marine cyanobacterium Synechococcus sp. NKBG 042902 weakly adhered to floating CFA blocks in BG-11 medium. Increasing the concentration of calcium ion in the culture medium enhanced adherence to CFA blocks.

  8. Antimicrobial and cytotoxic assessment of marine cyanobacteria - Synechocystis and Synechococcus.

    Science.gov (United States)

    Martins, R F; Ramos, M F; Herfindal, L; Sousa, J A; Skaerven, K; Vasconcelos, V M

    2008-01-22

    Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.

  9. Antimicrobial and Cytotoxic Assessment of Marine Cyanobacteria - Synechocystis and Synechococcus

    Directory of Open Access Journals (Sweden)

    Vitor M. Vasconcelos

    2008-01-01

    Full Text Available Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.

  10. Nitrogenase gene amplicons from global marine surface waters are dominated by genes of non-cyanobacteria

    DEFF Research Database (Denmark)

    Farnelid, Hanna; Andersson, Anders F.; Bertilsson, Stefan

    2011-01-01

    analysis of 79,090 nitrogenase (nifH) PCR amplicons encoding 7,468 unique proteins from surface samples (ten DNA samples and two RNA samples) collected at ten marine locations world-wide provides the first in-depth survey of a functional bacterial gene and yield insights into the composition and diversity...... by unicellular cyanobacteria, 42% of the identified non-cyanobacterial nifH clusters from the corresponding DNA samples were also detected in cDNA. The study indicates that non-cyanobacteria account for a substantial part of the nifH gene pool in marine surface waters and that these genes are at least...

  11. Antibacterial Activity of Marine and Black Band Disease Cyanobacteria against Coral-Associated Bacteria

    Science.gov (United States)

    Gantar, Miroslav; Kaczmarsky, Longin T.; Stanić, Dina; Miller, Aaron W.; Richardson, Laurie L.

    2011-01-01

    Black band disease (BBD) of corals is a cyanobacteria-dominated polymicrobial disease that contains diverse populations of heterotrophic bacteria. It is one of the most destructive of coral diseases and is found globally on tropical and sub-tropical reefs. We assessed ten strains of BBD cyanobacteria, and ten strains of cyanobacteria isolated from other marine sources, for their antibacterial effect on growth of heterotrophic bacteria isolated from BBD, from the surface mucopolysaccharide layer (SML) of healthy corals, and three known bacterial coral pathogens. Assays were conducted using two methods: co-cultivation of cyanobacterial and bacterial isolates, and exposure of test bacteria to (hydrophilic and lipophilic) cyanobacterial cell extracts. During co-cultivation, 15 of the 20 cyanobacterial strains tested had antibacterial activity against at least one of the test bacterial strains. Inhibition was significantly higher for BBD cyanobacteria when compared to other marine cyanobacteria. Lipophilic extracts were more active than co-cultivation (extracts of 18 of the 20 strains were active) while hydrophilic extracts had very limited activity. In some cases co-cultivation resulted in stimulation of BBD and SML bacterial growth. Our results suggest that BBD cyanobacteria are involved in structuring the complex polymicrobial BBD microbial community by production of antimicrobial compounds. PMID:22073011

  12. Toxicity of chlorpyrifos on some marine cyanobacteria species

    International Nuclear Information System (INIS)

    Shoaib, N.; Siddiqui, A.; Khalid, H.

    2012-01-01

    Pakistan is an agricultural country and a wide variety of pesticides are used on its cropland. Pesticides pose serious threats to the natural ecosystem. In the present study cyanobacteria (blue green algae) were used to assess the ecotoxicological effect of chlorpyrifos (organophosphate pesticide). Cyanobacteria are the base of the food web providing food resource to consumers in higher trophic level. Cyanobacteria were isolated and purified from water samples collected from Manora channel. Fast growing cultures of cyanobacteria were used to assess the toxicity of test pesticide . The Light and Dark method was used to determine the primary production of the organisms. The acute toxicity of chlorpyrifos was determined by calculating IC/sub 50/ of the test organisms. The IC/sub 50/ was found to be 0.074, 0.013, 0.08 and 0.3 ppm for Synechocystis aquatilis, Komvophoron minutum, Gloeocapsa crepidinum and Gloeocapsa sanguinea when exposed to chlorpyrifos pesticide . Laboratory experiments with cyanobacteria have demonstrated that organophosphate pesticides are potent inhibitors of photosynthesis. (author)

  13. Genes and Structural Proteins of the Phage Syn5 of the Marine Cyanobacteria Synechococcus

    Science.gov (United States)

    2005-09-01

    Morgan et al., 2002; van de Putte et al., 1980). Inversion of the segment is controlled by a phage encoded invertase , expressed by the gene gin, which...growth of marine planktonic cyanobacteria. Methods in Enzymology , 167, 100-105. 170 Weigele, P.R., Scanlon, E. and King, J. (2003) Homotrimeric, beta

  14. Nitrogenase gene amplicons from global marine surface waters are dominated by genes of non-cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Hanna Farnelid

    Full Text Available Cyanobacteria are thought to be the main N(2-fixing organisms (diazotrophs in marine pelagic waters, but recent molecular analyses indicate that non-cyanobacterial diazotrophs are also present and active. Existing data are, however, restricted geographically and by limited sequencing depths. Our analysis of 79,090 nitrogenase (nifH PCR amplicons encoding 7,468 unique proteins from surface samples (ten DNA samples and two RNA samples collected at ten marine locations world-wide provides the first in-depth survey of a functional bacterial gene and yield insights into the composition and diversity of the nifH gene pool in marine waters. Great divergence in nifH composition was observed between sites. Cyanobacteria-like genes were most frequent among amplicons from the warmest waters, but overall the data set was dominated by nifH sequences most closely related to non-cyanobacteria. Clusters related to Alpha-, Beta-, Gamma-, and Delta-Proteobacteria were most common and showed distinct geographic distributions. Sequences related to anaerobic bacteria (nifH Cluster III were generally rare, but preponderant in cold waters, especially in the Arctic. Although the two transcript samples were dominated by unicellular cyanobacteria, 42% of the identified non-cyanobacterial nifH clusters from the corresponding DNA samples were also detected in cDNA. The study indicates that non-cyanobacteria account for a substantial part of the nifH gene pool in marine surface waters and that these genes are at least occasionally expressed. The contribution of non-cyanobacterial diazotrophs to the global N(2 fixation budget cannot be inferred from sequence data alone, but the prevalence of non-cyanobacterial nifH genes and transcripts suggest that these bacteria are ecologically significant.

  15. Affinities of the Aphanocapsa feldmanni-like cyanobacteria from the marine sponge Xestospongia muta based on genetic and morphological analyses

    NARCIS (Netherlands)

    Gomez, R.; Erpenbeck, D.J.G.; Richelle-Maurer, E.; van Dijk, T.R.; Woldringh, C.L.; van Soest, R.W.M.

    2004-01-01

    The marine sponge Xestospongia muta (Porifera: Demospongiae: Haplosclerida) harbours cyanobacteria in its peripheral tissue that have been described as having an Aphanocapsa feldmanni-type appearance. Through subsequent cell fractionation steps we obtained a virtually pure cell suspension of the

  16. The Potential Use of Marine Microalgae and Cyanobacteria in Cosmetics and Thalassotherapy

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    M. Lourdes Mourelle

    2017-11-01

    Full Text Available The use of microalgae and cyanobacteria for nutritional purposes dates back thousands of years; during the last few decades, microalgae culture has improved to become one of the modern biotechnologies. This has allowed high amounts of algal biomass to be obtained for use in different applications. Currently, the global production of microalgae and cyanobacteria is predominately aimed at applications with high added value given that algal biomass contains pigments, proteins, essential fatty acids, polysaccharides, vitamins, and minerals, all of which are of great interest in the preparation of natural products, both as food and in cosmetics. Hence, the bioactive components from microalgae can be incorporated in cosmetic and cosmeceutical formulations, and can help achieve benefits including the maintenance of skin structure and function. Thalassotherapy involves using seawater and all related marine elements, including macroalgae, however, there has been limited use of microalgae. Microalgae and cyanobacteria could be incorporated into health and wellness treatments applied in thalassotherapy centers due to their high concentration of biologically active substances that are of interest in skin care. This paper briefly reviews the current and potential cosmetic and cosmeceutical applications of marine microalgae and cyanobacteria compounds and also recommends its use in thalassotherapy well-being treatments.

  17. Are known cyanotoxins involved in the toxicity of picoplanktonic and filamentous North Atlantic marine cyanobacteria?

    Science.gov (United States)

    Frazão, Bárbara; Martins, Rosário; Vasconcelos, Vitor

    2010-06-21

    Eight marine cyanobacteria strains of the genera Cyanobium, Leptolyngbya, Oscillatoria, Phormidium, and Synechococcus were isolated from rocky beaches along the Atlantic Portuguese central coast and tested for ecotoxicity. Strains were identified by morphological characteristics and by the amplification and sequentiation of the 16S rDNA. Bioactivity of dichloromethane, methanol and aqueous extracts was assessed by the Artemia salina bioassay. Peptide toxin production was screened by matrix assisted laser desorption/ionization time of flight mass spectrometry. Molecular analysis of the genes involved in the production of known cyanotoxins such as microcystins, nodularins and cylindrospermopsin was also performed. Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones. Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain. The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

  18. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    Science.gov (United States)

    Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A. C.

    2014-01-01

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review. PMID:25356733

  19. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  20. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A.C.

    2014-01-01

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  1. New records of benthic marine algae and Cyanobacteria for Costa Rica, and a comparison with other Central American countries

    Science.gov (United States)

    Bernecker, Andrea; Wehrtmann, Ingo S.

    2009-09-01

    We present the results of an intensive sampling program carried out from 2000 to 2007 along both coasts of Costa Rica, Central America. The presence of 44 species of benthic marine algae is reported for the first time for Costa Rica. Most of the new records are Rhodophyta (27 spp.), followed by Chlorophyta (15 spp.), and Heterokontophyta, Phaeophycea (2 spp.). Overall, the currently known marine flora of Costa Rica is comprised of 446 benthic marine algae and 24 Cyanobacteria. This species number is an under estimation, and will increase when species of benthic marine algae from taxonomic groups where only limited information is available (e.g., microfilamentous benthic marine algae, Cyanobacteria) are included. The Caribbean coast harbors considerably more benthic marine algae (318 spp.) than the Pacific coast (190 spp.); such a trend has been observed in all neighboring countries. Compared to other Central American countries, Costa Rica has the highest number of reported benthic marine algae; however, Panama may have a similarly high diversity after unpublished results from a Rhodophyta survey (Wysor, unpublished) are included. Sixty-two species have been found along both the Pacific and Caribbean coasts of Costa Rica; we discuss this result in relation to the emergence of the Central American Isthmus.

  2. Description of new genera and species of marine cyanobacteria from the Portuguese Atlantic coast.

    Science.gov (United States)

    Brito, Ângela; Ramos, Vitor; Mota, Rita; Lima, Steeve; Santos, Arlete; Vieira, Jorge; Vieira, Cristina P; Kaštovský, Jan; Vasconcelos, Vitor M; Tamagnini, Paula

    2017-06-01

    Aiming at increasing the knowledge on marine cyanobacteria from temperate regions, we previously isolated and characterized 60 strains from the Portuguese foreshore and evaluate their potential to produce secondary metabolites. About 15% of the obtained 16S rRNA gene sequences showed less than 97% similarity to sequences in the databases revealing novel biodiversity. Herein, seven of these strains were extensively characterized and their classification was re-evaluated. The present study led to the proposal of five new taxa, three genera (Geminobacterium, Lusitaniella, and Calenema) and two species (Hyella patelloides and Jaaginema litorale). Geminobacterium atlanticum LEGE 07459 is a chroococcalean that shares morphological characteristics with other unicellular cyanobacterial genera but has a distinct phylogenetic position and particular ultrastructural features. The description of the Pleurocapsales Hyella patelloides LEGE 07179 includes novel molecular data for members of this genus. The filamentous isolates of Lusitaniella coriacea - LEGE 07167, 07157 and 06111 - constitute a very distinct lineage, and seem to be ubiquitous on the Portuguese coast. Jaaginema litorale LEGE 07176 has distinct characteristics compared to their marine counterparts, and our analysis indicates that this genus is polyphyletic. The Synechococcales Calenema singularis possess wider trichomes than Leptolyngbya, and its phylogenetic position reinforces the establishment of this new genus. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Effect of UV-B and high visual radiation on photosynthesis in freshwater (nostoc spongiaeforme) and marine (Phormidium corium) cyanobacteria.

    Science.gov (United States)

    Bhandari, Rupali; Sharma, Prabhat Kumar

    2007-08-01

    Human activity is causing depletion of ozone in stratosphere, resulting in increased UV-B radiation and global warming. However, impact of these climatic changes on the aquatic organism (especially marine) is not fully understood. Here, we have studied the effect of excess UV-B and visible radiation on photosynthetic pigments, fatty acids content, lipid peroxidation, nitrogen content, nitrogen reductase activity and membrane proteins, induction of mycosporine-like amino acids (MAAs) and antioxidant enzymes superoxide dismutase (SOD) and ascorbate peroxidase (APX) in freshwater (Nostoc spongiaeform) and marine (Phormidium corium) cyanobacteria. UV-B treatment resulted in an increase in photosynthetic pigments in Nostoc and decrease in Phormidium, but high light treatment caused photobleaching of most of the pigments in both the species. Unsaturation level of fatty acids of both total and glycolipids remained unchanged in both the cyanobacteria, as a result of UV-B and high light treatments. Saturated fatty acids of total and glycolipids declined slightly in Nostoc by both the treatments. but remained unchanged in Phormidium. No changes in the unsaturated lipid content in our study probably suggested adaptation of the organism to the treatments. However, both treatments resulted in peroxidation of membrane lipids, indicating oxidative damage to lipids without any change in the level of unsaturation of fatty acid in the cell membrane. Qualitative and quantitative changes were observed in membrane protein profile due to the treatments. Cyanobacteria were able to synthesize MAAs in response to the UV-B treatment. Both treatments also increased the activities of SOD and APX. In conclusion, the study demonstrated induction of antioxidants such as SOD and APX under visible light treatment and screening pigment (MAAs) under UV-B treatment, which might protect the cyanobacteria from oxidative damage caused by high light and UV-B radiation.

  4. Inhibition of nitrogenase by oxygen in marine cyanobacteria controls the global nitrogen and oxygen cycles

    Science.gov (United States)

    Berman-Frank, I.; Chen, Y.-B.; Gerchman, Y.; Dismukes, G. C.; Falkowski, P. G.

    2005-03-01

    Cyanobacterial N2-fixation supplies the vast majority of biologically accessible inorganic nitrogen to nutrient-poor aquatic ecosystems. The process, catalyzed by the heterodimeric protein complex, nitrogenase, is thought to predate that of oxygenic photosynthesis. Remarkably, while the enzyme plays such a critical role in Earth's biogeochemical cycles, the activity of nitrogenase in cyanobacteria is markedly inhibited in vivo at a post-translational level by the concentration of O2 in the contemporary atmosphere leading to metabolic and biogeochemical inefficiency in N2 fixation. We illustrate this crippling effect with data from Trichodesmium spp. an important contributor of "new nitrogen" to the world's subtropical and tropical oceans. The enzymatic inefficiency of nitrogenase imposes a major elemental taxation on diazotrophic cyanobacteria both in the costs of protein synthesis and for scarce trace elements, such as iron. This restriction has, in turn, led to a global limitation of fixed nitrogen in the contemporary oceans and provides a strong biological control on the upper bound of oxygen concentration in Earth's atmosphere.

  5. Isolation, identification, screening of toxicity and oligopeptides of some marine and brackish cyanobacteria from Norwegian and Pakistani waters, in the search for bioactive natural compounds

    OpenAIRE

    Hameed, Shaista

    2009-01-01

    Cyanobacteria produce a number of bioactive compounds, most of them are oligopeptides. Almost all are known from freshwater species. The aim of this study was to search for marine and brackish water species producing bioactive compounds. To reach this goal, new strains were isolated from Norwegian and Pakistani coastal waters. These and additional strains from NIVA, UiO and UiB culture collections (24 in total), belonging to Chroococcales and Oscillatoriales, were identified based on morpholo...

  6. Biodiesel production from marine cyanobacteria cultured in plate and tubular photobioreactors.

    Science.gov (United States)

    Selvan, B Karpanai; Revathi, M; Piriya, P Sobana; Vasan, P Thirumalai; Prabhu, D Immuanual Gilwax; Vennison, S John

    2013-03-01

    Carbon (neutral) based renewable liquid biofuels are alternative to petroleum derived transport fuels that contribute to global warming and are of a limited availability. Microalgae based biofuels are considered as promising source of energy. Lyngbya sp. and Synechococcus sp. were studied for the possibility of biodiesel production in different media such as ASNIII, sea water enrichment medium and BG11. The sea water enrichment medium was found superior in enhancing the growth rate of these microalgae. Nitrogen depletion has less effect in total chlorophyll a content, at the same time the lipid content was increased in both Lyngbya sp. and Synechococcus sp. by 1.4 and 1.2 % respectively. Increase in salinity from 0.5-1.0 M also showed an increase in the lipid content to 2.0 and 0.8 % in these strains; but a salinity of 1.5 M has a total inhibitory effect in the growth. The total biomass yield was comparatively higher in tubular LED photobioreactor than the fluorescent flat plated photobioreactor. Lipid extraction was obtained maximum at 60 degrees C in 1:10 sample: solvent ratio. GC-MS analysis of biodiesel showed high content of polyunsaturated fatty acids (PUFA; 4.86 %) than saturated fatty acid (SFA; 4.10 %). Biodiesel production was found maximum in Synechococcus sp. than Lyngbya sp. The viscosity of the biodiesel was closely related to conventional diesel. The results strongly suggest that marine microalgae could be used as a renewable energy source for biodiesel production.

  7. Nitrogen Fixation in Cyanobacteria

    NARCIS (Netherlands)

    Stal, L.J.

    2008-01-01

    Cyanobacteria are oxygenic photosynthetic bacteria that are widespread in marine, freshwater and terrestrial environments and many of them are capable of fixing atmospheric nitrogen. But ironically, nitrogenase, the enzyme that is responsible for the reduction of N2, is extremely sensitive to O2.

  8. Indicators: Cyanobacteria

    Science.gov (United States)

    Cyanobacteria, also referred to as blue-green algae, naturally occur in all freshwater ecosystems. However, too many nutrients such as phosphorus and nitrogen in the waterway can result in conditions that lead to cyanobacterial blooms.

  9. A Review Study on Macrolides Isolated from Cyanobacteria.

    Science.gov (United States)

    Wang, Mengchuan; Zhang, Jinrong; He, Shan; Yan, Xiaojun

    2017-04-26

    Cyanobacteria are rich sources of structurally-diverse molecules with promising pharmacological activities. Marine cyanobacteria have been proven to be true producers of some significant bioactive metabolites from marine invertebrates. Macrolides are a class of bioactive compounds isolated from marine organisms, including marine microorganisms in particular. The structural characteristics of macrolides from cyanobacteria mainly manifest in the diversity of carbon skeletons, complexes of chlorinated thiazole-containing molecules and complex spatial configuration. In the present work, we systematically reviewed the structures and pharmacological activities of macrolides from cyanobacteria. Our data would help establish an effective support system for the discovery and development of cyanobacterium-derived macrolides.

  10. Cyanobacteria in Coral Reef Ecosystems: A Review

    Directory of Open Access Journals (Sweden)

    L. Charpy

    2012-01-01

    Full Text Available Cyanobacteria have dominated marine environments and have been reef builders on Earth for more than three million years (myr. Cyanobacteria still play an essential role in modern coral reef ecosystems by forming a major component of epiphytic, epilithic, and endolithic communities as well as of microbial mats. Cyanobacteria are grazed by reef organisms and also provide nitrogen to the coral reef ecosystems through nitrogen fixation. Recently, new unicellular cyanobacteria that express nitrogenase were found in the open ocean and in coral reef lagoons. Furthermore, cyanobacteria are important in calcification and decalcification. All limestone surfaces have a layer of boring algae in which cyanobacteria often play a dominant role. Cyanobacterial symbioses are abundant in coral reefs; the most common hosts are sponges and ascidians. Cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. Cyanobacteria can also form pathogenic microbial consortia in association with other microbes on living coral tissues, causing coral tissue lysis and death, and considerable declines in coral reefs. In deep lagoons, coccoid cyanobacteria are abundant and are grazed by ciliates, heteroflagellates, and the benthic coral reef community. Cyanobacteria produce metabolites that act as attractants for some species and deterrents for some grazers of the reef communities.

  11. The marine cyanobacterium

    NARCIS (Netherlands)

    Pade, N.; Compaoré, J.; Klähn, S.; Stal, L.J.; Hagemann, M.

    2012-01-01

    Compatible solutes are small organic molecules that are involved in the acclimation to various stresses such as temperature and salinity. Marine or moderate halotolerant cyanobacteria accumulate glucosylglycerol, while cyanobacteria with low salt tolerance (freshwater strains) usually accumulate

  12. Cyanobacteria from Terrestrial and Marine Sources Contain Apoptogens Able to Overcome Chemoresistance in Acute Myeloid Leukemia Cells

    Science.gov (United States)

    Liu, Liwei; Herfindal, Lars; Jokela, Jouni; Shishido, Tania Keiko; Wahlsten, Matti; Døskeland, Stein Ove; Sivonen, Kaarina

    2014-01-01

    In this study, we investigated forty cyanobacterial isolates from biofilms, gastropods, brackish water and symbiotic lichen habitats. Their aqueous and organic extracts were used to screen for apoptosis-inducing activity against acute myeloid leukemia cells. A total of 28 extracts showed cytotoxicity against rat acute myeloid leukemia (IPC-81) cells. The design of the screen made it possible to eliminate known toxins, such as microcystins and nodularin, or known metabolites with anti-leukemic activity, such as adenosine and its analogs. A cytotoxicity test on human embryonic kidney (HEK293T) fibroblasts indicated that 21 of the 28 extracts containing anti-acute myeloid leukemia (AML) activity showed selectivity in favor of leukemia cells. Extracts L26-O and L30-O were able to partly overcome the chemotherapy resistance induced by the oncogenic protein Bcl-2, whereas extract L1-O overcame protection from the deletion of the tumor suppressor protein p53. In conclusion, cyanobacteria are a prolific resource for anti-leukemia compounds that have potential for pharmaceutical applications. Based on the variety of cellular responses, we also conclude that the different anti-leukemic compounds in the cyanobacterial extracts target different elements of the death machinery of mammalian cells. PMID:24705501

  13. Cyanobacteria from Terrestrial and Marine Sources Contain Apoptogens Able to Overcome Chemoresistance in Acute Myeloid Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Liwei Liu

    2014-04-01

    Full Text Available In this study, we investigated forty cyanobacterial isolates from biofilms, gastropods, brackish water and symbiotic lichen habitats. Their aqueous and organic extracts were used to screen for apoptosis-inducing activity against acute myeloid leukemia cells. A total of 28 extracts showed cytotoxicity against rat acute myeloid leukemia (IPC-81 cells. The design of the screen made it possible to eliminate known toxins, such as microcystins and nodularin, or known metabolites with anti-leukemic activity, such as adenosine and its analogs. A cytotoxicity test on human embryonic kidney (HEK293T fibroblasts indicated that 21 of the 28 extracts containing anti-acute myeloid leukemia (AML activity showed selectivity in favor of leukemia cells. Extracts L26-O and L30-O were able to partly overcome the chemotherapy resistance induced by the oncogenic protein Bcl-2, whereas extract L1-O overcame protection from the deletion of the tumor suppressor protein p53. In conclusion, cyanobacteria are a prolific resource for anti-leukemia compounds that have potential for pharmaceutical applications. Based on the variety of cellular responses, we also conclude that the different anti-leukemic compounds in the cyanobacterial extracts target different elements of the death machinery of mammalian cells.

  14. Oxygen and the light-dark cycle of nitrogenase activity in two unicellular cyanobacteria

    NARCIS (Netherlands)

    Compaore, J.; Stal, L.J.

    2010-01-01

    Cyanobacteria capable of fixing dinitrogen exhibit various strategies to protect nitrogenase from inactivation by oxygen. The marine Crocosphaera watsonii WH8501 and the terrestrial Gloeothece sp. PCC6909 are unicellular diazotrophic cyanobacteria that are capable of aerobic nitrogen fixation. These

  15. Moorea producens gen. nov., sp. nov. and Moorea bouillonii comb. nov., tropical marine cyanobacteria rich in bioactive secondary metabolites.

    Science.gov (United States)

    Engene, Niclas; Rottacker, Erin C; Kaštovský, Jan; Byrum, Tara; Choi, Hyukjae; Ellisman, Mark H; Komárek, Jiří; Gerwick, William H

    2012-05-01

    The filamentous cyanobacterial genus Moorea gen. nov., described here under the provisions of the International Code of Botanical Nomenclature, is a cosmopolitan pan-tropical group abundant in the marine benthos. Members of the genus Moorea are photosynthetic (containing phycocyanin, phycoerythrin, allophycocyanin and chlorophyll a), but non-diazotrophic (lack heterocysts and nitrogenase reductase genes). The cells (discoid and 25-80 µm wide) are arranged in long filaments (algae blooms and, due to morphological resemblance to the genus Lyngbya, this group has often been incorrectly cited in the literature. We here describe two species of the genus Moorea: Moorea producens sp. nov. (type species of the genus) with 3L(T) as the nomenclature type, and Moorea bouillonii comb. nov. with PNG5-198(R) as the nomenclature type.

  16. CYANOBACTERIA OF THE GENUS PROCHLOROTHRIX

    Directory of Open Access Journals (Sweden)

    Alexander Vasilievich Pinevich

    2012-05-01

    Full Text Available Green cyanobacteria are distinguished from blue-green ones by the possession of a chlorophyll-containing light harvesting antenna. Three genera of green cyanobacteria, namely Acaryochloris, Prochlorococcus and Prochloron, are unicellular and of marine habitat; Prochlorococcus marinus attracts most attention due to its outstanding role in prime productivity. The fourth genus, Prochlorothrix, is represented by filamentous freshwater strains. Unlike the rest of green cyanobacteria, Prochlorothrix is paradoxically rare: it has been isolated from two European locations only. Taking into account fluctuating blooms, morphological resemblance with Planktothrix and Pseudanabaena, and unsuccessful enrichment of Prochlorothrix, the preferred strategy of search for this cyanobacterium is based on PCR with natural DNA and specific primers. This approach already demonstrates a broader distribution of Prochlorothrix: marker genes have been found in at least two additional locations. Despite the growing evidence for naturally occurring Prochlorothrix, there are only a few cultivated strains, and only one of them (PCC 9006 is claimed to be axenic. In multixenic cultures, Prochlorothrix is accompanied by heterotrophic bacteria, indicating a consortium-type association. The genus Prochlorothrix includes two species: P. hollandica and P. scandica based on distinctions in genomic DNA, cell size, temperature optimum, and fatty acid composition of membrane lipids. In this short review, the properties of cyanobacteria of the genus Prochlorothrix are described, and the evolutionary scenario of green cyanobacteria, especially taking into account their role in the origin of simple chloroplast is given.

  17. Cyanofuels: biofuels from cyanobacteria. Reality and perspectives.

    Science.gov (United States)

    Sarsekeyeva, Fariza; Zayadan, Bolatkhan K; Usserbaeva, Aizhan; Bedbenov, Vladimir S; Sinetova, Maria A; Los, Dmitry A

    2015-08-01

    Cyanobacteria are represented by a diverse group of microorganisms that, by virtue of being a part of marine and freshwater phytoplankton, significantly contribute to the fixation of atmospheric carbon via photosynthesis. It is assumed that ancient cyanobacteria participated in the formation of earth's oil deposits. Biomass of modern cyanobacteria may be converted into bio-oil by pyrolysis. Modern cyanobacteria grow fast; they do not compete for agricultural lands and resources; they efficiently convert excessive amounts of CO2 into biomass, thus participating in both carbon fixation and organic chemical production. Many cyanobacterial species are easier to genetically manipulate than eukaryotic algae and other photosynthetic organisms. Thus, the cyanobacterial photosynthesis may be directed to produce carbohydrates, fatty acids, or alcohols as renewable sources of biofuels. Here we review the recent achievements in the developments and production of cyanofuels-biofuels produced from cyanobacterial biomass.

  18. Recent developments in therapeutic applications of Cyanobacteria.

    Science.gov (United States)

    Raja, Rathinam; Hemaiswarya, Shanmugam; Ganesan, Venkatesan; Carvalho, Isabel S

    2016-05-01

    The cyanobacteria (blue-green algae) are photosynthetic prokaryotes having applications in human health with numerous biological activities and as a dietary supplement. It is used as a food supplement because of its richness in nutrients and digestibility. Many cyanobacteria (Microcystis sp, Anabaena sp, Nostoc sp, Oscillatoria sp., etc.) produce a great variety of secondary metabolites with potent biological activities. Cyanobacteria produce biologically active and chemically diverse compounds belonging to cyclic peptides, lipopeptides, fatty acid amides, alkaloids and saccharides. More than 50% of the marine cyanobacteria are potentially exploitable for extracting bioactive substances which are effective in killing cancer cells by inducing apoptotic death. Their role as anti-viral, anti-tumor, antimicrobial, anti-HIV and a food additive have also been well established. However, such products are at different stages of clinical trials and only a few compounds have reached to the market.

  19. Fermentation in cyanobacteria

    NARCIS (Netherlands)

    Stal, L.J.; Moezelaar, R.

    1997-01-01

    Although cyanobacteria are oxygenic phototrophic organisms, they often thrive in environments that become periodically anoxic. This is particularly the case in the dark when photosynthetic oxygen evolution does not take place. Whereas cyanobacteria generally utilize endogenous storage carbohydrate

  20. Endosymbiotic heterocystous cyanobacteria synthesize different heterocyst glycolipids than free-living heterocystous cyanobacteria

    NARCIS (Netherlands)

    Schouten, S.; Villareal, T.A.; Hopmans, E.C.; Mets, A.; Swanson, K.M.; Sinninghe Damsté, J.S.

    2013-01-01

    The heterocysts of limnetic nitrogen-fixing filamentous cyanobacteria contain unique glycolipids in their cell wall that create the distinctive gas impermeability of the heterocyst cell wall as well as serve as biomarker lipids for these microbes. It has been assumed that marine free-living and

  1. Genetically Engineered Cyanobacteria

    Science.gov (United States)

    Zhou, Ruanbao (Inventor); Gibbons, William (Inventor)

    2015-01-01

    The disclosed embodiments provide cyanobacteria spp. that have been genetically engineered to have increased production of carbon-based products of interest. These genetically engineered hosts efficiently convert carbon dioxide and light into carbon-based products of interest such as long chained hydrocarbons. Several constructs containing polynucleotides encoding enzymes active in the metabolic pathways of cyanobacteria are disclosed. In many instances, the cyanobacteria strains have been further genetically modified to optimize production of the carbon-based products of interest. The optimization includes both up-regulation and down-regulation of particular genes.

  2. Cyanobacteria Index (MERIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset shows the concentration of cyanobacteria cells/ml in fresh water bodies and estuaries of the Ohio and Florida derived from 300x300 meter MEdium...

  3. Cyanobacteria of Greece: an annotated checklist

    Science.gov (United States)

    Ourailidis, Iordanis; Panou, Manthos; Pappas, Nikos

    2016-01-01

    Abstract Background The checklist of Greek Cyanobacteria was created in the framework of the Greek Taxon Information System (GTIS), an initiative of the LifeWatchGreece Research Infrastructure (ESFRI) that has resumed efforts to compile a complete checklist of species reported from Greece. This list was created from exhaustive search of the scientific literature of the last 60 years. All records of taxa known to occur in Greece were taxonomically updated. New information The checklist of Greek Cyanobacteria comprises 543 species, classified in 130 genera, 41 families, and 8 orders. The orders Synechococcales and Oscillatoriales have the highest number of species (158 and 153 species, respectively), whereas these two orders along with Nostocales and Chroococcales cover 93% of the known Greek cyanobacteria species. It is worth mentioning that 18 species have been initially described from Greek habitats. The marine epilithic Ammatoidea aegea described from Saronikos Gulf is considered endemic to this area. Our bibliographic review shows that Greece hosts a high diversity of cyanobacteria, suggesting that the Mediterranean area is also a hot spot for microbes. PMID:27956851

  4. Cyanobacteria of Greece: an annotated checklist.

    Science.gov (United States)

    Gkelis, Spyros; Ourailidis, Iordanis; Panou, Manthos; Pappas, Nikos

    2016-01-01

    The checklist of Greek Cyanobacteria was created in the framework of the Greek Taxon Information System (GTIS), an initiative of the LifeWatchGreece Research Infrastructure (ESFRI) that has resumed efforts to compile a complete checklist of species reported from Greece. This list was created from exhaustive search of the scientific literature of the last 60 years. All records of taxa known to occur in Greece were taxonomically updated. The checklist of Greek Cyanobacteria comprises 543 species, classified in 130 genera, 41 families, and 8 orders. The orders Synechococcales and Oscillatoriales have the highest number of species (158 and 153 species, respectively), whereas these two orders along with Nostocales and Chroococcales cover 93% of the known Greek cyanobacteria species. It is worth mentioning that 18 species have been initially described from Greek habitats. The marine epilithic Ammatoidea aegea described from Saronikos Gulf is considered endemic to this area. Our bibliographic review shows that Greece hosts a high diversity of cyanobacteria, suggesting that the Mediterranean area is also a hot spot for microbes.

  5. Cyanobacteria as a Source for Novel Anti-Leukemic Compounds.

    Science.gov (United States)

    Humisto, Anu; Herfindal, Lars; Jokela, Jouni; Karkman, Antti; Bjørnstad, Ronja; Choudhury, Romi R; Sivonen, Kaarina

    2016-01-01

    Cyanobacteria are an inspiring source of bioactive secondary metabolites. These bioactive agents are a diverse group of compounds which are varying in their bioactive targets, the mechanisms of action, and chemical structures. Cyanobacteria from various environments, especially marine benthic cyanobacteria, are found to be rich sources for the search for novel bioactive compounds. Several compounds with anticancer activities have been discovered from cyanobacteria and some of these have succeeded to enter the clinical trials. Varying anticancer agents are needed to overcome increasing challenges in cancer treatments. Different search methods are used to reveal anticancer compounds from natural products, but cell based methods are the most common. Cyanobacterial bioactive compounds as agents against acute myeloid leukemia are not well studied. Here we examined our new results combined with previous studies of anti-leukemic compounds from cyanobacteria with emphasis to reveal common features in strains producing such activity. We report that cyanobacteria harbor specific anti-leukemic compounds since several studied strains induced apoptosis against AML cells but were inactive against non-malignant cells like hepatocytes. We noted that particularly benthic strains from the Baltic Sea, such as Anabaena sp., were especially potential AML apoptosis inducers. Taken together, this review and re-analysis of data demonstrates the power of maintaining large culture collections for the search for novel bioactivities, and also how anti-AML activity in cyanobacteria can be revealed by relatively simple and low-cost assays.

  6. Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

    Science.gov (United States)

    Martins, Joana; Vasconcelos, Vitor

    2015-11-13

    Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

  7. Diverse taxa of cyanobacteria produce beta-N-methylamino-L-alanine, a neurotoxic amino acid.

    Science.gov (United States)

    Cox, Paul Alan; Banack, Sandra Anne; Murch, Susan J; Rasmussen, Ulla; Tien, Georgia; Bidigare, Robert Richard; Metcalf, James S; Morrison, Louise F; Codd, Geoffrey A; Bergman, Birgitta

    2005-04-05

    Cyanobacteria can generate molecules hazardous to human health, but production of the known cyanotoxins is taxonomically sporadic. For example, members of a few genera produce hepatotoxic microcystins, whereas production of hepatotoxic nodularins appears to be limited to a single genus. Production of known neurotoxins has also been considered phylogenetically unpredictable. We report here that a single neurotoxin, beta-N-methylamino-L-alanine, may be produced by all known groups of cyanobacteria, including cyanobacterial symbionts and free-living cyanobacteria. The ubiquity of cyanobacteria in terrestrial, as well as freshwater, brackish, and marine environments, suggests a potential for wide-spread human exposure.

  8. Diverse taxa of cyanobacteria produce β-N-methylamino-l-alanine, a neurotoxic amino acid

    Science.gov (United States)

    Cox, Paul Alan; Banack, Sandra Anne; Murch, Susan J.; Rasmussen, Ulla; Tien, Georgia; Bidigare, Robert Richard; Metcalf, James S.; Morrison, Louise F.; Codd, Geoffrey A.; Bergman, Birgitta

    2005-01-01

    Cyanobacteria can generate molecules hazardous to human health, but production of the known cyanotoxins is taxonomically sporadic. For example, members of a few genera produce hepatotoxic microcystins, whereas production of hepatotoxic nodularins appears to be limited to a single genus. Production of known neurotoxins has also been considered phylogenetically unpredictable. We report here that a single neurotoxin, β-N-methylamino-l-alanine, may be produced by all known groups of cyanobacteria, including cyanobacterial symbionts and free-living cyanobacteria. The ubiquity of cyanobacteria in terrestrial, as well as freshwater, brackish, and marine environments, suggests a potential for wide-spread human exposure. PMID:15809446

  9. Cyanobacteria toxins in the Salton Sea.

    Science.gov (United States)

    Carmichael, Wayne W; Li, RenHui

    2006-04-19

    of Synechococcus was identified by PCR as being closest to known marine forms of this genus. Analyses of affected grebe livers found microcystins at levels that may account for some of the acute mortalities. The production of microcystins by a marine Synechococcus indicates that microcystins may be a more common occurrence in marine environments - a finding not recognized before this work. Further research should be done to define the distribution of microcystin producing marine cyanobacteria and to determine exposure/response effects of microcystins and possibly other cyanotoxins in the Salton Sea. Future efforts to reduce avian mortalities and remediate the Salton Sea should evaluate vectors by which microcystins enter avian species and ways to control and mitigate toxic cyanobacteria waterblooms at the Salton Sea.

  10. Iron-Tolerant Cyanobacteria: Ecophysiology and Fingerprinting

    Science.gov (United States)

    Brown, I. I.; Mummey, D.; Lindsey, J.; McKay, D. S.

    2006-01-01

    Although the iron-dependent physiology of marine and freshwater cyanobacterial strains has been the focus of extensive study, very few studies dedicated to the physiology and diversity of cyanobacteria inhabiting iron-depositing hot springs have been conducted. One of the few studies that have been conducted [B. Pierson, 1999] found that cyanobacterial members of iron depositing bacterial mat communities might increase the rate of iron oxidation in situ and that ferrous iron concentrations up to 1 mM significantly stimulated light dependent consumption of bicarbonate, suggesting a specific role for elevated iron in photosynthesis of cyanobacteria inhabiting iron-depositing hot springs. Our recent studies pertaining to the diversity and physiology of cyanobacteria populating iron-depositing hot springs in Great Yellowstone area (Western USA) indicated a number of different isolates exhibiting elevated tolerance to Fe(3+) (up to 1 mM). Moreover, stimulation of growth was observed with increased Fe(3+) (0.02-0.4 mM). Molecular fingerprinting of unialgal isolates revealed a new cyanobacterial genus and species Chroogloeocystis siderophila, an unicellular cyanobacterium with significant EPS sheath harboring colloidal Fe(3+) from iron enriched media. Our preliminary data suggest that some filamentous species of iron-tolerant cyanobacteria are capable of exocytosis of iron precipitated in cytoplasm. Prior to 2.4 Ga global oceans were likely significantly enriched in soluble iron [Lindsay et al, 2003], conditions which are not conducive to growth of most contemporary oxygenic cyanobacteria. Thus, iron-tolerant CB may have played important physiological and evolutionary roles in Earths history.

  11. Toxicology of freshwater cyanobacteria.

    Science.gov (United States)

    Liyanage, H M; Arachchi, D N Magana; Abeysekara, T; Guneratne, L

    2016-07-02

    Many chemical contaminants in drinking water have been shown to cause adverse health effects in humans after prolonged exposure. Cyanobacteria are one of the most potent and diverse groups of photosynthetic prokaryotes. One key component of cyanobacterial success in the environment is the production of potent toxins as secondary metabolites, which have been responsible for numerous adverse health impacts in humans. Anthropogenic activities have led to the increase of eutrophication in freshwater bodies' worldwide, causing cyanobacterial blooms to become more frequent. The present article will discuss about harmful cyanobacteria and their toxicology with special references to microcystin, nodularin, and cylindrospermopsin.

  12. The toxins of Cyanobacteria.

    Science.gov (United States)

    Patocka, J

    2001-01-01

    Cyanobacteria, formerly called "blue-green algae", are simple, primitive photosynthetic microorganism wide occurrence in fresh, brackish and salt waters. Forty different genera of Cyanobacteria are known and many of them are producers of potent toxins responsible for a wide array of human illnesses, aquatic mammal and bird morbidity and mortality, and extensive fish kills. These cyanotoxins act as neurotoxins or hepatotoxins and are structurally and functionally diverse, and many are derived from unique biosynthetic pathways. All known cyanotoxins and their chemical and toxicological characteristics are presented in this article.

  13. Advances in Oceanography and Limnology - Themed Issue - Cyanobacteria

    Czech Academy of Sciences Publication Activity Database

    Babica, Pavel (ed.); Capelli, C. (ed.); Drobac, D. (ed.); Gkelis, S. (ed.)

    2017-01-01

    Roč. 8, č. 1 (2017), s. 1-178 ISSN 1947-573X Institutional support: RVO:67985939 Keywords : cyanobacterial water blooms * cyanobacterial water blooms * cyanobacteria Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Marine biology, freshwater biology, limnology http://pagepressjournals.org/index.php/aiol/issue/view/460

  14. Cyanobacteria: an economic perspective

    NARCIS (Netherlands)

    Sharma, N.K.; Rai, A.K.; Stal, L.J.

    2014-01-01

    Written by leading experts in the field, Cyanobacteria: An Economic Perspective is a comprehensive edited volume covering all areas of an important field and its application to energy, medicine and agriculture. Issues related to environment, food and energy have presented serious challenge to the

  15. Ultraviolet radiation and cyanobacteria.

    Science.gov (United States)

    Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun

    2014-12-01

    Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Glycolipid biosynthesis in cyanobacteria

    International Nuclear Information System (INIS)

    Van Dusen, W.J.; Jaworski, J.G.

    1987-01-01

    The biosynthesis of monogalactosyldiacyl-glycerol (MGDG) was studied in five different cyanobacteria. Previous work has shown Anabaena variabilis to synthesize both MGDG and monoglucosyl-diacylglycerol (MG1cDG) with MG1cDG being the precursor of MGDG. They have examined four other cyanobacteria to determine if a similar relationship exists. The cyanobacteria studied were Anabaena variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis nidulans, and Anacystis marina. Each were grown in liquid culture and lipids were labeled with 14 C]CO 2 for 20 min., 1.0 hr, 1.0 hr + 10 hr chase. Glycolipids were analyzed by initial separation of MGDG and MG1cDG by TLC followed by further analysis by HPLC. Complete separation of molecular species was obtained isocratically on an ODS column. All of the cyanobacteria labeled 16-C and 18-C fatty acids except for A. marina which labeled only 14-C and 16-C fatty acids. Desaturation of the fatty acids could be observed in the 1.0 hr and chase experiments. All were capable of labeling both MG1cDG and MGDG with the precursor-product relationship being observed. There does not appear to be a direct relationship between the epimerization of the sugar moiety and fatty acid desaturation

  17. New lantibiotics from cyanobacteria

    OpenAIRE

    Yang, Jiahui Jr

    2016-01-01

    Lantibiotics are a subgroup of bacteriocins, produced by Gram-positive bacteria to inhibit the growth of closely related strains. They are used as food preservatives e.g. nisin, and some are in clinical trials, e.g. duramycin A and microbisporicin. Cinnamycin is a 19 amino acid lantibiotic that inhibits the growth of Gram-positive rods. Recent work suggests that cyanobacteria might be able to make variants of cinnamycin. Here I determined the product of a cinnamycin biosynthetic pathway prese...

  18. Bacterial control of cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, Luyanda L

    2017-08-01

    Full Text Available of biological control appears to be direct contact. • Ndlela, L. L. et al. (2016) ‘An overview of cyanobacterial bloom occurrences and research in Africa over the last decade’, Harmful Algae, 60 • Gumbo, J.R. et al. (2010) The Isolation and identification... of Predatory Bacteria from a Microcystis algal Bloom.. African Journal of Biotechnology, 9. *Special acknowledgement goes to the National Research foundation for funding this presentation Bacterial control of cyanobacteria Luyanda...

  19. Antifungal compounds from cyanobacteria.

    Science.gov (United States)

    Shishido, Tânia K; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P; Permi, Perttu; Andreote, Ana P D; Fiore, Marli F; Sivonen, Kaarina

    2015-04-13

    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.

  20. Antifungal Compounds from Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Tânia K. Shishido

    2015-04-01

    Full Text Available 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.

  1. One Health and Toxic Cyanobacteria

    Science.gov (United States)

    One Health and toxic cyanobacteria Blooms of toxic freshwater blue-green algae or cyanobacteria (HABs) have been in the news after HABs associated with human and animal health problems have been reported in Florida, California and Utah during 2016. HABs occur in warm, slow moving...

  2. Oleic acid biosynthesis in cyanobacteria

    International Nuclear Information System (INIS)

    VanDusen, W.J.; Jaworski, J.G.

    1986-01-01

    The biosynthesis of fatty acids in cyanobacteria is very similar to the well characterized system found in green plants. However, the initial desaturation of stearic acid in cyanobacteria appears to represent a significant departure from plant systems in which stearoyl-ACP is the exclusive substrate for desaturation. In Anabaena variabilis, the substrate appears to be monoglucosyldiacylglycerol, a lipid not found in plants. The authors examined five different cyanobacteria to determine if the pathway in A. variabilis was generally present in other cyanobacteria. The cyanobacteria studied were A. variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis marina, and Anacystis nidulans. Each were grown in liquid culture, harvested, and examined for stearoyl-ACP desaturase activity or incubated with 14 CO 2 . None of the cyanobacteria contained any stearoyl-ACP desaturase activity in whole homogenates or 105,000g supernatants. All were capable of incorporating 14 CO 2 into monoglucosyldiacylglycerol and results from incubations of 20 min, 1 hr, 1 hr + 10 hr chase were consistent with monoglucosyldiacylglycerol serving as precursor for monogalctosyldiacylglycerol. Thus, initial evidence is consistent with oleic acid biosynthesis occurring by desaturation of stearoyl-monoglucosyldiacylglycerol in all cyanobacteria

  3. Signature proteins for the major clades of Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Mathews Divya W

    2010-01-01

    Full Text Available Abstract Background The phylogeny and taxonomy of cyanobacteria is currently poorly understood due to paucity of reliable markers for identification and circumscription of its major clades. Results A combination of phylogenomic and protein signature based approaches was used to characterize the major clades of cyanobacteria. Phylogenetic trees were constructed for 44 cyanobacteria based on 44 conserved proteins. In parallel, Blastp searches were carried out on each ORF in the genomes of Synechococcus WH8102, Synechocystis PCC6803, Nostoc PCC7120, Synechococcus JA-3-3Ab, Prochlorococcus MIT9215 and Prochlor. marinus subsp. marinus CCMP1375 to identify proteins that are specific for various main clades of cyanobacteria. These studies have identified 39 proteins that are specific for all (or most cyanobacteria and large numbers of proteins for other cyanobacterial clades. The identified signature proteins include: (i 14 proteins for a deep branching clade (Clade A of Gloebacter violaceus and two diazotrophic Synechococcus strains (JA-3-3Ab and JA2-3-B'a; (ii 5 proteins that are present in all other cyanobacteria except those from Clade A; (iii 60 proteins that are specific for a clade (Clade C consisting of various marine unicellular cyanobacteria (viz. Synechococcus and Prochlorococcus; (iv 14 and 19 signature proteins that are specific for the Clade C Synechococcus and Prochlorococcus strains, respectively; (v 67 proteins that are specific for the Low B/A ecotype Prochlorococcus strains, containing lower ratio of chl b/a2 and adapted to growth at high light intensities; (vi 65 and 8 proteins that are specific for the Nostocales and Chroococcales orders, respectively; and (vii 22 and 9 proteins that are uniquely shared by various Nostocales and Oscillatoriales orders, or by these two orders and the Chroococcales, respectively. We also describe 3 conserved indels in flavoprotein, heme oxygenase and protochlorophyllide oxidoreductase proteins that

  4. Hydrogen production by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Chaudhuri Surabhi

    2005-12-01

    Full Text Available Abstract The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate. Cyanobacteria are highly promising microorganism for hydrogen production. In comparison to the traditional ways of hydrogen production (chemical, photoelectrical, Cyanobacterial hydrogen production is commercially viable. This review highlights the basic biology of cynobacterial hydrogen production, strains involved, large-scale hydrogen production and its future prospects. While integrating the existing knowledge and technology, much future improvement and progress is to be done before hydrogen is accepted as a commercial primary energy source.

  5. Monitoring Cyanobacteria with Satellites Webinar

    Science.gov (United States)

    real-world satellite applications can quantify cyanobacterial harmful algal blooms and related water quality parameters. Provisional satellite derived cyanobacteria data and different software tools are available to state environmental and health agencies.

  6. The marine cyanobacterium Crocosphaera watsonii WH8501 synthesizes the compatible solute trehalose by a laterally acquired OtsAB fusion protein

    NARCIS (Netherlands)

    Pade, N.; Compaoré, J.; Klähn, S.; Stal, L.J.; Hagemann, M.

    2012-01-01

    Compatible solutes are small organic molecules that are involved in the acclimation to various stresses such as temperature and salinity. Marine or moderate halotolerant cyanobacteria accumulate glucosylglycerol, while cyanobacteria with low salt tolerance (freshwater strains) usually accumulate

  7. Fossilized glycolipids reveal past oceanic N2 fixation by heterocystous cyanobacteria

    Science.gov (United States)

    Bauersachs, Thorsten; Speelman, Eveline N.; Hopmans, Ellen C.; Reichart, Gert-Jan; Schouten, Stefan; Damsté, Jaap S. Sinninghe

    2010-01-01

    N2-fixing cyanobacteria play an essential role in sustaining primary productivity in contemporary oceans and freshwater systems. However, the significance of N2-fixing cyanobacteria in past nitrogen cycling is difficult to establish as their preservation potential is relatively poor and specific biological markers are presently lacking. Heterocystous N2-fixing cyanobacteria synthesize unique long-chain glycolipids in the cell envelope covering the heterocyst cell to protect the oxygen-sensitive nitrogenase enzyme. We found that these heterocyst glycolipids are remarkably well preserved in (ancient) lacustrine and marine sediments, unambiguously indicating the (past) presence of N2-fixing heterocystous cyanobacteria. Analysis of Pleistocene sediments of the eastern Mediterranean Sea showed that heterocystous cyanobacteria, likely as epiphytes in symbiosis with planktonic diatoms, were particularly abundant during deposition of sapropels. Eocene Arctic Ocean sediments deposited at a time of large Azolla blooms contained glycolipids typical for heterocystous cyanobacteria presently living in symbiosis with the freshwater fern Azolla, indicating that this symbiosis already existed in that time. Our study thus suggests that heterocystous cyanobacteria played a major role in adding “new” fixed nitrogen to surface waters in past stratified oceans. PMID:20966349

  8. The conifer biomarkers dehydroabietic and abietic acids are widespread in Cyanobacteria

    Science.gov (United States)

    Costa, Maria Sofia; Rego, Adriana; Ramos, Vitor; Afonso, Tiago B.; Freitas, Sara; Preto, Marco; Lopes, Viviana; Vasconcelos, Vitor; Magalhães, Catarina; Leão, Pedro N.

    2016-01-01

    Terpenes, a large family of natural products with important applications, are commonly associated with plants and fungi. The diterpenoids dehydroabietic and abietic acids are defense metabolites abundant in resin, and are used as biomarkers for conifer plants. We report here for the first time that the two diterpenoid acids are produced by members of several genera of cyanobacteria. Dehydroabietic acid was isolated from two cyanobacterial strains and its identity was confirmed spectroscopically. One or both of the diterpenoids were detected in the cells of phylogenetically diverse cyanobacteria belonging to four cyanobacterial ‘botanical orders’, from marine, estuarine and inland environments. Dehydroabietic acid was additionally found in culture supernatants. We investigated the natural role of the two resin acids in cyanobacteria using ecologically-relevant bioassays and found that the compounds inhibited the growth of a small coccoid cyanobacterium. The unexpected discovery of dehydroabietic and abietic acids in a wide range of cyanobacteria has implications for their use as plant biomarkers. PMID:26996104

  9. Circadian Rhythms in Cyanobacteria

    Science.gov (United States)

    Golden, Susan S.

    2015-01-01

    SUMMARY Life on earth is subject to daily and predictable fluctuations in light intensity, temperature, and humidity created by rotation of the earth. Circadian rhythms, generated by a circadian clock, control temporal programs of cellular physiology to facilitate adaptation to daily environmental changes. Circadian rhythms are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Here we introduce the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942. We review the current understanding of the cyanobacterial clock, emphasizing recent work that has generated a more comprehensive understanding of how the circadian oscillator becomes synchronized with the external environment and how information from the oscillator is transmitted to generate rhythms of biological activity. These results have changed how we think about the clock, shifting away from a linear model to one in which the clock is viewed as an interactive network of multifunctional components that are integrated into the context of the cell in order to pace and reset the oscillator. We conclude with a discussion of how this basic timekeeping mechanism differs in other cyanobacterial species and how information gleaned from work in cyanobacteria can be translated to understanding rhythmic phenomena in other prokaryotic systems. PMID:26335718

  10. Secondary metabolites of cyanobacteria Nostoc sp.

    Science.gov (United States)

    Kobayashi, Akio; Kajiyama, Shin-Ichiro

    1998-03-01

    Cyanobacteria attracted much attention recently because of their secondary metabolites with potent biological activities and unusual structures. This paper reviews some recent studies on the isolation, structural, elucidation and biological activities of the bioactive compounds from cyanobacteria Nostoc species.

  11. Climate change and regulation of hepatotoxin production in Cyanobacteria.

    Science.gov (United States)

    Gehringer, Michelle M; Wannicke, Nicola

    2014-04-01

    Harmful, bloom-forming cyanobacteria (CyanoHABs) are occurring with increasing regularity in freshwater and marine ecosystems. The most commonly occurring cyanobacterial toxins are the hepatotoxic microcystin and nodularin. These cyclic hepta- and pentapeptides are synthesised nonribosomally by the gene products of the toxin gene clusters mcy and nda, respectively. Understanding of the regulation of hepatotoxin production is incomplete, although there is strong evidence supporting the roles of iron, light, higher nitrate availability and inorganic carbon in modulating microcystin levels. The majority of these studies have focused on the unicellular freshwater, microcystin-producing strain of Microcystis aeruginosa, with little attention being paid to terrestrial or marine toxin producers. This review intends to investigate the regulation of microcystin and nodularin production in unicellular and filamentous diazotrophic cyanobacteria against the background of changing climate conditions. Special focus is given to diazotrophic filamentous cyanobacteria, for example Nodularia spumigena, capable of regulating their nitrogen levels by actively fixing dinitrogen. By combining data from significant studies, an overall scheme of the regulation of toxin production is presented, focussing specifically on nodularin production in diazotrophs against the background of increasing carbon dioxide concentrations and temperatures envisaged under current climate change models. Furthermore, the risk of sustaining and spreading CyanoHABs in the future ocean is evaluated. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. Incorporating nitrogen fixing cyanobacteria in the global biogeochemical model HAMOCC

    Science.gov (United States)

    Paulsen, Hanna; Ilyina, Tatiana; Six, Katharina

    2015-04-01

    Nitrogen fixation by marine diazotrophs plays a fundamental role in the oceanic nitrogen and carbon cycle as it provides a major source of 'new' nitrogen to the euphotic zone that supports biological carbon export and sequestration. Since most global biogeochemical models include nitrogen fixation only diagnostically, they are not able to capture its spatial pattern sufficiently. Here we present the incorporation of an explicit, dynamic representation of diazotrophic cyanobacteria and the corresponding nitrogen fixation in the global ocean biogeochemical model HAMOCC (Hamburg Ocean Carbon Cycle model), which is part of the Max Planck Institute for Meteorology Earth system model (MPI-ESM). The parameterization of the diazotrophic growth is thereby based on available knowledge about the cyanobacterium Trichodesmium spp., which is considered as the most significant pelagic nitrogen fixer. Evaluation against observations shows that the model successfully reproduces the main spatial distribution of cyanobacteria and nitrogen fixation, covering large parts of the tropical and subtropical oceans. Besides the role of cyanobacteria in marine biogeochemical cycles, their capacity to form extensive surface blooms induces a number of bio-physical feedback mechanisms in the Earth system. The processes driving these interactions, which are related to the alteration of heat absorption, surface albedo and momentum input by wind, are incorporated in the biogeochemical and physical model of the MPI-ESM in order to investigate their impacts on a global scale. First preliminary results will be shown.

  13. Grazing livestock are exposed to terrestrial cyanobacteria

    OpenAIRE

    McGorum , Bruce C; Pirie , R Scott; Glendinning , Laura; McLachlan , Gerry; Metcalf , James S; Banack , Sandra A; Cox , Paul A; Codd , Geoffrey A

    2015-01-01

    While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in al...

  14. Evolution of saxitoxin synthesis in cyanobacteria and dinoflagellates.

    Science.gov (United States)

    Hackett, Jeremiah D; Wisecaver, Jennifer H; Brosnahan, Michael L; Kulis, David M; Anderson, Donald M; Bhattacharya, Debashish; Plumley, F Gerald; Erdner, Deana L

    2013-01-01

    Dinoflagellates produce a variety of toxic secondary metabolites that have a significant impact on marine ecosystems and fisheries. Saxitoxin (STX), the cause of paralytic shellfish poisoning, is produced by three marine dinoflagellate genera and is also made by some freshwater cyanobacteria. Genes involved in STX synthesis have been identified in cyanobacteria but are yet to be reported in the massive genomes of dinoflagellates. We have assembled comprehensive transcriptome data sets for several STX-producing dinoflagellates and a related non-toxic species and have identified 265 putative homologs of 13 cyanobacterial STX synthesis genes, including all of the genes directly involved in toxin synthesis. Putative homologs of four proteins group closely in phylogenies with cyanobacteria and are likely the functional homologs of sxtA, sxtG, and sxtB in dinoflagellates. However, the phylogenies do not support the transfer of these genes directly between toxic cyanobacteria and dinoflagellates. SxtA is split into two proteins in the dinoflagellates corresponding to the N-terminal portion containing the methyltransferase and acyl carrier protein domains and a C-terminal portion with the aminotransferase domain. Homologs of sxtB and N-terminal sxtA are present in non-toxic strains, suggesting their functions may not be limited to saxitoxin production. Only homologs of the C-terminus of sxtA and sxtG were found exclusively in toxic strains. A more thorough survey of STX+ dinoflagellates will be needed to determine if these two genes may be specific to SXT production in dinoflagellates. The A. tamarense transcriptome does not contain homologs for the remaining STX genes. Nevertheless, we identified candidate genes with similar predicted biochemical activities that account for the missing functions. These results suggest that the STX synthesis pathway was likely assembled independently in the distantly related cyanobacteria and dinoflagellates, although using some

  15. IRON-TOLERANT CYANOBACTERIA: IMPLICATIONS FOR ASTROBIOLOGY

    Science.gov (United States)

    Brown, Igor I.; Allen, Carlton C.; Mummey, Daniel L.; Sarkisova, Svetlana A.; McKay, David S.

    2006-01-01

    The review is dedicated to the new group of extremophiles - iron tolerant cyanobacteria. The authors have analyzed earlier published articles about the ecology of iron tolerant cyanobacteria and their diversity. It was concluded that contemporary iron depositing hot springs might be considered as relative analogs of Precambrian environment. The authors have concluded that the diversity of iron-tolerant cyanobacteria is understudied. The authors also analyzed published data about the physiological peculiarities of iron tolerant cyanobacteria. They made the conclusion that iron tolerant cyanobacteria may oxidize reduced iron through the photosystem of cyanobacteria. The involvement of both Reaction Centers 1 and 2 is also discussed. The conclusion that iron tolerant protocyanobacteria could be involved in banded iron formations generation is also proposed. The possible mechanism of the transition from an oxygenic photosynthesis to an oxygenic one is also discussed. In the final part of the review the authors consider the possible implications of iron tolerant cyanobacteria for astrobiology.

  16. Anticancer Drugs from Marine Flora: An Overview

    OpenAIRE

    Sithranga Boopathy, N.; Kathiresan, K.

    2010-01-01

    Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharide...

  17. Utilization of the terrestrial cyanobacteria

    Science.gov (United States)

    Katoh, Hiroshi; Tomita-Yokotani, Kaori; Furukawa, Jun; Kimura, Shunta; Yokoshima, Mika; Yamaguchi, Yuji; Takenaka, Hiroyuki

    The terrestrial, N _{2}-fixing cyanobacterium, Nostoc commune has expected to utilize for agriculture, food and terraforming cause of its extracellular polysaccharide, desiccation tolerance and nitrogen fixation. Previously, the first author indicated that desiccation related genes were analyzed and the suggested that the genes were related to nitrogen fixation and metabolisms. In this report, we suggest possibility of agriculture, using the cyanobacterium. Further, we also found radioactive compounds accumulated N. commune (cyanobacterium) in Fukushima, Japan after nuclear accident. Thus, it is investigated to decontaminate radioactive compounds from the surface soil by the cyanobacterium and showed to accumulate radioactive compounds using the cyanobacterium. We will discuss utilization of terrestrial cyanobacteria under closed environment. Keyword: Desiccation, terrestrial cyanobacteria, bioremediation, agriculture

  18. Extracellular proteins: Novel key components of metal resistance in cyanobacteria?

    Directory of Open Access Journals (Sweden)

    Joaquin eGiner-Lamia

    2016-06-01

    Full Text Available Metals are essential for all living organisms and required for fundamental biochemical processes. However, when in excess, metals can turn into highly-toxic agents able to disrupt cell membranes, alter enzymatic activities and damage DNA. Metal concentrations are therefore tightly controlled inside cells, particularly in cyanobacteria. Cyanobacteria are ecologically relevant prokaryotes that perform oxygenic photosynthesis and can be found in many different marine and freshwater ecosystems, including environments contaminated with heavy metals. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been widely studied in cyanobacteria. So far, most studies have focused on how cells are capable of controlling their internal metal pools, with a strong bias towards the analysis of intracellular processes. Ultrastructure, modulation of physiology, dynamic changes in transcription and protein levels have been studied, but what takes place in the extracellular environment when cells are exposed to an unbalanced metal availability remains largely unknown. The interest in studying the subset of proteins present in the extracellular space has only recently begun and the identification and functional analysis of the cyanobacterial exoproteomes are just emerging. Remarkably, metal-related proteins such as the copper-chaperone CopM or the iron-binding protein FutA2 have already been identified outside the cell. With this perspective, we aim to raise the awareness that metal-resistance mechanisms are not yet fully known and hope to motivate future studies assessing the role of extracellular proteins on bacterial metal homeostasis, with a special focus on cyanobacteria.

  19. Spatial analysis of freshwater lake cyanobacteria blooms, 2008-2011

    Science.gov (United States)

    Background/Question/Methods Cyanobacteria and associated harmful algal blooms cause significant social, economic, and environmental impacts. Cyanobacteria synthesize hepatotoxins, neurotoxins, and dermatotoxins, affecting the health of humans and other species. The Cyanobacteria ...

  20. Tiny Microbes with a Big Impact: The Role of Cyanobacteria and Their Metabolites in Shaping Our Future

    Directory of Open Access Journals (Sweden)

    Sophie Mazard

    2016-05-01

    Full Text Available Cyanobacteria are among the first microorganisms to have inhabited the Earth. Throughout the last few billion years, they have played a major role in shaping the Earth as the planet we live in, and they continue to play a significant role in our everyday lives. Besides being an essential source of atmospheric oxygen, marine cyanobacteria are prolific secondary metabolite producers, often despite the exceptionally small genomes. Secondary metabolites produced by these organisms are diverse and complex; these include compounds, such as pigments and fluorescent dyes, as well as biologically-active compounds with a particular interest for the pharmaceutical industry. Cyanobacteria are currently regarded as an important source of nutrients and biofuels and form an integral part of novel innovative energy-efficient designs. Being autotrophic organisms, cyanobacteria are well suited for large-scale biotechnological applications due to the low requirements for organic nutrients. Recent advances in molecular biology techniques have considerably enhanced the potential for industries to optimize the production of cyanobacteria secondary metabolites with desired functions. This manuscript reviews the environmental role of marine cyanobacteria with a particular focus on their secondary metabolites and discusses current and future developments in both the production of desired cyanobacterial metabolites and their potential uses in future innovative projects.

  1. Tiny Microbes with a Big Impact: The Role of Cyanobacteria and Their Metabolites in Shaping Our Future.

    Science.gov (United States)

    Mazard, Sophie; Penesyan, Anahit; Ostrowski, Martin; Paulsen, Ian T; Egan, Suhelen

    2016-05-17

    Cyanobacteria are among the first microorganisms to have inhabited the Earth. Throughout the last few billion years, they have played a major role in shaping the Earth as the planet we live in, and they continue to play a significant role in our everyday lives. Besides being an essential source of atmospheric oxygen, marine cyanobacteria are prolific secondary metabolite producers, often despite the exceptionally small genomes. Secondary metabolites produced by these organisms are diverse and complex; these include compounds, such as pigments and fluorescent dyes, as well as biologically-active compounds with a particular interest for the pharmaceutical industry. Cyanobacteria are currently regarded as an important source of nutrients and biofuels and form an integral part of novel innovative energy-efficient designs. Being autotrophic organisms, cyanobacteria are well suited for large-scale biotechnological applications due to the low requirements for organic nutrients. Recent advances in molecular biology techniques have considerably enhanced the potential for industries to optimize the production of cyanobacteria secondary metabolites with desired functions. This manuscript reviews the environmental role of marine cyanobacteria with a particular focus on their secondary metabolites and discusses current and future developments in both the production of desired cyanobacterial metabolites and their potential uses in future innovative projects.

  2. Cyanobacteria, neurotoxins and water resources: are there implications for human neurodegenerative disease?

    Science.gov (United States)

    Metcalf, James S; Codd, Geoffrey A

    2009-01-01

    Cyanobacteria are cosmopolitan microbes that inhabit marine, freshwater and terrestrial environments. Under favourable conditions in waterbodies, they can form massive populations (blooms and scums), which present hazards to human and animal health. Such cyanobacteria often contain a variety of toxic substances (cyanotoxins) that can exist as both cell-associated and free forms in the surrounding water. Some cyanotoxins are highly neurotoxic and act through a variety of mechanisms. Recent findings of the production of the neurotoxin beta-N-methylamino-L-alanine (BMAA) by cyanobacteria in aquatic environments, and of BMAA in brain and cerebrospinal fluid samples of amyotrophic lateral sclerosis and Alzheimer's disease victims, raises the possibility that people may be exposed to waterborne BMAA of cyanobacterial origin and that this may contribute to human neurodegenerative disease. An understanding of the risks presented by waterborne BMAA and of available mitigation strategies to reduce this potential exposure is needed.

  3. Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes.

    Science.gov (United States)

    Kehr, Jan-Christoph; Gatte Picchi, Douglas; Dittmann, Elke

    2011-01-01

    Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

  4. Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

    Directory of Open Access Journals (Sweden)

    Jan-Christoph Kehr

    2011-12-01

    Full Text Available Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS and polyketide synthase (PKS pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.

  5. Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Veaudor, Théo; Chauvat, Franck

    2016-01-01

    Cyanobacteria are fascinating photosynthetic prokaryotes that are regarded as the ancestors of the plant chloroplast; the purveyors of oxygen and biomass for the food chain; and promising cell factories for an environmentally friendly production of chemicals. In colonizing most waters and soils of our planet, cyanobacteria are inevitably challenged by environmental stresses that generate DNA damages. Furthermore, many strains engineered for biotechnological purposes can use DNA recombination to stop synthesizing the biotechnological product. Hence, it is important to study DNA recombination and repair in cyanobacteria for both basic and applied research. This review reports what is known in a few widely studied model cyanobacteria and what can be inferred by mining the sequenced genomes of morphologically and physiologically diverse strains. We show that cyanobacteria possess many E. coli-like DNA recombination and repair genes, and possibly other genes not yet identified. E. coli-homolog genes are unevenly distributed in cyanobacteria, in agreement with their wide genome diversity. Many genes are extremely well conserved in cyanobacteria (mutMS, radA, recA, recFO, recG, recN, ruvABC, ssb, and uvrABCD), even in small genomes, suggesting that they encode the core DNA repair process. In addition to these core genes, the marine Prochlorococcus and Synechococcus strains harbor recBCD (DNA recombination), umuCD (mutational DNA replication), as well as the key SOS genes lexA (regulation of the SOS system) and sulA (postponing of cell division until completion of DNA reparation). Hence, these strains could possess an E. coli-type SOS system. In contrast, several cyanobacteria endowed with larger genomes lack typical SOS genes. For examples, the two studied Gloeobacter strains lack alkB, lexA, and sulA; and Synechococcus PCC7942 has neither lexA nor recCD. Furthermore, the Synechocystis PCC6803 lexA product does not regulate DNA repair genes. Collectively, these findings

  6. MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

    NARCIS (Netherlands)

    DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

    A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur

  7. Cyanobacteria facilitate parasite epidemics in Daphnia.

    Science.gov (United States)

    Tellenbach, C; Tardent, N; Pomati, F; Keller, B; Hairston, N G; Wolinska, J; Spaak, P

    2016-12-01

    The seasonal dominance of cyanobacteria in the phytoplankton community of lake ecosystems can have severe implications for higher trophic levels. For herbivorous zooplankton such as Daphnia, cyanobacteria have poor nutritional value and some species can produce toxins affecting zooplankton survival and reproduction. Here we present another, hitherto largely unexplored aspect of cyanobacteria, namely that they can increase Daphnia susceptibility to parasites. In a 12-yr monthly time-series analysis of the Daphnia community in Greifensee (Switzerland), we observed that cyanobacteria density correlated significantly with the epidemics of a common gut parasite of Daphnia, Caullerya mesnili, regardless of what cyanobacteria species was present or whether it was colonial or filamentous. The temperature from the previous month also affected the occurrence of Caullerya epidemics, either directly or indirectly by the promotion of cyanobacterial growth. A laboratory experiment confirmed that cyanobacteria increase the susceptibility of Daphnia to Caullerya, and suggested a possible involvement of cyanotoxins or other chemical traits of cyanobacteria in this process. These findings expand our understanding of the consequences of toxic cyanobacterial blooms for lake ecosystems and might be relevant for epidemics experienced by other aquatic species. © 2016 by the Ecological Society of America.

  8. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H 2 O, and CO 2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  9. Bioinformatic analysis of the distribution of inorganic carbon transporters and prospective targets for bioengineering to increase Ci uptake by cyanobacteria.

    Science.gov (United States)

    Gaudana, Sandeep B; Zarzycki, Jan; Moparthi, Vamsi K; Kerfeld, Cheryl A

    2015-10-01

    Cyanobacteria have evolved a carbon-concentrating mechanism (CCM) which has enabled them to inhabit diverse environments encompassing a range of inorganic carbon (Ci: [Formula: see text] and CO2) concentrations. Several uptake systems facilitate inorganic carbon accumulation in the cell, which can in turn be fixed by ribulose 1,5-bisphosphate carboxylase/oxygenase. Here we survey the distribution of genes encoding known Ci uptake systems in cyanobacterial genomes and, using a pfam- and gene context-based approach, identify in the marine (alpha) cyanobacteria a heretofore unrecognized number of putative counterparts to the well-known Ci transporters of beta cyanobacteria. In addition, our analysis shows that there is a huge repertoire of transport systems in cyanobacteria of unknown function, many with homology to characterized Ci transporters. These can be viewed as prospective targets for conversion into ancillary Ci transporters through bioengineering. Increasing intracellular Ci concentration coupled with efforts to increase carbon fixation will be beneficial for the downstream conversion of fixed carbon into value-added products including biofuels. In addition to CCM transporter homologs, we also survey the occurrence of rhodopsin homologs in cyanobacteria, including bacteriorhodopsin, a class of retinal-binding, light-activated proton pumps. Because they are light driven and because of the apparent ease of altering their ion selectivity, we use this as an example of re-purposing an endogenous transporter for the augmentation of Ci uptake by cyanobacteria and potentially chloroplasts.

  10. Engineering cyanobacteria as photosynthetic feedstock factories.

    Science.gov (United States)

    Hays, Stephanie G; Ducat, Daniel C

    2015-03-01

    Carbohydrate feedstocks are at the root of bioindustrial production and are needed in greater quantities than ever due to increased prioritization of renewable fuels with reduced carbon footprints. Cyanobacteria possess a number of features that make them well suited as an alternative feedstock crop in comparison to traditional terrestrial plant species. Recent advances in genetic engineering, as well as promising preliminary investigations of cyanobacteria in a number of distinct production regimes have illustrated the potential of these aquatic phototrophs as biosynthetic chassis. Further improvements in strain productivities and design, along with enhanced understanding of photosynthetic metabolism in cyanobacteria may pave the way to translate cyanobacterial theoretical potential into realized application.

  11. Harnessing transcription for bioproduction in cyanobacteria

    DEFF Research Database (Denmark)

    Stensjö, Karin; Vavitsas, Konstantinos; Tyystjärvi, Taina

    2018-01-01

    Sustainable production of biofuels and other valuable compounds is one of our future challenges. One tempting possibility is to use photosynthetic cyanobacteria as production factories. Currently, tools for genetic engineering of cyanobacteria are yet not good enough to exploit the full potential...... of cyanobacteria. A wide variety of expression systems will be required to adjust both the expression of heterologous enzyme(s) and metabolic routes to the best possible balance, allowing the optimal production of a particular substance. In bacteria, transcription, especially the initiation of transcription, has...

  12. Photomixotrophic chemical production in cyanobacteria.

    Science.gov (United States)

    Matson, Morgan M; Atsumi, Shota

    2018-04-01

    The current global dependence on fossil fuels for both energy and chemical production has spurred concerns regarding long-term resource security and environmental detriments resulting from increased CO 2 levels. Through the installation of exogenous metabolic pathways, engineered cyanobacteria strains can directly fix CO 2 into industrially relevant chemicals currently produced from petroleum. This review highlights some of the studies that have successfully implemented photomixotrophic conditions to increase cyanobacterial chemical production. Supplementation with fixed carbon sources provides additional carbon building blocks and energy to enhance production and occasionally aid in growth. Photomixotrophic production has increased titers up to 5-fold over traditional autotrophic conditions, demonstrating promising applications for future commercialization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Liberation of ammonia by cyanobacteria

    International Nuclear Information System (INIS)

    Newton, J.W.

    1986-01-01

    Photoheterotrophic nitrogen-fixing cyanobacteria release ammonia when treated with methionine sulfoximine (MSX) to inhibit nitrogen incorporation into protein. This released ammonia can be derived from recently fixed nitrogen (nitrogen atmosphere) or endogenous reserves (argon atmosphere). Anaerobic ammonia release requires light and is stimulated by the photosystem II herbicides DCMU and Atrazine, regardless of the source of ammonia. As much as one quarter of the total cellular nitrogen can be released as ammonia by cyanbacteria treated with MSX and DCMU under argon in light. Chromatography of cell extracts indicates that virtually all cellular proteins are degraded. DCMU and Atrazine, at very low concentration, inhibit sustained uptake of the ammonia analog 14 C methylamine. These data indicate that the herbicides interrupt ammonia uptake and retention by the cells, and support a role for photosystem II in ammonia metabolism

  14. Liberation of ammonia by cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Newton, J.W.

    1986-04-01

    Photoheterotrophic nitrogen-fixing cyanobacteria release ammonia when treated with methionine sulfoximine (MSX) to inhibit nitrogen incorporation into protein. This released ammonia can be derived from recently fixed nitrogen (nitrogen atmosphere) or endogenous reserves (argon atmosphere). Anaerobic ammonia release requires light and is stimulated by the photosystem II herbicides DCMU and Atrazine, regardless of the source of ammonia. As much as one quarter of the total cellular nitrogen can be released as ammonia by cyanbacteria treated with MSX and DCMU under argon in light. Chromatography of cell extracts indicates that virtually all cellular proteins are degraded. DCMU and Atrazine, at very low concentration, inhibit sustained uptake of the ammonia analog /sup 14/C methylamine. These data indicate that the herbicides interrupt ammonia uptake and retention by the cells, and support a role for photosystem II in ammonia metabolism.

  15. Hydrogen production by several cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dhruv; Kumar, H.D. (Banaras Hindu Univ., Varanasi (India). Dept. of Botany)

    1992-11-01

    Twenty species belonging to eleven genera of nitrogen-fixing and non-nitrogen-fixing cyanobacteria were screened for production of hydrogen. Only one species each of Nostoc and Anabaena showed light-and nitrogenase-dependent aerobic hydrogen production. The highest rate of aerobic hydrogen production was recorded in Anabaena sp. strain CA. When incubated anaerobically under 99% Ar + 1% CO[sub 2], all the tested strains produced hydrogen. Nickel supplementation completely abolished hydrogen production both under aerobic and anaerobic conditions, except in Anabaena sp. strain CA, where only the rate of production was decreased. Species of Plectonema, Oscillatoria and Spirulina showed methyl viologen-dependent (hydrogenase-dependent) hydrogen production. Other physiological activities were also studied with a view to selecting a suitable organism for large-scale production of hydrogen. (author)

  16. Diel infection of cyanobacteria by cyanophages

    Directory of Open Access Journals (Sweden)

    Tianchi eNi

    2016-01-01

    Full Text Available Cyanobacteria exhibit biological rhythms as an adaptation to the daily light-dark (diel cycle. Light is also crucial for bacteriophages (cyanophages that infect cyanobacteria. As the first step of infection, the adsorption of some cyanophages to their host cells is light-dependent. Moreover, cyanophage replication is affected by light intensity and possibly the host cell cycle. Photosynthesis and carbon metabolism genes have been found in cyanophage genomes. With these genes, cyanophages may affect the host metabolic rhythm. Field studies suggest that cyanophage infection of cyanobacteria in aquatic environments is synchronized directly or indirectly to the light-dark cycle. These discoveries are beginning to reveal how the daily light-dark cycle shapes the interaction of cyanophages and cyanobacteria, which eventually influences matter and energy transformation in aquatic environments.

  17. Engineering cyanobacteria for fuels and chemicals production.

    Science.gov (United States)

    Zhou, Jie; Li, Yin

    2010-03-01

    The world's energy and global warming crises call for sustainable, renewable, carbon-neutral alternatives to replace fossil fuel resources. Currently, most biofuels are produced from agricultural crops and residues, which lead to concerns about food security and land shortage. Compared to the current biofuel production system, cyanobacteria, as autotrophic prokaryotes, do not require arable land and can grow to high densities by efficiently using solar energy, CO(2), water, and inorganic nutrients. Moreover, powerful genetic techniques of cyanobacteria have been developed. For these reasons, cyanobacteria, which carry out oxygenic photosynthesis, are attractive hosts for production of fuels and chemicals. Recently, several chemicals including ethanol, isobutanol and isoprene have been produced by engineered cyanobacteria directly using solar energy, CO(2), and water. Cyanobacterium is therefore a potential novel cell factory for fuels and chemicals production to address global energy security and climate change issues.

  18. Human health effects and remotely sensed cyanobacteria

    Science.gov (United States)

    Cyanobacteria blooms (HAB) pose a potential health risk to beachgoers, including HAB-associated gastrointestinal, respiratory and dermal illness. We conducted a prospective study of beachgoers at a Great Lakes beach during July – September, 2003. We recorded each participan...

  19. Measuring N2 Pressure Using Cyanobacteria

    Science.gov (United States)

    Silverman, S. N.; Kopf, S.; Gordon, R.; Bebout, B.; Som, S.

    2017-11-01

    We have shown that cyanobacteria can record information about N2 partial pressure both morphologically and isotopically, and thus may serve as useful geobarometers to help us better understand Earth's ancient atmosphere.

  20. Agencies collaborate, develop a cyanobacteria assessment network

    Science.gov (United States)

    Schaeffer, Blake A.; Loftin, Keith A.; Stumpf, Richard P.; Werdell, P. Jeremy

    2015-01-01

    Cyanobacteria are a genetically diverse group of photosynthetic microorganisms that occupy a broad range of habitats on land and water all over the world. They release toxins that can cause lung and skin irritation, alter the taste and odor of potable water, and cause human and animal illness. Cyanobacteria blooms occur worldwide, and climate change may increase the frequency, duration, and extent of these bloom events.

  1. Degradation of textile dyes by cyanobacteria.

    Science.gov (United States)

    Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

    Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  2. Water Pollution, and Treatments Part III: Biodegradation of Oil in Refineries Waste Water and Oils Adsorbed in Agricultural Wastes by Selected Strains of Cyanobacteria

    International Nuclear Information System (INIS)

    El-Emary, M.M.; Ali, N.A.; Naguib, M.M.

    2011-01-01

    The main objective of this study is to determine the biological degradation of oil hydrocarbons and sulfur compounds of Marine Balayim crude oil and its refined products by selected indigenous Cyanobacteria strains. The oils used were Marine Balayim crude oil, skimmed oil and some refined products such as gasoline, kerosene, gas oil, fuel oil and petroleum coke. The selected organisms in the current study are the Blue-Green Algae Cyanobacteria, Oscillatoria limentica. This organism was collected from the hyper saline environment of the solar lake in Taba, Sinai, Egypt. The results obtained revealed that the utilization of such strains can be used for the bioremediation of oily waste water.

  3. Toxic cyanobacteria and cyanotoxins in public hot springs in Saudi Arabia.

    Science.gov (United States)

    Mohamed, Zakaria A

    2008-01-01

    Toxic cyanobacteria are well reported in rivers, lakes and even marine environments, but the toxin production of cyanobacteria in hot springs is largely unexplored. Therefore, the present study investigated the presence of toxic cyanobacteria and cyanotoxins in public hot springs in Saudi Arabia. The results of an enzyme-linked immunosorbent assay (ELISA) revealed that Saudi spring cyanobacterial mats contained microcystins (MCYSTs) at concentrations ranging from 468 to 512.5 microg g(-1). The Limulus amebocyte lystae (LAL) assay detected lipopolysaccharide (LPS) endotoxins in these mats at concentrations ranging from 433.3 to 506.8 EU g(-1). MCYSTs and endotoxins were also detected in spring waters at levels of 5.7 microg l(-1) and 640 EU ml(-1), respectively, exceeding WHO's provisional guideline value for MCYST-LR in drinking-water. High-performance liquid chromatography (HPLC) analysis revealed that only Oscillatoria limosa and Synechococcus lividus can produce MCYSTs with a profile consisting of MCYST-RR and -LR. Based on the LAL assay, 12 out of 17 cyanobacterial species contained LPS at concentrations ranging from 0.93 to 21.06 EU g(-1). However, not all LPS of these species were toxic to mice. This study suggests that the hot springs in the world including Saudi Arabia should be screened for toxic cyanobacteria to avoid the exposure of people recreating and bathing in spring waters to cyanobacterial toxins.

  4. Forecasting cyanobacteria dominance in Canadian temperate lakes.

    Science.gov (United States)

    Persaud, Anurani D; Paterson, Andrew M; Dillon, Peter J; Winter, Jennifer G; Palmer, Michelle; Somers, Keith M

    2015-03-15

    Predictive models based on broad scale, spatial surveys typically identify nutrients and climate as the most important predictors of cyanobacteria abundance; however these models generally have low predictive power because at smaller geographic scales numerous other factors may be equally or more important. At the lake level, for example, the ability to forecast cyanobacteria dominance is of tremendous value to lake managers as they can use such models to communicate exposure risks associated with recreational and drinking water use, and possible exposure to algal toxins, in advance of bloom occurrence. We used detailed algal, limnological and meteorological data from two temperate lakes in south-central Ontario, Canada to determine the factors that are closely linked to cyanobacteria dominance, and to develop easy to use models to forecast cyanobacteria biovolume. For Brandy Lake (BL), the strongest and most parsimonious model for forecasting % cyanobacteria biovolume (% CB) included water column stability, hypolimnetic TP, and % cyanobacteria biovolume two weeks prior. For Three Mile Lake (TML), the best model for forecasting % CB included water column stability, hypolimnetic TP concentration, and 7-d mean wind speed. The models for forecasting % CB in BL and TML are fundamentally different in their lag periods (BL = lag 1 model and TML = lag 2 model) and in some predictor variables despite the close proximity of the study lakes. We speculate that three main factors (nutrient concentrations, water transparency and lake morphometry) may have contributed to differences in the models developed, and may account for variation observed in models derived from large spatial surveys. Our results illustrate that while forecast models can be developed to determine when cyanobacteria will dominate within two temperate lakes, the models require detailed, lake-specific calibration to be effective as risk-management tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. REVIEW PAPER-MARINE MICROBIAL BIOACTIVE COMPOUNDS

    OpenAIRE

    Kalyani. P*, Hemalatha. K. P. J

    2016-01-01

    Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and...

  6. The origin of multicellularity in cyanobacteria

    Science.gov (United States)

    2011-01-01

    Background Cyanobacteria are one of the oldest and morphologically most diverse prokaryotic phyla on our planet. The early development of an oxygen-containing atmosphere approximately 2.45 - 2.22 billion years ago is attributed to the photosynthetic activity of cyanobacteria. Furthermore, they are one of the few prokaryotic phyla where multicellularity has evolved. Understanding when and how multicellularity evolved in these ancient organisms would provide fundamental information on the early history of life and further our knowledge of complex life forms. Results We conducted and compared phylogenetic analyses of 16S rDNA sequences from a large sample of taxa representing the morphological and genetic diversity of cyanobacteria. We reconstructed ancestral character states on 10,000 phylogenetic trees. The results suggest that the majority of extant cyanobacteria descend from multicellular ancestors. Reversals to unicellularity occurred at least 5 times. Multicellularity was established again at least once within a single-celled clade. Comparison to the fossil record supports an early origin of multicellularity, possibly as early as the "Great Oxygenation Event" that occurred 2.45 - 2.22 billion years ago. Conclusions The results indicate that a multicellular morphotype evolved early in the cyanobacterial lineage and was regained at least once after a previous loss. Most of the morphological diversity exhibited in cyanobacteria today —including the majority of single-celled species— arose from ancient multicellular lineages. Multicellularity could have conferred a considerable advantage for exploring new niches and hence facilitated the diversification of new lineages. PMID:21320320

  7. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    NARCIS (Netherlands)

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms

  8. Cyanobacteria as Cell Factories to Produce Plant Secondary Metabolites

    OpenAIRE

    Xue, Yong; He, Qingfang

    2015-01-01

    Cyanobacteria represent a promising platform for the production of plant secondary metabolites. Their capacity to express plant P450 proteins, which have essential functions in the biosynthesis of many plant secondary metabolites, makes cyanobacteria ideal for this purpose, and their photosynthetic capability allows cyanobacteria to grow with simple nutrient inputs. This review summarizes the advantages of using cyanobacteria to transgenically produce plant secondary metabolites. Some techniq...

  9. Terpenoids and Their Biosynthesis in Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Bagmi Pattanaik

    2015-01-01

    Full Text Available Terpenoids, or isoprenoids, are a family of compounds with great structural diversity which are essential for all living organisms. In cyanobacteria, they are synthesized from the methylerythritol-phosphate (MEP pathway, using glyceraldehyde 3-phosphate and pyruvate produced by photosynthesis as substrates. The products of the MEP pathway are the isomeric five-carbon compounds isopentenyl diphosphate and dimethylallyl diphosphate, which in turn form the basic building blocks for formation of all terpenoids. Many terpenoid compounds have useful properties and are of interest in the fields of pharmaceuticals and nutrition, and even potentially as future biofuels. The MEP pathway, its function and regulation, and the subsequent formation of terpenoids have not been fully elucidated in cyanobacteria, despite its relevance for biotechnological applications. In this review, we summarize the present knowledge about cyanobacterial terpenoid biosynthesis, both regarding the native metabolism and regarding metabolic engineering of cyanobacteria for heterologous production of non-native terpenoids.

  10. Terpenoids and Their Biosynthesis in Cyanobacteria

    Science.gov (United States)

    Pattanaik, Bagmi; Lindberg, Pia

    2015-01-01

    Terpenoids, or isoprenoids, are a family of compounds with great structural diversity which are essential for all living organisms. In cyanobacteria, they are synthesized from the methylerythritol-phosphate (MEP) pathway, using glyceraldehyde 3-phosphate and pyruvate produced by photosynthesis as substrates. The products of the MEP pathway are the isomeric five-carbon compounds isopentenyl diphosphate and dimethylallyl diphosphate, which in turn form the basic building blocks for formation of all terpenoids. Many terpenoid compounds have useful properties and are of interest in the fields of pharmaceuticals and nutrition, and even potentially as future biofuels. The MEP pathway, its function and regulation, and the subsequent formation of terpenoids have not been fully elucidated in cyanobacteria, despite its relevance for biotechnological applications. In this review, we summarize the present knowledge about cyanobacterial terpenoid biosynthesis, both regarding the native metabolism and regarding metabolic engineering of cyanobacteria for heterologous production of non-native terpenoids. PMID:25615610

  11. Color of cyanobacteria: some methodological aspects

    International Nuclear Information System (INIS)

    Prieto, Beatriz; Sanmartin, Patricia; Aira, Noelia; Silva, Benita

    2010-01-01

    Although the color of cyanobacteria is a very informative characteristic, no standardized protocol has, so far, been established for defining the color in an objective way, and, therefore, direct comparison of experimental results obtained by different research groups is not possible. In the present study, we used colorimetric measurements and conventional statistical tools to determine the effects on the measurement of the color of cyanobacteria, of the concentration of the microorganisms and their moisture content, as well as of the size of the target area and the minimum number of measurements. It was concluded that the color measurement is affected by every factor studied, but that this can be controlled for by making at least 10 consecutive measurements/9.62 cm 2 at different randomly selected points on the surface of filters completely covered by films of cyanobacteria in which the moisture contents are higher than 50%.

  12. Cyanobacteria: Promising biocatalysts for sustainable chemical production.

    Science.gov (United States)

    Knoot, Cory J; Ungerer, Justin; Wangikar, Pramod P; Pakrasi, Himadri B

    2018-04-06

    Cyanobacteria are photosynthetic prokaryotes showing great promise as biocatalysts for the direct conversion of CO 2 into fuels, chemicals, and other value-added products. Introduction of just a few heterologous genes can endow cyanobacteria with the ability to transform specific central metabolites into many end products. Recent engineering efforts have centered around harnessing the potential of these microbial biofactories for sustainable production of chemicals conventionally produced from fossil fuels. Here, we present an overview of the unique chemistry that cyanobacteria have been co-opted to perform. We highlight key lessons learned from these engineering efforts and discuss advantages and disadvantages of various approaches. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Occurrence of cyanobacteria genera in the Vaal Dam: implications ...

    African Journals Online (AJOL)

    The occurrence of cyanobacteria genera in the Vaal Dam was analysed and the factors that influence its dominance in the particular reservoir were also investigated. The study was motivated by the effects of the secondary metabolites of cyanobacteria genera on potable water production. Cyanobacteria genera have been ...

  14. Recruitment of bloom-forming cyanobacteria and its driving factors ...

    African Journals Online (AJOL)

    Based on most of the literature, this paper reviewed the progress made in following aspects: cognition to cyanobacteria recruitment, various traps for studying cyanobacteria recruitment in lakes, recruitment patterns of some species of cyanobacteria, and the driving factors for recruitment. Additionally, perspective studies of ...

  15. Genome-wide analysis of putative peroxiredoxin in unicellular and filamentous cyanobacteria.

    Science.gov (United States)

    Cui, Hongli; Wang, Yipeng; Wang, Yinchu; Qin, Song

    2012-11-16

    Cyanobacteria are photoautotrophic prokaryotes with wide variations in genome sizes and ecological habitats. Peroxiredoxin (PRX) is an important protein that plays essential roles in protecting own cells against reactive oxygen species (ROS). PRXs have been identified from mammals, fungi and higher plants. However, knowledge on cyanobacterial PRXs still remains obscure. With the availability of 37 sequenced cyanobacterial genomes, we performed a comprehensive comparative analysis of PRXs and explored their diversity, distribution, domain structure and evolution. Overall 244 putative prx genes were identified, which were abundant in filamentous diazotrophic cyanobacteria, Acaryochloris marina MBIC 11017, and unicellular cyanobacteria inhabiting freshwater and hot-springs, while poor in all Prochlorococcus and marine Synechococcus strains. Among these putative genes, 25 open reading frames (ORFs) encoding hypothetical proteins were identified as prx gene family members and the others were already annotated as prx genes. All 244 putative PRXs were classified into five major subfamilies (1-Cys, 2-Cys, BCP, PRX5_like, and PRX-like) according to their domain structures. The catalytic motifs of the cyanobacterial PRXs were similar to those of eukaryotic PRXs and highly conserved in all but the PRX-like subfamily. Classical motif (CXXC) of thioredoxin was detected in protein sequences from the PRX-like subfamily. Phylogenetic tree constructed of catalytic domains coincided well with the domain structures of PRXs and the phylogenies based on 16s rRNA. The distribution of genes encoding PRXs in different unicellular and filamentous cyanobacteria especially those sub-families like PRX-like or 1-Cys PRX correlate with the genome size, eco-physiology, and physiological properties of the organisms. Cyanobacterial and eukaryotic PRXs share similar conserved motifs, indicating that cyanobacteria adopt similar catalytic mechanisms as eukaryotes. All cyanobacterial PRX proteins

  16. Genome-wide comparative analysis of metacaspases in unicellular and filamentous cyanobacteria

    Directory of Open Access Journals (Sweden)

    Qin Song

    2010-03-01

    Full Text Available Abstract Background Cyanobacteria are an ancient group of photoautotrophic prokaryotes with wide variations in genome size and ecological habitat. Metacaspases (MCAs are cysteine proteinases that have sequence homology to caspases and play essential roles in programmed cell death (PCD. MCAs have been identified in several prokaryotes, fungi and plants; however, knowledge about cyanobacterial metacaspases still remains obscure. With the availability of sequenced genomes of 33 cyanobacteria, we perform a comparative analysis of metacaspases and explore their distribution, domain structure and evolution. Results A total of 58 putative MCAs were identified, which are abundant in filamentous diazotrophic cyanobacteria and Acaryochloris marina MBIC 11017 and absent in all Prochlorococcus and marine Synechococcus strains, except Synechococcus sp. PCC 7002. The Cys-His dyad of caspase superfamily is conserved, while mutations (Tyr in place of His and Ser/Asn/Gln/Gly instead of Cys are also detected in some cyanobacteria. MCAs can be classified into two major families (α and β based on the additional domain structure. Ten types and a total of 276 additional domains were identified, most of which involves in signal transduction. Apoptotic related NACHT domain was also found in two cyanobacterial MCAs. Phylogenetic tree of MCA catalytic P20 domains coincides well with the domain structure and the phylogenies based on 16s rRNA. Conclusions The existence and quantity of MCA genes in unicellular and filamentous cyanobacteria are a function of the genome size and ecological habitat. MCAs of family α and β seem to evolve separately and the recruitment of WD40 additional domain occurs later than the divergence of the two families. In this study, a general framework of sequence-structure-function connections for the metacaspases has been revealed, which may provide new targets for function investigation.

  17. Collective evolution of cyanobacteria and cyanophages mediated by horizontal gene transfer

    Science.gov (United States)

    Shih, Hong-Yan; Rogers, Tim; Goldenfeld, Nigel

    We describe a model for how antagonistic predator-prey coevolution can lead to mutualistic adaptation to an environment, as a result of horizontal gene transfer. Our model is a simple description of ecosystems such as marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. These genes evolve more rapidly in the virosphere than the bacterial pan-genome, and thus the bacterial population could potentially benefit from phage predation. By modeling both the barrier to predation and horizontal gene transfer, we study this balance between individual sacrifice and collective benefits. The outcome is an emergent mutualistic coevolution of improved photosynthesis capability, benefiting both bacteria and phage. This form of multi-level selection can contribute to niche stratification in the cyanobacteria-phage ecosystem. This work is supported in part by a cooperative agreement with NASA, Grant NNA13AA91A/A0018.

  18. Convergent Evolution of Ergothioneine Biosynthesis in Cyanobacteria.

    Science.gov (United States)

    Liao, Cangsong; Seebeck, Florian P

    2017-11-02

    Biosynthesis of N-α-trimethyl-2-thiohistidine (ergothioneine) is a frequent trait in cyanobacteria. This sulfur compound may provide essential relief from oxidative stress related to oxygenic photosynthesis. The central steps in ergothioneine biosynthesis are catalyzed by a histidine methyltransferase and an iron-dependent sulfoxide synthase. In this report, we present evidence that some cyanobacteria recruited and adapted a sulfoxide synthase from a different biosynthetic pathway to make ergothioneine. The discovery of a second origin of ergothioneine production underscores the physiological importance of this metabolite and highlights the evolutionary malleability of the thiohistidine biosynthetic machinery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. 14CO2 fixation pattern of cyanobacteria

    International Nuclear Information System (INIS)

    Erdmann, N.; Schiewer, U.

    1985-01-01

    The 14 CO 2 fixation pattern of three cyanobacteria in the light and dark were studied. Two different chromatographic methods widely used for separating labelled photosynthetic intermediates were compared. After ethanolic extraction, a rather uniform fixation pattern reflecting mainly the β-carboxylation pathway is obtained for all 3 species. Of the intermediates, glucosylglycerol is specific and high citrulline and low malate contents are fairly specific to cyanobacteria. The composition of the 14 CO 2 fixation pattern is hardly affected by changes in temperature or light intensity, but it is severely affected by changes in the water potential of the medium. (author)

  20. Optical researches for cyanobacteria bloom monitoring in Curonian Lagoon

    Science.gov (United States)

    Shirshin, Evgeny A.; Budylin, Gleb B.; Yakimov, Boris P.; Voloshina, Olga V.; Karabashev, Genrik S.; Evdoshenko, Marina A.; Fadeev, Victor V.

    2016-04-01

    Cyanobacteria bloom is a great ecological problem of Curonian Lagoon and Baltic Sea. The development of novel methods for the on-line control of cyanobacteria concentration and, moreover, for prediction of bloom spreading is of interest for monitoring the state of ecosystem. Here, we report the results of the joint application of hyperspectral measurements and remote sensing of Curonian Lagoon in July 2015 aimed at the assessment of cyanobacteria communities. We show that hyperspectral data allow on-line detection and qualitative estimation of cyanobacteria concentration, while the remote sensing data indicate the possibility of cyanobacteria bloom detection using the spectral features of upwelling irradiation.

  1. Summer heatwaves promote blooms of harmful cyanobacteria

    NARCIS (Netherlands)

    K.D Joehnk; J. Huisman; J. Sharples; B.P. Sommeijer (Ben); P.M. Visser (Petra); J.M. Stroom

    2008-01-01

    htmlabstractDense surface blooms of toxic cyanobacteria in eutrophic lakes may lead to mass mortalities of fish and birds, and provide a serious health threat for cattle, pets, and humans. It has been argued that global warming may increase the incidence of harmful algal blooms. Here, we report on a

  2. Summer heatwaves promote blooms of harmful cyanobacteria

    NARCIS (Netherlands)

    Jöhnk, K.D.; Huisman, J.; Sharples, J.; Sommeijer, B.; Visser, P.M.; Stroom, J.M.

    2008-01-01

    Dense surface blooms of toxic cyanobacteria in eutrophic lakes may lead to mass mortalities of fish and birds, and provide a serious health threat for cattle, pets, and humans. It has been argued that global warming may increase the incidence of harmful algal blooms. Here, we report on a lake

  3. Determination of the Glycogen Content in Cyanobacteria.

    Science.gov (United States)

    De Porcellinis, Alice; Frigaard, Niels-Ulrik; Sakuragi, Yumiko

    2017-07-17

    Cyanobacteria accumulate glycogen as a major intracellular carbon and energy storage during photosynthesis. Recent developments in research have highlighted complex mechanisms of glycogen metabolism, including the diel cycle of biosynthesis and catabolism, redox regulation, and the involvement of non-coding RNA. At the same time, efforts are being made to redirect carbon from glycogen to desirable products in genetically engineered cyanobacteria to enhance product yields. Several methods are used to determine the glycogen contents in cyanobacteria, with variable accuracies and technical complexities. Here, we provide a detailed protocol for the reliable determination of the glycogen content in cyanobacteria that can be performed in a standard life science laboratory. The protocol entails the selective precipitation of glycogen from the cell lysate and the enzymatic depolymerization of glycogen to generate glucose monomers, which are detected by a glucose oxidase-peroxidase (GOD-POD) enzyme coupled assay. The method has been applied to Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002, two model cyanobacterial species that are widely used in metabolic engineering. Moreover, the method successfully showed differences in the glycogen contents between the wildtype and mutants defective in regulatory elements or glycogen biosynthetic genes.

  4. Grazing livestock are exposed to terrestrial cyanobacteria.

    Science.gov (United States)

    McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A

    2015-02-25

    While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

  5. Bloom Dynamics of Cyanobacteria and Their Toxins: Environmental Health Impacts and Mitigation Strategies

    Science.gov (United States)

    Rastogi, Rajesh P.; Madamwar, Datta; Incharoensakdi, Aran

    2015-01-01

    Cyanobacteria are ecologically one of the most prolific groups of phototrophic prokaryotes in both marine and freshwater habitats. Both the beneficial and detrimental aspects of cyanobacteria are of considerable significance. They are important primary producers as well as an immense source of several secondary products, including an array of toxic compounds known as cyanotoxins. Abundant growth of cyanobacteria in freshwater, estuarine, and coastal ecosystems due to increased anthropogenic eutrophication and global climate change has created serious concern toward harmful bloom formation and surface water contamination all over the world. Cyanobacterial blooms and the accumulation of several cyanotoxins in water bodies pose severe ecological consequences with high risk to aquatic organisms and global public health. The proper management for mitigating the worldwide incidence of toxic cyanobacterial blooms is crucial for maintenance and sustainable development of functional ecosystems. Here, we emphasize the emerging information on the cyanobacterial bloom dynamics, toxicology of major groups of cyanotoxins, as well as a perspective and integrative approach to their management. PMID:26635737

  6. Novel Metabolic Attributes of the Genus Cyanothece, Comprising a Group of Unicellular Nitrogen-Fixing Cyanobacteria

    Science.gov (United States)

    Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A.; Pakrasi, Himadri B.

    2011-01-01

    ABSTRACT The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. PMID:21972240

  7. Electricity generation from digitally printed cyanobacteria.

    Science.gov (United States)

    Sawa, Marin; Fantuzzi, Andrea; Bombelli, Paolo; Howe, Christopher J; Hellgardt, Klaus; Nixon, Peter J

    2017-11-06

    Microbial biophotovoltaic cells exploit the ability of cyanobacteria and microalgae to convert light energy into electrical current using water as the source of electrons. Such bioelectrochemical systems have a clear advantage over more conventional microbial fuel cells which require the input of organic carbon for microbial growth. However, innovative approaches are needed to address scale-up issues associated with the fabrication of the inorganic (electrodes) and biological (microbe) parts of the biophotovoltaic device. Here we demonstrate the feasibility of using a simple commercial inkjet printer to fabricate a thin-film paper-based biophotovoltaic cell consisting of a layer of cyanobacterial cells on top of a carbon nanotube conducting surface. We show that these printed cyanobacteria are capable of generating a sustained electrical current both in the dark (as a 'solar bio-battery') and in response to light (as a 'bio-solar-panel') with potential applications in low-power devices.

  8. Pathological effects of cyanobacteria on sea fans in southeast Florida.

    Science.gov (United States)

    Kiryu, Y; Landsberg, J H; Peters, E C; Tichenor, E; Burleson, C; Perry, N

    2015-07-01

    In early August 2008, observations by divers indicated that sea fans, particularly Gorgonia ventalina, Gorgonia flabellum, and Iciligorgia schrammi, were being covered by benthic filamentous cyanobacteria. From August 2008 through January 2009 and again in April 2009, tissue samples from a targeted G. ventalina colony affected by cyanobacteria and from a nearby, apparently healthy (without cyanobacteria) control colony, were collected monthly for histopathological examination. The primary cellular response of the sea fan to overgrowth by cyanobacteria was an increase in the number of acidophilic amoebocytes (with their granular contents dispersed) that were scattered throughout the coenenchyme tissue. Necrosis of scleroblasts and zooxanthellae and infiltration of degranulated amoebocytes were observed in the sea fan surface tissues at sites overgrown with cyanobacteria. Fungal hyphae in the axial skeleton were qualitatively more prominent in cyanobacteria-affected sea fans than in controls. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Ionizing radiation and photosynthetic ability of cyanobacteria

    International Nuclear Information System (INIS)

    Agarwal, Rachna; Sainis, Jayashree K.

    2006-01-01

    Unicellular photoautotrophic cyanobacteria, Anacystis nidulans when exposed to lethal dose of 1.5 kGy of 60 Co γ- radiation (D 10 = 257.32 Gy) were as effective photosynthetical as unirradiated controls immediately after irradiation although level of ROS was higher by several magnitudes in these irradiated cells. The results suggested the preservation of the functional integrity of thylakoids even after exposure to lethal dose of ionizing radiation. (author)

  10. Light-dependent electrogenic activity of cyanobacteria.

    Directory of Open Access Journals (Sweden)

    John M Pisciotta

    2010-05-01

    Full Text Available Cyanobacteria account for 20-30% of Earth's primary photosynthetic productivity and convert solar energy into biomass-stored chemical energy at the rate of approximately 450 TW [1]. These single-cell microorganisms are resilient predecessors of all higher oxygenic phototrophs and can be found in self-sustaining, nitrogen-fixing communities the world over, from Antarctic glaciers to the Sahara desert [2].Here we show that diverse genera of cyanobacteria including biofilm-forming and pelagic strains have a conserved light-dependent electrogenic activity, i.e. the ability to transfer electrons to their surroundings in response to illumination. Naturally-growing biofilm-forming photosynthetic consortia also displayed light-dependent electrogenic activity, demonstrating that this phenomenon is not limited to individual cultures. Treatment with site-specific inhibitors revealed the electrons originate at the photosynthetic electron transfer chain (P-ETC. Moreover, electrogenic activity was observed upon illumination only with blue or red but not green light confirming that P-ETC is the source of electrons. The yield of electrons harvested by extracellular electron acceptor to photons available for photosynthesis ranged from 0.05% to 0.3%, although the efficiency of electron harvesting likely varies depending on terminal electron acceptor.The current study illustrates that cyanobacterial electrogenic activity is an important microbiological conduit of solar energy into the biosphere. The mechanism responsible for electrogenic activity in cyanobacteria appears to be fundamentally different from the one exploited in previously discovered electrogenic bacteria, such as Geobacter, where electrons are derived from oxidation of organic compounds and transported via a respiratory electron transfer chain (R-ETC [3], [4]. The electrogenic pathway of cyanobacteria might be exploited to develop light-sensitive devices or future technologies that convert solar

  11. Adventures with cyanobacteria: a personal perspective

    Directory of Open Access Journals (Sweden)

    Govindjee e

    2011-07-01

    Full Text Available Cyanobacteria, or the blue-green algae as they used to be called until 1974, are the oldest oxygenic photosynthesizers. We summarize here adventures with them since the early 1960s. This includes studies on light absorption by cyanobacteria, excitation energy transfer at room temperature down to liquid helium temperature, fluorescence (kinetics as well as spectra and its relationship to photosynthesis, and afterglow (or thermoluminescence from them. Further, we summarize experiments on their two-light reaction - two-pigment system, as well as the unique role of bicarbonate (hydrogen carbonate on the electron acceptor side of their photosystem II, PSII. This review, in addition, includes a discussion on the regulation of changes in phycobilins (mostly in PSII and chlorophyll a (Chl a; mostly in photosystem I, PSI under oscillating light, on the relationship of the slow fluorescence increase (the so-called S to M rise, especially in the presence of diuron in minute time scale with the so-called state-changes, and on the possibility of limited oxygen evolution in mixotrophic PSI (minus mutants, up to 30 minutes, in the presence of glucose. We end this review with a brief discussion on the position of cyanobacteria in the evolution of photosynthetic systems.

  12. Cyanobacteria and cyanotoxins in freshwaters of Uruguay

    Directory of Open Access Journals (Sweden)

    Sylvia Bonilla

    2015-12-01

    Full Text Available Cyanobacterial blooms are a worldwide environmental problem. This phenomenon is typically associated with eutrophication (nutrient enrichment and changes in hydrology. In this study we analysed the distribution of planktonic cyanobacteria in Uruguay and their toxins (microcystin, saxitoxin and cylindrospermopsin, working with an interagency team (OSE, DINAMA, IM, University of the Republic and IIBCE. An historical data base (n = 3061 for 64 ecosystems, years 1980-2014 was generated. Differences between lotic and lentic ecosystems were found in terms of chlorophyll a and nutrient concentrations, usually indicating eutrophication. Two geo-referenced maps for the country were generated with cyanobacteria biomass indicators and the most relevant toxin (microcystin, according to risk levels suggested by the World Health Organization for recreational waters. The areas of greatest risk of exposure were the reservoirs of large rivers (Uruguay and Río Negro and Río de la Plata beaches. In the second part of the study, up to 20 mg L-1of microcystin was quantified in bloom (scum samples, as well as the presence of genes that suggest more microcystin varieties, potentially with greater toxicity. This study provides basic information about the distribution of cyanobacteria in Uruguayan freshwaters that will be useful for national monitoring programs and scientific research.

  13. Genetic engineering of cyanobacteria as biodiesel feedstock.

    Energy Technology Data Exchange (ETDEWEB)

    Ruffing, Anne.; Trahan, Christine Alexandra; Jones, Howland D. T.

    2013-01-01

    Algal biofuels are a renewable energy source with the potential to replace conventional petroleum-based fuels, while simultaneously reducing greenhouse gas emissions. The economic feasibility of commercial algal fuel production, however, is limited by low productivity of the natural algal strains. The project described in this SAND report addresses this low algal productivity by genetically engineering cyanobacteria (i.e. blue-green algae) to produce free fatty acids as fuel precursors. The engineered strains were characterized using Sandias unique imaging capabilities along with cutting-edge RNA-seq technology. These tools are applied to identify additional genetic targets for improving fuel production in cyanobacteria. This proof-of-concept study demonstrates successful fuel production from engineered cyanobacteria, identifies potential limitations, and investigates several strategies to overcome these limitations. This project was funded from FY10-FY13 through the President Harry S. Truman Fellowship in National Security Science and Engineering, a program sponsored by the LDRD office at Sandia National Laboratories.

  14. Metabolic engineering tools in model cyanobacteria.

    Science.gov (United States)

    Carroll, Austin L; Case, Anna E; Zhang, Angela; Atsumi, Shota

    2018-03-26

    Developing sustainable routes for producing chemicals and fuels is one of the most important challenges in metabolic engineering. Photoautotrophic hosts are particularly attractive because of their potential to utilize light as an energy source and CO 2 as a carbon substrate through photosynthesis. Cyanobacteria are unicellular organisms capable of photosynthesis and CO 2 fixation. While engineering in heterotrophs, such as Escherichia coli, has result in a plethora of tools for strain development and hosts capable of producing valuable chemicals efficiently, these techniques are not always directly transferable to cyanobacteria. However, recent efforts have led to an increase in the scope and scale of chemicals that cyanobacteria can produce. Adaptations of important metabolic engineering tools have also been optimized to function in photoautotrophic hosts, which include Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9, 13 C Metabolic Flux Analysis (MFA), and Genome-Scale Modeling (GSM). This review explores innovations in cyanobacterial metabolic engineering, and highlights how photoautotrophic metabolism has shaped their development. Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  15. Advances in Metabolic Engineering of Cyanobacteria for Photosynthetic Biochemical Production

    OpenAIRE

    Lai, Martin C.; Lan, Ethan I.

    2015-01-01

    Engineering cyanobacteria into photosynthetic microbial cell factories for the production of biochemicals and biofuels is a promising approach toward sustainability. Cyanobacteria naturally grow on light and carbon dioxide, bypassing the need of fermentable plant biomass and arable land. By tapping into the central metabolism and rerouting carbon flux towards desirable compound production, cyanobacteria are engineered to directly convert CO2 into various chemicals. This review discusses the d...

  16. Proteomic analysis of post translational modifications in cyanobacteria.

    Science.gov (United States)

    Xiong, Qian; Chen, Zhuo; Ge, Feng

    2016-02-16

    Cyanobacteria are a diverse group of Gram-negative bacteria and the only prokaryotes capable of oxygenic photosynthesis. Recently, cyanobacteria have attracted great interest due to their crucial roles in global carbon and nitrogen cycles and their ability to produce clean and renewable biofuels. To survive in various environmental conditions, cyanobacteria have developed a complex signal transduction network to sense environmental signals and implement adaptive changes. The post-translational modifications (PTMs) systems play important regulatory roles in the signaling networks of cyanobacteria. The systematic investigation of PTMs could contribute to the comprehensive description of protein species and to elucidate potential biological roles of each protein species in cyanobacteria. Although the proteomic studies of PTMs carried out in cyanobacteria were limited, these data have provided clues to elucidate their sophisticated sensing mechanisms that contribute to their evolutionary and ecological success. This review aims to summarize the current status of PTM studies and recent publications regarding PTM proteomics in cyanobacteria, and discuss the novel developments and applications for the analysis of PTMs in cyanobacteria. Challenges, opportunities and future perspectives in the proteomics studies of PTMs in cyanobacteria are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Optical propagation analysis in photobioreactor measurements on cyanobacteria

    Science.gov (United States)

    Fanjul-Vélez, F.; Arce-Diego, J. L.

    2017-12-01

    Biotechnology applications are nowadays increasing in many areas, from agriculture to biochemistry, or even biomedicine. Knowledge on biological processes is becoming essential in order to be able to adequately estimate and control the production of these elements. Cyanobacteria present the capability of producing oxygen and biomass, from CO2 and light irradiation. Therefore, they could be fundamental for human subsistence in adverse environments, as basic needs of breathing and food would be guaranteed. Cyanobacteria cultivation, as other microorganisms, is carried out in photo-bioreactors. The adequate design of photobioreactors greatly influences elements production throughput. This design includes optical illumination and optical measurement of cyanobacteria growth. In this work an analysis of optical measurement of cyanobacteria growth in a photobioreactor is made. As cyanobacteria are inhomogeneous elements, the influence of light scattering is significant. Several types of cyanobacteria are considered, as long as several spatial profiles and irradiances of the incident light. Depending on cyanobacteria optical properties, optical distribution of transmitted light can be estimated. These results allow an appropriate consideration, in the optical design, of the relationship between detected light and cyanobacteria growth. As a consequence, the most adequate conditions of elements production from cyanobacteria could be estimated.

  18. Oxygen and temperature in relation to nitrogen fixation in cyanobacteria: In the daily life of cyanobacteria

    NARCIS (Netherlands)

    Compaoré, J.

    2010-01-01

    The results described in this thesis reveal that unicellular diazotrophic cyanobacteria are unable to fix N2 under fully aerobic conditions. This suggests that in their natural environment these organisms must be exposed to O2 concentrations well below air saturation at least during the periods that

  19. Immense Essence of Excellence: Marine Microbial Bioactive Compounds

    OpenAIRE

    Ira Bhatnagar; Se-Kwon Kim

    2010-01-01

    Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and...

  20. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae

    NARCIS (Netherlands)

    Wijffels, R.H.; Kruse, O.; Hellingwerf, K.J.

    2013-01-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments.Cyanobacteria are promising host organisms for

  1. Diversity and dynamics of potentially toxic cyanobacteria and their ...

    African Journals Online (AJOL)

    Bloom–forming freshwater cyanobacteria pose human and livestock health problems due to their ability to produce toxins and other bioactive compounds. Some non-toxic cyanobacteria accumulate as buoyant surface dwelling scums and thick mats which affect the benthic fauna by degrading aquatic habitats and giving ...

  2. Baltic cyanobacteria- A source of biologically active compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Mazur-Marzec, H.; Błaszczyk, A.; Felczykowska, A.; Hohlfeld, N.; Kobos, J.; Toruńska-Sitarz, A.; PrabhaDevi; Montalva`o, S.; DeSouza, L.; Tammela, P.; Mikosik, A.; Bloch, S.; Nejman-Faleńczyk, B.; Węgrzyn, G.

    cyanobacteria, enzyme activity, enzyme inhibitors, immunological activity, natural products, nonribosomal peptides, plant growth regulators 2 INTRODUCTION Cyanobacteria are Gram-negative bacteria which are widely distributed in many water bodies..., immunological, 4 antimicrobial and plant growth tests. The overall aim of the experiments was to identify strains showing the most promising biological activity for potential biotechnological application. MATERIALS AND METHODS Isolation, culture...

  3. Human Health and Toxic Cyanobacteria – What do we know?

    Science.gov (United States)

    Human Health and Toxic Cyanobacteria – What do we know?Elizabeth D. HilbornWarm, eutrophic surface water systems support the development of toxic cyanobacteria blooms in North Carolina and worldwide. These conditions are increasing with expanding human populations and clima...

  4. Association of non-heterocystous cyanobacteria with crop plants

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2010-01-01

    Cyanobacteria have the ability to form associations with organisms from all domains of life, notably with plants, which they provide with fixed nitrogen, among other substances. This study was aimed at developing artificial associations between non-heterocystous cyanobacteria and selected crop

  5. Light scattering influence in cyanobacteria suspensions inside a photobioreactor

    Science.gov (United States)

    Fanjul-Vélez, F.; Arce-Diego, J. L.

    2018-02-01

    The application of biotechnology is increasing in areas such as agriculture, biochemistry or biomedicine. Growing bacteria or algae could be beneficial for supplying fuel, drugs, food or oxygen, among other products. An adequate knowledge of biological processes is becoming essential to estimate and control products production. Cyanobacteria are particularly appropriate for producing oxygen and biomass, by consuming mainly carbon dioxide and light irradiation. These capacities could be employed to provide human subsistence in adverse environments, as basic breathing and food needs would be satisfied. Cyanobacteria growing is carried out in bioreactors. As light irradiation is quite relevant for their behavior, photobioreactors are needed. Photobioreactors are designed to supply and control the amounts of elements they need, in order to maximize growth. The adequate design of photobioreactors greatly influences production throughput. This design includes, on the optical side, optical illumination and optical measurement of cyanobacteria growth. The influence of optical scattering is fundamental for maximizing cyanobacteria growing, as long as for adequately measure this growth. In this work, optical scattering in cyanobacteria suspensions is analyzed. Optical properties of cyanobacteria and its relationship with concentration is taken into account. Several types of cyanobacteria are considered. The influence of different beam spatial profiles and irradiances is studied by a Monte Carlo approach. The results would allow the consideration of the influence of optical scattering in the detected optical signal employed for growth monitoring, as a function of cyanobacteria type and optical beam parameters.

  6. Cyanobacteria species identified in the Weija and Kpong reservoirs ...

    African Journals Online (AJOL)

    The Kpong and Weija reservoirs supply drinking water to Accra, Ghana. This study was conducted to identify the cyanobacteria present in these reservoirs and to ascertain whether current treatment processes remove whole cyanobacteria cells from the drinking water produced. Cyanotoxins are mostly cell bound and could ...

  7. Genes, Genomes, and Assemblages of Modern Anoxygenic Photosynthetic Cyanobacteria as Proxies for Ancient Cyanobacteria

    Science.gov (United States)

    Grim, S. L.; Dick, G.

    2015-12-01

    Oxygenic photosynthetic (OP) cyanobacteria were responsible for the production of O2 during the Proterozoic. However, the extent and degree of oxygenation of the atmosphere and oceans varied for over 2 Ga after OP cyanobacteria first appeared in the geologic record. Cyanobacteria capable of anoxygenic photosynthesis (AP) may have altered the trajectory of oxygenation, yet the scope of their role in the Proterozoic is not well known. Modern cyanobacterial populations from Middle Island Sinkhole (MIS), Michigan and a handful of cultured cyanobacterial strains, are capable of OP and AP. With their metabolic versatility, these microbes may approximate ancient cyanobacterial assemblages that mediated Earth's oxygenation. To better characterize the taxonomic and genetic signatures of these modern AP/OP cyanobacteria, we sequenced 16S rRNA genes and conducted 'omics analyses on cultured strains, lab mesocosms, and MIS cyanobacterial mat samples collected over multiple years from May to September. Diversity in the MIS cyanobacterial mat is low, with one member of Oscillatoriales dominating at all times. However, Planktothrix members are more abundant in the cyanobacterial community in late summer and fall. The shift in cyanobacterial community composition may be linked to seasonally changing light intensity. In lab mesocosms of MIS microbial mat, we observed a shift in dominant cyanobacterial groups as well as the emergence of Chlorobium, bacteria that specialize in AP. These shifts in microbial community composition and metabolism are likely in response to changing environmental parameters such as the availability of light and sulfide. Further research is needed to understand the impacts of the changing photosynthetic community on oxygen production and the entire microbial consortium. Our study connects genes and genomes of AP cyanobacteria to their environment, and improves understanding of cyanobacterial metabolic strategies that may have shaped Earth's redox evolution.

  8. Cyanobacteria as a platform for biofuel production

    Directory of Open Access Journals (Sweden)

    Nicole E Nozzi

    2013-09-01

    Full Text Available Cyanobacteria have great potential as a platform for biofuel production because of their fast growth, ability to fix carbon dioxide gas, and their genetic tractability. Furthermore they do not require fermentable sugars or arable land for growth and so competition with cropland would be greatly reduced. In this perspective we discuss the challenges and areas for improvement most pertinent for advancing cyanobacterial fuel production, including: improving genetic parts, carbon fixation, metabolic flux, nutrient requirements on a large scale, and photosynthetic efficiency using natural light.

  9. Natural Product Biosynthetic Diversity and Comparative Genomics of the Cyanobacteria.

    Science.gov (United States)

    Dittmann, Elke; Gugger, Muriel; Sivonen, Kaarina; Fewer, David P

    2015-10-01

    Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with intricate chemical structures and potent biological activities. The bulk of these natural products are known from just a handful of genera. Recent efforts have elucidated the mechanisms underpinning the biosynthesis of a diverse array of natural products from cyanobacteria. Many of the biosynthetic mechanisms are unique to cyanobacteria or rarely described from other organisms. Advances in genome sequence technology have precipitated a deluge of genome sequences for cyanobacteria. This makes it possible to link known natural products to biosynthetic gene clusters but also accelerates the discovery of new natural products through genome mining. These studies demonstrate that cyanobacteria encode a huge variety of cryptic gene clusters for the production of natural products, and the known chemical diversity is likely to be just a fraction of the true biosynthetic capabilities of this fascinating and ancient group of organisms. Copyright © 2015. Published by Elsevier Ltd.

  10. Mini-review: Inhibition of biofouling by marine microorganisms.

    Science.gov (United States)

    Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

    2013-01-01

    Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

  11. Genome-wide analysis of putative peroxiredoxin in unicellular and filamentous cyanobacteria

    Directory of Open Access Journals (Sweden)

    Cui Hongli

    2012-11-01

    Full Text Available Abstract Background Cyanobacteria are photoautotrophic prokaryotes with wide variations in genome sizes and ecological habitats. Peroxiredoxin (PRX is an important protein that plays essential roles in protecting own cells against reactive oxygen species (ROS. PRXs have been identified from mammals, fungi and higher plants. However, knowledge on cyanobacterial PRXs still remains obscure. With the availability of 37 sequenced cyanobacterial genomes, we performed a comprehensive comparative analysis of PRXs and explored their diversity, distribution, domain structure and evolution. Results Overall 244 putative prx genes were identified, which were abundant in filamentous diazotrophic cyanobacteria, Acaryochloris marina MBIC 11017, and unicellular cyanobacteria inhabiting freshwater and hot-springs, while poor in all Prochlorococcus and marine Synechococcus strains. Among these putative genes, 25 open reading frames (ORFs encoding hypothetical proteins were identified as prx gene family members and the others were already annotated as prx genes. All 244 putative PRXs were classified into five major subfamilies (1-Cys, 2-Cys, BCP, PRX5_like, and PRX-like according to their domain structures. The catalytic motifs of the cyanobacterial PRXs were similar to those of eukaryotic PRXs and highly conserved in all but the PRX-like subfamily. Classical motif (CXXC of thioredoxin was detected in protein sequences from the PRX-like subfamily. Phylogenetic tree constructed of catalytic domains coincided well with the domain structures of PRXs and the phylogenies based on 16s rRNA. Conclusions The distribution of genes encoding PRXs in different unicellular and filamentous cyanobacteria especially those sub-families like PRX-like or 1-Cys PRX correlate with the genome size, eco-physiology, and physiological properties of the organisms. Cyanobacterial and eukaryotic PRXs share similar conserved motifs, indicating that cyanobacteria adopt similar catalytic

  12. Photobioreactor cultivation strategies for microalgae and cyanobacteria.

    Science.gov (United States)

    Johnson, Tylor J; Katuwal, Sarmila; Anderson, Gary A; Gu, Liping; Zhou, Ruanbao; Gibbons, William R

    2018-03-08

    The current burden on fossil-derived chemicals and fuels combined with the rapidly increasing global population has led to a crucial need to develop renewable and sustainable sources of chemicals and biofuels. Photoautotrophic microorganisms, including cyanobacteria and microalgae, have garnered a great deal of attention for their capability to produce these chemicals from carbon dioxide, mineralized water, and solar energy. While there have been substantial amounts of research directed at scaling-up production from these microorganisms, several factors have proven difficult to overcome, including high costs associated with cultivation, photobioreactor construction, and artificial lighting. Decreasing these costs will substantially increase the economic feasibility of these production processes. Thus, the purpose of this review is to describe various photobioreactor designs, and then provide an overview on lighting systems, mixing, gas transfer, and the hydrodynamics of bubbles. These factors must be considered when the goal of a production process is economic feasibility. Targets for improving microalgae and cyanobacteria cultivation media, including water reduction strategies will also be described. As fossil fuel reserves continue to be depleted and the world population continues to increase, it is imperative that renewable chemical and biofuel production processes be developed toward becoming economically feasible. Thus, it is essential that future research is directed toward improving these processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  13. Marine Synechococcus Aggregation

    Science.gov (United States)

    Neuer, S.; Deng, W.; Cruz, B. N.; Monks, L.

    2016-02-01

    Cyanobacteria are considered to play an important role in the oceanic biological carbon pump, especially in oligotrophic regions. But as single cells are too small to sink, their carbon export has to be mediated by aggregate formation and possible consumption by zooplankton producing sinking fecal pellets. Here we report results on the aggregation of the ubiquitous marine pico-cyanobacterium Synechococcus as a model organism. We first investigated the mechanism behind such aggregation by studying the potential role of transparent exopolymeric particles (TEP) and the effects of nutrient (nitrogen or phosphorus) limitation on the TEP production and aggregate formation of these pico-cyanobacteria. We further studied the aggregation and subsequent settling in roller tanks and investigated the effects of the clays kaolinite and bentonite in a series of concentrations. Our results show that despite of the lowered growth rates, Synechococcus in nutrient limited cultures had larger cell-normalized TEP production, formed a greater volume of aggregates, and resulted in higher settling velocities compared to results from replete cultures. In addition, we found that despite their small size and lack of natural ballasting minerals, Synechococcus cells could still form aggregates and sink at measureable velocities in seawater. Clay minerals increased the number and reduced the size of aggregates, and their ballasting effects increased the sinking velocity and carbon export potential of aggregates. In comparison with the Synechococcus, we will also present results of the aggregation of the pico-cyanobacterium Prochlorococcus in roller tanks. These results contribute to our understanding in the physiology of marine Synechococcus as well as their role in the ecology and biogeochemistry in oligotrophic oceans.

  14. Potential of industrial biotechnology with cyanobacteria and eukaryotic microalgae.

    Science.gov (United States)

    Wijffels, René H; Kruse, Olaf; Hellingwerf, Klaas J

    2013-06-01

    Both cyanobacteria and eukaryotic microalgae are promising organisms for sustainable production of bulk products such as food, feed, materials, chemicals and fuels. In this review we will summarize the potential and current biotechnological developments. Cyanobacteria are promising host organisms for the production of small molecules that can be secreted such as ethanol, butanol, fatty acids and other organic acids. Eukaryotic microalgae are interesting for products for which cellular storage is important such as proteins, lipids, starch and alkanes. For the development of new and promising lines of production, strains of both cyanobacteria and eukaryotic microalgae have to be improved. Transformation systems have been much better developed in cyanobacteria. However, several products would be preferably produced with eukaryotic microalgae. In the case of cyanobacteria a synthetic-systems biology approach has a great potential to exploit cyanobacteria as cell factories. For eukaryotic microalgae transformation systems need to be further developed. A promising strategy is transformation of heterologous (prokaryotic and eukaryotic) genes in established eukaryotic hosts such as Chlamydomonas reinhardtii. Experimental outdoor pilots under containment for the production of genetically modified cyanobacteria and microalgae are in progress. For full scale production risks of release of genetically modified organisms need to be assessed. Copyright © 2013. Published by Elsevier Ltd.

  15. Geographical patterns in cyanobacteria distribution: climate influence at regional scale.

    Science.gov (United States)

    Pitois, Frédéric; Thoraval, Isabelle; Baurès, Estelle; Thomas, Olivier

    2014-01-28

    Cyanobacteria are a component of public health hazards in freshwater environments because of their potential as toxin producers. Eutrophication has long been considered the main cause of cyanobacteria outbreak and proliferation, whereas many studies emphasized the effect of abiotic parameters (mainly temperature and light) on cell growth rate or toxin production. In view of the growing concerns of global change consequences on public health parameters, this study attempts to enlighten climate influence on cyanobacteria at regional scale in Brittany (NW France). The results show that homogeneous cyanobacteria groups are associated with climatic domains related to temperature, global radiation and pluviometry, whereas microcystins (MCs) occurrences are only correlated to local cyanobacteria species composition. As the regional climatic gradient amplitude is similar to the projected climate evolution on a 30-year timespan, a comparison between the present NW and SE situations was used to extrapolate the evolution of geographical cyanobacteria distribution in Brittany. Cyanobacteria composition should shift toward species associated with more frequent Microcystins occurrences along a NW/SE axis whereas lakes situated along a SW/NE axis should transition to species (mainly Nostocales) associated with lower MCs detection frequencies.

  16. Microcystin production in epiphytic cyanobacteria on submerged macrophytes.

    Science.gov (United States)

    Mohamed, Zakaria A; Al Shehri, Abdulrahman M

    2010-06-15

    Cyanotoxins have been largely studied in planktonic and benthic cyanobacteria, but microcystin (MCYST) production in epiphytic cyanobacteria has not been reported yet. The present study reports for the first time the MCYST production in epiphytic cyanobacteria on submerged macrophytes. During this study, four common submerged macrophytes in eutrophic pond in Saudi Arabia were surveyed for the presence of toxic epiphytic cyanobacteria. The results showed that chlorophyll-a and total biovolume of epiphytic cyanobacteria differed significantly among submerged plants with highest values obtained in Stratiotes aloides and lowest in Elodea canadensis. Epiphytic materials collected from Ceratophyllum demersum and S. aloides had higher species diversities than materials collected from E. canadensis and Myriophyllum verticillatum. The cyanobacteria, Merismopedia tenuissima and Leptolyngbya boryana were recorded with a high abundance in epiphytic materials collected from all submerged macrohpytes. Based on Enzyme-linked immunosorbent assay (ELISA), these two species were found to produce MCYSTs (MCYSTs) with concentrations of 1438 and 630 microg g(-1) dry weight, respectively. HPLC analysis of the methanolic extracts of the two species showed that M. tenuissima extract contained MCYST-RR and -LR/demethyl LR plus 3 minor unidentified MCYSTs, while L. boryana extract contained MCYST-YR, -LR/demethyl LR, and 2 minor unidentified MCYSTs. This study suggests that epiphytic species should be considered during monitoring of toxic cyanobacteria in water sources. 2010 Elsevier Ltd. All rights reserved.

  17. Estimating Cyanobacteria Community Dynamics and its Relationship with Environmental Factors

    Science.gov (United States)

    Luo, Wenhuai; Chen, Huirong; Lei, Anping; Lu, Jun; Hu, Zhangli

    2014-01-01

    The cyanobacteria community dynamics in two eutrophic freshwater bodies (Tiegang Reservoir and Shiyan Reservoir) was studied with both a traditional microscopic counting method and a PCR-DGGE genotyping method. Results showed that cyanobacterium Phormidium tenue was the predominant species; twenty-six cyanobacteria species were identified in water samples collected from the two reservoirs, among which fourteen were identified with the morphological method and sixteen with the PCR-DGGE method. The cyanobacteria community composition analysis showed a seasonal fluctuation from July to December. The cyanobacteria population peaked in August in both reservoirs, with cell abundances of 3.78 × 108 cells L-1 and 1.92 × 108 cells L-1 in the Tiegang and Shiyan reservoirs, respectively. Canonical Correspondence Analysis (CCA) was applied to further investigate the correlation between cyanobacteria community dynamics and environmental factors. The result indicated that the cyanobacteria community dynamics was mostly correlated with pH, temperature and total nitrogen. This study demonstrated that data obtained from PCR-DGGE combined with a traditional morphological method could reflect cyanobacteria community dynamics and its correlation with environmental factors in eutrophic freshwater bodies. PMID:24448632

  18. Ammonium photo-production by heterocytous cyanobacteria: potentials and constraints.

    Science.gov (United States)

    Grizeau, Dominique; Bui, Lan Anh; Dupré, Catherine; Legrand, Jack

    2016-08-01

    Over the last decades, production of microalgae and cyanobacteria has been developed for several applications, including novel foods, cosmetic ingredients and more recently biofuel. The sustainability of these promising developments can be hindered by some constraints, such as water and nutrient footprints. This review surveys data on N2-fixing cyanobacteria for biomass production and ways to induce and improve the excretion of ammonium within cultures under aerobic conditions. The nitrogenase complex is oxygen sensitive. Nevertheless, nitrogen fixation occurs under oxic conditions due to cyanobacteria-specific characteristics. For instance, in some cyanobacteria, the vegetative cell differentiation in heterocyts provides a well-adapted anaerobic microenvironment for nitrogenase protection. Therefore, cell cultures of oxygenic cyanobacteria have been grown in laboratory and pilot photobioreactors (Dasgupta et al., 2010; Fontes et al., 1987; Moreno et al., 2003; Nayak & Das, 2013). Biomass production under diazotrophic conditions has been shown to be controlled by environmental factors such as light intensity, temperature, aeration rate, and inorganic carbon concentration, also, more specifically, by the concentration of dissolved oxygen in the culture medium. Currently, there is little information regarding the production of extracellular ammonium by heterocytous cyanobacteria. This review compares the available data on maximum ammonium concentrations and analyses the specific rate production in cultures grown as free or immobilized filamentous cyanobacteria. Extracellular production of ammonium could be coupled, as suggested by recent research on non-diazotrophic cyanobacteria, to that of other high value metabolites. There is little information available regarding the possibility for using diazotrophic cyanobacteria as cellular factories may be in regard of the constraints due to nitrogen fixation.

  19. Horizontal transfer of a eukaryotic plastid-targeted protein gene to cyanobacteria

    Directory of Open Access Journals (Sweden)

    Keeling Patrick J

    2007-06-01

    Full Text Available Abstract Background Horizontal or lateral transfer of genetic material between distantly related prokaryotes has been shown to play a major role in the evolution of bacterial and archaeal genomes, but exchange of genes between prokaryotes and eukaryotes is not as well understood. In particular, gene flow from eukaryotes to prokaryotes is rarely documented with strong support, which is unusual since prokaryotic genomes appear to readily accept foreign genes. Results Here, we show that abundant marine cyanobacteria in the related genera Synechococcus and Prochlorococcus acquired a key Calvin cycle/glycolytic enzyme from a eukaryote. Two non-homologous forms of fructose bisphosphate aldolase (FBA are characteristic of eukaryotes and prokaryotes respectively. However, a eukaryotic gene has been inserted immediately upstream of the ancestral prokaryotic gene in several strains (ecotypes of Synechococcus and Prochlorococcus. In one lineage this new gene has replaced the ancestral gene altogether. The eukaryotic gene is most closely related to the plastid-targeted FBA from red algae. This eukaryotic-type FBA once replaced the plastid/cyanobacterial type in photosynthetic eukaryotes, hinting at a possible functional advantage in Calvin cycle reactions. The strains that now possess this eukaryotic FBA are scattered across the tree of Synechococcus and Prochlorococcus, perhaps because the gene has been transferred multiple times among cyanobacteria, or more likely because it has been selectively retained only in certain lineages. Conclusion A gene for plastid-targeted FBA has been transferred from red algae to cyanobacteria, where it has inserted itself beside its non-homologous, functional analogue. Its current distribution in Prochlorococcus and Synechococcus is punctate, suggesting a complex history since its introduction to this group.

  20. Anticancer drugs from marine flora: an overview.

    Science.gov (United States)

    Sithranga Boopathy, N; Kathiresan, K

    2010-01-01

    Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

  1. Microbial Profiling Of Cyanobacteria From VIT Lake

    Directory of Open Access Journals (Sweden)

    Swati Singh

    2015-08-01

    Full Text Available The application of molecular biological methods to study the diversity and ecology of micro-organisms in natural environments has been practice in mid-1980. The aim of our research is to access the diversity composition and functioning of complex microbial community found in VIT Lake. Molecular ecology is a new field in which microbes can be recognized and their function can be understood at the DNA or RNA level which is useful for constructing genetically modified microbes by recombinant DNA technology for reputed use in the environment. In this research first we will isolate cyanobacteria in lab using conventional methods like broth culture and spread plate method then we will analyze their morphology using various staining methods and DNA and protein composition using electrophoresis method. The applications of community profiling approaches will advance our understanding of the functional role of microbial diversity in VIT Lake controls on microbial community composition.

  2. Dynamics of photosynthetic activity of cyanobacteria after gut ...

    African Journals Online (AJOL)

    African Journal of Biotechnology ... carp and goldfish, whereas there was a significant stimulation of photosynthetic activity of diatom and green algae following the depressed cyanobacteria during cultivation. The mainly stimulated eukaryotic algae species were Fragilariaceae and Scenedesmus obliquus by microscopy.

  3. Metabolic engineering of cyanobacteria for the synthesis of commodity products

    NARCIS (Netherlands)

    Angermayr, S.A.; Gorchs Rovira, A.; Hellingwerf, K.J.

    2015-01-01

    Through metabolic engineering cyanobacteria can be employed in biotechnology. Combining the capacity for oxygenic photosynthesis and carbon fixation with an engineered metabolic pathway allows carbon-based product formation from CO2, light, and water directly. Such cyanobacterial 'cell factories'

  4. Cyanobacteria as photosynthetic biocatalysts: a systems biology perspective.

    Science.gov (United States)

    Gudmundsson, Steinn; Nogales, Juan

    2015-01-01

    The increasing need to replace oil-based products and to address global climate change concerns has triggered considerable interest in photosynthetic microorganisms. Cyanobacteria, in particular, have great potential as biocatalysts for fuels and fine-chemicals. During the last few years the biotechnological applications of cyanobacteria have experienced an unprecedented increase and the use of these photosynthetic organisms for chemical production is becoming a tangible reality. However, the field is still immature and many concerns about the economic feasibility of the biotechnological potential of cyanobacteria remain. In this review we describe recent successes in biofuel and fine-chemical production using cyanobacteria. We discuss the role of the photosynthetic metabolism and highlight the need for systems-level metabolic optimization in order to achieve the true potential of cyanobacterial biocatalysts.

  5. Cyanobacteria and cyanotoxins at the river-estuarine transition.

    Science.gov (United States)

    Bukaveckas, Paul A; Franklin, Rima; Tassone, Spencer; Trache, Brendan; Egerton, Todd

    2018-06-01

    We examined seasonal and longitudinal patterns in the occurrence of toxic cyanobacteria in the James River Estuary (Virginia). Highest chlorophyll and cyanobacteria levels were observed in the tidal freshwater segment, particularly during dry summers when freshwater replacement time was long. Cyanobacteria accounted for a small proportion of phytoplankton biomass (7-15%), and Microcystis comprised a small proportion of the cyanobacteria (85% of samples in July, August and September), fish tissues (87% of planktivorous fishes) and shellfish (83% of individuals). Generic indicators of algal blooms (chlorophyll and algal biomass) had limited utility for predicting microcystin concentrations. However, chlorophyll was found to be a useful predictor for the probability of exceeding specific toxin thresholds. Tissue microcystin concentrations were highest in fish and shellfish collected from the tidal fresh segment, but were detectable in biota collected from the oligohaline at distances 50 km seaward. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Nitrogen fixation by cyanobacteria stimulates production in Baltic food webs.

    Science.gov (United States)

    Karlson, Agnes M L; Duberg, Jon; Motwani, Nisha H; Hogfors, Hedvig; Klawonn, Isabell; Ploug, Helle; Barthel Svedén, Jennie; Garbaras, Andrius; Sundelin, Brita; Hajdu, Susanna; Larsson, Ulf; Elmgren, Ragnar; Gorokhova, Elena

    2015-06-01

    Filamentous, nitrogen-fixing cyanobacteria form extensive summer blooms in the Baltic Sea. Their ability to fix dissolved N2 allows cyanobacteria to circumvent the general summer nitrogen limitation, while also generating a supply of novel bioavailable nitrogen for the food web. However, the fate of the nitrogen fixed by cyanobacteria remains unresolved, as does its importance for secondary production in the Baltic Sea. Here, we synthesize recent experimental and field studies providing strong empirical evidence that cyanobacterial nitrogen is efficiently assimilated and transferred in Baltic food webs via two major pathways: directly by grazing on fresh or decaying cyanobacteria and indirectly through the uptake by other phytoplankton and microbes of bioavailable nitrogen exuded from cyanobacterial cells. This information is an essential step toward guiding nutrient management to minimize noxious blooms without overly reducing secondary production, and ultimately most probably fish production in the Baltic Sea.

  7. Cyanobacteria Occurrence and Nitrogen Fixation Rates in the ...

    African Journals Online (AJOL)

    Keywords: Cyanobacteria, Nitrogen Fixation, Seagrass, Seaweed Farming. Abstract—The .... during every sampling period, using a mercury thermometer and a ..... Capone, D.G. (1993) Determination of nitrogenase activity in aquatic samples ...

  8. Human Health Effects Associated with Exposure to Toxic Cyanobacteria

    Science.gov (United States)

    Reports of toxic cyanobacteria blooms are increasing worldwide. Warming and eutrophic surface water systems support the development of blooms. We examine the evidence for adverse human health effects associated with exposure to toxic blooms in drinking water, recreational water a...

  9. Design of magnetic akaganeite-cyanobacteria hybrid biofilms

    International Nuclear Information System (INIS)

    Dahoumane, Si Amar; Djediat, Chakib; Yepremian, Claude; Coute, Alain; Fievet, Fernand; Brayner, Roberta

    2010-01-01

    Common Anabaena cyanobacteria are shown to form intra-cellularly akaganeite β-FeOOH nanorods of well-controlled size and unusual morphology at room temperature. High-resolution transmission electron microscopy showed that these nanorods present a complex arrangement of pores forming a spongelike structure. These hybrid akaganeite-cyanobacteria were used to form 'one-pot' hybrid biofilms. The hybrid biofilm presents higher coercivity (H c = 44.6 kA m -1 (560 Oe)) when compared to lyophilized akaganeite-cyanobacteria powder (H c = 0.8 kA m -1 (10 Oe)) due to the quasi-assembly of the cells on the glass substrate compared to the lyophilized randomly akaganeite-cyanobacteria powder.

  10. Nutritional quality of two cyanobacteria : How rich is 'poor' food?

    DEFF Research Database (Denmark)

    Schmidt, K.; Jonasdottir, Sigrun

    1997-01-01

    Cyanobacteria have often been described to be nutritionally inadequate and to interfere with zooplankton feeding. In laboratory experiments we offered 2 cyanobacteria, a unicellular Microcystis aeruginosa strain and the filamentous Nodularia sprumigena, to the calanoid copepod Acartia tonsa...... as the sole diet and in food mixtures with the nutritious diatom Thalassiosira weissflogii. Egg production was used as criterion of food quality. The use of cyanobacteria alone was an insufficient diet. However, with increasing additions of M. aeruginosa and N. spumigena to the diatom, different effects were...... observed. Large additions of cyanobacteria resulted in lower egg production and often in elevated mortality of the females, but small additions of M. aeruginosa caused an increase of about 25 % in egg production compared to a pure diatom diet. The influence of similar low concentrations of N. spumigena...

  11. Antibacterial and antifungal activities of selected microalgae and cyanobacteria

    Czech Academy of Sciences Publication Activity Database

    Najdenski, H. M.; Gigova, L. G.; Iliev, I. I.; Pilarski, P. S.; Lukavský, Jaromír; Tsvetkova, I. V.; Ninova, M. S.; Kussovski, V. K.

    2013-01-01

    Roč. 48, č. 7 (2013), s. 1533-1540 ISSN 0950-5423 Institutional support: RVO:67985939 Keywords : antimicrobial activity * cyanobacteria * microalgae Subject RIV: EF - Botanics Impact factor: 1.354, year: 2013

  12. Beneficial effects of aluminum enrichment on nitrogen-fixing cyanobacteria in the South China Sea.

    Science.gov (United States)

    Liu, Jiaxing; Zhou, Linbin; Ke, Zhixin; Li, Gang; Shi, Rongjun; Tan, Yehui

    2018-04-01

    Few studies focus on the effects of aluminum (Al) on marine nitrogen-fixing cyanobacteria, which play important roles in the ocean nitrogen cycling. To examine the effects of Al on the nitrogen-fixing cyanobacteria, bioassay experiments in the oligotrophic South China Sea (SCS) and culture of Crocosphaera watsonii in the laboratory were conducted. Field data showed that 200 nM Al stimulated the growth and the nitrogenase gene expression of Trichodesmium and unicellular diazotrophic cyanobacterium group A, and the nitrogen fixation rates of the whole community. Laboratory experiments demonstrated that Al stimulated the growth and nitrogen fixation of C. watsonii under phosphorus limited conditions. Both field and laboratory results indicated that Al could stimulate the growth of diazotrophs and nitrogen fixation in oligotrophic oceans such as the SCS, which is likely related to the utilization of phosphorus, implying that Al plays an important role in the ocean nitrogen and carbon cycles by influencing nitrogen fixation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Unicellular cyanobacteria with a new mode of life: the lack of photosynthetic oxygen evolution allows nitrogen fixation to proceed.

    Science.gov (United States)

    Bothe, Hermann; Tripp, H James; Zehr, Jonathan P

    2010-10-01

    Some unicellular N(2)-fixing cyanobacteria have recently been found to lack a functional photosystem II of photosynthesis. Such organisms, provisionally termed UCYN-A, of the oceanic picoplanktion are major contributors to the global marine N-input by N(2)-fixation. Since their photosystem II is inactive, they can perform N(2)-fixation during the day. UCYN-A organisms cannot be cultivated as yet. Their genomic analysis indicates that they lack genes coding for enzymes of the Calvin cycle, the tricarboxylic acid cycle and for the biosynthesis of several amino acids. The carbon source in the ocean that allows them to thrive in such high abundance has not been identified. Their genomic analysis implies that they metabolize organic carbon by a new mode of life. These unicellular N(2)-fixing cyanobacteria of the oceanic picoplankton are evolutionarily related to spheroid bodies present in diatoms of the family Epithemiaceae, such as Rhopalodia gibba. More recently, spheroid bodies were ultimately proven to be related to cyanobacteria and to express nitrogenase. They have been reported to be completely inactive in all photosynthetic reactions despite the presence of thylakoids. Sequence data show that R. gibba and its spheroid bodies are an evolutionarily young symbiosis that might serve as a model system to unravel early events in the evolution of chloroplasts. The cell metabolism of UCYN-A and the spheroid bodies may be related to that of the acetate photoassimilating green alga Chlamydobotrys.

  14. Morphology and elemental composition of recent and fossil cyanobacteria

    Science.gov (United States)

    St. Amand, Ann; Hoover, Richard B.; Jerman, Gregory A.; Coston, James; Rozanov, Alexei Y.

    2005-09-01

    Cyanobacteria (cyanophyta, cyanoprokaryota, and blue-green algae) are an ancient, diverse and abundant group of photosynthetic oxygenic microorganisms. Together with other bacteria and archaea, the cyanobacteria have been the dominant life forms on Earth for over 3.5 billion years. Cyanobacteria occur in some of our planets most extreme environments - hot springs and geysers, hypersaline and alkaline lakes, hot and cold deserts, and the polar ice caps. They occur in a wide variety of morphologies. Unlike archaea and other bacteria, which are typically classified in pure culture by their physiological, biochemical and phylogenetic properties, the cyanobacteria have historically been classified based upon their size and morphological characteristics. These include the presence or absence of heterocysts, sheath, uniseriate or multiseriate trichomes, true or false branching, arrangement of thylakoids, reproduction by akinetes, binary fission, hormogonia, fragmentation, presence/absence of motility etc. Their antiquity, distribution, structural and chemical differentiation, diversity, morphological complexity and large size compared to most other bacteria, makes the cyanobacteria ideal candidates for morphological biomarkers in returned Astromaterials. We have obtained optical (nomarski and phase contrast)/fluorescent (blue and green excitation) microscopy images using an Olympus BX60 compound microscope and Field Emission Scanning Electron Microscopy images and EDAX elemental compositions of living and fossil cyanobacteria. The S-4000 Hitachi Field Emission Scanning Electron Microscope (FESEM) has been used to investigate microfossils in freshly fractured interior surfaces of terrestrial rocks and the cells, hormogonia, sheaths and trichomes of recent filamentous cyanobacteria. We present Fluorescent and FESEM Secondary and Backscattered Electron images and associated EDAX elemental analyses of recent and fossil cyanobacteria, concentrating on representatives of the

  15. CyanoBase: the cyanobacteria genome database update 2010.

    Science.gov (United States)

    Nakao, Mitsuteru; Okamoto, Shinobu; Kohara, Mitsuyo; Fujishiro, Tsunakazu; Fujisawa, Takatomo; Sato, Shusei; Tabata, Satoshi; Kaneko, Takakazu; Nakamura, Yasukazu

    2010-01-01

    CyanoBase (http://genome.kazusa.or.jp/cyanobase) is the genome database for cyanobacteria, which are model organisms for photosynthesis. The database houses cyanobacteria species information, complete genome sequences, genome-scale experiment data, gene information, gene annotations and mutant information. In this version, we updated these datasets and improved the navigation and the visual display of the data views. In addition, a web service API now enables users to retrieve the data in various formats with other tools, seamlessly.

  16. CyanoBase: the cyanobacteria genome database update 2010

    OpenAIRE

    Nakao, Mitsuteru; Okamoto, Shinobu; Kohara, Mitsuyo; Fujishiro, Tsunakazu; Fujisawa, Takatomo; Sato, Shusei; Tabata, Satoshi; Kaneko, Takakazu; Nakamura, Yasukazu

    2009-01-01

    CyanoBase (http://genome.kazusa.or.jp/cyanobase) is the genome database for cyanobacteria, which are model organisms for photosynthesis. The database houses cyanobacteria species information, complete genome sequences, genome-scale experiment data, gene information, gene annotations and mutant information. In this version, we updated these datasets and improved the navigation and the visual display of the data views. In addition, a web service API now enables users to retrieve the data in var...

  17. Glycogen production for biofuels by the euryhaline cyanobacteria Synechococcus sp. strain PCC 7002 from an oceanic environment.

    Science.gov (United States)

    Aikawa, Shimpei; Nishida, Atsumi; Ho, Shih-Hsin; Chang, Jo-Shu; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-01-01

    Oxygenic photosynthetic microorganisms such as cyanobacteria and microalgae have attracted attention as an alternative carbon source for the next generation of biofuels. Glycogen abundantly accumulated in cyanobacteria is a promising feedstock which can be converted to ethanol through saccharification and fermentation processes. In addition, the utilization of marine cyanobacteria as a glycogen producer can eliminate the need for a freshwater supply. Synechococcus sp. strain PCC 7002 is a fast-growing marine coastal euryhaline cyanobacteria, however, the glycogen yield has not yet been determined. In the present study, the effects of light intensity, CO2 concentration, and salinity on the cell growth and glycogen content were investigated in order to maximize glycogen production in Synechococcus sp. strain PCC 7002. The optimal culture conditions for glycogen production in Synechococcus sp. strain PCC 7002 were investigated. The maximum glycogen production of 3.5 g L(-1) for 7 days (a glycogen productivity of 0.5 g L(-1) d(-1)) was obtained under a high light intensity, a high CO2 level, and a nitrogen-depleted condition in brackish water. The glycogen production performance in Synechococcus sp. strain PCC 7002 was the best ever reported in the α-polyglucan (glycogen or starch) production of cyanobacteria and microalgae. In addition, the robustness of glycogen production in Synechococcus sp. strain PCC 7002 to salinity was evaluated in seawater and freshwater. The peak of glycogen production of Synechococcus sp. strain PCC 7002 in seawater and freshwater were 3.0 and 1.8 g L(-1) in 7 days, respectively. Glycogen production in Synechococcus sp. strain PCC 7002 maintained the same level in seawater and half of the level in freshwater compared with the optimal result obtained in brackish water. We conclude that Synechococcus sp. strain PCC 7002 has high glycogen production activity and glycogen can be provided from coastal water accompanied by a fluctuation

  18. Nitrogen fixed by cyanobacteria is utilized by deposit-feeders.

    Science.gov (United States)

    Karlson, Agnes M L; Gorokhova, Elena; Elmgren, Ragnar

    2014-01-01

    Benthic communities below the photic zone depend for food on allochthonous organic matter derived from seasonal phytoplankton blooms. In the Baltic Sea, the spring diatom bloom is considered the most important input of organic matter, whereas the contribution of the summer bloom dominated by diazotrophic cyanobacteria is less understood. The possible increase in cyanobacteria blooms as a consequence of eutrophication and climate change calls for evaluation of cyanobacteria effects on benthic community functioning and productivity. Here, we examine utilization of cyanobacterial nitrogen by deposit-feeding benthic macrofauna following a cyanobacteria bloom at three stations during two consecutive years and link these changes to isotopic niche and variations in body condition (assayed as C:N ratio) of the animals. Since nitrogen-fixing cyanobacteria have δ(15)N close to -2‰, we expected the δ(15)N in the deposit-feeders to decrease after the bloom if their assimilation of cyanobacteria-derived nitrogen was substantial. We also expected the settled cyanobacteria with their associated microheterotrophic community and relatively high nitrogen content to increase the isotopic niche area, trophic diversity and dietary divergence between individuals (estimated as the nearest neighbour distance) in the benthic fauna after the bloom. The three surface-feeding species (Monoporeia affinis, Macoma balthica and Marenzelleria arctia) showed significantly lower δ(15)N values after the bloom, while the sub-surface feeder Pontoporeia femorata did not. The effect of the bloom on isotopic niche varied greatly between stations; populations which increased niche area after the bloom had better body condition than populations with reduced niche, regardless of species. Thus, cyanobacterial nitrogen is efficiently integrated into the benthic food webs in the Baltic, with likely consequences for their functioning, secondary production, transfer efficiency, trophic interactions, and

  19. Nitrogen fixed by cyanobacteria is utilized by deposit-feeders.

    Directory of Open Access Journals (Sweden)

    Agnes M L Karlson

    Full Text Available Benthic communities below the photic zone depend for food on allochthonous organic matter derived from seasonal phytoplankton blooms. In the Baltic Sea, the spring diatom bloom is considered the most important input of organic matter, whereas the contribution of the summer bloom dominated by diazotrophic cyanobacteria is less understood. The possible increase in cyanobacteria blooms as a consequence of eutrophication and climate change calls for evaluation of cyanobacteria effects on benthic community functioning and productivity. Here, we examine utilization of cyanobacterial nitrogen by deposit-feeding benthic macrofauna following a cyanobacteria bloom at three stations during two consecutive years and link these changes to isotopic niche and variations in body condition (assayed as C:N ratio of the animals. Since nitrogen-fixing cyanobacteria have δ(15N close to -2‰, we expected the δ(15N in the deposit-feeders to decrease after the bloom if their assimilation of cyanobacteria-derived nitrogen was substantial. We also expected the settled cyanobacteria with their associated microheterotrophic community and relatively high nitrogen content to increase the isotopic niche area, trophic diversity and dietary divergence between individuals (estimated as the nearest neighbour distance in the benthic fauna after the bloom. The three surface-feeding species (Monoporeia affinis, Macoma balthica and Marenzelleria arctia showed significantly lower δ(15N values after the bloom, while the sub-surface feeder Pontoporeia femorata did not. The effect of the bloom on isotopic niche varied greatly between stations; populations which increased niche area after the bloom had better body condition than populations with reduced niche, regardless of species. Thus, cyanobacterial nitrogen is efficiently integrated into the benthic food webs in the Baltic, with likely consequences for their functioning, secondary production, transfer efficiency, trophic

  20. Stress Sensors and Signal Transducers in Cyanobacteria

    Science.gov (United States)

    Los, Dmitry A.; Zorina, Anna; Sinetova, Maria; Kryazhov, Sergey; Mironov, Kirill; Zinchenko, Vladislav V.

    2010-01-01

    In living cells, the perception of environmental stress and the subsequent transduction of stress signals are primary events in the acclimation to changes in the environment. Some molecular sensors and transducers of environmental stress cannot be identified by traditional and conventional methods. Based on genomic information, a systematic approach has been applied to the solution of this problem in cyanobacteria, involving mutagenesis of potential sensors and signal transducers in combination with DNA microarray analyses for the genome-wide expression of genes. Forty-five genes for the histidine kinases (Hiks), 12 genes for serine-threonine protein kinases (Spks), 42 genes for response regulators (Rres), seven genes for RNA polymerase sigma factors, and nearly 70 genes for transcription factors have been successfully inactivated by targeted mutagenesis in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Screening of mutant libraries by genome-wide DNA microarray analysis under various stress and non-stress conditions has allowed identification of proteins that perceive and transduce signals of environmental stress. Here we summarize recent progress in the identification of sensory and regulatory systems, including Hiks, Rres, Spks, sigma factors, transcription factors, and the role of genomic DNA supercoiling in the regulation of the responses of cyanobacterial cells to various types of stress. PMID:22294932

  1. A novel potassium channel in photosynthetic cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Manuela Zanetti

    Full Text Available Elucidation of the structure-function relationship of a small number of prokaryotic ion channels characterized so far greatly contributed to our knowledge on basic mechanisms of ion conduction. We identified a new potassium channel (SynK in the genome of the cyanobacterium Synechocystis sp. PCC6803, a photosynthetic model organism. SynK, when expressed in a K(+-uptake-system deficient E. coli strain, was able to recover growth of these organisms. The protein functions as a potassium selective ion channel when expressed in Chinese hamster ovary cells. The location of SynK in cyanobacteria in both thylakoid and plasmamembranes was revealed by immunogold electron microscopy and Western blotting of isolated membrane fractions. SynK seems to be conserved during evolution, giving rise to a TPK (two-pore K(+ channel family member which is shown here to be located in the thylakoid membrane of Arabidopsis. Our work characterizes a novel cyanobacterial potassium channel and indicates the molecular nature of the first higher plant thylakoid cation channel, opening the way to functional studies.

  2. Genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits

    Directory of Open Access Journals (Sweden)

    Nylander Johan AA

    2011-06-01

    Full Text Available Abstract Background Cyanobacteria belong to an ancient group of photosynthetic prokaryotes with pronounced variations in their cellular differentiation strategies, physiological capacities and choice of habitat. Sequencing efforts have shown that genomes within this phylum are equally diverse in terms of size and protein-coding capacity. To increase our understanding of genomic changes in the lineage, the genomes of 58 contemporary cyanobacteria were analysed for shared and unique orthologs. Results A total of 404 protein families, present in all cyanobacterial genomes, were identified. Two of these are unique to the phylum, corresponding to an AbrB family transcriptional regulator and a gene that escapes functional annotation although its genomic neighbourhood is conserved among the organisms examined. The evolution of cyanobacterial genome sizes involves a mix of gains and losses in the clade encompassing complex cyanobacteria, while a single event of reduction is evident in a clade dominated by unicellular cyanobacteria. Genome sizes and gene family copy numbers evolve at a higher rate in the former clade, and multi-copy genes were predominant in large genomes. Orthologs unique to cyanobacteria exhibiting specific characteristics, such as filament formation, heterocyst differentiation, diazotrophy and symbiotic competence, were also identified. An ancestral character reconstruction suggests that the most recent common ancestor of cyanobacteria had a genome size of approx. 4.5 Mbp and 1678 to 3291 protein-coding genes, 4%-6% of which are unique to cyanobacteria today. Conclusions The different rates of genome-size evolution and multi-copy gene abundance suggest two routes of genome development in the history of cyanobacteria. The expansion strategy is driven by gene-family enlargment and generates a broad adaptive potential; while the genome streamlining strategy imposes adaptations to highly specific niches, also reflected in their different

  3. Genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits

    Science.gov (United States)

    2011-01-01

    Background Cyanobacteria belong to an ancient group of photosynthetic prokaryotes with pronounced variations in their cellular differentiation strategies, physiological capacities and choice of habitat. Sequencing efforts have shown that genomes within this phylum are equally diverse in terms of size and protein-coding capacity. To increase our understanding of genomic changes in the lineage, the genomes of 58 contemporary cyanobacteria were analysed for shared and unique orthologs. Results A total of 404 protein families, present in all cyanobacterial genomes, were identified. Two of these are unique to the phylum, corresponding to an AbrB family transcriptional regulator and a gene that escapes functional annotation although its genomic neighbourhood is conserved among the organisms examined. The evolution of cyanobacterial genome sizes involves a mix of gains and losses in the clade encompassing complex cyanobacteria, while a single event of reduction is evident in a clade dominated by unicellular cyanobacteria. Genome sizes and gene family copy numbers evolve at a higher rate in the former clade, and multi-copy genes were predominant in large genomes. Orthologs unique to cyanobacteria exhibiting specific characteristics, such as filament formation, heterocyst differentiation, diazotrophy and symbiotic competence, were also identified. An ancestral character reconstruction suggests that the most recent common ancestor of cyanobacteria had a genome size of approx. 4.5 Mbp and 1678 to 3291 protein-coding genes, 4%-6% of which are unique to cyanobacteria today. Conclusions The different rates of genome-size evolution and multi-copy gene abundance suggest two routes of genome development in the history of cyanobacteria. The expansion strategy is driven by gene-family enlargment and generates a broad adaptive potential; while the genome streamlining strategy imposes adaptations to highly specific niches, also reflected in their different functional capacities. A few

  4. Determination of Oxygen Production by Cyanobacteria in Desert Environment Soil

    Science.gov (United States)

    Bueno Prieto, J. E.

    2009-12-01

    The cyanobacteria have been characterized for being precursor in the production of oxygen. By means of photosynthetic reactions, they provide oxygen to the environment that surrounds them and they capture part of surrounding dioxide of carbon. This way it happened since the primitive Earth until today. Besides, these microorganisms can support the harmful effects of ultraviolet radiation. The presence of cyanobacterias in an environment like a dry tropical bioma, such as the geographical location called Desert of The Tatacoa (Huila - Colombia), is determinant to establish parameters in the search of biological origin of atmospheric oxygen detected in Mars. In that case, I work with a random sample of not rhizospheric soil, taken to 15 cm of depth. After determining the presence of cyanobacterias in the sample, this one was in laboratory to stimulate the oxygen production. The presence of oxygen in Mars is very interesting. Since oxygen gas is very reactive, it disappear if it is not renewed; the possibility that this renovation of oxygen has a biological origin is encouraging, bearing in mind that in a dry environment and high radiation such as the studied one, the production of oxygen by cyanobacterias is notable. Also it is necessary to keep in mind that the existence of cyanobacterias would determine water presence in Mars subsoil and the nutrients cycles renovation. An interesting exploration possibility for some future space probe to Mars might be the study of worldwide distribution of oxygen concentration in this planet and this way, indentify zones suitable for microbian life.

  5. Human health effects associated with exposure to toxic Cyanobacteria – what is the evidence?

    Science.gov (United States)

    Reports of toxic cyanobacteria blooms are increasing worldwide, as warming water and eutrophic surface water systems support the development of blooms. As awareness of toxic cyanobacteria blooms increases, reports of associated human and animal illnesses have also increased, but ...

  6. Expanding models of lake trophic state to predict cyanobacteria in lakes

    Science.gov (United States)

    Background/Question/Methods: Cyanobacteria are a primary taxonomic group associated with harmful algal blooms in lakes. Understanding the drivers of cyanobacteria presence has important implications for lake management and for the protection of human and ecosystem health. Chlor...

  7. C5 glycolipids of heterocystous cyanobacteria track symbiont abundance in the diatom Hemiaulus hauckii across the tropical North Atlantic

    Science.gov (United States)

    Bale, Nicole J.; Villareal, Tracy A.; Hopmans, Ellen C.; Brussaard, Corina P. D.; Besseling, Marc; Dorhout, Denise; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2018-03-01

    Diatom-diazotroph associations (DDAs) include marine heterocystous cyanobacteria found as exosymbionts and endosymbionts in multiple diatom species. Heterocysts are the site of N2 fixation and have thickened cell walls containing unique heterocyst glycolipids which maintain a low oxygen environment within the heterocyst. The endosymbiotic cyanobacterium Richelia intracellularis found in species of the diatom genus Hemiaulus and Rhizosolenia makes heterocyst glycolipids (HGs) which are composed of C30 and C32 diols and triols with pentose (C5) moieties that are distinct from limnetic cyanobacterial HGs with predominantly hexose (C6) moieties. Here we applied a method for analysis of intact polar lipids to the study of HGs in suspended particulate matter (SPM) and surface sediment from across the tropical North Atlantic. The study focused on the Amazon plume region, where DDAs are documented to form extensive surface blooms, in order to examine the utility of C5 HGs as markers for DDAs as well as their transportation to underlying sediments. C30 and C32 triols with C5 pentose moieties were detected in both marine SPM and surface sediments. We found a significant correlation between the water column concentration of these long-chain C5 HGs and DDA symbiont counts. In particular, the concentrations of both the C5 HGs (1-(O-ribose)-3,27,29-triacontanetriol (C5 HG30 triol) and 1-(O-ribose)-3,29,31-dotriacontanetriol (C5 HG32 triol)) in SPM exhibited a significant correlation with the number of Hemiaulus hauckii symbionts. This result strengthens the idea that long-chain C5 HGs can be applied as biomarkers for marine endosymbiotic heterocystous cyanobacteria. The presence of the same C5 HGs in surface sediment provides evidence that they are effectively transported to the sediment and hence have potential as biomarkers for studies of the contribution of DDAs to the paleo-marine N cycle.

  8. Rapid reactivation of cyanobacterial photosynthesis and migration upon rehydration of desiccated marine microbial mats

    NARCIS (Netherlands)

    Chennu, Arjun; Grinham, Alistair; Polerecky, Lubos; de Beer, Dirk; Al-Najjar, Mohammad A.A.

    2015-01-01

    Desiccated cyanobacterial mats are the dominant biological feature in the Earth's arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution

  9. Competition and facilitation between the marine nitrogen-fixing cyanobacterium Cyanothece and its associated bacterial community

    NARCIS (Netherlands)

    Brauer, Verena S; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-Guns, Veronique; Weissing, Franz J; Stal, Lucas J; Huisman, Jef

    2015-01-01

    N2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N2-fixing cyanobacterium Cyanothece

  10. Phylogeny of culturable cyanobacteria from Brazilian mangroves.

    Science.gov (United States)

    Silva, Caroline Souza Pamplona; Genuário, Diego Bonaldo; Vaz, Marcelo Gomes Marçal Vieira; Fiore, Marli Fátima

    2014-03-01

    The cyanobacterial community from Brazilian mangrove ecosystems was examined using a culture-dependent method. Fifty cyanobacterial strains were isolated from soil, water and periphytic samples collected from Cardoso Island and Bertioga mangroves using specific cyanobacterial culture media. Unicellular, homocytous and heterocytous morphotypes were recovered, representing five orders, seven families and eight genera (Synechococcus, Cyanobium, Cyanobacterium, Chlorogloea, Leptolyngbya, Phormidium, Nostoc and Microchaete). All of these novel mangrove strains had their 16S rRNA gene sequenced and BLAST analysis revealed sequence identities ranging from 92.5 to 99.7% when they were compared with other strains available in GenBank. The results showed a high variability of the 16S rRNA gene sequences among the genotypes that was not associated with the morphologies observed. Phylogenetic analyses showed several branches formed exclusively by some of these novel 16S rRNA gene sequences. BLAST and phylogeny analyses allowed for the identification of Nodosilinea and Oxynema strains, genera already known to exhibit poor morphological diacritic traits. In addition, several Nostoc and Leptolyngbya morphotypes of the mangrove strains may represent new generic entities, as they were distantly affiliated with true genera clades. The presence of non-ribosomal peptide synthetase, polyketide synthase, microcystin and saxitoxin genes were detected in 20.5%, 100%, 37.5% and 33.3%, respectively, of the 44 tested isolates. A total of 134 organic extracts obtained from 44 strains were tested against microorganisms, and 26% of the extracts showed some antimicrobial activity. This is the first polyphasic study of cultured cyanobacteria from Brazilian mangrove ecosystems using morphological, genetic and biological approaches. Copyright © 2014 Elsevier GmbH. All rights reserved.

  11. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts

    DEFF Research Database (Denmark)

    Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos

    2016-01-01

    The chloroplasts found in plants and algae, and photosynthetic microorganisms such as cyanobacteria, are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused...... on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals, as well as complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression...... of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the production levels to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons...

  12. CyanoClust: comparative genome resources of cyanobacteria and plastids.

    Science.gov (United States)

    Sasaki, Naobumi V; Sato, Naoki

    2010-01-01

    Cyanobacteria, which perform oxygen-evolving photosynthesis as do chloroplasts of plants and algae, are one of the best-studied prokaryotic phyla and one from which many representative genomes have been sequenced. Lack of a suitable comparative genomic database has been a problem in cyanobacterial genomics because many proteins involved in physiological functions such as photosynthesis and nitrogen fixation are not catalogued in commonly used databases, such as Clusters of Orthologous Proteins (COG). CyanoClust is a database of homolog groups in cyanobacteria and plastids that are produced by the program Gclust. We have developed a web-server system for the protein homology database featuring cyanobacteria and plastids. Database URL: http://cyanoclust.c.u-tokyo.ac.jp/.

  13. Protein (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available ut This Database Database Description Download License Update History of This Database Site Policy | Contact Us Protein (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive ... ...List Contact us PGDBj - Ortholog DB Protein (Cyanobacteria) Data detail Data name Protein (Cyanobacteria) DO...switchLanguage; BLAST Search Image Search Home About Archive Update History Data

  14. Taxon (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available of This Database Site Policy | Contact Us Taxon (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive ... ...List Contact us PGDBj - Ortholog DB Taxon (Cyanobacteria) Data detail Data name Taxon (Cyanobacteria) DOI 10...switchLanguage; BLAST Search Image Search Home About Archive Update History Data

  15. Limited Multiplication of Symbiotic Cyanobacteria of Azolla spp. on Artificial Media

    Science.gov (United States)

    Tang, L. F.; Watanabe, I.; Liu, C. C.

    1990-01-01

    We examined various media and conditions to isolate symbiotic cyanobacteria from the leaf cavities of Azolla spp. Cyanobacteria survived and multiplied to a limited extent on a medium with fructose, Casamino Acids, yeast extract, and NaNO3 under 1% O2. These cyanobacteria were antigenically identical to the endosymbionts. Images PMID:16348366

  16. Lysogenic infection in sub-tropical freshwater cyanobacteria cultures and natural blooms

    NARCIS (Netherlands)

    Steenhauer, L.M.; Pollard, P.C.; Brussaard, C.P.D.; Säwström, C.

    2014-01-01

    Lysogeny has been reported for a few freshwater cyanobacteria cultures, but it is unknown how prevalent it is in freshwater cyanobacteria in situ. Here we tested for lysogeny in (a) cultures of eight Australian species of subtropical freshwater cyanobacteria; (b) seven strains of one species:

  17. Bioactive secondary metabolites from marine microbes for drug discovery.

    Science.gov (United States)

    Nikapitiya, Chamilani

    2012-01-01

    The isolation and extraction of novel bioactive secondary metabolites from marine microorganisms have a biomedical potential for future drug discovery as the oceans cover 70% of the planet's surface and life on earth originates from sea. Wide range of novel bioactive secondary metabolites exhibiting pharmacodynamic properties has been isolated from marine microorganisms and many to be discovered. The compounds isolated from marine organisms (macro and micro) are important in their natural form and also as templates for synthetic modifications for the treatments for variety of deadly to minor diseases. Many technical issues are yet to overcome before wide-scale bioprospecting of marine microorganisms becomes a reality. This chapter focuses on some novel secondary metabolites having antitumor, antivirus, enzyme inhibitor, and other bioactive properties identified and isolated from marine microorganisms including bacteria, actinomycetes, fungi, and cyanobacteria, which could serve as potentials for drug discovery after their clinical trials. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Detection of Bioactive Exometabolites Produced by the Filamentous Marine Cyanobacterium Geitlerinema sp.

    OpenAIRE

    Caicedo, Nelson H.; Kumirska, Jolanta; Neumann, Jennifer; Stolte, Stefan; Thöming, Jorg

    2011-01-01

    Marine cyanobacteria are noted for their ability to excrete metabolites with biotic properties. This paper focuses on such exometabolites obtained from the culture of the marine filamentous cyanobacterium Geitlerinema sp. strain, their purification and subsequent analyses. By this means the recoveries of the active compounds, a prerequisite for properly determining their concentration, are quantified here for the first time. We demonstrate a new procedure using Amberlite XAD-1180 resin in com...

  19. Toolboxes for cyanobacteria: Recent advances and future direction.

    Science.gov (United States)

    Sun, Tao; Li, Shubin; Song, Xinyu; Diao, Jinjin; Chen, Lei; Zhang, Weiwen

    2018-05-03

    Photosynthetic cyanobacteria are important primary producers and model organisms for studying photosynthesis and elements cycling on earth. Due to the ability to absorb sunlight and utilize carbon dioxide, cyanobacteria have also been proposed as renewable chassis for carbon-neutral "microbial cell factories". Recent progresses on cyanobacterial synthetic biology have led to the successful production of more than two dozen of fuels and fine chemicals directly from CO 2 , demonstrating their potential for scale-up application in the future. However, compared with popular heterotrophic chassis like Escherichia coli and Saccharomyces cerevisiae, where abundant genetic tools are available for manipulations at levels from single gene, pathway to whole genome, limited genetic tools are accessible to cyanobacteria. Consequently, this significant technical hurdle restricts both the basic biological researches and further development and application of these renewable systems. Though still lagging the heterotrophic chassis, the vital roles of genetic tools in tuning of gene expression, carbon flux re-direction as well as genome-wide manipulations have been increasingly recognized in cyanobacteria. In recent years, significant progresses on developing and introducing new and efficient genetic tools have been made for cyanobacteria, including promoters, riboswitches, ribosome binding site engineering, clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease (CRISPR/Cas) systems, small RNA regulatory tools and genome-scale modeling strategies. In this review, we critically summarize recent advances on development and applications as well as technical limitations and future directions of the genetic tools in cyanobacteria. In addition, toolboxes feasible for using in large-scale cultivation are also briefly discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Is Monoglucosyldiacylglycerol a Precursor to Monogalactosyldiacylglycerol in All Cyanobacteria?

    Science.gov (United States)

    Sato, Naoki

    2015-10-01

    Monogalactosyldiacylglycerol (MGDG) is ubiquitous in the photosynthetic membranes of cyanobacteria and chloroplasts. It is synthesized by galactosylation of diacylglycerol (DAG) in the chloroplasts, whereas it is produced by epimerization of monoglucosyldiacylglycerol (GlcDG) in at least several cyanobacteria that have been analyzed such as Synechocystis sp. PCC 6803. A previous study, however, showed that the mgdE gene encoding the epimerase is absent in some cyanobacteria such as Gloeobacter violaceus, Thermosynechococcus elongatus and Acaryochloris marina. In addition, the N-terminal 'fatty acid hydroxylase' domain is lacking in the MgdE protein of Prochlorococcus marinus. These problems may cast doubt upon the general (or exclusive) role of MgdE in the epimerization of GlcDG to MGDG in cyanobacteria. In addition, GlcDG is usually present at a very low level, and the structural determination of endogenous GlcDG has not been accomplished with cyanobacterial samples. In this study, I determined the structure of GlcDG from Anabaena variabilis by (1)H- and (13)C-nuclear magnetic resonance (NMR) spectroscopy. I then showed that G. violaceus, T. elongatus, A. marina and P. marinus contain GlcDG. In all cases, GlcDG consisted of fewer unsaturated molecular species than MGDG, providing further evidence that GlcDG is a precursor to MGDG. The conversion of GlcDG to MGDG was also demonstrated by radiolabeling and chase experiments in G. violaceus and P. marinus. These results demonstrate that all the analyzed cyanobacteria contain GlcDG, which is converted to MGDG, and suggest that an alternative epimerase is required for MGDG synthesis in these cyanobacteria. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Hot and toxic: Temperature regulates microcystin release from cyanobacteria.

    Science.gov (United States)

    Walls, Jeremy T; Wyatt, Kevin H; Doll, Jason C; Rubenstein, Eric M; Rober, Allison R

    2018-01-01

    The mechanisms regulating toxin release by cyanobacteria are poorly understood despite the threat cyanotoxins pose to water quality and human health globally. To determine the potential for temperature to regulate microcystin release by toxin-producing cyanobacteria, we evaluated seasonal patterns of water temperature, cyanobacteria biomass, and extracellular microcystin concentration in a eutrophic freshwater lake dominated by Planktothrix agardhii. We replicated seasonal variation in water temperature in a concurrent laboratory incubation experiment designed to evaluate cause-effect relationships between temperature and toxin release. Lake temperature ranged from 3 to 27°C and cyanobacteria biomass increased with warming up to 18°C, but declined rapidly thereafter with further increases in temperature. Extracellular microcystin concentration was tightly coupled with temperature and was most elevated between 20 and 25°C, which was concurrent with the decline in cyanobacteria biomass. A similar trend was observed in laboratory incubations where productivity-specific microcystin release was most elevated between 20 and 25°C and then declined sharply at 30°C. We applied generalized linear mixed modeling to evaluate the strength of water temperature as a predictor of cyanobacteria abundance and microcystin release, and determined that warming≥20°C would result in a 36% increase in microcystin release when Chlorophyll a was ≤50μgl -1 . These results show a temperature threshold for toxin release in P. agardhii, which demonstrates a potential to use water temperature to forecast bloom severity in eutrophic lakes where blooms can persist year-round with varying degrees of toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  3. Marine pollution

    International Nuclear Information System (INIS)

    Albaiges, J.

    1989-01-01

    This book covers the following topics: Transport of marine pollutants; Transformation of pollutants in the marine environment; Biological effects of marine pollutants; Sources and transport of oil pollutants in the Persian Gulf; Trace metals and hydrocarbons in Syrian coastal waters; and Techniques for analysis of trace pollutants

  4. Large-scale bioprospecting of cyanobacteria, micro- and macroalgae from the Aegean Sea.

    Science.gov (United States)

    Montalvão, Sofia; Demirel, Zeliha; Devi, Prabha; Lombardi, Valter; Hongisto, Vesa; Perälä, Merja; Hattara, Johannes; Imamoglu, Esra; Tilvi, Supriya Shet; Turan, Gamze; Dalay, Meltem Conk; Tammela, Päivi

    2016-05-25

    Marine organisms constitute approximately one-half of the total global biodiversity, being rich reservoirs of structurally diverse biofunctional components. The potential of cyanobacteria, micro- and macroalgae as sources of antimicrobial, antitumoral, anti-inflammatory, and anticoagulant compounds has been reported extensively. Nonetheless, biological activities of marine fauna and flora of the Aegean Sea have remained poorly studied when in comparison to other areas of the Mediterranean Sea. In this study, we screened the antimicrobial, antifouling, anti-inflammatory and anticancer potential of in total 98 specimens collected from the Aegean Sea. Ethanol extract of diatom Amphora cf capitellata showed the most promising antimicrobial results against Candida albicans while the extract of diatom Nitzschia communis showed effective results against Gram-positive bacterium, S. aureus. Extracts from the red alga Laurencia papillosa and from three Cystoseira species exhibited selective antiproliferative activity against cancer cell lines and an extract from the brown alga Dilophus fasciola showed the highest anti-inflammatory activity as measured in primary microglial and astrocyte cell cultures as well as by the reduction of proinflammatory cytokines. In summary, our study demonstrates that the Aegean Sea is a rich source of species that possess interesting potential for developing industrial applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Marine genomics

    DEFF Research Database (Denmark)

    Oliveira Ribeiro, Ângela Maria; Foote, Andrew David; Kupczok, Anne

    2017-01-01

    Marine ecosystems occupy 71% of the surface of our planet, yet we know little about their diversity. Although the inventory of species is continually increasing, as registered by the Census of Marine Life program, only about 10% of the estimated two million marine species are known. This lag......-throughput sequencing approaches have been helping to improve our knowledge of marine biodiversity, from the rich microbial biota that forms the base of the tree of life to a wealth of plant and animal species. In this review, we present an overview of the applications of genomics to the study of marine life, from...

  6. In silico screening for candidate chassis strains of free fatty acid-producing cyanobacteria

    KAUST Repository

    Motwalli, Olaa Amin

    2017-01-05

    Background Finding a source from which high-energy-density biofuels can be derived at an industrial scale has become an urgent challenge for renewable energy production. Some microorganisms can produce free fatty acids (FFA) as precursors towards such high-energy-density biofuels. In particular, photosynthetic cyanobacteria are capable of directly converting carbon dioxide into FFA. However, current engineered strains need several rounds of engineering to reach the level of production of FFA to be commercially viable; thus new chassis strains that require less engineering are needed. Although more than 120 cyanobacterial genomes are sequenced, the natural potential of these strains for FFA production and excretion has not been systematically estimated. Results Here we present the FFA SC (FFASC), an in silico screening method that evaluates the potential for FFA production and excretion of cyanobacterial strains based on their proteomes. A literature search allowed for the compilation of 64 proteins, most of which influence FFA production and a few of which affect FFA excretion. The proteins are classified into 49 orthologous groups (OGs) that helped create rules used in the scoring/ranking of algorithms developed to estimate the potential for FFA production and excretion of an organism. Among 125 cyanobacterial strains, FFASC identified 20 candidate chassis strains that rank in their FFA producing and excreting potential above the specifically engineered reference strain, Synechococcus sp. PCC 7002. We further show that the top ranked cyanobacterial strains are unicellular and primarily include Prochlorococcus (order Prochlorales) and marine Synechococcus (order Chroococcales) that cluster phylogenetically. Moreover, two principal categories of enzymes were shown to influence FFA production the most: those ensuring precursor availability for the biosynthesis of lipids, and those involved in handling the oxidative stress associated to FFA synthesis. Conclusion To

  7. In silico screening for candidate chassis strains of free fatty acid-producing cyanobacteria.

    Science.gov (United States)

    Motwalli, Olaa; Essack, Magbubah; Jankovic, Boris R; Ji, Boyang; Liu, Xinyao; Ansari, Hifzur Rahman; Hoehndorf, Robert; Gao, Xin; Arold, Stefan T; Mineta, Katsuhiko; Archer, John A C; Gojobori, Takashi; Mijakovic, Ivan; Bajic, Vladimir B

    2017-01-05

    Finding a source from which high-energy-density biofuels can be derived at an industrial scale has become an urgent challenge for renewable energy production. Some microorganisms can produce free fatty acids (FFA) as precursors towards such high-energy-density biofuels. In particular, photosynthetic cyanobacteria are capable of directly converting carbon dioxide into FFA. However, current engineered strains need several rounds of engineering to reach the level of production of FFA to be commercially viable; thus new chassis strains that require less engineering are needed. Although more than 120 cyanobacterial genomes are sequenced, the natural potential of these strains for FFA production and excretion has not been systematically estimated. Here we present the FFA SC (FFASC), an in silico screening method that evaluates the potential for FFA production and excretion of cyanobacterial strains based on their proteomes. A literature search allowed for the compilation of 64 proteins, most of which influence FFA production and a few of which affect FFA excretion. The proteins are classified into 49 orthologous groups (OGs) that helped create rules used in the scoring/ranking of algorithms developed to estimate the potential for FFA production and excretion of an organism. Among 125 cyanobacterial strains, FFASC identified 20 candidate chassis strains that rank in their FFA producing and excreting potential above the specifically engineered reference strain, Synechococcus sp. PCC 7002. We further show that the top ranked cyanobacterial strains are unicellular and primarily include Prochlorococcus (order Prochlorales) and marine Synechococcus (order Chroococcales) that cluster phylogenetically. Moreover, two principal categories of enzymes were shown to influence FFA production the most: those ensuring precursor availability for the biosynthesis of lipids, and those involved in handling the oxidative stress associated to FFA synthesis. To our knowledge FFASC is the first

  8. Toxicity of trichloroethylene (TCE) on some algae and cyanobacteria

    Czech Academy of Sciences Publication Activity Database

    Lukavský, Jaromír; Furnadzhieva, S.; Dittrt, František

    2011-01-01

    Roč. 86, č. 2 (2011), 226-231 ISSN 0007-4861 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z20600510 Keywords : toxicity * cyanobacteria * trichloroethylene Subject RIV: EF - Botanics Impact factor: 1.018, year: 2011

  9. Risk Levels of Toxic Cyanobacteria in Portuguese Recreational Freshwaters

    Directory of Open Access Journals (Sweden)

    Carina Menezes

    2017-10-01

    Full Text Available Portuguese freshwater reservoirs are important socio-economic resources, namely for recreational use. National legislation concerning bathing waters does not include mandatory levels or guidelines for cyanobacteria and cyanotoxins. This is an issue of concern since cyanotoxin-based evidence is insufficient to change the law, and the collection of scientific evidence has been hampered by the lack of regulatory levels for cyanotoxins in bathing waters. In this work, we evaluate the profile of cyanobacteria and microcystins (MC in eight freshwater reservoirs from the center of Portugal, used for bathing/recreation, in order to determine the risk levels concerning toxic cyanobacteria occurrence. Three of the reservoirs did not pose a risk of MC contamination. However, two reservoirs presented a high risk in 7% of the samples according to the World Health Organization (WHO guidelines for MC in bathing waters (above 20 µg/L. In the remaining three reservoirs, the risk concerning microcystins occurrence was low. However, they exhibited recurrent blooms and persistent contamination with MC up to 4 µg/L. Thus, the risk of exposure to MC and potential acute and/or chronic health outcomes should not be disregarded in these reservoirs. These results contribute to characterize the cyanobacterial blooms profile and to map the risk of toxic cyanobacteria and microcystins occurrence in Portuguese inland waters.

  10. Antibacterial activities of the extracts of cyanobacteria and green ...

    African Journals Online (AJOL)

    In compliance to the recent surveys on algal species and their potentials to produce biologically active compounds, seven algal species belonging to cyanobacteria such as Spirulina platensis, Nostoc linckia, Phormidium autumnale, Tolypothrix distorta and Microcystis aeruginosa and green algae such as Chlorella vulgaris, ...

  11. Inoculation effects of two South African cyanobacteria strains on ...

    African Journals Online (AJOL)

    Two South African cyanobacteria strains (coded 3g and 7e) of the genus Nostoc were evaluated for improvement of the aggregate stability of a silty loam soil with low organic C content and compared with Nostoc strain 9v isolated from a Tanzanian soil. The soil was either cropped with maize or non-cropped and inoculated ...

  12. Cyanobacteria Occurrence and Nitrogen Fixation Rates in the ...

    African Journals Online (AJOL)

    The occurrence and biological nitrogen fixation rates of epiphytic and benthic diazotrophs were studied in seagrass meadows at sites with seaweed farms and at a control site without seaweed farms from two locations, Chwaka Bay and Jambiani, along the east coast of. Zanzibar. Ten species of cyanobacteria were ...

  13. Characterization of rhizo-cyanobacteria and their associations with ...

    African Journals Online (AJOL)

    Four heterocystous cyanobacteria, belonging to the genera Anabaena and Nostoc isolated from the rhizosphere of wheat, were tested for their ability to form associations with the roots of wheat seedlings under light and dark conditions using hydroponics. The cyanobacterial strains formed close associations with wheat ...

  14. Cyanobacteria and cyanotoxins in the source water from Lake ...

    African Journals Online (AJOL)

    The phytoplankton community and cyanotoxins in Lake Chivero (formerly Lake McIlwaine) and the presence of cyanotoxins in treated drinking water were investigated between 2003 and 2004. A typical seasonal succession of Cyanobacteria species occurred from January to April, Bacillariophyta from May to July, and ...

  15. Cyanobacteria and cyanobacterial toxins in the alkaline-saline ...

    African Journals Online (AJOL)

    Physicochemical parameters, phytoplankton communities, microcystin (MC) concentrations and potential MC-producing cyanobacteria were investigated in Lakes Natron and Momela, Tanzania. In Lake Big Momela, concentrations of soluble reactive phosphorus, nitrate and ammonia were 7.1, 2.6 and 0.9 μg/L, respectively ...

  16. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts.

    Science.gov (United States)

    Nielsen, Agnieszka Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos; Wlodarczyk, Artur Jacek; Gnanasekaran, Thiyagarajan; Perestrello Ramos H de Jesus, Maria; King, Brian Christopher; Bakowski, Kamil; Jensen, Poul Erik

    2016-07-01

    Chloroplasts in plants and algae and photosynthetic microorganisms such as cyanobacteria are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals and complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression of the appropriate pathways, but this requires optimization of carbon flux and reducing power, and a thorough understanding of regulatory pathways. Secretion or storage of the compounds produced can be exploited for the isolation or confinement of the desired compounds. In this review, we explore the use of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the levels of production to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons derived from the photosynthetic light reactions, appears to be non-limiting, but redirection of the fixed carbon via precursor molecules presents a challenge. We also discuss the available synthetic biology tools and the need to expand the molecular toolbox to facilitate cellular reprogramming for increased production yields in both cyanobacteria and chloroplasts. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  17. Engineering cyanobacteria for direct biofuel production from CO2

    NARCIS (Netherlands)

    Savakis, P.; Hellingwerf, K.J.

    2015-01-01

    For a sustainable future of our society it is essential to close the global carbon cycle. Oxidised forms of carbon, in particular CO2, can be used to synthesise energy-rich organic molecules. Engineered cyanobacteria have attracted attention as catalysts for the direct conversion of CO2 into reduced

  18. Variability of Chroococcus (Cyanobacteria) morphospecies with regard to phylogenetic relationships

    Czech Academy of Sciences Publication Activity Database

    Komárková, Jaroslava; Jezberová, J.; Komárek, O.; Zapomělová, E.

    2010-01-01

    Roč. 639, č. 1 (2010), s. 69-83 ISSN 0018-8158 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : morphological variability * Cyanobacteria * reservoirs Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 1.964, year: 2010

  19. Environmental factors that influence cyanobacteria and geosmin occurrence in reservoirs

    Science.gov (United States)

    Journey, Celeste A.; Beaulieu, Karen M.; Bradley, Paul M.; Bradley, Paul M.

    2013-01-01

    Phytoplankton are small to microscopic, free-floating algae that inhabit the open water of freshwater, estuarine, and saltwater systems. In freshwater lake and reservoirs systems, which are the focus of this chapter, phytoplankton communities commonly consist of assemblages of the major taxonomic groups, including green algae, diatoms, dinoflagellates, and cyanobacteria. Cyanobacteria are a diverse group of single-celled organisms that can exist in a wide range of environments, not just open water, because of their adaptability. It is the adaptability of cyanobacteria that enables this group to dominate the phytoplankton community and even form nuisance or harmful blooms under certain environmental conditions. In fact, cyanobacteria are predicted to adapt favorably to future climate change in freshwater systems compared to other phytoplankton groups because of their tolerance to rising temperatures, enhanced vertical thermal stratification of aquatic ecosystems, and alterations in seasonal and interannual weather patterns. Understanding those environmental conditions that favor cyanobacterial dominance and bloom formation has been the focus of research throughout the world because of the concomitant production and release of nuisance and toxic cyanobacterial-derived compounds. However, the complex interaction among the physical, chemical, and biological processes within lakes, reservoirs, and large rivers often makes it difficult to identify primary environmental factors that cause the production and release of these cyanobacterial by-products.

  20. Cyanobacteria HABs - Causes, Prevention, and Mitigation Workgroup Report.

    Science.gov (United States)

    Cyanobacteria (blue-green algae) are estimated to have evolved 3.5 billion years ago, at which time they began to add oxygen to the existing anaerobic atmosphere, actually changing the chemistry of the planet and allowing new life forms to evolve. These ubiquitous microbes are capable of tolerating ...

  1. The cyanobacteria toxins, microcystins – emerging risks to human health

    Science.gov (United States)

    Dialysis patients appear to be at increased risk for exposure to cyanobacteria toxins; episodes of microcystin (MCYST) exposure via dialysate during 1996 and 2001 have been previously reported. During 2001, as many as 44 renal insufficiency patients were exposed to contaminated d...

  2. cyanoScope: Mapping cyanobacteria one slide at a time

    Science.gov (United States)

    cyanoScope is a new initiative for engaging the public, and particularly citizen scientists, to assist with mapping potentially harmful algal blooms throughout New England. Cyanobacteria are important members of the phytoplankton assemblages in lakes. In most situations these p...

  3. One Health and Toxic Cyanobacteria | Science Inventory | US ...

    Science.gov (United States)

    One Health and toxic cyanobacteria Blooms of toxic freshwater blue-green algae or cyanobacteria (HABs) have been in the news after HABs associated with human and animal health problems have been reported in Florida, California and Utah during 2016. HABs occur in warm, slow moving or stagnant surface waters that are enriched with nutrients such as nitrogen and phosphorous. People are exposed to potentially toxic HABs during recreation in contaminated water, after exposure to contaminated drinking water or to blue-green algae supplements. Animals may be exposed to toxic HABs after drinking contaminated surface waters or coming into contact with HABs then ingesting cyanobacteria from their bodies during self-grooming activities. As HABs are being reported more frequently in the US, it is important for veterinarians to secure good exposure histories and to recognize the potential signs and health consequences of HAB exposures. We will review the current knowledge about human and animal health effects associated with freshwater HABs and scenarios that pose the highest risks for illnesses and deaths. This abstract does not necessarily reflect EPA policy. This is a summary of One Health and Cyanobacteria for public health and public practice veterinarians at the American Veterinary Medical Association annual convention. This product is associated with SSWR 4.01B

  4. Evidence for bacterial chemotaxis to cyanobacteria from a radioassay technique

    International Nuclear Information System (INIS)

    Kangatharalingam, N.; Wang, Lizhu; Priscu, J.C.

    1991-01-01

    Lyngbya birgei and Aphanizomenon flos-aquae elicited a significant chemotactic attraction of Aeromonas hydrophila compared with controls lacking cyanobacteria. There was a positive exponential relationship between biomass (chlorophyll a) of L. birgei and A. flos-aquae and chemotactic attraction of A. hydrophila. The assay equipment was simple and reliable and could be used to study bacterial chemotaxis in other species in situ

  5. A gene expression study on strains of Nostoc (Cyanobacteria ...

    African Journals Online (AJOL)

    Cyanobacteria are well known for their production of a multitude of highly allelopathic compounds. These products have features such as incorporation of non-proteinogenic amino acids which are characteristics of peptides biosynthesized by non-ribosomal peptide synthetases (NRPSs). Some of these peptides have ...

  6. Critical assessment of chitosan as coagulant to remove cyanobacteria

    NARCIS (Netherlands)

    Lürling, Miquel; Noyma, Natalia Pessoa; Magalhães, Leonardo de; Miranda, Marcela; Mucci, Maíra; Oosterhout, Frank van; Huszar, Vera L.M.; Marinho, Marcelo Manzi

    2017-01-01

    Removal of cyanobacteria from the water column using a coagulant and a ballast compound is a promising technique to mitigate nuisance. As coagulant the organic, biodegradable polymer chitosan has been promoted. Results in this study show that elevated pH, as may be common during cyanobacterial

  7. Nodularia (Cyanobacteria, Nostocaceae): a phylogenetically uniform genus with variable phenotypes

    Czech Academy of Sciences Publication Activity Database

    Řeháková, Klára; Mareš, Jan; Lukešová, Alena; Zapomělová, Eliška; Bernardová, Kateřina; Hrouzek, Pavel

    2014-01-01

    Roč. 172, č. 3 (2014), s. 235-246 ISSN 1179-3155 R&D Projects: GA ČR(CZ) GA14-18067S; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:60077344 ; RVO:61388971 Keywords : cyanobacteria * Nodularia * taxonomy Subject RIV: EF - Botanics Impact factor: 1.318, year: 2014

  8. N-2 fixation by non-heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bergman, B.; Gallon, J.R.; Rai, A.N.; Stal, L.J.

    1997-01-01

    Many, though not all, non-heterocystous cyanobacteria can fix N-2. However, very few strains can fix N-2 aerobically. Nevertheless, these organisms may make a substantial contribution to the global nitrogen cycle. In this general review, N-2 fixation by laboratory cultures and natural populations of

  9. BMAA extraction of cyanobacteria samples: which method to choose?

    Science.gov (United States)

    Lage, Sandra; Burian, Alfred; Rasmussen, Ulla; Costa, Pedro Reis; Annadotter, Heléne; Godhe, Anna; Rydberg, Sara

    2016-01-01

    β-N-Methylamino-L-alanine (BMAA), a neurotoxin reportedly produced by cyanobacteria, diatoms and dinoflagellates, is proposed to be linked to the development of neurological diseases. BMAA has been found in aquatic and terrestrial ecosystems worldwide, both in its phytoplankton producers and in several invertebrate and vertebrate organisms that bioaccumulate it. LC-MS/MS is the most frequently used analytical technique in BMAA research due to its high selectivity, though consensus is lacking as to the best extraction method to apply. This study accordingly surveys the efficiency of three extraction methods regularly used in BMAA research to extract BMAA from cyanobacteria samples. The results obtained provide insights into possible reasons for the BMAA concentration discrepancies in previous publications. In addition and according to the method validation guidelines for analysing cyanotoxins, the TCA protein precipitation method, followed by AQC derivatization and LC-MS/MS analysis, is now validated for extracting protein-bound (after protein hydrolysis) and free BMAA from cyanobacteria matrix. BMAA biological variability was also tested through the extraction of diatom and cyanobacteria species, revealing a high variance in BMAA levels (0.0080-2.5797 μg g(-1) DW).

  10. Phenotypic and genetic diversification of Pseudanabaena spp. (cyanobacteria)

    NARCIS (Netherlands)

    Acinas, S.G.; Haverkamp, T.H.A.; Huisman, J.; Stal, L.J.

    2009-01-01

    Pseudanabaena species are poorly known filamentous bloom-forming cyanobacteria closely related to Limnothrix. We isolated 28 Pseudanabaena strains from the Baltic Sea (BS) and the Albufera de Valencia (AV; Spain). By combining phenotypic and genotypic approaches, the phylogeny, diversity and

  11. The occurrence and removal of algae (including cyanobacteria) and ...

    African Journals Online (AJOL)

    Cyanobacterial bloom formation in freshwaters, such as rivers, lakes and dams, is known to occur throughout the world. The Vaalkop Dam, which serves as source to the Vaalkop drinking water treatment works (DWTW), is no exception. Blooms of cyanobacteria occur annually in Vaalkop Dam as well as in dams from which ...

  12. Cyanobacteria of the thermal spring at Pancharevo, Sofia, Bulgaria.

    Czech Academy of Sciences Publication Activity Database

    Lukavský, Jaromír; Furnadzhieva, S.; Pilarski, P.

    2011-01-01

    Roč. 70, č. 2 (2011), 191-208 ISSN 0365-0588 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : cyanobacteria * Thermal spring * Pancharevo, Sofia, Bulgaria Subject RIV: EF - Botanics Impact factor: 0.702, year: 2011

  13. Critical assessment of chitosan as coagulant to remove cyanobacteria

    NARCIS (Netherlands)

    Lurling, Miguel; Noyma, Natalia Pessoa; Magalhães, de Leonardo; Miranda, Marcela; Mucci, Maíra; Oosterhout, van F.; Huszar, Vera L.M.; Marinho, Marcelo Manzi

    2017-01-01

    Removal of cyanobacteria from the water column using a coagulant and a ballast compound is a promising technique to mitigate nuisance. As coagulant the organic, biodegradable polymer chitosan has been promoted. Results in this study show that elevated pH, as may be common during cyanobacterial

  14. Ecology: a niche for cyanobacteria containing chlorophyll d

    DEFF Research Database (Denmark)

    Kühl, Michael; Chen, Min; Ralph, Peter J

    2005-01-01

    we demonstrate photosynthetic activity in Acaryochloris-like phototrophs that live underneath minute coral-reef invertebrates (didemnid ascidians) in a shaded niche enriched in near-infrared light. This discovery clarifies how these cyanobacteria are able to thrive as free-living organisms...

  15. Assessment of cyanobacteria impact on bathing water quality in Poland

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2012-12-01

    Full Text Available Introduction: Quality of bathing water is of key importance for bathers’ health, mainly due to the fact, that each year millions of people use bathing sites as places for recreation and sport activities. Most of the bathing sites are of adequate quality of water, but still there are cases of health risk because bathing water is polluted. One of the main health risk factor in bathing water are cyanobacteria and their blooms. Cyanobacteria are microorganisms of morphological features of bacteria and algae. They live in colonies, which in large quantities show up as streaks, dense foam on the water surface. The aim of this paper was to assess the impact of cyanobacteria blooms on health regarding bathing water quality in Poland. Materials and methods: Assessment covered all bathing sites in Poland supervised by Polish National Sanitary Inspection (PIS in the period from 2007 to 2009. The base was data collected during bathing water monitoring conducted by PIS and their formal decisions of bathing bans introduced in response to revealed bathing water pollution. Results and discussion: The results of assessment indicate, that about one-fourth of all bathing bans in Poland was due to cyanobacteria blooms. Conclusions: Every fifth bathing sites located on artificial lake or water reservoir and every tenth on the sea bathing sites were polluted. Average period of bathing ban due to cyanobacteria blooms in Poland varies. Relatively the shortest bathing bans were observed on the sea bathing sites (no longer than one week on average. Much longer were bathing bans on lakes and artificial lakes (one month on average.

  16. Genetic and genomic analysis of RNases in model cyanobacteria.

    Science.gov (United States)

    Cameron, Jeffrey C; Gordon, Gina C; Pfleger, Brian F

    2015-10-01

    Cyanobacteria are diverse photosynthetic microbes with the ability to convert CO2 into useful products. However, metabolic engineering of cyanobacteria remains challenging because of the limited resources for modifying the expression of endogenous and exogenous biochemical pathways. Fine-tuned control of protein production will be critical to optimize the biological conversion of CO2 into desirable molecules. Messenger RNAs (mRNAs) are labile intermediates that play critical roles in determining the translation rate and steady-state protein concentrations in the cell. The majority of studies on mRNA turnover have focused on the model heterotrophic bacteria Escherichia coli and Bacillus subtilis. These studies have elucidated many RNA modifying and processing enzymes and have highlighted the differences between these Gram-negative and Gram-positive bacteria, respectively. In contrast, much less is known about mRNA turnover in cyanobacteria. We generated a compendium of the major ribonucleases (RNases) and provide an in-depth analysis of RNase III-like enzymes in commonly studied and diverse cyanobacteria. Furthermore, using targeted gene deletion, we genetically dissected the RNases in Synechococcus sp. PCC 7002, one of the fastest growing and industrially attractive cyanobacterial strains. We found that all three cyanobacterial homologs of RNase III and a member of the RNase II/R family are not essential under standard laboratory conditions, while homologs of RNase E/G, RNase J1/J2, PNPase, and a different member of the RNase II/R family appear to be essential for growth. This work will enhance our understanding of native control of gene expression and will facilitate the development of an RNA-based toolkit for metabolic engineering in cyanobacteria.

  17. Assessing the antibiotic susceptibility of freshwater cyanobacteria spp.

    Directory of Open Access Journals (Sweden)

    Elsa eDias

    2015-08-01

    Full Text Available Freshwater is a vehicle for the emergence and dissemination of antibiotic resistance. Cyanobacteria are ubiquitous in freshwater, where they are exposed to antibiotics and resistant organisms, but their role on water resistome was never evaluated. Data concerning the effects of antibiotics on cyanobacteria, obtained by distinct methodologies, is often contradictory. This emphasizes the importance of developing procedures to understand the trends of antibiotic susceptibility in cyanobacteria. In this study we aimed to evaluate the susceptibility of four cyanobacterial isolates from different genera (Microcystis aeruginosa, Aphanizomenon gracile, Chrisosporum bergii, Planktothix agradhii, and among them nine isolates from the same specie (M. aeruginosa to distinct antibiotics (amoxicillin, ceftazidime, ceftriaxone, kanamycine, gentamicine, tetracycline, trimethoprim, nalidixic acid, norfloxacin. We used a method adapted from the bacteria standard broth microdilution. Cyanobacteria were exposed to serial dilution of each antibiotic (0.0015-1.6 mg/L in Z8 medium (20 ± 1 ºC; 14/10 h L/D cycle; light intensity 16 ± 4 µEm-2 s-1. Cell growth was followed overtime (OD450nm/microscopic examination and the minimum inhibitory concentrations (MICs were calculated for each antibiotic/isolate. We found that -lactams exhibited the lower MICs, aminoglycosides, tetracycline and norfloxacine presented intermediate MICs; none of the isolates were susceptible to trimethoprim and nalidixic acid. The reduced susceptibility of all tested cyanobacteria to some antibiotics suggests that they might be naturally non-susceptible to these compounds, or that that they might became non-susceptible due to antibiotic contamination pressure, or to the transfer of genes from resistant bacteria present in the environment.

  18. Applications of Cyanobacteria in Biofuel Production

    DEFF Research Database (Denmark)

    Möllers, K. Benedikt

    and to evolve from a wasteful petrochemical system into a sustainable bio-based society, biofuels and the introduction of bio-refineries play an essential role. Aquatic phototrophs are promising organisms to employ photosynthetic capacities as well as the derived carbohydrates for the production of biofuels......, enzymatic conversion of lignocellulosic biomass for further fermentation or as a platform chemical in a bio-refinery concept. Autotrophically cultivated cells of the marine model cyanobacterium Synechococcus sp. PCC 7002 (Synechococcus) were exposed to mild nitrogen starvation which has been identified...... for fermentation of plant waste material or a substitute for yeast extract. By mimicking photosynthetic electron transport from light excited photo pigments to LPMOs in combination with a reductant and cellulose as substrate, a 100-fold increase in catalytic activity of LPMOs was observed. Also, it was found...

  19. Marine biology

    International Nuclear Information System (INIS)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  20. Inferring Properties of Ancient Cyanobacteria from Biogeochemical Activity and Genomes of Siderophilic Cyanobacteria

    Science.gov (United States)

    McKay, David S.; Brown, I. I.; Tringe, S. G.; Thomas-Keprta, K. E.; Bryant, D. A.; Sarkisova, S. S.; Malley, K.; Sosa, O.; Klatt, C. G.; McKay, D. S.

    2010-01-01

    Interrelationships between life and the planetary system could have simultaneously left landmarks in genomes of microbes and physicochemical signatures in the lithosphere. Verifying the links between genomic features in living organisms and the mineralized signatures generated by these organisms will help to reveal traces of life on Earth and beyond. Among contemporary environments, iron-depositing hot springs (IDHS) may represent one of the most appropriate natural models [1] for insights into ancient life since organisms may have originated on Earth and probably Mars in association with hydrothermal activity [2,3]. IDHS also seem to be appropriate models for studying certain biogeochemical processes that could have taken place in the late Archean and,-or early Paleoproterozoic eras [4, 5]. It has been suggested that inorganic polyphosphate (PPi), in chains of tens to hundreds of phosphate residues linked by high-energy bonds, is environmentally ubiquitous and abundant [6]. Cyanobacteria (CB) react to increased heavy metal concentrations and UV by enhanced generation of PPi bodies (PPB) [7], which are believed to be signatures of life [8]. However, the role of PPi in oxygenic prokaryotes for the suppression of oxidative stress induced by high Fe is poorly studied. Here we present preliminary results of a new mechanism of Fe mineralization in oxygenic prokaryotes, the effect of Fe on the generation of PPi bodies in CB, as well as preliminary analysis of the diversity and phylogeny of proteins involved in the prevention of oxidative stress in phototrophs inhabiting IDHS.

  1. BASIC: Baltic Sea cyanobacteria. An investigation of the structure and dynamics of water blooms of cyanobacteria in the Baltic Sea––responses to a changing environment

    NARCIS (Netherlands)

    Stal, L.J.; Albertano, P.; Bergman, B.; Von Bröckel, K.; Gallon, J.R.; Hayes, P.K.; Sivonen, K.; Walsby, A.E.

    2003-01-01

    The blooms of cyanobacteria that develop each summer in the Baltic Sea are composed of two functional groups, namely the small-sized picocyanobacteria (Synechococcus sp.) and the larger, colony-forming, filamentous N2-fixing cyanobacteria. The former encompassed both red (phycoerythrin-rich) and

  2. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high ... or by any means without permission in writing from the copyright holder. ..... Journal of Chemical Engineering Research and Design 82 ... Indian Ocean Marine Science Association Technical.

  3. Marine Biomedicine

    Science.gov (United States)

    Bang, Frederik B.

    1977-01-01

    Describes early scientific research involving marine invertebrate pathologic processes that may have led to new insights into human disease. Discussed are inquiries of Metchnikoff, Loeb, and Cantacuzene (immunolgic responses in sea stars, horseshoe crabs, and marine worms, respectively). Describes current research stemming from these early…

  4. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  5. Production of the Neurotoxin BMAA by a Marine Cyanobacterium

    Directory of Open Access Journals (Sweden)

    Paul Alan Cox

    2007-12-01

    Full Text Available Diverse species of cyanobacteria have recently been discovered to produce theneurotoxic non-protein amino acid β-methylamino-L-alanine (BMAA. In Guam, BMAAhas been studied as a possible environmental toxin in the diets of indigenous Chamorropeople known to have high levels of Amyotrophic Lateral Sclerosis/ ParkinsonismDementia Complex (ALS/PDC. BMAA has been found to accumulate in brain tissues ofpatients with progressive neurodegenerative illness in North America. In Guam, BMAAwas found to be produced by endosymbiotic cyanobacteria of the genus Nostoc which livein specialized cycad roots. We here report detection of BMAA in laboratory cultures of afree-living marine species of Nostoc. We successfully detected BMAA in this marinespecies of Nostoc with five different methods: HPLC-FD, UPLC-UV, Amino AcidAnalyzer, LC/MS, and Triple Quadrupole LC/MS/MS. This consensus of five differentanalytical methods unequivocally demonstrates the presence of BMAA in this marinecyanobacterium. Since protein-associated BMAA can accumulate in increasing levelswithin food chains, it is possible that biomagnification of BMAA could occur in marineecosystems similar to the biomagnification of BMAA in terrestrial ecosystems. Productionof BMAA by marine cyanobacteria may represent another route of human exposure toBMAA. Since BMAA at low concentrations causes the death of motor neurons, low levelsof BMAA exposure may trigger motor neuron disease in genetically vulnerableindividuals.

  6. Cyanobacteria as Chassis for Industrial Biotechnology: Progress and Prospects

    Science.gov (United States)

    Al-Haj, Lamya; Lui, Yuen Tin; Abed, Raeid M.M.; Gomaa, Mohamed A.; Purton, Saul

    2016-01-01

    Cyanobacteria hold significant potential as industrial biotechnology (IB) platforms for the production of a wide variety of bio-products ranging from biofuels such as hydrogen, alcohols and isoprenoids, to high-value bioactive and recombinant proteins. Underpinning this technology, are the recent advances in cyanobacterial “omics” research, the development of improved genetic engineering tools for key species, and the emerging field of cyanobacterial synthetic biology. These approaches enabled the development of elaborate metabolic engineering programs aimed at creating designer strains tailored for different IB applications. In this review, we provide an overview of the current status of the fields of cyanobacterial omics and genetic engineering with specific focus on the current molecular tools and technologies that have been developed in the past five years. The paper concludes by giving insights on future commercial applications of cyanobacteria and highlights the challenges that need to be addressed in order to make cyanobacterial industrial biotechnology more feasible in the near future. PMID:27916886

  7. Genetic instability in cyanobacteria – an elephant in the room?

    Directory of Open Access Journals (Sweden)

    Patrik R. Jones

    2014-05-01

    Full Text Available Many research groups are interested in engineering the metabolism of cyanobacteria with the objective to convert solar energy, CO2 and water (perhaps also N2 into commercially valuable products. Towards this objective, many challenges stand in the way before sustainable production can be realized. One of these challenges, potentially, is genetic instability. Although only a handful of reports of this phenomenon are available in the scientific literature, it does appear to be a real issue that so far has not been studied much in cyanobacteria. With this brief perspective, I wish to raise the awareness of this potential issue and hope to inspire future studies on the topic as I believe it will make an important contribution to enabling sustainable large-scale biotechnology in the future using liquid photobiological microorganisms.

  8. Chlorophyll a with a farnesyl tail in thermophilic cyanobacteria.

    Science.gov (United States)

    Wiwczar, Jessica M; LaFountain, Amy M; Wang, Jimin; Frank, Harry A; Brudvig, Gary W

    2017-11-01

    Photosystem II (PSII) of oxygenic photosynthetic organisms normally contains exclusively chlorophyll a (Chl a) as its major light-harvesting pigment. Chl a canonically consists of the chlorin headgroup with a 20-carbon, 4-isoprene unit, phytyl tail. We have examined the 1.9 Å crystal structure of PSII from thermophilic cyanobacteria reported by Shen and coworkers in 2012 (PDB accession of 3ARC/3WU2). A newly refined electron density map from this structure, presented here, reveals that some assignments of the cofactors may be different from those modeled in the 3ARC/3WU2 structure, including a specific Chl a that appears to have a truncated tail by one isoprene unit. We provide experimental evidence using high-performance liquid chromatography and mass spectrometry for a small population of Chl a esterified to a 15-carbon farnesyl tail in PSII of thermophilic cyanobacteria.

  9. Diversity of Cyanobacteria in the Zasavica river, Serbia

    Directory of Open Access Journals (Sweden)

    Predojević Dragana

    2015-01-01

    Full Text Available Cyanobacteria are ancient organisms that are capable of colonizing different habitats in various climatic zones due to their plasticity and rapid accommodation. They are a widely studied group of microorganisms due to the presence of many potentially toxic and invasive species. The aim of this research was a diversity exploration of the freshwater Cyanobacteria in the Zasavica River, which is part of the Special Nature Reserve “Zasavica” in Serbia. Organisms were sampled once a month at two study sites during one year. Phytoplankton and metaphyton analysis showed the presence of 50 freshwater cyanobacterial taxa, of which 12 are new taxa for Serbia. Three invasive and potentially toxic species (Cylindrospermopsis raciborskii, Sphaerospermopsis aphanizomenoides and Raphidiopsis mediterranea were recorded only in metaphyton in April at one site. It can be expected that, if conditions change, this species can migrate and form phytoplankton blooms. [Projekat Ministarstva nauke Republike Srbije, br. ON 176020

  10. Preliminary Assessment of Cyanobacteria Diversity and Toxic Potential in Ten Freshwater Lakes in Selangor, Malaysia.

    Science.gov (United States)

    Sinang, Som Cit; Poh, Keong Bun; Shamsudin, Syakirah; Sinden, Ann

    2015-10-01

    Toxic cyanobacteria blooms are increasing in magnitude and frequency worldwide. However, this issue has not been adequately addressed in Malaysia. Therefore, this study aims to better understand eutrophication levels, cyanobacteria diversity, and microcystin concentrations in ten Malaysian freshwater lakes. The results revealed that most lakes were eutrophic, with total phosphorus and total chlorophyll-a concentrations ranging from 15 to 4270 µg L(-1) and 1.1 to 903.1 µg L(-1), respectively. Cyanobacteria were detected in all lakes, and identified as Microcystis spp., Planktothrix spp., Phormidium spp., Oscillatoria spp., and Lyngbya spp. Microcystis spp. was the most commonly observed and most abundant cyanobacteria recorded. Semi-quantitative microcystin analysis indicated the presence of microcystin in all lakes. These findings illustrate the potential health risk of cyanobacteria in Malaysia freshwater lakes, thus magnifying the importance of cyanobacteria monitoring and management in Malaysian waterways.

  11. CYANOBACTERIA FOR MITIGATING METHANE EMISSION FROM SUBMERGED PADDY FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Upasana Mishra; Shalini Anand [Department of Environmental Studies, Inderprastha Engineering College, Sahibabad, Ghaziabad (India)

    2008-09-30

    Atmospheric methane, a potent greenhouse gas with high absorption potential for infrared radiation, is responsible for one forth of the total anticipated warming. It is forming a major part of green house gases, next after carbon dioxide. Its concentration has been increasing alarmingly on an average at the rate of one percent per year. Atmospheric methane, originating mainly from biogenic sources such as paddy fields, natural wetlands and landfills, accounts for 15-20% of the world's total anthropogenic methane emission. With intensification of rice cultivation in coming future, methane emissions from paddy fields are anticipated to increase. India's share in world's rice production is next after to China and likewise total methane emission from paddy fields also. Methane oxidation through planktophytes, particularly microalgae which are autotrophic and abundant in rice rhizospheres, hold promise in controlling methane emission from submerged paddy fields. The present study is focused on the role of nitrogen fixing, heterocystous cyanobacteria and Azolla (a water fern harboring a cyanobacterium Anabaena azollae) as biological sink for headspace concentration of methane in flooded soils. In this laboratory study, soil samples containing five potent nitrogen fixer cyanobacterial strains from paddy fields, were examined for their methane reducing potential. Soil sample without cyanobacterial strain was tested and taken as control. Anabaena sp. was found most effective in inhibiting methane concentration by 5-6 folds over the control. Moist soil cores treated with chemical nitrogen, urea, in combination with cyanobacteria mixture, Azolla microphylla or cyanobacteria mixture plus Azolla microphylla exhibited significance reduction in the headspace concentration of methane than the soil cores treated with urea alone. Contrary to other reports, this study also demonstrates that methane oxidation in soil core samples from paddy fields was stimulated by

  12. Subcellular distribution of glutathione and cysteine in cyanobacteria

    OpenAIRE

    Zechmann, Bernd; Tomašić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-01-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine,...

  13. CyanoClust: comparative genome resources of cyanobacteria and plastids

    OpenAIRE

    Sasaki, Naobumi V.; Sato, Naoki

    2010-01-01

    Cyanobacteria, which perform oxygen-evolving photosynthesis as do chloroplasts of plants and algae, are one of the best-studied prokaryotic phyla and one from which many representative genomes have been sequenced. Lack of a suitable comparative genomic database has been a problem in cyanobacterial genomics because many proteins involved in physiological functions such as photosynthesis and nitrogen fixation are not catalogued in commonly used databases, such as Clusters of Orthologous Protein...

  14. Assessment of the effects of As(III) treatment on cyanobacteria lipidomic profiles by LC-MS and MCR-ALS.

    Science.gov (United States)

    Marques, Aline S; Bedia, Carmen; Lima, Kássio M G; Tauler, Romà

    2016-08-01

    Cyanobacteria are a group of photosynthetic, nitrogen-fixing bacteria present in a wide variety of habitats such as freshwater, marine, and terrestrial ecosystems. In this work, the effects of As(III), a major toxic environmental pollutant, on the lipidomic profiles of two cyanobacteria species (Anabaena and Planktothrix agardhii) were assessed by means of a recently proposed method based on the concept of regions of interest (ROI) in liquid chromatography mass spectroscopy (LC-MS) together with multivariate curve resolution alternating least squares (MCR-ALS). Cyanobacteria were exposed to two concentrations of As(III) for a week, and lipid extracts were analyzed by ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in full scan mode. The data obtained were compressed by means of the ROI strategy, and the resulting LC-MS data sets were analyzed by the MCR-ALS method. Comparison of profile peak areas resolved by MCR-ALS in control and exposed samples allowed the discrimination of lipids whose concentrations were changed due to As(III) treatment. The tentative identification of these lipids revealed an important reduction of the levels of some galactolipids such as monogalactosyldiacylglycerol, the pigment chlorophyll a and its degradation product, pheophytin a, as well as carotene compounds such as 3-hydroxycarotene and carotene-3,3'-dione, all of these compounds being essential in the photosynthetic process. These results suggested that As(III) induced important changes in the composition of lipids of cyanobacteria, which were able to compromise their energy production processes. Graphical abstract Steps of the proposed LC-MS + MCR-ALS procedure.

  15. Cyanobacteria as efficient producers of mycosporine-like amino acids.

    Science.gov (United States)

    Jain, Shikha; Prajapat, Ganshyam; Abrar, Mustari; Ledwani, Lalita; Singh, Anoop; Agrawal, Akhil

    2017-09-01

    Mycosporine-like amino acids are the most common group of transparent ultraviolet radiation absorbing intracellular secondary metabolites. These molecules absorb light in the range of ultraviolet-A and -B with a maximum absorbance between 310 and 362 nm. Cyanobacteria might have faced the most deleterious ultraviolet radiation, which leads to an evolution of ultraviolet protecting mycosporine-like amino acids for efficient selection in the environment. In the last 30 years, scientists have investigated various cyanobacteria for novel mycosporine-like amino acids, applying different induction techniques. This review organizes all the cyanobacterial groups that produce various mycosporine-like amino acids. We found out that cyanobacteria belonging to orders Synechococcales, Chroococcales, Oscillatoriales, and Nostocales are frequently studied for the presence of mycosporine-like amino acids, while orders Gloeobacterales, Spirulinales, Pleurocapsales, and Chroococcidiopsidales are still need to be investigated. Nostoc and Anabaena strains are major studied genus for the mycosporine-like amino acids production. Hence, this review will give further insight to the readers about potential mycosporine-like amino acid producing cyanobacterial groups in future investigations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Synthetic Biology of Cyanobacteria: Unique Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Bertram M Berla

    2013-08-01

    Full Text Available Photosynthetic organisms, and especially cyanobacteria, hold great promise as sources of renewably-produced fuels, bulk and specialty chemicals, and nutritional products. Synthetic biology tools can help unlock cyanobacteria’s potential for these functions, but unfortunately tool development for these organisms has lagged behind that for S. cerevisiae and E. coli. While these organisms may in many cases be more difficult to work with as ‘chassis’ strains for synthetic biology than certain heterotrophs, the unique advantages of autotrophs in biotechnology applications as well as the scientific importance of improved understanding of photosynthesis warrant the development of these systems into something akin to a ‘green E. coli’. In this review, we highlight unique challenges and opportunities for development of synthetic biology approaches in cyanobacteria. We review classical and recently developed methods for constructing targeted mutants in various cyanobacterial strains, and offer perspective on what genetic tools might most greatly expand the ability to engineer new functions in such strains. Similarly, we review what genetic parts are most needed for the development of cyanobacterial synthetic biology. Finally, we highlight recent methods to construct genome-scale models of cyanobacterial metabolism and to use those models to measure properties of autotrophic metabolism. Throughout this paper, we discuss some of the unique challenges of a diurnal, autotrophic lifestyle along with how the development of synthetic biology and biotechnology in cyanobacteria must fit within those constraints.

  17. Use of cyanobacteria to assess water quality in running waters

    International Nuclear Information System (INIS)

    Douterelo, I.; Perona, E.; Mateo, P.

    2004-01-01

    Epilithic cyanobacterial communities in rivers in the province of Madrid (Spain) and their relationship with water quality were studied. Sampling locations above and below outlets for sewage effluent and other wastes from human settlements were selected. We aimed to evaluate the use of cyanobacteria as potential indicators of pollution in running waters. Large increases in nutrient concentrations were always observed at downstream sampling sites. A decrease in species richness and the Margalef diversity index were associated with these increases in nutrient load. Differences in cyanobacterial community structure were also observed. A higher proportion of cyanobacteria belonging to the Oscillatoriales order predominated at sampling sites with higher nutrient content. However, Nostocales species were more abundant at upstream sites characterized by lower nutrient load than at downstream locations. The soluble reactive phosphate (SRP) had a threshold effect on cyanobacterial biomass: a decrease in phycobiliprotein content as SRP increased, reaching a minimum, followed by an increase in abundance. This increase may be attributed to hypertrophic conditions in those locations. Our results and literature data confirm the suitability of this phototroph community for monitoring eutrophication in rivers - Taxonomic composition of cyanobacteria is a sensitive indicator of river water quality

  18. Integration vector for the cyanobacteria Synechocystis sp. 6803

    International Nuclear Information System (INIS)

    Shestakov, S.V.; Elanskaya, I.V.; Bibikova, M.V.

    1985-01-01

    The authors have constructed recombinant plasmid DNA molecules with fragments of chromosomal DNA of the cyanobacterium Synechocystis 6803 in the vector plasmid pACYC 184, carrying markers for resistance against tetracycline (TC/sup r/) and chloramphenicol (Cm/sup r/). The authors also present their scheme of constructing integration vectors for Synechocystis 6803. To demonstrate integration of the recombinant plasmids of pSIS and pSIB series into the chromosomes of cyanobacteria, chromosomal DNA was isolated from the Cm/sup r/ transformants of Synechocystis 6803, and used for blot-hybridization using P 32-labeled plasmid DNA of pACYC 184. The hybridization results show that the chromosomal DNA isolated from the Cm/sup r/ transformants of cyanobacteria carries a region homologous with plasmid pACYC 184, whereas the DNA from wild type cells does not hybridize with pACYC 184. The transformation frequency of the Synechocystis 6803 cells by chromosomal DNA from the Cm/sup r/ clones of cyanobacteria was 3-7 x 10 -5 , which corresponds to the frequency of chromosomal transformation for other markers

  19. Use of cyanobacteria to assess water quality in running waters

    Energy Technology Data Exchange (ETDEWEB)

    Douterelo, I.; Perona, E.; Mateo, P

    2004-02-01

    Epilithic cyanobacterial communities in rivers in the province of Madrid (Spain) and their relationship with water quality were studied. Sampling locations above and below outlets for sewage effluent and other wastes from human settlements were selected. We aimed to evaluate the use of cyanobacteria as potential indicators of pollution in running waters. Large increases in nutrient concentrations were always observed at downstream sampling sites. A decrease in species richness and the Margalef diversity index were associated with these increases in nutrient load. Differences in cyanobacterial community structure were also observed. A higher proportion of cyanobacteria belonging to the Oscillatoriales order predominated at sampling sites with higher nutrient content. However, Nostocales species were more abundant at upstream sites characterized by lower nutrient load than at downstream locations. The soluble reactive phosphate (SRP) had a threshold effect on cyanobacterial biomass: a decrease in phycobiliprotein content as SRP increased, reaching a minimum, followed by an increase in abundance. This increase may be attributed to hypertrophic conditions in those locations. Our results and literature data confirm the suitability of this phototroph community for monitoring eutrophication in rivers - Taxonomic composition of cyanobacteria is a sensitive indicator of river water quality.

  20. Biomineralization Patterns of Intracellular Carbonatogenesis in Cyanobacteria: Molecular Hypotheses

    Directory of Open Access Journals (Sweden)

    Jinhua Li

    2016-02-01

    Full Text Available The recent discovery of intracellular carbonatogenesis in several cyanobacteria species has challenged the traditional view that this process was extracellular and not controlled. However, a detailed analysis of the size distribution, chemical composition and 3-D-arrangement of carbonates in these cyanobacteria is lacking. Here, we characterized these features in Candidatus Gloeomargarita lithophora C7 and Candidatus Synechococcus calcipolaris G9 by conventional transmission electron microscopy, tomography, ultramicrotomy, and scanning transmission X-ray microscopy (STXM. Both Ca. G. lithophora C7 and Ca. S. calcipolaris G9 formed numerous polyphosphate granules adjacent or engulfing Ca-carbonate inclusions when grown in phosphate-rich solutions. Ca-carbonates were scattered within Ca. G. lithophora C7 cells under these conditions, but sometimes arranged in one or several chains. In contrast, Ca-carbonates formed at cell septa in Ca. S. calcipolaris G9 and were segregated equally between daughter cells after cell division, arranging as distorted disks at cell poles. The size distribution of carbonates evolved from a positively to a negatively skewed distribution as particles grew. Conventional ultramicrotomy did not preserve Ca-carbonates explaining partly why intracellular calcification has been overlooked in the past. All these new observations allow discussing with unprecedented insight some nucleation and growth processes occurring in intracellularly calcifying cyanobacteria with a particular emphasis on the possible involvement of intracellular compartments and cytoskeleton.

  1. Light-dependent governance of cell shape dimensions in cyanobacteria

    Directory of Open Access Journals (Sweden)

    Beronda L Montgomery

    2015-05-01

    Full Text Available The regulation of cellular dimension is important for the function and survival of cells. Cellular dimensions, such as size and shape, are regulated throughout the life cycle of bacteria and can be adapted in response to environmental changes to fine-tune cellular fitness. Cell size and shape are generally coordinated with cell growth and division. Cytoskeletal regulation of cell shape and cell wall biosynthesis and/or deposition occurs in a range of organisms. Photosynthetic organisms, such as cyanobacteria, particularly exhibit light-dependent regulation of morphogenes and generation of reactive oxygen species and other signals that can impact cellular dimensions. Environmental signals initiate adjustments of cellular dimensions, which may be vitally important for optimizing resource acquisition and utilization or for coupling the cellular dimensions with the regulation of subcellular organization to maintain optimal metabolism. Although the involvement of cytoskeletal components in the regulation of cell shape is widely accepted, the signaling factors that regulate cytoskeletal and other distinct components involved in cell shape control, particularly in response to changes in external light cues, remain to be fully elucidated. In this review, factors impacting the inter-coordination of growth and division, the relationship between the regulation of cellular dimensions and central carbon metabolism, and consideration of the effects of specific environment signals, primarily light, on cell dimensions in cyanobacteria will be discussed. Current knowledge about the molecular bases of the light-dependent regulation of cellular dimensions and cell shape in cyanobacteria will be highlighted.

  2. Biodegradation of Dimethyl Phthalate by Freshwater Unicellular Cyanobacteria.

    Science.gov (United States)

    Zhang, Xiaohui; Liu, Lincong; Zhang, Siping; Pan, Yan; Li, Jing; Pan, Hongwei; Xu, Shiguo; Luo, Feng

    2016-01-01

    The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, Cyanothece sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours' incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP.

  3. Biodegradation of Dimethyl Phthalate by Freshwater Unicellular Cyanobacteria

    Science.gov (United States)

    Zhang, Xiaohui; Liu, Lincong; Zhang, Siping; Pan, Yan; Li, Jing; Pan, Hongwei

    2016-01-01

    The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, Cyanothece sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours' incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP. PMID:28078293

  4. Cluster (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available 3090”. This cluster ID is uniquely-assigned by the PGDBj Ortholog Database. Cluster size Number of proteins ...ster About This Database Database Description Download License Update History of This Database Site Policy | Contact Us Cluster (Cyanobacteria) - PGDBj - Ortholog DB | LSDB Archive ... ...List Contact us PGDBj - Ortholog DB Cluster (Cyanobacteria) Data detail Data name Cluster (Cyanobacteria) DO...switchLanguage; BLAST Search Image Search Home About Archive Update History Data

  5. Cyanobacteria: Photoautotrophic Microbial Factories for the Sustainable Synthesis of Industrial Products

    OpenAIRE

    Lau, Nyok-Sean; Matsui, Minami; Abdullah, Amirul Al-Ashraf

    2015-01-01

    Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of int...

  6. Immobilized periphytic cyanobacteria for removal of nitrogenous compounds and phosphorus from shrimp farm wastewater

    OpenAIRE

    BANERJEE, SANJOY; KHATOON, HELENA; SHARIFF, MOHAMED; YUSOFF, FATIMAH

    2015-01-01

    Cyanobacteria can be used to remove nitrogenous compounds from wastewater, but a major bottleneck in the process is the separation of cyanobacterial biomass from the treated water discharge, which may cause eutrophication. The current study assessed the suitability of three periphytic cyanobacteria (Geitlerinema sp., Gloeotrichia sp., and Lyngbya sp.) isolated from shrimp ponds. These cyanobacteria were immobilized by self-adhesion to polyvinyl chloride sheets, forming mats, and were screened...

  7. Nonribosomal Peptides from Marine Microbes and Their Antimicrobial and Anticancer Potential

    Directory of Open Access Journals (Sweden)

    Shivankar Agrawal

    2017-11-01

    Full Text Available Marine environments are largely unexplored and can be a source of new molecules for the treatment of many diseases such as malaria, cancer, tuberculosis, HIV etc. The Marine environment is one of the untapped bioresource of getting pharmacologically active nonribosomal peptides (NRPs. Bioprospecting of marine microbes have achieved many remarkable milestones in pharmaceutics. Till date, more than 50% of drugs which are in clinical use belong to the nonribosomal peptide or mixed polyketide-nonribosomal peptide families of natural products isolated from marine bacteria, cyanobacteria and fungi. In recent years large numbers of nonribosomal have been discovered from marine microbes using multi-disciplinary approaches. The present review covers the NRPs discovered from marine microbes and their pharmacological potential along with role of genomics, proteomics and bioinformatics in discovery and development of nonribosomal peptides drugs.

  8. Decomposition in pelagic marine ecosytems

    International Nuclear Information System (INIS)

    Lucas, M.I.

    1986-01-01

    During the decomposition of plant detritus, complex microbial successions develop which are dominated in the early stages by a number of distinct bacterial morphotypes. The microheterotrophic community rapidly becomes heterogenous and may include cyanobacteria, fungi, yeasts and bactivorous protozoans. Microheterotrophs in the marine environment may have a biomass comparable to that of all other heterotrophs and their significance as a resource to higher trophic orders, and in the regeneration of nutrients, particularly nitrogen, that support 'regenerated' primary production, has aroused both attention and controversy. Numerous methods have been employed to measure heterotrophic bacterial production and activity. The most widely used involve estimates of 14 C-glucose uptake; the frequency of dividing cells; the incorporation of 3 H-thymidine and exponential population growth in predator-reduced filtrates. Recent attempts to model decomposition processes and C and N fluxes in pelagic marine ecosystems are described. This review examines the most sensitive components and predictions of the models with particular reference to estimates of bacterial production, net growth yield and predictions of N cycling determined by 15 N methodology. Directed estimates of nitrogen (and phosphorus) flux through phytoplanktonic and bacterioplanktonic communities using 15 N (and 32 P) tracer methods are likely to provide more realistic measures of nitrogen flow through planktonic communities

  9. Health risk assessment standards of cyanobacteria bloom occurrence in bathing sites

    Directory of Open Access Journals (Sweden)

    Agnieszka Stankiewicz

    2011-03-01

    Full Text Available Threat for human health appears during a massive cyanobacteria bloom in potable water used for human consumption or in basins used for recreational purposes. General health risk assessment standards and preventive measures to be taken by sanitation service were presented in scope of: – evaluation of cyanobacteria bloom occurrence in bathing sites / water bodies, – procedures in case of cyanobacteria bloom, including health risk assessment and decision making process to protect users’ health at bathing sites, – preventive measures, to be taken in case of cyanobacteria bloom occurrence in bathing sites and basins, where bathing sites are located.

  10. Cyanobacteria: Photoautotrophic Microbial Factories for the Sustainable Synthesis of Industrial Products.

    Science.gov (United States)

    Lau, Nyok-Sean; Matsui, Minami; Abdullah, Amirul Al-Ashraf

    2015-01-01

    Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of interest. Equipped with the ability to degrade environmental pollutants and remove heavy metals, cyanobacteria are promising tools for bioremediation and wastewater treatment. Cyanobacteria are characterized by the ability to produce a spectrum of bioactive compounds with antibacterial, antifungal, antiviral, and antialgal properties that are of pharmaceutical and agricultural significance. Several strains of cyanobacteria are also sources of high-value chemicals, for example, pigments, vitamins, and enzymes. Recent advances in biotechnological approaches have facilitated researches directed towards maximizing the production of desired products in cyanobacteria and realizing the potential of these bacteria for various industrial applications. In this review, the potential of cyanobacteria as sources of energy, bioactive compounds, high-value chemicals, and tools for aquatic bioremediation and recent progress in engineering cyanobacteria for these bioindustrial applications are discussed.

  11. Cyanobacteria: Photoautotrophic Microbial Factories for the Sustainable Synthesis of Industrial Products

    Science.gov (United States)

    Lau, Nyok-Sean; Matsui, Minami; Abdullah, Amirul Al-Ashraf

    2015-01-01

    Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of interest. Equipped with the ability to degrade environmental pollutants and remove heavy metals, cyanobacteria are promising tools for bioremediation and wastewater treatment. Cyanobacteria are characterized by the ability to produce a spectrum of bioactive compounds with antibacterial, antifungal, antiviral, and antialgal properties that are of pharmaceutical and agricultural significance. Several strains of cyanobacteria are also sources of high-value chemicals, for example, pigments, vitamins, and enzymes. Recent advances in biotechnological approaches have facilitated researches directed towards maximizing the production of desired products in cyanobacteria and realizing the potential of these bacteria for various industrial applications. In this review, the potential of cyanobacteria as sources of energy, bioactive compounds, high-value chemicals, and tools for aquatic bioremediation and recent progress in engineering cyanobacteria for these bioindustrial applications are discussed. PMID:26199945

  12. Cyanobacteria: Photoautotrophic Microbial Factories for the Sustainable Synthesis of Industrial Products

    Directory of Open Access Journals (Sweden)

    Nyok-Sean Lau

    2015-01-01

    Full Text Available Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of interest. Equipped with the ability to degrade environmental pollutants and remove heavy metals, cyanobacteria are promising tools for bioremediation and wastewater treatment. Cyanobacteria are characterized by the ability to produce a spectrum of bioactive compounds with antibacterial, antifungal, antiviral, and antialgal properties that are of pharmaceutical and agricultural significance. Several strains of cyanobacteria are also sources of high-value chemicals, for example, pigments, vitamins, and enzymes. Recent advances in biotechnological approaches have facilitated researches directed towards maximizing the production of desired products in cyanobacteria and realizing the potential of these bacteria for various industrial applications. In this review, the potential of cyanobacteria as sources of energy, bioactive compounds, high-value chemicals, and tools for aquatic bioremediation and recent progress in engineering cyanobacteria for these bioindustrial applications are discussed.

  13. Screening of Norharmane from Seven Cyanobacteria by High-performance Liquid Chromatography.

    Science.gov (United States)

    Karan, Tunay; Erenler, Ramazan

    2017-10-01

    Cyanobacteria, including pharmaceutically and medicinally valuable compounds attract the great attention lately. Norharmane (9H-pyrido (3,4-b) indole found in some cyanobacteria revealed a great number of biological effects. Seven cyanobacteria were isolated and identified from Yesilirmak River and Gaziosmanpasa University Campus to determine the norharmane content. Cyanobacteria collected from Tokat, Turkey were isolated and identified by morphologically. Norharmane (9H-pyrido [3,4-b] indole) quantities were presented for seven cyanobacteria, Chroococcus minutus (Kütz.) Nägeli, Geitlerinema carotinosum (Geitler) Anagnostidis, Nostoc linckia Bornet ex Bornet and Flahault, Anabaena oryzae F. E. Fritsch, Oscillatoria limnetica Lemmermann, Phormidium sp . Kützing ex Gomont, and Cylindrospermum sp . Kutzing ex E. Bornet and C. Flahault by high-performance liquid chromatography. The norharmane amount indicated for cyanobacterial culture media altered in a species-dependent kind in the range of 0.81-10.87 μg/g. C. minutus produced the most norharmane among the investigated cyanobacteria as 10.87 μg/g. Cyanobacteria could be an important source of norharmane as well as pharmaceutically valuable compounds. Seven cyanobacteria were isolated and identified from Yesilirmak RiverQuantitative analysis of norharmane was executed on isolated cyanobacteriaFour cyanobecteria species included the norharmane Chroococcus minutus contained the most norharmane (10.87 μg/g). Abbreviations used: HPLC: High performance liquid chromatograph.

  14. IMPROVING CYANOBACTERIA AND CYANOTOXIN MONITORING IN SURFACE WATERS FOR DRINKING WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    Jing Li

    2017-06-01

    Full Text Available Cyanobacteria in fresh water can cause serious threats to drinking water supplies. Managing cyanobacterial blooms particularly at small drinking water treatment plants is challenging. Because large amount of cyanobacteria may cause clogging in the treatment process and various cyanotoxins are hard to remove, while they may cause severe health problems. There is lack of instructions of what cyanobacteria/toxin amount should trigger what kind of actions for drinking water management except for Microcystins. This demands a Cyanobacteria Management Tool (CMT to help regulators/operators to improve cyanobacteria/cyanotoxin monitoring in surface waters for drinking water supply. This project proposes a CMT tool, including selecting proper indicators for quick cyanobacteria monitoring and verifying quick analysis methods for cyanobacteria and cyanotoxin. This tool is suggested for raw water management regarding cyanobacteria monitoring in lakes, especially in boreal forest climate. In addition, it applies to regions that apply international WHO standards for water management. In Swedish context, drinking water producers which use raw water from lakes that experience cyanobacterial blooms, need to create a monitoring routine for cyanobacteria/cyanotoxin and to monitor beyond such as Anatoxins, Cylindrospermopsins and Saxitoxins. Using the proposed CMT tool will increase water safety at surface water treatment plants substantially by introducing three alerting points for actions. CMT design for each local condition should integrate adaptive monitoring program.

  15. Screening of Norharmane from Seven Cyanobacteria by High-performance Liquid Chromatography

    Science.gov (United States)

    Karan, Tunay; Erenler, Ramazan

    2017-01-01

    Background: Cyanobacteria, including pharmaceutically and medicinally valuable compounds attract the great attention lately. Norharmane (9H-pyrido (3,4-b) indole found in some cyanobacteria revealed a great number of biological effects. Objective: Seven cyanobacteria were isolated and identified from Yesilirmak River and Gaziosmanpasa University Campus to determine the norharmane content. Materials and Methods: Cyanobacteria collected from Tokat, Turkey were isolated and identified by morphologically. Norharmane (9H-pyrido [3,4-b] indole) quantities were presented for seven cyanobacteria, Chroococcus minutus (Kütz.) Nägeli, Geitlerinema carotinosum (Geitler) Anagnostidis, Nostoc linckia Bornet ex Bornet and Flahault, Anabaena oryzae F. E. Fritsch, Oscillatoria limnetica Lemmermann, Phormidium sp. Kützing ex Gomont, and Cylindrospermum sp. Kutzing ex E. Bornet and C. Flahault by high-performance liquid chromatography. Results: The norharmane amount indicated for cyanobacterial culture media altered in a species-dependent kind in the range of 0.81–10.87 μg/g. C. minutus produced the most norharmane among the investigated cyanobacteria as 10.87 μg/g. Conclusion: Cyanobacteria could be an important source of norharmane as well as pharmaceutically valuable compounds. SUMMARY Seven cyanobacteria were isolated and identified from Yesilirmak RiverQuantitative analysis of norharmane was executed on isolated cyanobacteriaFour cyanobecteria species included the norharmaneChroococcus minutus contained the most norharmane (10.87 μg/g). Abbreviations used: HPLC: High performance liquid chromatograph. PMID:29142439

  16. T4 genes in the marine ecosystem: studies of the T4-like cyanophages and their role in marine ecology

    Directory of Open Access Journals (Sweden)

    Millard Andrew D

    2010-10-01

    Full Text Available Abstract From genomic sequencing it has become apparent that the marine cyanomyoviruses capable of infecting strains of unicellular cyanobacteria assigned to the genera Synechococcus and Prochlorococcus are not only morphologically similar to T4, but are also genetically related, typically sharing some 40-48 genes. The large majority of these common genes are the same in all marine cyanomyoviruses so far characterized. Given the fundamental physiological differences between marine unicellular cyanobacteria and heterotrophic hosts of T4-like phages it is not surprising that the study of cyanomyoviruses has revealed novel and fascinating facets of the phage-host relationship. One of the most interesting features of the marine cyanomyoviruses is their possession of a number of genes that are clearly of host origin such as those involved in photosynthesis, like the psbA gene that encodes a core component of the photosystem II reaction centre. Other host-derived genes encode enzymes involved in carbon metabolism, phosphate acquisition and ppGpp metabolism. The impact of these host-derived genes on phage fitness has still largely to be assessed and represents one of the most important topics in the study of this group of T4-like phages in the laboratory. However, these phages are also of considerable environmental significance by virtue of their impact on key contributors to oceanic primary production and the true extent and nature of this impact has still to be accurately assessed.

  17. Computational analysis of LexA regulons in Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Su Zhengchang

    2010-09-01

    Full Text Available Abstract Background The transcription factor LexA plays an important role in the SOS response in Escherichia coli and many other bacterial species studied. Although the lexA gene is encoded in almost every bacterial group with a wide range of evolutionary distances, its precise functions in each group/species are largely unknown. More recently, it has been shown that lexA genes in two cyanobacterial genomes Nostoc sp. PCC 7120 and Synechocystis sp. PCC 6803 might have distinct functions other than the regulation of the SOS response. To gain a general understanding of the functions of LexA and its evolution in cyanobacteria, we conducted the current study. Results Our analysis indicates that six of 33 sequenced cyanobacterial genomes do not harbor a lexA gene although they all encode the key SOS response genes, suggesting that LexA is not an indispensable transcription factor in these cyanobacteria, and that their SOS responses might be regulated by different mechanisms. Our phylogenetic analysis suggests that lexA was lost during the course of evolution in these six cyanobacterial genomes. For the 26 cyanobacterial genomes that encode a lexA gene, we have predicted their LexA-binding sites and regulons using an efficient binding site/regulon prediction algorithm that we developed previously. Our results show that LexA in most of these 26 genomes might still function as the transcriptional regulator of the SOS response genes as seen in E. coli and other organisms. Interestingly, putative LexA-binding sites were also found in some genomes for some key genes involved in a variety of other biological processes including photosynthesis, drug resistance, etc., suggesting that there is crosstalk between the SOS response and these biological processes. In particular, LexA in both Synechocystis sp. PCC6803 and Gloeobacter violaceus PCC7421 has largely diverged from those in other cyanobacteria in the sequence level. It is likely that LexA is no longer a

  18. Phylogeography and pigment type diversity of Synechococcus cyanobacteria in surface waters of the northwestern pacific ocean.

    Science.gov (United States)

    Xia, Xiaomin; Partensky, Frédéric; Garczarek, Laurence; Suzuki, Koji; Guo, Cui; Yan Cheung, Shun; Liu, Hongbin

    2017-01-01

    The widespread unicellular cyanobacteria Synechococcus are major contributors to global marine primary production. Here, we report their abundance, phylogenetic diversity (as assessed using the RNA polymerase gamma subunit gene rpoC1) and pigment diversity (as indirectly assessed using the laterally transferred cpeBA genes, encoding phycoerythrin-I) in surface waters of the northwestern Pacific Ocean, sampled over nine distinct cruises (2008-2015). Abundance of Synechococcus was low in the subarctic ocean and South China Sea, intermediate in the western subtropical Pacific Ocean, and the highest in the Japan and East China seas. Clades I and II were by far the most abundant Synechococcus lineages, the former dominating in temperate cold waters and the latter in (sub)tropical waters. Clades III and VI were also fairly abundant in warm waters, but with a narrower distribution than clade II. One type of chromatic acclimater (3dA) largely dominated the Synechococcus communities in the subarctic ocean, while another (3dB) and/or cells with a fixed high phycourobilin to phycoerythrobilin ratio (pigment type 3c) predominated at mid and low latitudes. Altogether, our results suggest that the variety of pigment content found in most Synechococcus clades considerably extends the niches that they can colonize and therefore the whole genus habitat. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Prominent Human Health Impacts from Several Marine Microbes: History, Ecology, and Public Health Implications

    Directory of Open Access Journals (Sweden)

    P. K. Bienfang

    2011-01-01

    Full Text Available This paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. These examples include three types of dinoflagellates (Gambierdiscus spp., Karenia brevis, and Alexandrium fundyense, BMAA-producing cyanobacteria, and infectious microbes. The dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have plagued coastal populations over time. Research interest on the potential for marine cyanobacteria to contribute BMAA into human food supplies has been derived by BMAA's discovery in cycad seeds and subsequent implication as the putative cause of amyotrophic lateral sclerosis/parkinsonism dementia complex among the Chamorro people of Guam. Recent UPLC/MS analyses indicate that recent reports that BMAA is prolifically distributed among marine cyanobacteria at high concentrations may be due to analyte misidentification in the analytical protocols being applied for BMAA. Common infectious microbes (including enterovirus, norovirus, Salmonella, Campylobacter, Shigella, Staphylococcus aureus, Cryptosporidium, and Giardia cause gastrointestinal and skin-related illness. These microbes can be introduced from external human and animal sources, or they can be indigenous to the marine environment.

  20. Phycobiliproteins: A Novel Green Tool from Marine Origin Blue-Green Algae and Red Algae.

    Science.gov (United States)

    Chandra, Rashmi; Parra, Roberto; Iqbal, Hafiz M N

    2017-01-01

    Marine species are comprising about a half of the whole global biodiversity; the sea offers an enormous resource for novel bioactive compounds. Several of the marine origin species show multifunctional bioactivities and characteristics that are useful for a discovery and/or reinvention of biologically active compounds. For millennia, marine species that includes cyanobacteria (blue-green algae) and red algae have been targeted to explore their enormous potential candidature status along with a wider spectrum of novel applications in bio- and non-bio sectors of the modern world. Among them, cyanobacteria are photosynthetic prokaryotes, phylogenetically a primitive group of Gramnegative prokaryotes, ranging from Arctic to Antarctic regions, capable of carrying out photosynthesis and nitrogen fixation. In the recent decade, a great deal of research attention has been paid on the pronouncement of bio-functional proteins along with novel peptides, vitamins, fine chemicals, renewable fuel and bioactive compounds, e.g., phycobiliproteins from marine species, cyanobacteria and red algae. Interestingly, they are extensively commercialized for natural colorants in food and cosmetics, antimicrobial, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective agents and fluorescent neo-glycoproteins as probes for single particle fluorescence imaging fluorescent applications in clinical and immunological analysis. However, a comprehensive knowledge and technological base for augmenting their commercial utilities are lacking. Therefore, this paper will provide an overview of the phycobiliproteins-based research literature from marine cyanobacteria and red algae. This review is also focused towards analyzing global and commercial activities with application oriented-based research. Towards the end, the information is also given on the potential biotechnological and biomedical applications of phycobiliproteins. Copyright© Bentham Science Publishers; For any queries, please

  1. Tropical dermatology: marine and aquatic dermatology.

    Science.gov (United States)

    Haddad, Vidal; Lupi, Omar; Lonza, Juan Pedro; Tyring, Stephen K

    2009-11-01

    Dermatoses caused by marine organisms are frequently seen in dermatology clinics worldwide. Cutaneous injuries after exposure to marine environments include bacterial and fungal infections and lesions caused by aquatic plants and protists. Some of these diseases are well known by dermatologists, such as Vibrio vulnificus septicemia and erysipeloid, but others are uncommon, such as envenomation caused by ingestion or contact with certain dinoflagellates or cyanobacteria, which are associated with rashes that can begin within minutes after exposure. Many marine/aquatic invertebrates, such as sponges, cnidarians, echinoderms, crustaceans, and mollusks, are associated with different kinds of dermatologic lesions that can vary from irritant or allergic contact dermatitis to physical trauma and envenomations. These cutaneous lesions may result in mild local reactions or can be associated with severe systemic reactions. Invertebrate animals, such as cnidarians, sea urchins, and worms, and aquatic vertebrates, such as venomous fishes and stingrays, are commonly associated with skin lesions in many countries, where they can constitute occupational dermatoses among fishermen and scuba divers, but they can also be observed among persons who contact these animals in kitchens or beaches. The presence of unusual lesions, a recent travel history, and/or a report of contact with an aquatic environment (including ownership of a marine or freshwater aquarium) should alert the dermatologist to the etiology of the cutaneous problems. After completing this learning activity, participants should be able to recognize the cutaneous manifestations of marine/aquatic infections, bites, stings, and wounds, etc., treat the cutaneous manifestations of marine/aquatic injuries, and help prevent marine/aquatic injuries.

  2. Rapid Reactivation of Cyanobacterial Photosynthesis and Migration upon Rehydration of Desiccated Marine Microbial Mats

    KAUST Repository

    Chennu, Arjun

    2015-12-24

    Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.

  3. Rapid Reactivation of Cyanobacterial Photosynthesis and Migration upon Rehydration of Desiccated Marine Microbial Mats

    KAUST Repository

    Chennu, Arjun; Grinham, Alistair; Polerecky, Lubos; de Beer, Dirk; Alnajjar, Mohammad Ahmad

    2015-01-01

    Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.

  4. Marine Science

    African Journals Online (AJOL)

    between humans and the coastal and marine environment. ... The journal has a new and more modern layout, published online only, and the editorial .... the population structure of Platorchestia fayetta sp. nov. and their interaction with the.

  5. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the ... tidal height and amplitude can influence light penetra- ...... to environmental parameters in cage culture area of Sepanggar Bay, Malaysia.

  6. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ... consist of special issues on major events or important thematic issues. ... of sources, including plant and animal by- products.

  7. Marine biotoxins

    National Research Council Canada - National Science Library

    2004-01-01

    ... (ciguatera fish poisoning). It discusses in detail the causative toxins produced by marine organisms, chemical structures and analytical methods, habitat and occurrence of the toxin-producing organisms, case studies and existing regulations...

  8. Marine Science

    African Journals Online (AJOL)

    pod diversity and distribution are important especially since studies on marine biodiversity are scarce .... Method II –. Zamoum &. Furla (2012) protocol. Method III. – Geist et al (2008) protocol ..... Public Library Of Science One 8: 51273.

  9. Marine pollution

    International Nuclear Information System (INIS)

    Clark, R.B.

    1992-01-01

    The effects of petroleum, waste materials, halogenated hydrocarbons, radioactivity and heat on the marine ecosystem, the fishing industry and human health are discussed using the example of the North Sea. (orig.) [de

  10. Marine Science

    African Journals Online (AJOL)

    No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form ... to optimize nucleic acid extraction protocols from marine gastropods, present an ...... Greenfield., Gomez E, Harvell CD, Sale PF, Edwards.

  11. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high ..... circulation patterns include the nutrient-rich Somali ...... matical Structures in Computer Science 24: e240311.

  12. Marine insects

    National Research Council Canada - National Science Library

    Cheng, Lanna

    1976-01-01

    .... Not only are true insects, such as the Collembola and insect parasites of marine birds and mammals, considered, but also other kinds of intertidal air-breathing arthropods, notably spiders, scorpions...

  13. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue .... shell growth is adversely affected. ... local stressors in action, such as ocean acidification ..... that the distribution of many intertidal sessile animals.

  14. Cyanobacteria and prawn farming in northern New South Wales, Australia--a case study on cyanobacteria diversity and hepatotoxin bioaccumulation

    International Nuclear Information System (INIS)

    Kankaanpaeae, Harri T.; Holliday, Jon; Schroeder, Helge; Goddard, Timothy J.; Fister, Richard von; Carmichael, Wayne W.

    2005-01-01

    Harmful cyanobacteria pose a hazard to aquatic ecosystems due to toxins (hepatotoxic microcystins, nodularins, and cylindrospermopsin) they produce. The microcystins and nodularins are potent toxins, which are also tumor promoters. The microcystins and nodularins may accumulate into aquatic organisms and be transferred to higher trophic levels, and eventually affect vector animals and consumers. Prawn farming is a rapidly growing industry in Australia. Because information regarding effects of cyanobacteria at prawn farms was lacking, we examined diversity of cyanobacteria and toxin production plus bioaccumulation into black tiger prawns (Penaeus monodon) under both field (northern New South Wales, Australia, December 2001-April 2002) and laboratory conditions. Samples were analyzed for hepatotoxins using enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). The maximum density of cyanobacteria (1 x 10 6 to 4 x 10 6 cells/l) was reached in April. Cyanobacteria encountered were Oscillatoria sp. (up to 4 x 10 6 cells/l), Pseudanabaena sp. (up to 1.8 x 10 6 cells/l), Microcystis sp. (up to 3.5 x 10 4 cells/l), and Aphanocapsa sp. (up to 2 x 10 4 cells/l). An uncommon cyanobacterium, Romeria sp. (up to 2.2 x 10 6 cells/l), was also observed. Contrasting earlier indications, toxic Nodularia spumigena was absent. Despite that both Oscillatoria sp. and Microcystis sp. are potentially hepatotoxic, hepatotoxin levels in phytoplankton samples remained low (up to 0.5-1.2 mg/kg dw; ELISA) in 2001-2002. ELISA was found suitable not only for phytoplankton but prawn tissues as well. Enzymatic pretreatment improved extractability of hepatotoxin from cyanobacteria (nodularin from N. spumigena as an example), but did not generally increase toxin recovery from prawn hepatopancreas. There were slightly increasing hepatotoxin concentrations in prawn hepatopancreas (from 6-20 to 20-80 μg/kg dw; ELISA) during the study. Hepatotoxin concentrations in

  15. Analysis of Life Cycle within Various Strains of Cyanobacteria with a Focus on Internal Regulators & Toxin Production

    Science.gov (United States)

    Cyanobacteria are photosynthetic bacteria that exhibit some similarities to algae and can be found naturally in lakes, streams, ponds, and other surface waters. However, toxin producing cyanobacteria have become an increasing concern as growth rates have been escalating. Neverthe...

  16. EnviroAtlas Cyanobacteria Assessment Network (CyAN) Dashboard: A Tool for Data Visualization and Exploratory Analysis

    Science.gov (United States)

    Economic, health, and environmental impacts of cyanobacteria and associated harmful algal blooms are increasingly recognized by policymakers, managers, and scientific researchers. However, spatially-distributed, long-term data on cyanobacteria blooms are largely unavailable. The ...

  17. Anticancer Drugs from Marine Flora: An Overview

    Directory of Open Access Journals (Sweden)

    N. Sithranga Boopathy

    2010-01-01

    Full Text Available Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

  18. Mineralized remains of morphotypes of filamentous cyanobacteria in carbonaceous meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2005-09-01

    The quest for conclusive evidence of microfossils in meteorites has been elusive. Abiotic microstructures, mineral grains, and even coating artifacts may mimic unicellular bacteria, archaea and nanobacteria with simple spherical or rod morphologies (i.e., cocci, diplococci, bacilli, etc.). This is not the case for the larger and more complex microorganisms, colonies and microbial consortia and ecosystems. Microfossils of algae, cyanobacteria, and cyanobacterial and microbial mats have been recognized and described from many of the most ancient rocks on Earth. The filamentous cyanobacteria and sulphur-bacteria have very distinctive size ranges, complex and recognizable morphologies and visibly differentiated cellular microstructures. The taphonomic modes of fossilization and the life habits and processes of these microorganisms often result in distinctive chemical biosignatures associated with carbonization, silicification, calcification, phosphatization and metal-binding properties of their cell-walls, trichomes, sheaths and extracellular polymeric substances (EPS). Valid biogenicity is provided by the combination of a suite of known biogenic elements (that differ from the meteorite matrix) found in direct association with recognizable and distinct biological features and microstructures (e.g., uniseriate or multiseriate filaments, trichomes, sheaths and cells of proper size/size range); specialized cells (e.g., basal or apical cells, hormogonia, akinetes, and heterocysts); and evidence of growth characteristics (e.g., spiral filaments, robust or thin sheaths, laminated sheaths, true or false branching of trichomes, tapered or uniform filaments) and evidence of locomotion (e.g. emergent cells and trichomes, coiling hormogonia, and hollow or flattened and twisted sheaths). Since 1997 we have conducted Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) studies of freshly fractured interior surfaces of carbonaceous meteorites, terrestrial

  19. Occurrence of C35-C45 polyprenols in filamentous and unicellular cyanobacteria

    NARCIS (Netherlands)

    Bauersachs, T.; Schouten, S.; Compaore, J.; Stal, L.J.; Sinninghe Damsté, J.S.

    2010-01-01

    Polyprenols, regular (head-to-tail) isoprenoid alcohols with 7–9 prenyl units, were tentatively identified in several cultivated cyanobacteria. Heptaprenol (C35), octaprenol (C40) and a suite of nonaprenols (C45) were present in unicellular and filamentous non-heterocystous cyanobacteria, while they

  20. Occurrence of C35-C45 polyprenols in filamentous and unicellular cyanobacteria

    NARCIS (Netherlands)

    Bauersachs, T.; Schouten, S.; Compaoré, J.; Stal, L.J.; Sinninghe Damsté, J.S.

    2010-01-01

    Polyprenols, regular (head-to-tail) isoprenoid alcohols with 7-9 prenyl units, were tentatively identified in several cultivated cyanobacteria Heptaprenol (C35), octaprenol (C40) and a suite of nonaprenols (C45) were present in unicellular and filamentous non-heterocystous cyanobacteria, while they

  1. The economics of cyanobacteria-based biofuel production: challenges and opportunities

    NARCIS (Netherlands)

    Sharma, N.K.; Stal, L.J.; Sharma, N.K.; Rai, A.K.; Stal, L.J.

    2014-01-01

    In the current scenario, biofuels based on algae, including cyanobacteria, are expensive, complex to produce, and are only just entering the commercial phase in small quantities in pilot or demonstration plants. This chapter discusses the current scenario of using cyanobacteria for the production of

  2. In silico screening for candidate chassis strains of free fatty acid-producing cyanobacteria

    KAUST Repository

    Motwalli, Olaa Amin; Essack, Magbubah; Jankovic, Boris R.; Ji, Boyang; Liu, Xinyao; Ansari, Hifzur Rahman; Hoehndorf, Robert; Gao, Xin; Arold, Stefan T.; Mineta, Katsuhiko; Archer, John A.C.; Gojobori, Takashi; Mijakovic, Ivan; Bajic, Vladimir B.

    2017-01-01

    To our knowledge FFASC is the first in silico method to screen cyanobacteria proteomes for their potential to produce and excrete FFA, as well as the first attempt to parameterize the criteria derived from genetic characteristics that are favorable/non-favorable for this purpose. Thus, FFASC helps focus experimental evaluation only on the most promising cyanobacteria.

  3. A comparative study on three analytical methods for the determination of the neurotoxin BMAA in cyanobacteria

    NARCIS (Netherlands)

    Faassen, E.J.; Gillissen, F.; Lurling, M.

    2012-01-01

    The cyanobacterial neurotoxin ß-N-methylamino-L-alanine (BMAA) has been considered a serious health threat because of its putative role in multiple neurodegenerative diseases. First reports on BMAA concentrations in cyanobacteria were alarming: nearly all cyanobacteria were assumed to contain high

  4. Cyanobacteria, Toxins and Indicators: Full-Scale Monitoring & Bench-Scale Treatment Studies

    Science.gov (United States)

    Summary of: 1) Lake Erie 2014 bloom season full-scale treatment plant monitoring data for cyanobacteria and cyanobacteria toxins; 2) Follow-up work to examine the impact of pre-oxidation on suspensions of intact toxin-producing cyanobacterial cells.

  5. The Northeast Cyanobacteria Monitoring Program: One Program, Three Opportunities for You To Get Involved!

    Science.gov (United States)

    If you ever have noticed a waterbody with a layer of green scum coating its surface or a slick green film resembling a paint spill, you likely have witnessed a cyanobacteria bloom. Cyanobacteria, sometimes referred to as blue-green algae, are tiny organisms found naturally in aqu...

  6. Local mat-forming cyanobacteria effectively facilitate decontamination of radioactive cesium in rice fields

    International Nuclear Information System (INIS)

    Yamamoto, Atsushi; Yoshida, Shigeru; Okumura, Hiroshi; Inagaki, Masayo; Yamanishi, Hirokuni; Ito, Tetsuo; Furukawa, Michio

    2015-01-01

    The most effective and widespread method to decontaminate radioactive cesium from the Fukushima Daiichi Nuclear Power Plant Disaster was peeling topsoil. But the method had problems, such as large amounts of discarded soil and large-scale work. In nature, cyanobacteria formed biomats on the ground surface and facilitated peeling topsoil when the biomats dried. The cyanobacteria-facilitating peeling decontamination method utilized these cyanobacterial properties. Cyanobacteria are located all over Japan and 'local' cyanobacteria could be used for decontamination without introducing new species. Utilizing cyanobacteria could decrease the amount of discarded soil to about 30% and downsize the execution-scale to individual locations. Cyanobacterial biomats were easily cultivated, especially in rice fields, by maintaining wet conditions and exposure to 100 - 83% solar radiation. Shading by a thin net was helpful in maintaining an environment suitable for cyanobacteria. Nowadays, to prevent uptake of radioactive cesium into rice, K + is usually added to fertilizer in rice fields. The K + fertilization in rice fields might also enhance cyanobacterial capture of radioactive cesium, because high concentrations of K + enhanced cyanobacterial uptake of Cs + . Cyanobacteria could also mitigate the risk of radioactive cesium moving away from a decontaminating rice field. Therefore, the cyanobacteria-facilitating peeling decontamination method was proposed as an easy and safe 'D.I.Y.' method for both farmers and the environment. Besides, plowing rice fields with water before peeling improved the efficiency of this method, because plowing increased the radioactive cesium concentration in the topsoil. (author)

  7. Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.

    Directory of Open Access Journals (Sweden)

    Andrew M Dolman

    Full Text Available The importance of nitrogen (N versus phosphorus (P in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with the hypothesis that potentially N(2-fixing Nostocales taxa would be favoured in low N relative to P conditions. In particular Aphanizomenon gracile and the subtropical invasive species Cylindrospermopsis raciborskii often reached their highest biovolumes in lakes with high nitrogen relative to phosphorus concentration. Concentrations of all cyanotoxin groups increased with increasing TP and TN, congruent with the biovolumes of their likely producers. Microcystin concentration was strongly correlated with the biovolume of Planktothrix agardhii but concentrations of anatoxin, cylindrospermopsin and paralytic shellfish poison were not strongly related to any individual taxa. Cyanobacteria should not be treated as a single group when considering the potential effects of changes in nutrient loading on phytoplankton community structure and neither should the N(2-fixing Nostocales. This is of particular importance when considering the occurrence of cyanotoxins, as the two most abundant potentially toxin producing

  8. Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.

    Science.gov (United States)

    Dolman, Andrew M; Rücker, Jacqueline; Pick, Frances R; Fastner, Jutta; Rohrlack, Thomas; Mischke, Ute; Wiedner, Claudia

    2012-01-01

    The importance of nitrogen (N) versus phosphorus (P) in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with the hypothesis that potentially N(2)-fixing Nostocales taxa would be favoured in low N relative to P conditions. In particular Aphanizomenon gracile and the subtropical invasive species Cylindrospermopsis raciborskii often reached their highest biovolumes in lakes with high nitrogen relative to phosphorus concentration. Concentrations of all cyanotoxin groups increased with increasing TP and TN, congruent with the biovolumes of their likely producers. Microcystin concentration was strongly correlated with the biovolume of Planktothrix agardhii but concentrations of anatoxin, cylindrospermopsin and paralytic shellfish poison were not strongly related to any individual taxa. Cyanobacteria should not be treated as a single group when considering the potential effects of changes in nutrient loading on phytoplankton community structure and neither should the N(2)-fixing Nostocales. This is of particular importance when considering the occurrence of cyanotoxins, as the two most abundant potentially toxin producing Nostocales in our study

  9. Subcellular distribution of glutathione and cysteine in cyanobacteria.

    Science.gov (United States)

    Zechmann, Bernd; Tomasić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-10-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine, glutamate, and glycine. Cysteine is the limiting factor for glutathione biosynthesis which can be especially crucial for cyanobacteria, which rely on both the sufficient sulfur supply from the growth media and on the protection of glutathione against ROS that are produced during photosynthesis. In this study, we report a method that allows detection and visualization of the subcellular distribution of glutathione in Synechocystis sp. This method is based on immunogold cytochemistry with glutathione and cysteine antisera and computer-supported transmission electron microscopy. Labeling of glutathione and cysteine was restricted to the cytosol and interthylakoidal spaces. Glutathione and cysteine could not be detected in carboxysomes, cyanophycin granules, cell walls, intrathylakoidal spaces, periplasm, and vacuoles. The accuracy of the glutathione and cysteine labeling is supported by two observations. First, preadsorption of the antiglutathione and anticysteine antisera with glutathione and cysteine, respectively, reduced the density of the gold particles to background levels. Second, labeling of glutathione and cysteine was strongly decreased by 98.5% and 100%, respectively, in Synechocystis sp. cells grown on media without sulfur. This study indicates a strong similarity of the subcellular distribution of glutathione and cysteine in cyanobacteria and plastids of plants and provides a deeper insight into glutathione metabolism in bacteria.

  10. Biogeochemical Activity of Siderophilic Cyanobacteria: Implications for Paleobiogeochemistry

    Science.gov (United States)

    Brown, Igor I.; Sarkisova, Svetlana A.; Auyeung, Weng S.; Garrison, Dan; Allen, Carlton C.; McKay, David S.

    2007-01-01

    Understanding the patterns of iron oxidation by cyanobacteria (CB) has tremendous importance for paleobiogeochemistry, since cyanobacteria are presumed to have been involved in the global oxidation of ferrous iron during the Precambrian (Cloud, 1973). B.K. Pierson (1999, 2000) first proposed to study iron deposition in iron-depositing hot springs (ID HS) as a model for Precambrian Fe(2+) oxidation. However, neither the iron-dependent physiology of individual species of CB inhabiting iron-depositing hot springs nor their interactions with minerals enriched with iron have been examined thoroughly. Such study could shed light on ancient iron turnover. Cyanobacterial species isolated from ID HS demonstrate elevated tolerance to colloidal Fe(3+) (= 1 mM), while a concentration of 0.4 mM proved toxic for mesophilic Synechocystis PCC 6803. Isolates from ID HS require 0.4-0.6 mM Fe3+ for maximal growth while the iron requirement for Synechocystis is approximately one order of magnitude lower. We have also demonstrated that thick polysaccharide sheaths around cells of CB isolated from ID HS serve as repositories for precipitated iron. The growth of the mesophilic cyanobacteria Phromidium aa in iron-saturated (0.6 mM) DH medium did not lead to iron precipitation on its filament surfaces. However, a 14.3 fil.2 culture, isolated from an ID HS and incubated under the same conditions, was covered with dense layer of precipitated iron. Our results, taken together with Pierson s data concerning the ability of Fe2+ to stimulate photosynthesis in natural CB mats in ID HS, suggest that CB inhabiting ID HS may constitute a new group of the extremophiles - siderophilic CB. Our recent experiments have revealed for the first time that CB isolates from ID HS are also capable of biodeterioration - the etching of minerals, in particular glasses enriched with Fe, Al, Ti, O, and Si. Thus, Precambrian siderophilic cyanobacteria and their predecessors could have been involved not only in iron

  11. Variability of Chroococcus (Cyanobacteria) morphospecies with regard to phylogenetic relationships

    Czech Academy of Sciences Publication Activity Database

    Komárková, Jaroslava; Jezberová, Jitka; Komárek, Ondřej; Zapomělová, Eliška

    2010-01-01

    Roč. 639, č. 1 (2010), s. 69-83 ISSN 0018-8158. [Workshop of the International Association of Phytoplankton Taxonomy and Ecology /15./. Ramot, 23.10.2008-30.10.2008] R&D Projects: GA ČR(CZ) GA206/09/0309; GA ČR(CZ) GA206/07/0917 Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z50200510 Keywords : morphological variability * Cyanobacteria * reservoirs Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.964, year: 2010

  12. Zernike phase-contrast electron cryotomography applied to marine cyanobacteria infected with cyanophages.

    Science.gov (United States)

    Dai, Wei; Fu, Caroline; Khant, Htet A; Ludtke, Steven J; Schmid, Michael F; Chiu, Wah

    2014-11-01

    Advances in electron cryotomography have provided new opportunities to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase-contrast optics produces images with markedly increased contrast compared with images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods for obtaining 3D structures of cyanophage assembly intermediates in the host by subtomogram alignment, classification and averaging. Acquiring three or four tomographic tilt series takes ∼12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. The time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume.

  13. Zernike Phase Contrast Electron Cryo-Tomography Applied to Marine Cyanobacteria Infected with Cyanophages

    Science.gov (United States)

    Dai, Wei; Fu, Caroline; Khant, Htet A.; Ludtke, Steven J.; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Advances in electron cryo-tomography have provided a new opportunity to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase contrast optics produces images with dramatically increased contrast compared to images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods to obtain 3D structures of cyanophage assembly intermediates in the host, by subtomogram alignment, classification and averaging. Acquiring three to four tomographic tilt series takes approximately 12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. Time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume. PMID:25321408

  14. Precipitation of iron in windopane oyster shells by marine shell-boring cyanobacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Rao, V.P.; Iyer, S.D.

    filaments encrusted with black precipitate. Microchemical test (Prussian blue reaction) and wavelength dispersive x-ray analysis confirmed this precipitate to be of iron. Mineralogical studies of this black precipitate, using x-ray diffraction and scanning...

  15. Otters, Marine

    Science.gov (United States)

    Estes, James A.; Bodkin, James L.; Ben-David, M.; Perrin, William F.; Würsing, Bernd; Thewissen, J.G.M.

    2009-01-01

    The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates from freshwater habitats and some species still live in both environments. Contrasts among species within the otters, and among the otters, terrestrial mammals, and the more highly adapted pinnipeds and cetaceans provide powerful insights into mammalian adaptations to life in the sea (Estes, 1989). Among the marine mammals, sea otters (Enhydra lutris, Fig. 1) provide the clearest understanding of consumer-induced effects on ecosystem function. This is due in part to opportunities provided by history and in part to the relative ease with which shallow coastal systems where sea otters live can be observed and studied. Although more difficult to study than sea otters, other otter species reveal the connectivity among the marine, freshwater, and terrestrial systems. These three qualities of the otters – their comparative biology, their role as predators, and their role as agents of ecosystem connectivity – are what make them interesting to marine mammalogy.The following account provides a broad overview of the comparative biology and ecology of the otters, with particular emphasis on those species or populations that live in the sea. Sea otters are features prominently, in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments (Kenyon, 1969; Riedman and Estes, 1990).

  16. Antitumor activity of hierridin B, a cyanobacterial secondary metabolite found in both filamentous and unicellular marine strains.

    Directory of Open Access Journals (Sweden)

    Pedro N Leão

    Full Text Available Cyanobacteria are widely recognized as a valuable source of bioactive metabolites. The majority of such compounds have been isolated from so-called complex cyanobacteria, such as filamentous or colonial forms, which usually display a larger number of biosynthetic gene clusters in their genomes, when compared to free-living unicellular forms. Nevertheless, picocyanobacteria are also known to have potential to produce bioactive natural products. Here, we report the isolation of hierridin B from the marine picocyanobacterium Cyanobium sp. LEGE 06113. This compound had previously been isolated from the filamentous epiphytic cyanobacterium Phormidium ectocarpi SAG 60.90, and had been shown to possess antiplasmodial activity. A phylogenetic analysis of the 16S rRNA gene from both strains confirmed that these cyanobacteria derive from different evolutionary lineages. We further investigated the biological activity of hierridin B, and tested its cytotoxicity towards a panel of human cancer cell lines; it showed selective cytotoxicity towards HT-29 colon adenocarcinoma cells.

  17. Marine Battlefields

    DEFF Research Database (Denmark)

    Harðardóttir, Sara

    as they are an important food source for various marine animals. For both phytoand zooplankton predation is a major cause of mortality, and strategies for protection or avoidance are important for survival. Diatoms of the genera Nitzschia and Pseudo-nitzschia are known to produce a neuro-toxin, domoic acid (DA). Despite......Phytoplankton species are photosynthetic organisms found in most aquatic habitats. In the ocean, phytoplankton are tremendously important because they produce the energy that forms the base of the marine food web. Zooplankton feed on phytoplankton and mediate the energy to higher trophic levels...

  18. Phylogeny and Biogeography of Cyanobacteria and Their Produced Toxins

    Directory of Open Access Journals (Sweden)

    Agostinho Antunes

    2013-11-01

    Full Text Available Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.

  19. Phylogeny and Biogeography of Cyanobacteria and Their Produced Toxins

    Science.gov (United States)

    Moreira, Cristiana; Vasconcelos, Vitor; Antunes, Agostinho

    2013-01-01

    Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins. PMID:24189276

  20. Sustainable life support on Mars - the potential roles of cyanobacteria

    Science.gov (United States)

    Verseux, Cyprien; Baqué, Mickael; Lehto, Kirsi; de Vera, Jean-Pierre P.; Rothschild, Lynn J.; Billi, Daniela

    2016-01-01

    Even though technological advances could allow humans to reach Mars in the coming decades, launch costs prohibit the establishment of permanent manned outposts for which most consumables would be sent from Earth. This issue can be addressed by in situ resource utilization: producing part or all of these consumables on Mars, from local resources. Biological components are needed, among other reasons because various resources could be efficiently produced only by the use of biological systems. But most plants and microorganisms are unable to exploit Martian resources, and sending substrates from Earth to support their metabolism would strongly limit the cost-effectiveness and sustainability of their cultivation. However, resources needed to grow specific cyanobacteria are available on Mars due to their photosynthetic abilities, nitrogen-fixing activities and lithotrophic lifestyles. They could be used directly for various applications, including the production of food, fuel and oxygen, but also indirectly: products from their culture could support the growth of other organisms, opening the way to a wide range of life-support biological processes based on Martian resources. Here we give insights into how and why cyanobacteria could play a role in the development of self-sustainable manned outposts on Mars.

  1. Cyanobacteria perceive nitrogen status by sensing intracellular 2-oxoglutarate levels.

    Science.gov (United States)

    Muro-Pastor, M I; Reyes, J C; Florencio, F J

    2001-10-12

    The regulatory circuits that control nitrogen metabolism are relatively well known in several bacterial model groups. However, much less is understood about how the nitrogen status of the cell is perceived in vivo. In cyanobacteria, the transcription factor NtcA is required for regulation (activation or repression) of an extensive number of genes involved in nitrogen metabolism. In contrast, how NtcA activity is regulated is largely unknown. Assimilation of ammonium by most microorganisms occurs through the sequential action of two enzymes: glutamine synthetase (GS) and glutamate synthase. Interestingly, regulation of the expression of NtcA-dependent genes in the cyanobacterium Synechocystis sp. PCC 6803 is altered in mutants with modified levels of GS activity. Two types of mutants were analyzed: glnA null mutants that lack GS type I and gif mutants unable to inactivate GS in the presence of ammonium. Changes in the intracellular pools of 19 different amino acids and the keto acid 2-oxoglutarate were recorded in wild-type and mutant strains under different nitrogen conditions. Our data strongly indicate that the nitrogen status in cyanobacteria is perceived as changes in the intracellular 2-oxoglutarate pool.

  2. Enhanced limonene production in cyanobacteria reveals photosynthesis limitations.

    Science.gov (United States)

    Wang, Xin; Liu, Wei; Xin, Changpeng; Zheng, Yi; Cheng, Yanbing; Sun, Su; Li, Runze; Zhu, Xin-Guang; Dai, Susie Y; Rentzepis, Peter M; Yuan, Joshua S

    2016-12-13

    Terpenes are the major secondary metabolites produced by plants, and have diverse industrial applications as pharmaceuticals, fragrance, solvents, and biofuels. Cyanobacteria are equipped with efficient carbon fixation mechanism, and are ideal cell factories to produce various fuel and chemical products. Past efforts to produce terpenes in photosynthetic organisms have gained only limited success. Here we engineered the cyanobacterium Synechococcus elongatus PCC 7942 to efficiently produce limonene through modeling guided study. Computational modeling of limonene flux in response to photosynthetic output has revealed the downstream terpene synthase as a key metabolic flux-controlling node in the MEP (2-C-methyl-d-erythritol 4-phosphate) pathway-derived terpene biosynthesis. By enhancing the downstream limonene carbon sink, we achieved over 100-fold increase in limonene productivity, in contrast to the marginal increase achieved through stepwise metabolic engineering. The establishment of a strong limonene flux revealed potential synergy between photosynthate output and terpene biosynthesis, leading to enhanced carbon flux into the MEP pathway. Moreover, we show that enhanced limonene flux would lead to NADPH accumulation, and slow down photosynthesis electron flow. Fine-tuning ATP/NADPH toward terpene biosynthesis could be a key parameter to adapt photosynthesis to support biofuel/bioproduct production in cyanobacteria.

  3. Biosynthesis of anatoxin-a and analogues (anatoxins) in cyanobacteria.

    Science.gov (United States)

    Méjean, Annick; Paci, Guillaume; Gautier, Valérie; Ploux, Olivier

    2014-12-01

    Freshwater cyanobacteria produce secondary metabolites that are toxic to humans and animals, the so-called cyanotoxins. Among them, anatoxin-a and homoanatoxin-a are potent neurotoxins that are agonists of the nicotinic acetylcholine receptor. These alkaloids provoke a rapid death if ingested at low doses. Recently, the cluster of genes responsible for the biosynthesis of these toxins, the ana cluster, has been identified in Oscillatoria sp. PCC 6506, and a biosynthetic pathway was proposed. This biosynthesis was reconstituted in vitro using purified enzymes confirming the predicted pathway. One of the enzymes, AnaB a prolyl-acyl carrier protein oxidase, was crystallized and its three dimensional structure solved confirming its reaction mechanism. Three other ana clusters have now been identified and sequenced in other cyanobacteria. These clusters show similarities and some differences suggesting a common evolutionary origin. In particular, the cluster from Cylindrospermum stagnale PCC 7417, possesses an extra gene coding for an F420-dependent oxidoreductase that is likely involved in the biosynthesis of dihydroanatoxin-a. This review summarizes all these new data and discusses them in relation to the production of anatoxins in the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Marine Science

    African Journals Online (AJOL)

    Science. The journal has a new and more modern layout, published online only, and the editorial. Board was increased to include more disciplines pertaining to marine sciences. While important chal- lenges still lie ahead, we are steadily advancing our standard to increase visibility and dissemination throughout the global ...

  5. Marine Mammals.

    Science.gov (United States)

    Meith, Nikki

    Marine mammals have not only fascinated and inspired human beings for thousands of years, but they also support a big business by providing flesh for sea-borne factories, sustaining Arctic lifestyles and traditions, and attracting tourists to ocean aquaria. While they are being harpooned, bludgeoned, shot, netted, and trained to jump through…

  6. Marine Science

    African Journals Online (AJOL)

    Mauritius Marine Conservation Society through their. Abstract. While no populations of seals are resident in the tropical Indian Ocean, vagrant animals are occasionally sighted in the region. Here we detail two new sightings of pinnipeds in the Mascarene Islands (Mauritius, Reunion and Rodri- gues) since 1996 and review ...

  7. Marine Science

    African Journals Online (AJOL)

    J O U R N A L O F. Marine Science. Coral reefs of Mauritius in a changing global climate ..... in confined aquifers, and a lesser influence in uncon- fined systems. On the ... massive cloud cover during the critical months, some. 70% bleaching ...

  8. Marine Science

    African Journals Online (AJOL)

    Copy Editor Timothy Andrew. Published ... 2007; Zhou et al., 2009) and they play an important role in the ... At both sites, zonal variation in TMPB was evident with significantly higher C-biomass closer to ... ton is considered to be an essential parameter in eco- systems ...... logical significance of toxic marine dinoflagellates.

  9. Marine Science

    African Journals Online (AJOL)

    sustainable coastal development in the region, as well as contributing to the ... between humans and the coastal and marine environment. ... exploitation for timber, fuel wood, aquaculture, urban. Abstract. Given the high dependence of coastal communities on natural resources, mangrove conservation is a challenge in.

  10. Marine Science

    African Journals Online (AJOL)

    No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means ... USA/Norway ... The last couple of years have been a time of change for the Western Indian Ocean Journal of Marine.

  11. Marine Science

    African Journals Online (AJOL)

    Chief Editor José Paula | Faculty of Sciences of University of Lisbon, Portugal. Copy Editor Timothy Andrew. Published biannually. Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high quality research generated in the Western Indian Ocean (WIO) ...

  12. Supplementary Material for: In silico screening for candidate chassis strains of free fatty acid-producing cyanobacteria

    KAUST Repository

    Motwalli, Olaa Amin

    2017-01-01

    Abstract Background Finding a source from which high-energy-density biofuels can be derived at an industrial scale has become an urgent challenge for renewable energy production. Some microorganisms can produce free fatty acids (FFA) as precursors towards such high-energy-density biofuels. In particular, photosynthetic cyanobacteria are capable of directly converting carbon dioxide into FFA. However, current engineered strains need several rounds of engineering to reach the level of production of FFA to be commercially viable; thus new chassis strains that require less engineering are needed. Although more than 120 cyanobacterial genomes are sequenced, the natural potential of these strains for FFA production and excretion has not been systematically estimated. Results Here we present the FFA SC (FFASC), an in silico screening method that evaluates the potential for FFA production and excretion of cyanobacterial strains based on their proteomes. A literature search allowed for the compilation of 64 proteins, most of which influence FFA production and a few of which affect FFA excretion. The proteins are classified into 49 orthologous groups (OGs) that helped create rules used in the scoring/ranking of algorithms developed to estimate the potential for FFA production and excretion of an organism. Among 125 cyanobacterial strains, FFASC identified 20 candidate chassis strains that rank in their FFA producing and excreting potential above the specifically engineered reference strain, Synechococcus sp. PCC 7002. We further show that the top ranked cyanobacterial strains are unicellular and primarily include Prochlorococcus (order Prochlorales) and marine Synechococcus (order Chroococcales) that cluster phylogenetically. Moreover, two principal categories of enzymes were shown to influence FFA production the most: those ensuring precursor availability for the biosynthesis of lipids, and those involved in handling the oxidative stress associated to FFA synthesis

  13. The Green Berry Consortia of the Sippewissett Salt Marsh: Millimeter-Sized Aggregates of Diazotrophic Unicellular Cyanobacteria.

    Science.gov (United States)

    Wilbanks, Elizabeth G; Salman-Carvalho, Verena; Jaekel, Ulrike; Humphrey, Parris T; Eisen, Jonathan A; Buckley, Daniel H; Zinder, Stephen H

    2017-01-01

    Microbial interactions driving key biogeochemical fluxes often occur within multispecies consortia that form spatially heterogeneous microenvironments. Here, we describe the "green berry" consortia of the Sippewissett salt marsh (Falmouth, MA, United States): millimeter-sized aggregates dominated by an uncultured, diazotrophic unicellular cyanobacterium of the order Chroococcales (termed GB-CYN1). We show that GB-CYN1 is closely related to Crocosphaera watsonii (UCYN-B) and " Candidatus Atelocyanobacterium thalassa" (UCYN-A), two groups of unicellular diazotrophic cyanobacteria that play an important role in marine primary production. Other green berry consortium members include pennate diatoms and putative heterotrophic bacteria from the Alphaproteobacteria and Bacteroidetes . Tight coupling was observed between photosynthetic oxygen production and heterotrophic respiration. When illuminated, the green berries became supersaturated with oxygen. From the metagenome, we observed that GB-CYN1 encodes photosystem II genes and thus has the metabolic potential for oxygen production unlike UCYN-A. In darkness, respiratory activity rapidly depleted oxygen creating anoxia within the aggregates. Metagenomic data revealed a suite of nitrogen fixation genes encoded by GB-CYN1, and nitrogenase activity was confirmed at the whole-aggregate level by acetylene reduction assays. Metagenome reads homologous to marker genes for denitrification were observed and suggest that heterotrophic denitrifiers might co-occur in the green berries, although the physiology and activity of facultative anaerobes in these aggregates remains uncharacterized. Nitrogen fixation in the surface ocean was long thought to be driven by filamentous cyanobacterial aggregates, though recent work has demonstrated the importance of unicellular diazotrophic cyanobacteria (UCYN) from the order Chroococcales. The green berries serve as a useful contrast to studies of open ocean UCYN and may provide a tractable

  14. Immense essence of excellence: marine microbial bioactive compounds.

    Science.gov (United States)

    Bhatnagar, Ira; Kim, Se-Kwon

    2010-10-15

    Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms) that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic) and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin) or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery.

  15. Immense Essence of Excellence: Marine Microbial Bioactive Compounds

    Directory of Open Access Journals (Sweden)

    Ira Bhatnagar

    2010-10-01

    Full Text Available Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery.

  16. Unscrambling cyanobacteria community dynamics related to environmental factors

    Directory of Open Access Journals (Sweden)

    Mireia eBertos-Fortis

    2016-05-01

    Full Text Available Future climate scenarios in the Baltic Sea project an increase of cyanobacterial bloom frequency and duration, attributed to eutrophication and climate change. Some cyanobacteria can be toxic and their impact on ecosystem services is relevant for a sustainable sea. Yet, there is limited understanding of the mechanisms regulating cyanobacterial diversity and biogeography. Here we unravel successional patterns and changes in cyanobacterial community structure using a two-year monthly time-series during the productive season in a 100 km coastal-offshore transect using microscopy and high-throughput sequencing of 16S rRNA gene fragments. A total of 565 cyanobacterial OTUs were found, of which 231 where filamentous/colonial and 334 picocyanobacterial. Spatial differences in community structure between coastal and offshore waters were minor. An epidemic population structure (dominance of a single cluster was found for Aphanizomenon/Dolichospermum within the filamentous/colonial cyanobacterial community. In summer, this cluster simultaneously occurred with opportunistic clusters/OTUs e.g. Nodularia spumigena and Pseudanabaena. Picocyanobacteria, Synechococcus/Cyanobium, formed a consistent but highly diverse group. Overall, the potential drivers structuring summer cyanobacterial communities were temperature and salinity. However, the different responses to environmental factors among and within genera suggest high niche specificity for individual OTUs. The recruitment and occurrence of potentially toxic filamentous/colonial clusters was likely related to disturbance such as mixing events and short-term shifts in salinity, and not solely dependent on increasing temperature and nitrogen-limiting conditions. Nutrients did not explain further the changes in cyanobacterial community composition. Novel occurrence patterns were identified as a strong seasonal succession revealing a tight coupling between the emergence of opportunistic picocyanobacteria and

  17. Renewable energy from Cyanobacteria: energy production optimization by metabolic pathway engineering.

    Science.gov (United States)

    Quintana, Naira; Van der Kooy, Frank; Van de Rhee, Miranda D; Voshol, Gerben P; Verpoorte, Robert

    2011-08-01

    The need to develop and improve sustainable energy resources is of eminent importance due to the finite nature of our fossil fuels. This review paper deals with a third generation renewable energy resource which does not compete with our food resources, cyanobacteria. We discuss the current state of the art in developing different types of bioenergy (ethanol, biodiesel, hydrogen, etc.) from cyanobacteria. The major important biochemical pathways in cyanobacteria are highlighted, and the possibility to influence these pathways to improve the production of specific types of energy forms the major part of this review.

  18. A novel lineage of myoviruses infecting cyanobacteria is widespread in the oceans.

    Science.gov (United States)

    Sabehi, Gazalah; Shaulov, Lihi; Silver, David H; Yanai, Itai; Harel, Amnon; Lindell, Debbie

    2012-02-07

    Viruses infecting bacteria (phages) are thought to greatly impact microbial population dynamics as well as the genome diversity and evolution of their hosts. Here we report on the discovery of a novel lineage of tailed dsDNA phages belonging to the family Myoviridae and describe its first representative, S-TIM5, that infects the ubiquitous marine cyanobacterium, Synechococcus. The genome of this phage encodes an entirely unique set of structural proteins not found in any currently known phage, indicating that it uses lineage-specific genes for virion morphogenesis and represents a previously unknown lineage of myoviruses. Furthermore, among its distinctive collection of replication and DNA metabolism genes, it carries a mitochondrial-like DNA polymerase gene, providing strong evidence for the bacteriophage origin of the mitochondrial DNA polymerase. S-TIM5 also encodes an array of bacterial-like metabolism genes commonly found in phages infecting cyanobacteria including photosynthesis, carbon metabolism and phosphorus acquisition genes. This suggests a common gene pool and gene swapping of cyanophage-specific genes among different phage lineages despite distinct sets of structural and replication genes. All cytosines following purine nucleotides are methylated in the S-TIM5 genome, constituting a unique methylation pattern that likely protects the genome from nuclease degradation. This phage is abundant in the Red Sea and S-TIM5 gene homologs are widespread in the oceans. This unusual phage type is thus likely to be an important player in the oceans, impacting the population dynamics and evolution of their primary producing cyanobacterial hosts.

  19. The state of autotrophic ethanol production in Cyanobacteria.

    Science.gov (United States)

    Dexter, J; Armshaw, P; Sheahan, C; Pembroke, J T

    2015-07-01

    Ethanol production directly from CO2 , utilizing genetically engineered photosynthetic cyanobacteria as a biocatalyst, offers significant potential as a renewable and sustainable source of biofuel. Despite the current absence of a commercially successful production system, significant resources have been deployed to realize this goal. Utilizing the pyruvate decarboxylase from Zymomonas species, metabolically derived pyruvate can be converted to ethanol. This review of both peer-reviewed and patent literature focuses on the genetic modifications utilized for metabolic engineering and the resultant effect on ethanol yield. Gene dosage, induced expression and cassette optimizat-ion have been analyzed to optimize production, with production rates of 0·1-0·5 g L(-1) day(-1) being achieved. The current 'toolbox' of molecular manipulations and future directions focusing on applicability, addressing the primary challenges facing commercialization of cyanobacterial technologies are discussed. © 2015 The Society for Applied Microbiology.

  20. Engineering cyanobacteria to generate high-value products.

    Science.gov (United States)

    Ducat, Daniel C; Way, Jeffrey C; Silver, Pamela A

    2011-02-01

    Although many microorganisms have been used for the bioindustrial generation of valuable metabolites, the productive potential of cyanobacterial species has remained largely unexplored. Cyanobacteria possess several advantages as organisms for bioindustrial processes, including simple input requirements, tolerance of marginal agricultural environments, rapid genetics, and carbon-neutral applications that could be leveraged to address global climate change concerns. Here, we review recent research involving the engineering of cyanobacterial species for the production of valuable bioindustrial compounds, including natural cyanobacterial products (e.g. sugars and isoprene), biofuels (e.g. alcohols, alkanes and hydrogen), and other commodity chemicals. Biological and economic obstacles to scaled cyanobacterial production are highlighted, and methods for increasing cyanobacterial production efficiencies are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Toward solar biodiesel production from CO2 using engineered cyanobacteria.

    Science.gov (United States)

    Woo, Han Min; Lee, Hyun Jeong

    2017-05-01

    Metabolic engineering of cyanobacteria has received attention as a sustainable strategy to convert carbon dioxide to various biochemicals including fatty acid-derived biodiesel. Recently, Synechococcus elongatus PCC 7942, a model cyanobacterium, has been engineered to convert CO2 to fatty acid ethyl esters (FAEEs) as biodiesel. Modular pathway has been constructed for FAEE production. Several metabolic engineering strategies were discussed to improve the production levels of FAEEs, including host engineering by improving CO2 fixation rate and photosynthetic efficiency. In addition, protein engineering of key enzyme in S. elongatus PCC 7942 was implemented to address issues on FAEE secretions toward sustainable FAEE production from CO2. Finally, advanced metabolic engineering will promote developing biosolar cell factories to convert CO2 to feasible amount of FAEEs toward solar biodiesel. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Engineering cyanobacteria for direct biofuel production from CO2.

    Science.gov (United States)

    Savakis, Philipp; Hellingwerf, Klaas J

    2015-06-01

    For a sustainable future of our society it is essential to close the global carbon cycle. Oxidised forms of carbon, in particular CO2, can be used to synthesise energy-rich organic molecules. Engineered cyanobacteria have attracted attention as catalysts for the direct conversion of CO2 into reduced fuel compounds. Proof of principle for this approach has been provided for a vast range of commodity chemicals, mostly energy carriers, such as short chain and medium chain alcohols. More recently, research has focused on the photosynthetic production of compounds with higher added value, most notably terpenoids. Below we review the recent developments that have improved the state-of-the-art of this approach and speculate on future developments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Biodegradation and Utilization of Organophosphorus Pesticide Malathion by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Wael M. Ibrahim

    2014-01-01

    Full Text Available Three strains of filamentous Cyanobacteria were used to study their growth and utilization of organophosphorus pesticide malathion. A sharp decrease in the growth of the algal strains was observed by increasing the concentration of malathion. Amongst them Nostoc muscorum tolerated different concentrations and was recorded as the highest efficient strain for biodegradation (91% of this compound. Moreover, carbohydrate and protein content of their cells overtopped the other strains especially at higher concentrations. The algal strains were further subjected to grow under P-limitation in absence and presence of malathion. Although, the algal growth under P-limitation recorded a very poor level, a massive enhanced growth and phosphorous content of cells were obtained when the P-limited medium was amended with malathion. This study clarified that N. muscorum with its capability to utilize malathion as a sole phosphorous source is considered as an inexpensive and efficient biotechnology for remediation of organophosphorus pesticide from contaminated wastewater.

  4. Cyanobacteria Assessment Network (CyAN) - 2017 NASA ...

    Science.gov (United States)

    Presentation on the Cyanobacteria Assessment Network (CYAN) and how is supports the environmental management and public use of the U.S. lakes and estuaries by providing a capability of detecting and quantifying algal blooms and related water quality using satellite data records. To be presented to the NASA Science Mission Directorate Earth Science Division Applied Sciences Program at the NASA Water Resources PI Meeting. The meeting had over 65 attendees, including currently funded PIs, participants from Western States Water Council, UCAR, California Department of Water Resources, and Navajo Nation. Some highlights from the meeting included discussions around impact assessment, with a session moderated by VALUABLES as well as a water manager needs panel, lead by WWAO. Each PI presentation also included lessons learned about how to work in applied sciences, ensure partner engagement, and pave the path towards transition.

  5. UV-inducible DNA repair in the cyanobacteria Anabaena spp

    International Nuclear Information System (INIS)

    Levine, E.; Thiel, T.

    1987-01-01

    Strains of the filamentous cyanobacteria Anabaena spp. were capable of very efficient photoreactivation of UV irradiation-induced damage to DNA. Cells were resistant to several hundred joules of UV irradiation per square meter under conditions that allowed photoreactivation, and they also photoreactivated UV-damaged cyanophage efficiently. Reactivation of UV-irradiated cyanophage (Weigle reactivation) also occurred; UV irradiation of host cells greatly enhanced the plaque-forming ability of irradiated phage under nonphotoreactivating conditions. Postirradiation incubation of the host cells under conditions that allowed photoreactivation abolished the ability of the cells to perform Weigle reactivation of cyanophage N-1. Mitomycin C also induced Weigle reactivation of cyanophage N-1, but nalidixic acid did not. The inducible repair system (defined as the ability to perform Weigle reactivation of cyanophages) was relatively slow and inefficient compared with photoreactivation

  6. Metabolic Compensation and Circadian Resilience in Prokaryotic Cyanobacteria

    Science.gov (United States)

    Johnson, Carl Hirschie; Egli, Martin

    2014-01-01

    For a biological oscillator to function as a circadian pacemaker that confers a fitness advantage, its timing functions must be stable in response to environmental and metabolic fluctuations. One such stability enhancer, temperature compensation, has long been a defining characteristic of these timekeepers. However, an accurate biological timekeeper must also resist changes in metabolism, and this review suggests that temperature compensation is actually a subset of a larger phenomenon, namely metabolic compensation, which maintains the frequency of circadian oscillators in response to a host of factors that impinge on metabolism and would otherwise destabilize these clocks. The circadian system of prokaryotic cyanobacteria is an illustrative model because it is composed of transcriptional and nontranscriptional oscillators that are coupled to promote resilience. Moreover, the cyanobacterial circadian program regulates gene activity and metabolic pathways, and it can be manipulated to improve the expression of bioproducts that have practical value. PMID:24905782

  7. Photosynthetic production of diterpenoids in chloroplasts and cyanobacteria

    DEFF Research Database (Denmark)

    Vavitsas, Konstantinos

    Terpenoids are one of the largest classes of chemical compounds, some of them with industrial interest as nutraceuticals, biofuels, or chemical feedstocks. Diterpenoids are a large terpenoid subclass, and their chemical structure consists of a core skeleton of 20 carbon atoms. This skeleton can...... be further modified by cyclizing enzymes, and be decorated by the addition of chemical groups. Even though they are mainly plant-derived compounds, diterpenoid production in photosynthetic organisms is rather unexplored, with a few successful studies reported in the literature. In this thesis, I elaborate...... on the potential of using plant chloroplasts and cyanobacteria as biosynthetic vessels, with a focus on diterpenoid production, and on the potential direct linking of photosynthesis to drive electron-consuming enzymes, such as the monooxygenases cytochrome P450s. I subsequently present the full localization...

  8. Control of cytokinin and auxin homeostasis in cyanobacteria and algae

    Czech Academy of Sciences Publication Activity Database

    Žižková, Eva; Kubeš, Martin; Dobrev, Petre; Přibyl, Pavel; Šimura, J.; Zahajská, Lenka; Záveská Drábková, Lenka; Novák, Ondřej; Motyka, Václav

    2017-01-01

    Roč. 119, č. 1 (2017), s. 151-166 ISSN 0305-7364 R&D Projects: GA ČR(CZ) GA16-14649S; GA ČR GA15-22322S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 ; RVO:67985939 Keywords : solid-phase extraction * performance liquid-chromatography * yucca flavin monooxygenases * tandem mass-spectrometry * abscisic-acid * arabidopsis-thaliana * indole-3-acetic-acid iaa * endogenous cytokinins * chlorella-vulgaris * phenylacetic acid * Cytokinin * auxin * cyanobacteria * algae * metabolism * cytokinin oxidase/dehydrogenase * cytokinin 2-methylthioderivatives * trans-zeatin * indole-3-acetic acid * tRNA Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 4.041, year: 2016

  9. Challenges for mapping cyanotoxin patterns from remote sensing of cyanobacteria

    Science.gov (United States)

    Stumpf, Rick P; Davis, Timothy W.; Wynne, Timothy T.; Graham, Jennifer L.; Loftin, Keith A.; Johengen, T.H.; Gossiaux, D.; Palladino, D.; Burtner, A.

    2016-01-01

    Using satellite imagery to quantify the spatial patterns of cyanobacterial toxins has several challenges. These challenges include the need for surrogate pigments – since cyanotoxins cannot be directly detected by remote sensing, the variability in the relationship between the pigments and cyanotoxins – especially microcystins (MC), and the lack of standardization of the various measurement methods. A dual-model strategy can provide an approach to address these challenges. One model uses either chlorophyll-a (Chl-a) or phycocyanin (PC) collected in situ as a surrogate to estimate the MC concentration. The other uses a remote sensing algorithm to estimate the concentration of the surrogate pigment. Where blooms are mixtures of cyanobacteria and eukaryotic algae, PC should be the preferred surrogate to Chl-a. Where cyanobacteria dominate, Chl-a is a better surrogate than PC for remote sensing. Phycocyanin is less sensitive to detection by optical remote sensing, it is less frequently measured, PC laboratory methods are still not standardized, and PC has greater intracellular variability. Either pigment should not be presumed to have a fixed relationship with MC for any water body. The MC-pigment relationship can be valid over weeks, but have considerable intra- and inter-annual variability due to changes in the amount of MC produced relative to cyanobacterial biomass. To detect pigments by satellite, three classes of algorithms (analytic, semi-analytic, and derivative) have been used. Analytical and semi-analytical algorithms are more sensitive but less robust than derivatives because they depend on accurate atmospheric correction; as a result derivatives are more commonly used. Derivatives can estimate Chl-a concentration, and research suggests they can detect and possibly quantify PC. Derivative algorithms, however, need to be standardized in order to evaluate the reproducibility of parameterizations between lakes. A strategy for producing useful estimates

  10. Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

    International Nuclear Information System (INIS)

    Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R.

    2014-01-01

    In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

  11. Alkane biosynthesis genes in cyanobacteria and their transcriptional organization

    Directory of Open Access Journals (Sweden)

    Stephan eKlähn

    2014-07-01

    Full Text Available In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl-acyl carrier protein reductase (AAR and aldehyde deformylating oxygenase (ADO. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado and sll0209 (aar, that give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313 and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in

  12. Light influences cytokinin biosynthesis and sensing in Nostoc (cyanobacteria).

    Science.gov (United States)

    Frébortová, Jitka; Plíhal, Ondřej; Florová, Vendula; Kokáš, Filip; Kubiasová, Karolina; Greplová, Marta; Šimura, Jan; Novák, Ondřej; Frébort, Ivo

    2017-06-01

    Cytokinins are an important group of plant hormones that are also found in other organisms, including cyanobacteria. While various aspects of cytokinin function and metabolism are well understood in plants, the information is limited for cyanobacteria. In this study, we first experimentally confirmed a prenylation of tRNA by recombinant isopentenyl transferase NoIPT2 from Nostoc sp. PCC 7120, whose encoding gene we previously identified in Nostoc genome along with the gene for adenylate isopentenyl transferase NoIPT1. In contrast to NoIPT2, the transcription of NoIPT1 was strongly activated during the dark period and was followed by an increase in the cytokinin content several hours later in the light period. Dominant cytokinin metabolites detected at all time points were free bases and monophosphates of isopentenyladenine and cis-zeatin, while N-glucosides were not detected at all. Whole transcriptome differential expression analysis of cultures of the above Nostoc strain treated by cytokinin compared to untreated controls indicated that cytokinin together with light trigger expression of several genes related to signal transduction, including two-component sensor histidine kinases and two-component hybrid sensors and regulators. One of the affected histidine kinases with a cyclase/histidine kinase-associated sensory extracellular domain similar to the cytokinin-binding domain in plant cytokinin receptors was able to modestly bind isopentenyladenine. The data show that the genetic disposition allows Nostoc not only to produce free cytokinins and prenylate tRNA but also modulate the cytokinin biosynthesis in response to light, triggering complex changes in sensing and regulation. © 2017 Phycological Society of America.

  13. Alkane Biosynthesis Genes in Cyanobacteria and Their Transcriptional Organization

    Energy Technology Data Exchange (ETDEWEB)

    Klähn, Stephan; Baumgartner, Desirée; Pfreundt, Ulrike; Voigt, Karsten; Schön, Verena; Steglich, Claudia; Hess, Wolfgang R., E-mail: wolfgang.hess@biologie.uni-freiburg.de [Genetics and Experimental Bioinformatics, Institute of Biology 3, Faculty of Biology, University of Freiburg, Freiburg (Germany)

    2014-07-14

    In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl–acyl carrier protein reductase and aldehyde deformylating oxygenase. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short-chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado) and sll0209 (aar), which give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313, and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in cyanobacteria.

  14. Phosphoketolase pathway contributes to carbon metabolism in cyanobacteria.

    Science.gov (United States)

    Xiong, Wei; Lee, Tai-Chi; Rommelfanger, Sarah; Gjersing, Erica; Cano, Melissa; Maness, Pin-Ching; Ghirardi, Maria; Yu, Jianping

    2015-12-07

    Central carbon metabolism in cyanobacteria comprises the Calvin-Benson-Bassham (CBB) cycle, glycolysis, the pentose phosphate (PP) pathway and the tricarboxylic acid (TCA) cycle. Redundancy in this complex metabolic network renders the rational engineering of cyanobacterial metabolism for the generation of biomass, biofuels and chemicals a challenge. Here we report the presence of a functional phosphoketolase pathway, which splits xylulose-5-phosphate (or fructose-6-phosphate) to acetate precursor acetyl phosphate, in an engineered strain of the model cyanobacterium Synechocystis (ΔglgC/xylAB), in which glycogen synthesis is blocked, and xylose catabolism enabled through the introduction of xylose isomerase and xylulokinase. We show that this mutant strain is able to metabolise xylose to acetate on nitrogen starvation. To see whether acetate production in the mutant is linked to the activity of phosphoketolase, we disrupted a putative phosphoketolase gene (slr0453) in the ΔglgC/xylAB strain, and monitored metabolic flux using (13)C labelling; acetate and 2-oxoglutarate production was reduced in the light. A metabolic flux analysis, based on isotopic data, suggests that the phosphoketolase pathway metabolises over 30% of the carbon consumed by ΔglgC/xylAB during photomixotrophic growth on xylose and CO2. Disruption of the putative phosphoketolase gene in wild-type Synechocystis also led to a deficiency in acetate production in the dark, indicative of a contribution of the phosphoketolase pathway to heterotrophic metabolism. We suggest that the phosphoketolase pathway, previously uncharacterized in photosynthetic organisms, confers flexibility in energy and carbon metabolism in cyanobacteria, and could be exploited to increase the efficiency of cyanobacterial carbon metabolism and photosynthetic productivity.

  15. Rapid reactivation of cyanobacterial photosynthesis and migration upon rehydration of desiccated marine microbial mats

    Directory of Open Access Journals (Sweden)

    Arjun eChennu

    2015-12-01

    Full Text Available Desiccated cyanobacterial mats are the dominant biological feature in the Earth's arid zones. While the response of desiccated cyanobacteria to rehydration is well documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 minutes after rehydration chlorophyll a concentrations increased 2-5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min – 48 h involved migration of the reactivated cyanobacteria towards the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and aquatic origin. However the response of upward migration and its triggering factor appears to be mat-specific and likely linked to other factors.

  16. Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris M.; Belnap, Jayne; Evans, R. David; Kuske, Cheryl R.

    2012-01-01

    Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested a reduction in biocrust cyanobacterial biomass in the elevated CO2 treatment relative to the ambient controls. Additionally, SSU rRNA gene libraries and shotgun metagenomes showed reduced representation of cyanobacteria in the total microbial community. Taxonomic composition of the cyanobacteria was similar under ambient and elevated CO2 conditions, indicating the decline was manifest across multiple cyanobacterial lineages. Recruitment of cyanobacteria sequences from replicate shotgun metagenomes to cyanobacterial genomes representing major biocrust orders also suggested decreased abundance of cyanobacteria sequences across the majority of genomes tested. Functional assignment of cyanobacteria-related shotgun metagenome sequences indicated that four subsystem categories, three related to oxidative stress, were differentially abundant in relation to the elevated CO2 treatment. Taken together, these results suggest that elevated CO2 affected a generalized decrease in cyanobacteria in the biocrusts and may have favoured cyanobacteria with altered gene inventories for coping with oxidative stress.

  17. Synthetic algae and cyanobacteria: Great potential but what is the exposure risk?

    Science.gov (United States)

    Green algae and cyanobacteria (hereafter, algae) have the attractive properties of relatively simple genomes, rapid growth rates, and an ability to synthesize useful compounds using solar energy and carbon dioxide. They are attractive targets for applications of synthetic biology...

  18. Molecular phylogeny, population genetics, and evolution of heterocystous cyanobacteria using nifH gene sequences

    Czech Academy of Sciences Publication Activity Database

    Singh, P.; Singh, S. S.; Elster, Josef; Mishra, A. K.

    2013-01-01

    Roč. 250, č. 3 (2013), s. 751-764 ISSN 0033-183X Institutional support: RVO:67985939 Keywords : evolution * heterocystous cyanobacteria * nifH gene Subject RIV: EH - Ecology, Behaviour Impact factor: 3.171, year: 2013

  19. A state of the art of metabolic networks of unicellular microalgae and cyanobacteria for biofuel production.

    Science.gov (United States)

    Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

    2015-07-01

    The most promising and yet challenging application of microalgae and cyanobacteria is the production of renewable energy: biodiesel from microalgae triacylglycerols and bioethanol from cyanobacteria carbohydrates. A thorough understanding of microalgal and cyanobacterial metabolism is necessary to master and optimize biofuel production yields. To this end, systems biology and metabolic modeling have proven to be very efficient tools if supported by an accurate knowledge of the metabolic network. However, unlike heterotrophic microorganisms that utilize the same substrate for energy and as carbon source, microalgae and cyanobacteria require light for energy and inorganic carbon (CO2 or bicarbonate) as carbon source. This double specificity, together with the complex mechanisms of light capture, makes the representation of metabolic network nonstandard. Here, we review the existing metabolic networks of photoautotrophic microalgae and cyanobacteria. We highlight how these networks have been useful for gaining insight on photoautotrophic metabolism. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  20. Cyanobacteria: photosynthetic factories combining biodiversity, radiation resistance, and genetics to facilitate drug discovery.

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Dive, Vincent; Chauvat, Franck

    2017-02-01

    Cyanobacteria are ancient, abundant, and widely diverse photosynthetic prokaryotes, which are viewed as promising cell factories for the ecologically responsible production of chemicals. Natural cyanobacteria synthesize a vast array of biologically active (secondary) metabolites with great potential for human health, while a few genetic models can be engineered for the (low level) production of biofuels. Recently, genome sequencing and mining has revealed that natural cyanobacteria have the capacity to produce many more secondary metabolites than have been characterized. The corresponding panoply of enzymes (polyketide synthases and non-ribosomal peptide synthases) of interest for synthetic biology can still be increased through gene manipulations with the tools available for the few genetically manipulable strains. In this review, we propose to exploit the metabolic diversity and radiation resistance of cyanobacteria, and when required the genetics of model strains, for the production and radioactive ( 14 C) labeling of bioactive products, in order to facilitate the screening for new drugs.

  1. Production of cyanopeptolins, anabaenopeptins, and microcystins by the harmful cyanobacteria Anabaena 90 and Microcystis PCC 7806

    NARCIS (Netherlands)

    Tonk, L.; Welker, M.; Huisman, J.; Visser, P.M.

    2009-01-01

    This study investigated the effects of light intensity, temperature, and phosphorus limitation on the peptide production of the cyanobacteria Microcystis PCC 7806 and Anabaena 90. Microcystis PCC 7806 produced two microcystin variants and three cyanopeptolins, whereas Anabaena 90 produced four

  2. Estimation of photosynthesis in cyanobacteria by pulse-amplitude modulation chlorophyll fluorescence: problems and solutions.

    Science.gov (United States)

    Ogawa, Takako; Misumi, Masahiro; Sonoike, Kintake

    2017-09-01

    Cyanobacteria are photosynthetic prokaryotes and widely used for photosynthetic research as model organisms. Partly due to their prokaryotic nature, however, estimation of photosynthesis by chlorophyll fluorescence measurements is sometimes problematic in cyanobacteria. For example, plastoquinone pool is reduced in the dark-acclimated samples in many cyanobacterial species so that conventional protocol developed for land plants cannot be directly applied for cyanobacteria. Even for the estimation of the simplest chlorophyll fluorescence parameter, F v /F m , some additional protocol such as addition of DCMU or illumination of weak blue light is necessary. In this review, those problems in the measurements of chlorophyll fluorescence in cyanobacteria are introduced, and solutions to those problems are given.

  3. Evaluation of cyanobacteria cell count detection derived from MERIS imagery across the eastern USA

    Science.gov (United States)

    Inland waters across the United States (US) are at potential risk for increased outbreaks of toxic cyanobacteria (Cyano) harmful algal bloom (HAB) events resulting from elevated water temperatures and extreme hydrologic events attributable to climate change and increased nutrient...

  4. Open ocean pelago-benthic coupling: cyanobacteria as tracers of sedimenting salp faeces

    Science.gov (United States)

    Pfannkuche, Olaf; Lochte, Karin

    1993-04-01

    Coupling between surface water plankton and abyssal benthos was investigated during a mass development of salps ( Salpa fusiformis) in the Northeast Atlantic. Cyanobacteria numbers and composition of photosynthetic pigments were determined in faeces of captured salps from surface waters, sediment trap material, detritus from plankton hauls, surface sediments from 4500-4800 m depth and Holothurian gut contents. Cyanobacteria were found in all samples containing salp faeces and also in the guts of deep-sea Holothuria. The ratio between zeaxanthin (typical of cyanobacteria) and sum of chlorophyll a pigments was higher in samples from the deep sea when compared to fresh salp faeces, indicating that this carotenoid persisted longer in the sedimenting material than total chlorophyll a pigments. The microscopic and chemical observations allowed us to trace sedimenting salp faeces from the epipelagial to the abyssal benthos, and demonstrated their role as a fast and direct link between both systems. Cyanobacteria may provide a simple tracer for sedimenting phytodetritus.

  5. Microwhip scorpions (Palpigradi) feed on heterotrophic cyanobacteria in Slovak caves - a curiosity among Arachnida

    Czech Academy of Sciences Publication Activity Database

    Smrž, J.; Kováč, L.; Mikeš, J.; Lukešová, Alena

    2013-01-01

    Roč. 8, č. 10 (2013), e75989 E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : microwhip scorpions * heterotrophic cyanobacteria * Slovak caves Subject RIV: EG - Zoology Impact factor: 3.534, year: 2013

  6. Seven new species of Oculatella (Pseudanabaenales, Cyanobacteria): taxonomically recognizing cryptic diversification

    Czech Academy of Sciences Publication Activity Database

    Osorio-Santos, K.; Pietrasiak, N.; Bohunická, Markéta; Miscoe, L. H.; Kováčik, L.; Martin, M.P.; Johansen, J. R.

    2014-01-01

    Roč. 49, č. 4 (2014), s. 450-470 ISSN 0967-0262 Institutional support: RVO:67985939 Keywords : cryptic species * cyanobacteria * Pseudanabaenaceae Subject RIV: EF - Botanics Impact factor: 1.912, year: 2014

  7. Physiological tolerance and stoichiometric potential of cyanobacteria for hydrocarbon fuel production

    Czech Academy of Sciences Publication Activity Database

    Kamarainen, J.; Knoop, H.; Stanford, N.; Guerrero, F.; Akhtar, M. K.; Aro, E. M.; Steuer, Ralf; Jones, P. R.

    2012-01-01

    Roč. 162, č. 1 (2012), s. 67-74 ISSN 0168-1656 Institutional support: RVO:67179843 Keywords : Cyanobacteria * Hydrocarbon * Fuel * Toxicity * Stoichiometric potential Subject RIV: EH - Ecology, Behaviour Impact factor: 3.183, year: 2012

  8. Eutrophication and cyanobacteria in South Africa’s standing water bodies: A view from space

    CSIR Research Space (South Africa)

    Matthews, MW

    2015-05-01

    Full Text Available Satellite remote sensing can make a significant contribution to monitoring water quality in South African standing water bodies. Eutrophication, defined as enrichment by nutrients, and toxin-producing cyanobacteria (blue-green algae) blooms pose a...

  9. Antimicrobial assay and genetic screening of selected freshwater Cyanobacteria and identification of a biomolecule dihydro-2H-pyran-2-one derivative.

    Science.gov (United States)

    Srivastava, A; Singh, V K; Patnaik, S; Tripathi, J; Singh, P; Nath, G; Asthana, R K

    2017-04-01

    Explorations of freshwater Cyanobacteria as antimicrobial (bacteria, fungi and methicillin-resistant Staphylococcus aureus (MRSA) strains) drug resource using bioassay, NRPS (non-ribosomal polypeptide synthetase) and PKS (polyketide synthase) genes, as well as in silico approach. We have bioassayed the extracts of Phormidium CCC727, Geitlerinema CCC728, Arthrospira CCC729, Leptolyngbya CCC732, Phormidium CCC730, Phormidium CCC731 against six pathogenic bacteria comprising Gram (+ve): S. aureus including seven clinical MRSA and Enterococcus faecalis, Gram (-ve): Escherichia coli, Salmonella Typhimurium, Klebsiella pneumoniae and Shigella boydii along with non-pathogenic Enterobacter aerogenes as well as fungal strains (Cryptococcus neoformans and Candida albicans, C. krusei, C. tropicalis and Aspergillus niger) exhibiting antimicrobial potential. The NRPS and PKS genes of the target strains were also amplified and sequenced. The putative protein structures were predicted using bioinformatics approach. PKS gene expression indicated β keto-acyl synthase as one of the important active domains in the biomolecules related to antitumour and antifungal group. The simultaneous identification of the biomolecule (dihydro-2H-pyran-2-one derivative) was also inferred spectroscopically. Freshwater Cyanobacteria are prolific producers of secondary metabolite(s) that may act as the antimicrobial drug resource in addition to their much explored marine counterpart. © 2016 The Society for Applied Microbiology.

  10. Nitrogenase genes in non-cyanobacterial plankton: prevalence, diversity, and regulation in marine waters

    DEFF Research Database (Denmark)

    Riemann, Lasse; Farnelid, H.; Steward, G.F.

    2010-01-01

    Marine waters are generally considered to be nitrogen (N) limited and are therefore favourable environments for diazotrophs, i.e. organisms converting atmospheric N2 into ammonium or nitrogen oxides available for growth. In some regions, this import of N supports up to half of the primary...... productivity. Diazotrophic Cyanobacteria appear to be the major contributors to marine N2 fixation in surface waters, whereas the contribution of heterotrophic or chemoautotrophic diazotrophs to this process is usually regarded inconsequential. Culture-independent studies reveal that non......-cyanobacterial diazotrophs are diverse, widely distributed, and actively expressing the nitrogenase gene in marine and estuarine environments. The detection of nifH genes and nifH transcripts, even in N-replete marine waters, suggests that N2 fixation is an ecologically important process throughout the oceans. Because...

  11. Water sources for cyanobacteria below desert rocks in the Negev Desert determined by conductivity

    OpenAIRE

    McKay, Christopher P.

    2016-01-01

    We present year round meteorological and conductivity measurements of colonized hypolithic rocks in the Arava Valley, Negev Desert, Israel. The data indicate that while dew is common in the Negev it is not an important source of moisture for hypolithic organisms at this site. The dominance of cyanobacteria in the hypolithic community is consistent with predictions that cyanobacteria are confined to habitats supplied by rain. To monitor the presence of liquid water under the small Negev rocks ...

  12. Antibiotics-free stable polyhydroxyalkanoate (PHA) production from carbon dioxide by recombinant cyanobacteria.

    Science.gov (United States)

    Akiyama, Hideo; Okuhata, Hiroshi; Onizuka, Takuo; Kanai, Shozo; Hirano, Masahiko; Tanaka, Satoshi; Sasaki, Ken; Miyasaka, Hitoshi

    2011-12-01

    A practical antibiotics-free plasmid expression system in cyanobacteria was developed by using the complementation of cyanobacterial recA null mutation with the EscherichiacolirecA gene on the plasmid. This system was applied to the production of polyhydroxyalkanoate (PHA), a biodegradable plastic, and the transgenic cyanobacteria stably maintained the pha genes for PHA production in the antibiotics-free medium, and accumulated up to 52% cell dry weight of PHA. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania

    OpenAIRE

    Špakaitė, Ina

    2014-01-01

    The aim of the study was to investigate the morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania. The detailed research of freshwater and terrestrial Nostoc and Desmonostoc species provided new data on taxonomy, biology and ecology of these cyanobacteria and the overall diversity of algae in Lithuania. 20 Nostoc species and two intraspecific taxa, and 18 taxa to the Nostoc genus level were identified. Twelve Nostoc species and intraspecifi...

  14. Moss-cyanobacteria associations as biogenic sources of nitrogen in boreal forest ecosystems

    Directory of Open Access Journals (Sweden)

    Kathrin eRousk

    2013-06-01

    Full Text Available The biological fixation of atmospheric nitrogen (N is a major pathway for available N entering ecosystems. In N-limited boreal forests, a significant amount of N2 is fixed by cyanobacteria living in association with mosses, contributing up to 50 % to the total N input. In this review, we synthesize reports on the drivers of N2 fixation in feather moss-cyanobacteria associations to gain a deeper understanding of their role for ecosystem-N-cycling. Nitrogen fixation in moss-cyanobacteria associations is inhibited by N inputs and therefore, significant fixation occurs only in low N-deposition areas. While it has been shown that artificial N additions in the laboratory as well as in the field inhibit N2 fixation in moss-cyanobacteria associations, the type, as well as the amounts of N that enters the system, affect N2 fixation differently. Another major driver of N2 fixation is the moisture status of the cyanobacteria-hosting moss, wherein moist conditions promote N2 fixation. Mosses experience large fluctuations in their hydrological status, undergoing significant natural drying and rewetting cycles over the course of only a few hours, especially in summer, which likely compromises the N input to the system via N2 fixation. Perhaps the most central question, however, that remains unanswered is the fate of the fixed N2 in mosses. The cyanobacteria are likely to leak N, but whether this N is transferred to the soil and if so, at which rates and timescales, is unknown. Despite our increasing understanding of the drivers of N2 fixation, the role moss-cyanobacteria associations play in ecosystem-N-cycling remains unresolved. Further, the relationship mosses and cyanobacteria share is unknown to date and warrants further investigation.

  15. Population genetics, ecogenomics and physiological mechanisms of adaptation of Daphnia to cyanobacteria

    OpenAIRE

    Küster, Christian

    2012-01-01

    In many freshwater ecosystems Daphnia represent both, an important herbivorous grazer of phytoplankton and a major prey of planktivorous fish and invertebrate predators. Thus, Daphnia provide an important link for the transfer of energy and carbon from primary producers to higher trophic levels. In eutrophic lakes this transfer is often reduced by the occurrence of cyanobacteria that are known for their low food quality for Daphnia: Cyanobacteria lack essential sterols and polyunsaturated fat...

  16. Photocatalytic Cellulosic Electrospun Fibers for the Degradation of Potent Cyanobacteria Toxin Microcystin-LR

    Science.gov (United States)

    2012-01-01

    visible light activated or UV light activated), the surface area of the fiber mat, and loading solution pH all have an effect on the distribution of...photocatalysis with nanoparticles (such as titania, TiO2 ) show tremendous promise as a simple and energy efficient tech- nology for water purification and...LR (MC-LR). MC- LR is one of the most commonly found cyanobacteria toxins generated by the more frequently occurring cyanobacteria algae blooms in

  17. Diverse taxa of cyanobacteria produce β-N-methylamino-l-alanine, a neurotoxic amino acid

    OpenAIRE

    Cox, Paul Alan; Banack, Sandra Anne; Murch, Susan J.; Rasmussen, Ulla; Tien, Georgia; Bidigare, Robert Richard; Metcalf, James S.; Morrison, Louise F.; Codd, Geoffrey A.; Bergman, Birgitta

    2005-01-01

    Cyanobacteria can generate molecules hazardous to human health, but production of the known cyanotoxins is taxonomically sporadic. For example, members of a few genera produce hepatotoxic microcystins, whereas production of hepatotoxic nodularins appears to be limited to a single genus. Production of known neurotoxins has also been considered phylogenetically unpredictable. We report here that a single neurotoxin, β-N-methylamino-l-alanine, may be produced by all known groups of cyanobacteria...

  18. Is the distribution of nitrogen-fixing cyanobacteria in the oceans related to temperature?

    Science.gov (United States)

    Stal, Lucas J

    2009-07-01

    Approximately 50% of the global natural fixation of nitrogen occurs in the oceans supporting a considerable part of the new primary production. Virtually all nitrogen fixation in the ocean occurs in the tropics and subtropics where the surface water temperature is 25°C or higher. It is attributed almost exclusively to cyanobacteria. This is remarkable firstly because diazotrophic cyanobacteria are found in other environments irrespective of temperature and secondly because primary production in temperate and cold oceans is generally limited by nitrogen. Cyanobacteria are oxygenic phototrophic organisms that evolved a variety of strategies protecting nitrogenase from oxygen inactivation. Free-living diazotrophic cyanobacteria in the ocean are of the non-heterocystous type, namely the filamentous Trichodesmium and the unicellular groups A-C. I will argue that warm water is a prerequisite for these diazotrophic organisms because of the low-oxygen solubility and high rates of respiration allowing the organism to maintain anoxic conditions in the nitrogen-fixing cell. Heterocystous cyanobacteria are abundant in freshwater and brackish environments in all climatic zones. The heterocyst cell envelope is a tuneable gas diffusion barrier that optimizes the influx of both oxygen and nitrogen, while maintaining anoxic conditions inside the cell. It is not known why heterocystous cyanobacteria are absent from the temperate and cold oceans and seas.

  19. Responses to oxidative and heavy metal stresses in cyanobacteria: recent advances.

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Chauvat, Franck

    2014-12-31

    Cyanobacteria, the only known prokaryotes that perform oxygen-evolving photosynthesis, are receiving strong attention in basic and applied research. In using solar energy, water, CO2 and mineral salts to produce a large amount of biomass for the food chain, cyanobacteria constitute the first biological barrier against the entry of toxics into the food chain. In addition, cyanobacteria have the potential for the solar-driven carbon-neutral production of biofuels. However, cyanobacteria are often challenged by toxic reactive oxygen species generated under intense illumination, i.e., when their production of photosynthetic electrons exceeds what they need for the assimilation of inorganic nutrients. Furthermore, in requiring high amounts of various metals for growth, cyanobacteria are also frequently affected by drastic changes in metal availabilities. They are often challenged by heavy metals, which are increasingly spread out in the environment through human activities, and constitute persistent pollutants because they cannot be degraded. Consequently, it is important to analyze the protection against oxidative and metal stresses in cyanobacteria because these ancient organisms have developed most of these processes, a large number of which have been conserved during evolution. This review summarizes what is known regarding these mechanisms, emphasizing on their crosstalk.

  20. Molecular genetic improvements of cyanobacteria to enhance the industrial potential of the microbe: A review.

    Science.gov (United States)

    Johnson, Tylor J; Gibbons, Jaimie L; Gu, Liping; Zhou, Ruanbao; Gibbons, William R

    2016-11-01

    The rapid increase in worldwide population coupled with the increasing demand for fossil fuels has led to an increased urgency to develop sustainable sources of energy and chemicals from renewable resources. Using microorganisms to produce high-value chemicals and next-generation biofuels is one sustainable option and is the focus of much current research. Cyanobacteria are ideal platform organisms for chemical and biofuel production because they can be genetically engineered to produce a broad range of products directly from CO 2 , H 2 O, and sunlight, and require minimal nutrient inputs. The purpose of this review is to provide an overview on advances that have been or could be made to improve strains of cyanobacteria for industrial purposes. First, the benefits of using cyanobacteria as a platform for chemical and biofuel production are discussed. Next, an overview of cyanobacterial strain improvements by genetic engineering is provided. Finally, mutagenesis techniques to improve the industrial potential of cyanobacteria are described. Along with providing an overview on various areas of research that are currently being investigated to improve the industrial potential of cyanobacteria, this review aims to elucidate potential targets for future research involving cyanobacteria as an industrial microorganism. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1357-1371, 2016. © 2016 American Institute of Chemical Engineers.

  1. Sponges-Cyanobacteria associations: Global diversity overview and new data from the Eastern Mediterranean

    Science.gov (United States)

    Konstantinou, Despoina; Gerovasileiou, Vasilis; Voultsiadou, Eleni

    2018-01-01

    Sponge-cyanobacteria associations have attracted research interest from an ecological, evolutionary and biotechnological perspective. Current knowledge is, in its majority, “hidden” in metagenomics research studying the entire microbial communities of sponges, while knowledge on these associations is totally missing for certain geographic areas. In this study, we (a) investigated the occurrence of cyanobacteria in 18 sponge species, several of which are studied for the first time for their cyanobionts, from a previously unexplored eastern Mediterranean ecoregion, the Aegean Sea, (b) isolated sponge-associated cyanobacteria, and characterized them based on a polyphasic (morphological-morphometric and molecular phylogenetic analysis) approach, and (c) conducted a meta-analysis on the global diversity of sponge species hosting cyanobacteria, as well as the diversity of cyanobacterial symbionts. Our research provided new records for nine sponge species, previously unknown for this association, while the isolated cyanobacteria were found to form novel clades within Synechococcus, Leptolyngbyaceae, Pseudanabaenaceae, and Schizotrichaceae, whose taxonomic status requires further investigation; this is the first report of a Schizotrichaceae cyanobacterium associated with sponges. The extensive evaluation of the literature along with the new data from the Aegean Sea raised the number of sponge species known for hosting cyanobacteria to 320 and showed that the cyanobacterial diversity reported from sponges is yet underestimated. PMID:29596453

  2. The effect of temperature on the sensitivity of Daphnia magna to cyanobacteria is genus dependent.

    Science.gov (United States)

    Hochmuth, Jennifer D; De Schamphelaere, Karel A C

    2014-10-01

    In the present study, the authors investigated the effects of 6 different genera of cyanobacteria on multiple endpoints of Daphnia magna in a 21-d life table experiment conducted at 3 different temperatures (15 °C, 19 °C, and 23 °C). The specific aims were to test if the effect of temperature on Daphnia's sensitivity to cyanobacteria differed among different cyanobacteria and if the rank order from most to least harmful cyanobacteria to Daphnia reproduction changed or remained the same across the studied temperature range. Overall, the authors observed a decrease in harmful effects on reproduction with increasing temperature for Microcystis, Nodularia, and Aphanizomenon, and an increase in harmful effects with increasing temperature for Anabaena and Oscillatoria. No effect of temperature was observed on Daphnia sensitivity to Cylindrospermopsis. Harmful effects of Microcystis and Nodularia on reproduction appear to be mirrored by a decrease in length. On the other hand, harmful effects of Anabaena, Aphanizomenon, and Oscillatoria on reproduction were correlated with a decrease in intrinsic rate of natural increase, which was matched by a later onset of reproduction in exposures to Oscillatoria. In addition, the results suggest that the cyanobacteria rank order of harmfulness may change with temperature. Higher temperatures may increase the sensitivity of D. magna to the presence of some cyanobacteria (Anabaena and Oscillatoria) in their diet, whereas the harmful effects of others (Microcystis, Nodularia, and Aphanizomenon) may be reduced by higher temperatures. © 2014 SETAC.

  3. Utilization of hydrocarbons by cyanobacteria from microbial mats on oily coasts of the Gulf

    International Nuclear Information System (INIS)

    Al Hasan, R.H.; Sorkhoh, N.A.; Al Bader, D.; Radwan, S.S.

    1994-01-01

    Several pieces of evidence indicate that Microcoleus chthonoplastes and Phormidium corium, the predominant cyanobacteria in microbial mats on crude oil polluting the Arabian Gulf coasts, contribute to oil degradation by consuming individual n-alkanes. Both cyanobacteria grew phototrophically better in the presence of crude oil or individual n-alkanes than in their absence, indicating that hydrocarbons may have been utilized. This result was true when growth was measured in terms of dry biomass, as well as in terms of the content of biliprotein, the accessory pigment characteristic of cyanobacteria. The phototrophic biomass production by P. corium was directly proportional to the concentration of n-nonadecane (C 19 ) in the medium. The chlorophyll to carotene ratio of hydrocarbon-grown cyanobacteria did not decrease compared to the ratio in the absence of hydrocarbons, indicating that on hydrocarbons the organisms were not stressed. Comparing the fatty acid patterns of total lipids from hydrocarbon-grown cyanobacteria to those of the same organisms grown without hydrocarbons confirms that n-alkanes were taken up and oxidized to fatty acids by both cyanobacteria. (orig.)

  4. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  5. Marine Sciences

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    PNL research in the marine sciences is focused on establishing a basic understanding of the mechanisms of stress and tolerance in marine organisms exposed to contaminants. Several environmental stressors had been investigated in earlier energy-related research. In a landmark study, for example, PNL had established that the severity of fish disease caused by the common infectious agent, Flexobacter columnaris, was seriously aggravated by thermal enhancement and certain ecological factors. Subsequent studies demonstrated that the primary immune response in fish, challenged by columnaris, could be permanently suppressed by comparatively low tritium exposures. The research has suggested that a potential exists for a significant biological impact when an aquatic stressor is added to an ambient background of other stressors, which may include heat, heavy metal ions, radiation or infectious microorganisms. More recently, PNL investigators have shown that in response to heavy metal contaminants, animals synthesize specific proteins (metallothioneins), which bind and sequester metals in the animals, thus decreasing metal mobility and effects. Companion studies with host-specific intracellular pathogens are being used to investigate the effects of heavy metals on the synthesis of immune proteins, which mitigate disease processes. The results of these studies aid in predicting the ecological effects of energy-related contaminants on valued fin and shellfish species

  6. Seasonal morphological variability in an in situ Cyanobacteria monoculture: example from a persistent Cylindrospermopsis bloom in Lake Catemaco, Veracruz, Mexico

    OpenAIRE

    Owen Lind; Laura Dávalos-Lind; Carlos López; Martin López; Juli Dyble Bressie

    2016-01-01

    The phrase cyanobacteria bloom implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the bloom is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (108 trichomes L-1) population of potentially toxin-producing cyanobacteria, Cylindrospermopsis spp. The trichomes are present as straight and coiled morphotypes.  Th...

  7. A simple protocol for attenuating the auto-fluorescence of cyanobacteria for optimized fluorescence in situ hybridization (FISH) imaging.

    Science.gov (United States)

    Zeller, Perrine; Ploux, Olivier; Méjean, Annick

    2016-03-01

    Cyanobacteria contain pigments, which generate auto-fluorescence that interferes with fluorescence in situ hybridization (FISH) imaging of cyanobacteria. We describe simple chemical treatments using CuSO4 or H2O2 that significantly reduce the auto-fluorescence of Microcystis strains. These protocols were successfully applied in FISH experiments using 16S rRNA specific probes and filamentous cyanobacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Consequences of Modification of Photosystem Stoichiometry and Amount in Cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Vermaas, Willem [Arizona State Univ., Tempe, AZ (United States)

    2016-12-13

    The proposed research seeks to address two interconnected, important questions that impact photosynthetic processes and that reflect key differences between the photosynthetic systems of cyanobacteria and plants or algae. The first question is what are the reasons and consequences of the high photosystem I / photosystem II (PS I/PS II) ratio in many cyanobacteria, vs. a ratio that is close to unity in many plants and algae. The corresponding hypothesis is that most of PS I functions in cyclic electron transport, and that reduction in PS I will result primarily in a shortage of ATP rather than reducing power. This hypothesis will be tested by reducing the amount of PS I by changing the promoter region of the psaAB operon in the cyanobacterium Synechocystis sp. PCC 6803 and generating a range of mutants with different PS I content and thereby different PS I/PS II ratios, with some of the mutants having a PS II/PS I ratio closer to that in plants. The resulting mutants will be probed in terms of their growth rates, electron transfer rates, and P700 redox kinetics. A second question relates to a Mehler-type reaction catalyzed by two flavoproteins, Flv1 and Flv3, that accept electrons from PS I and that potentially function as an electron safety valve leading to no useful purpose of the photosynthesis-generated electrons. The hypothesis to be tested is that Flv1 and Flv3 use the electrons for useful purposes such as cyclic electron flow around PS I. This hypothesis will be tested by analysis of a mutant strain lacking flv3, the gene for one of the flavoproteins. This research is important for a more detailed understanding of the consequences of photosystem stoichiometry and amounts in a living system. Such an understanding is critical for not only insights in the regulatory systems of the organism but also to guide the development of biological or bio-hybrid systems for solar energy conversion into fuels.

  9. Mycosporine-Like Amino Acids and Marine Toxins - The Common and the Different

    Science.gov (United States)

    Klisch, Manfred; Häder, Donat-P.

    2008-01-01

    Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporine-like amino acids (MAAs). The latter form a group of water-soluble, low molecular-weight (generally < 400) compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences. PMID:18728764

  10. Mycosporine-Like Amino Acids and Marine Toxins - The Common and the Different

    Directory of Open Access Journals (Sweden)

    Donat P. Häder

    2008-05-01

    Full Text Available Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporinelike amino acids (MAAs. The latter form a group of water-soluble, low molecular-weight (generally < 400 compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences.

  11. Fate of cyanobacteria and their metabolites during water treatment sludge management processes

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Lionel, E-mail: lionel.ho@sawater.com.au [Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5000 (Australia); Centre for Water Management and Reuse, University of South Australia, Mawson Lakes, SA 5095 (Australia); Dreyfus, Jennifer; Boyer, Justine; Lowe, Todd [Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5000 (Australia); Bustamante, Heriberto; Duker, Phil [Sydney Water, PO Box 399, Parramatta, NSW 2124 (Australia); Meli, Tass [TRILITY Pty Ltd, PO Box 86, Appin, NSW 2560 (Australia); Newcombe, Gayle [Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5000 (Australia); Centre for Water Management and Reuse, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2012-05-01

    Cyanobacteria and their metabolites are an issue for water authorities; however, little is known as to the fate of coagulated cyanobacterial-laden sludge during waste management processes in water treatment plants (WTPs). This paper provides information on the cell integrity of Anabaena circinalis and Cylindrospermopsis raciborskii during: laboratory-scale coagulation/sedimentation processes; direct filtration and backwashing procedures; and cyanobacterial-laden sludge management practices. In addition, the metabolites produced by A. circinalis (geosmin and saxitoxins) and C. raciborskii (cylindrospermopsin) were investigated with respect to their release (and possible degradation) during each of the studied processes. Where sedimentation was used, coagulation effectively removed cyanobacteria (and intracellular metabolites) without any considerable exertion on coagulant demand. During direct filtration experiments, cyanobacteria released intracellular metabolites through a stagnation period, suggesting that more frequent backwashing of filters may be required to prevent floc build-up and metabolite release. Cyanobacteria appeared to be protected within the flocs, with minimal damage during backwashing of the filters. Within coagulant sludge, cyanobacteria released intracellular metabolites into the supernatant after 3 d, even though cells remained viable up to 7 d. This work has improved the understanding of cyanobacterial metabolite risks associated with management of backwash water and sludge and is likely to facilitate improvements at WTPs, including increased monitoring and the application of treatment strategies and operational practices, with respect to cyanobacterial-laden sludge and/or supernatant recycle management. - Highlights: Black-Right-Pointing-Pointer Coagulation removed cyanobacteria without an additional exertion on coagulant demand. Black-Right-Pointing-Pointer During a stagnation period in direct filtration intracellular metabolites were

  12. Fate of cyanobacteria and their metabolites during water treatment sludge management processes

    International Nuclear Information System (INIS)

    Ho, Lionel; Dreyfus, Jennifer; Boyer, Justine; Lowe, Todd; Bustamante, Heriberto; Duker, Phil; Meli, Tass; Newcombe, Gayle

    2012-01-01

    Cyanobacteria and their metabolites are an issue for water authorities; however, little is known as to the fate of coagulated cyanobacterial-laden sludge during waste management processes in water treatment plants (WTPs). This paper provides information on the cell integrity of Anabaena circinalis and Cylindrospermopsis raciborskii during: laboratory-scale coagulation/sedimentation processes; direct filtration and backwashing procedures; and cyanobacterial-laden sludge management practices. In addition, the metabolites produced by A. circinalis (geosmin and saxitoxins) and C. raciborskii (cylindrospermopsin) were investigated with respect to their release (and possible degradation) during each of the studied processes. Where sedimentation was used, coagulation effectively removed cyanobacteria (and intracellular metabolites) without any considerable exertion on coagulant demand. During direct filtration experiments, cyanobacteria released intracellular metabolites through a stagnation period, suggesting that more frequent backwashing of filters may be required to prevent floc build-up and metabolite release. Cyanobacteria appeared to be protected within the flocs, with minimal damage during backwashing of the filters. Within coagulant sludge, cyanobacteria released intracellular metabolites into the supernatant after 3 d, even though cells remained viable up to 7 d. This work has improved the understanding of cyanobacterial metabolite risks associated with management of backwash water and sludge and is likely to facilitate improvements at WTPs, including increased monitoring and the application of treatment strategies and operational practices, with respect to cyanobacterial-laden sludge and/or supernatant recycle management. - Highlights: ► Coagulation removed cyanobacteria without an additional exertion on coagulant demand. ► During a stagnation period in direct filtration intracellular metabolites were released. ► Cyanobacterial cells were not damaged

  13. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carlos J.; Reeve, Petra J.; Sawade, Emma [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Voldoire, Camille F. [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Newton, Kelly; Praptiwi, Radisti [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Collingnon, Lea [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); École Européenne de Chimie, Polymères et Matériaux (ECPM), Strasbourg 67087 (France); Dreyfus, Jennifer [Allwater, Adelaide Services Alliance, Wakefield St, Adelaide, SA 5001 (Australia); Hobson, Peter [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia); Gaget, Virginie [University of Adelaide, Ecology and Environmental Sciences, School of Biological Sciences, Adelaide, SA 5005 (Australia); Newcombe, Gayle, E-mail: gayle.newcombe@sawater.com.au [Australian Water Quality Centre, South Australian Water Corporation, Adelaide, SA 5000 (Australia)

    2016-09-15

    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10 days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. - Highlights: • Cyanobacteria in water treatment sludge significantly impact supernatant quality • Cyanobacteria can survive, and thrive, in sludge lagoon supernatant and in treatment sludge • Metabolite concentrations in cyanobacteria in sludge can increase up to 500% • The risk associated with supernatant recycling was assessed relative to available treatment barriers.

  14. Bryophyte-cyanobacteria associations during primary succession in recently Deglaciated areas of Tierra del Fuego (Chile).

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De Los Ríos, Asunción; Green, T G Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g-1 bryo. d-1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g-1 bryo. d-1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition.

  15. Microclimate and limits to photosynthesis in a diverse community of hypolithic cyanobacteria in northern Australia

    Science.gov (United States)

    Tracy, Christopher R.; Streten-Joyce, Claire; Dalton, Robert; Nussear, Kenneth E.; Gibb, Karen S.; Christian, Keith A.

    2010-01-01

    Hypolithic microbes, primarily cyanobacteria, inhabit the highly specialized microhabitats under translucent rocks in extreme environments. Here we report findings from hypolithic cyanobacteria found under three types of translucent rocks (quartz, prehnite, agate) in a semiarid region of tropical Australia. We investigated the photosynthetic responses of the cyanobacterial communities to light, temperature and moisture in the laboratory, and we measured the microclimatic variables of temperature and soil moisture under rocks in the field over an annual cycle. We also used molecular techniques to explore the diversity of hypolithic cyanobacteria in this community and their phylogenetic relationships within the context of hypolithic cyanobacteria from other continents. Based on the laboratory experiments, photosynthetic activity required a minimum soil moisture of 15% (by mass). Peak photosynthetic activity occurred between approximately 8°C and 42°C, though some photosynthesis occurred between −1°C and 51°C. Maximum photosynthesis rates also occurred at light levels of approximately 150–550 μmol m−2 s−1. We used the field microclimatic data in conjunction with these measurements of photosynthetic efficiency to estimate the amount of time the hypolithic cyanobacteria could be photosynthetically active in the field. Based on these data, we estimated that conditions were appropriate for photosynthetic activity for approximately 942 h (∼75 days) during the year. The hypolithic cyanobacteria community under quartz, prehnite and agate rocks was quite diverse both within and between rock types. We identified 115 operational taxonomic units (OTUs), with each rock hosting 8–24 OTUs. A third of the cyanobacteria OTUs from northern Australia grouped with Chroococcidiopsis, a genus that has been identified from hypolithic and endolithic communities from the Gobi, Mojave, Atacama and Antarctic deserts. Several OTUs identified from northern Australia have

  16. Bloom-Forming Cyanobacteria Support Copepod Reproduction and Development in the Baltic Sea

    Science.gov (United States)

    Hogfors, Hedvig; Motwani, Nisha H.; Hajdu, Susanna; El-Shehawy, Rehab; Holmborn, Towe; Vehmaa, Anu; Engström-Öst, Jonna; Brutemark, Andreas; Gorokhova, Elena

    2014-01-01

    It is commonly accepted that summer cyanobacterial blooms cannot be efficiently utilized by grazers due to low nutritional quality and production of toxins; however the evidence for such effects in situ is often contradictory. Using field and experimental observations on Baltic copepods and bloom-forming diazotrophic filamentous cyanobacteria, we show that cyanobacteria may in fact support zooplankton production during summer. To highlight this side of zooplankton-cyanobacteria interactions, we conducted: (1) a field survey investigating linkages between cyanobacteria, reproduction and growth indices in the copepod Acartia tonsa; (2) an experiment testing relationships between ingestion of the cyanobacterium Nodularia spumigena (measured by molecular diet analysis) and organismal responses (oxidative balance, reproduction and development) in the copepod A. bifilosa; and (3) an analysis of long term (1999–2009) data testing relationships between cyanobacteria and growth indices in nauplii of the copepods, Acartia spp. and Eurytemora affinis, in a coastal area of the northern Baltic proper. In the field survey, N. spumigena had positive effects on copepod egg production and egg viability, effectively increasing their viable egg production. By contrast, Aphanizomenon sp. showed a negative relationship with egg viability yet no significant effect on the viable egg production. In the experiment, ingestion of N. spumigena mixed with green algae Brachiomonas submarina had significant positive effects on copepod oxidative balance, egg viability and development of early nauplial stages, whereas egg production was negatively affected. Finally, the long term data analysis identified cyanobacteria as a significant positive predictor for the nauplial growth in Acartia spp. and E. affinis. Taken together, these results suggest that bloom forming diazotrophic cyanobacteria contribute to feeding and reproduction of zooplankton during summer and create a favorable growth

  17. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge

    International Nuclear Information System (INIS)

    Pestana, Carlos J.; Reeve, Petra J.; Sawade, Emma; Voldoire, Camille F.; Newton, Kelly; Praptiwi, Radisti; Collingnon, Lea; Dreyfus, Jennifer; Hobson, Peter; Gaget, Virginie; Newcombe, Gayle

    2016-01-01

    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10 days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. - Highlights: • Cyanobacteria in water treatment sludge significantly impact supernatant quality • Cyanobacteria can survive, and thrive, in sludge lagoon supernatant and in treatment sludge • Metabolite concentrations in cyanobacteria in sludge can increase up to 500% • The risk associated with supernatant recycling was assessed relative to available treatment barriers

  18. Bloom-forming cyanobacteria support copepod reproduction and development in the Baltic Sea.

    Science.gov (United States)

    Hogfors, Hedvig; Motwani, Nisha H; Hajdu, Susanna; El-Shehawy, Rehab; Holmborn, Towe; Vehmaa, Anu; Engström-Öst, Jonna; Brutemark, Andreas; Gorokhova, Elena

    2014-01-01

    It is commonly accepted that summer cyanobacterial blooms cannot be efficiently utilized by grazers due to low nutritional quality and production of toxins; however the evidence for such effects in situ is often contradictory. Using field and experimental observations on Baltic copepods and bloom-forming diazotrophic filamentous cyanobacteria, we show that cyanobacteria may in fact support zooplankton production during summer. To highlight this side of zooplankton-cyanobacteria interactions, we conducted: (1) a field survey investigating linkages between cyanobacteria, reproduction and growth indices in the copepod Acartia tonsa; (2) an experiment testing relationships between ingestion of the cyanobacterium Nodularia spumigena (measured by molecular diet analysis) and organismal responses (oxidative balance, reproduction and development) in the copepod A. bifilosa; and (3) an analysis of long term (1999-2009) data testing relationships between cyanobacteria and growth indices in nauplii of the copepods, Acartia spp. and Eurytemora affinis, in a coastal area of the northern Baltic proper. In the field survey, N. spumigena had positive effects on copepod egg production and egg viability, effectively increasing their viable egg production. By contrast, Aphanizomenon sp. showed a negative relationship with egg viability yet no significant effect on the viable egg production. In the experiment, ingestion of N. spumigena mixed with green algae Brachiomonas submarina had significant positive effects on copepod oxidative balance, egg viability and development of early nauplial stages, whereas egg production was negatively affected. Finally, the long term data analysis identified cyanobacteria as a significant positive predictor for the nauplial growth in Acartia spp. and E. affinis. Taken together, these results suggest that bloom forming diazotrophic cyanobacteria contribute to feeding and reproduction of zooplankton during summer and create a favorable growth

  19. Bryophyte-Cyanobacteria Associations during Primary Succession in Recently Deglaciated Areas of Tierra del Fuego (Chile)

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De los Ríos, Asunción; Green, T. G. Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G.

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g−1 bryo. d−1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g−1 bryo. d−1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition. PMID:24819926

  20. Cyanobacteria and Microalgae: Thermoeconomic Considerations in Biofuel Production

    Directory of Open Access Journals (Sweden)

    Umberto Lucia

    2018-01-01

    Full Text Available In thermodynamics, the useful work in any process can be evaluated by using the exergy quantity. The analyses of irreversibility are fundamental in the engineering design and in the productive processes’ development in order to obtain the economic growth. Recently, the use has been improved also in the thermodynamic analysis of the socio-economic context. Consequently, the exergy lost is linked to the energy cost required to maintain the productive processes themselves. The fundamental role of the fluxes and the interaction between systems and their environment is highlighted. The equivalent wasted primary resource value for the work-hour is proposed as an indicator to support the economic considerations on the biofuel production by using biomass and bacteria. The equivalent wasted primary resource value for the work-hour is proposed as an indicator to support the economic considerations of the biofuel production by using biomass and bacteria. Moreover, the technological considerations can be developed by using the exergy inefficiency. Consequently, bacteria use can be compared with other means of biofuel production, taking into account both the technologies and the economic considerations. Cyanobacteria results as the better organism for biofuel production.

  1. Primary endosymbiosis: have cyanobacteria and Chlamydiae ever been roommates?

    Directory of Open Access Journals (Sweden)

    Philippe Deschamps

    2014-12-01

    Full Text Available Eukaryotes acquired the ability to process photosynthesis by engulfing a cyanobacterium and transforming it into a genuine organelle called the plastid. This event, named primary endosymbiosis, occurred once more than a billion years ago, and allowed the emergence of the Archaeplastida, a monophyletic supergroup comprising the green algae and plants, the red algae and the glaucophytes. Of the other known cases of symbiosis between cyanobacteria and eukaryotes, none has achieved a comparable level of cell integration nor reached the same evolutionary and ecological success than primary endosymbiosis did. Reasons for this unique accomplishment are still unknown and difficult to comprehend. The exploration of plant genomes has revealed a considerable amount of genes closely related to homologs of Chlamydiae bacteria, and probably acquired by horizontal gene transfer. Several studies have proposed that these transferred genes, which are mostly involved in the functioning of the plastid, may have helped the settlement of primary endosymbiosis. Some of these studies propose that Chlamydiae and cyanobacterial symbionts coexisted in the eukaryotic host of the primary endosymbiosis, and that Chlamydiae provided solutions for the metabolic symbiosis between the cyanobacterium and the host, ensuring the success of primary endosymbiosis. In this review, I present a reevaluation of the contribution of Chlamydiae genes to the genome of Archaeplastida and discuss the strengths and weaknesses of this tripartite model for primary endosymbiosis.

  2. Production of volatile organic compounds by cyanobacteria Synechococcus sp.

    Science.gov (United States)

    Hiraiwa, M.; Abe, M.; Hashimoto, S.

    2014-12-01

    Phytoplankton are known to produce volatile organic compounds (VOCs), which contribute to environmental problems such as global warming and decomposition of stratospheric ozone. For example, picophytoplankton, such as Prochlorococcus and Synechococcus, are distributed in freshwater and oceans worldwide, accounting for a large proportion of biomass and primary production in the open ocean. However, to date, little is known about the production of VOCs by picophytoplankton. In this study, VOCs production by cyanobacteria Synechococcus sp. (NIES-981) was investigated. Synechococcus sp. was obtained from the National Institute for Environmental Studies (NIES), Japan, and cultured at 24°C in autoclaved f/2-Si medium under 54 ± 3 µE m-2 s-1 (1 E = 1 mol of photons) with a 12-h light and 12-h dark cycle. VOCs concentrations were determined using a purge-and-trap gas chromatograph-mass spectrometer (Agilent 5973). The concentrations of chlorophyll a (Chl a) were also determined using a fluorometer (Turner TD-700). Bromomethane (CH3Br) and isoprene were produced by Synechococcus sp. Isoprene production was similar to those of other phytoplankton species reported earlier. Isoprene was produced when Chl a was increasing in the early stage of the incubation period (5-15 days of incubation time, exponential phase), but CH3Br was produced when Chl a was reduced in the late stage of the incubation period (30-40 days of incubation time, death phase).

  3. Determination of Volatile Organic Compounds in Selected Strains of Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Ivan Milovanović

    2015-01-01

    Full Text Available Microalgal biomass can be used in creating various functional food and feed products, but certain species of microalgae and cyanobacteria are known to produce various compounds causing off-flavour. In this work, we investigated selected cyanobacterial strains of Spirulina, Anabaena, and Nostoc genera originating from Serbia, with the aim of determining the chemical profile of volatile organic compounds produced by these organisms. Additionally, the influence of nitrogen level during growth on the production of volatile compounds was investigated for Nostoc and Anabaena strains. In addition, multivariate techniques, namely, principal component analysis (PCA and hierarchical cluster analysis (HCA, were used for making distinction among different microalgal strains. The results show that the main volatile compounds in these species are medium chain length alkanes, but other odorous compounds such as 2-methylisoborneol (0.51–4.48%, 2-pentylfuran (0.72–8.98%, β-cyclocitral (0.00–1.17%, and β-ionone (1.15–2.72% were also detected in the samples. Addition of nitrogen to growth medium was shown to negatively affect the production of 2-methylisoborneol, while geosmin was not detected in any of the analyzed samples, which indicates that the manipulation of growth conditions may be useful in reducing levels of some unwanted odor-causing components.

  4. Evaluation of cyanobacteria cell count detection derived from ...

    Science.gov (United States)

    Inland waters across the United States (US) are at potential risk for increased outbreaks of toxic cyanobacteria (Cyano) harmful algal bloom (HAB) events resulting from elevated water temperatures and extreme hydrologic events attributable to climate change and increased nutrient loadings associated with intensive agricultural practices. Current monitoring efforts are limited in scope due to resource limitations, analytical complexity, and data integration efforts. The goals of this study were to validate a new ocean color algorithm for satellite imagery that could potentially be used to monitor CyanoHAB events in near real-time to provide a compressive monitoring capability for freshwater lakes (>100 ha). The algorithm incorporated narrow spectral bands specific to the European Space Agency’s (ESA’s) MEdium Resolution Imaging Spectrometer (MERIS) instrument that were optimally oriented at phytoplankton pigment absorption features including phycocyanin at 620 nm. A validation of derived Cyano cell counts was performed using available in situ data assembled from existing monitoring programs across eight states in the eastern US over a 39-month period (2009–2012). Results indicated that MERIS provided robust estimates for Low (10,000–109,000 cells/mL) and Very High (>1,000,000 cells/mL) cell enumeration ranges (approximately 90% and 83%, respectively). However, the results for two intermediate ranges (110,000–299,000 and 300,000–1,000,000 cells/mL)

  5. Cyanobacteria and macroalgae in ecosystem of the Neva estuary

    Directory of Open Access Journals (Sweden)

    Nikulina V. N.

    2011-07-01

    Full Text Available The Baltic Sea and Neva estuary are plagued by coastal eutrophication. In order to estimate the scale of the problem, quantitative estimates of phytoplankton and macroalgal mats were determined in the Neva estuary. Long-term monitoring (1982–2009 of phytoplankton showed changes in its species composition and abundance. Summer phytoplankton biomass increased significantly in the 1990s, with concomitant changes in species composition, despite a decline of nutrients in the Neva estuary. The cyanobacteria Planktothrix agardhii became a dominant species. The summer biomass of phytoplankton reached a maximum of 5.2 ± 0.4 mg·L-1 in 2002–2004. Monitoring of macroalgal community in the coastal area of the Neva estuary from 2002 to 2009 showed the dominance of the filamentous green alga Cladophora glomerata in the phytobenthos. Average biomass of macroalgae in inner and outer estuary differed significantly at 132 ± 29 and 310 ± 67 g DW·m-2, respectively. This study showed, that fluctuations in macroalgal biomass reflected human influence on estuary, although it was less sensitive to human impact than the phytoplankton community. Thus qualitative and quantitative characteristics of phytoplankton and macroalgal blooms can indicate anthropogenic influence on the ecosystem, and help to better manage the Neva estuary.

  6. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    Energy Technology Data Exchange (ETDEWEB)

    Queiroga, Fernando Ramos [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Marques-Santos, Luis Fernando [Laboratório de Biologia Celular e do Desenvolvimento (LABID), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Hégaret, Hélène [Laboratoire des Sciences de l' Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER, Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, 29280, Plouzané (France); Sassi, Roberto [Laboratório de Ambientes Recifais e Biotecnologia de Microalgas (LARBIM), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Farias, Natanael Dantas; Santana, Lucas Nunes [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); and others

    2017-06-15

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  7. Epidemiology of recreational exposure to freshwater cyanobacteria – an international prospective cohort study

    Directory of Open Access Journals (Sweden)

    Burns John W

    2006-04-01

    Full Text Available Abstract Background Case studies and anecdotal reports have documented a range of acute illnesses associated with exposure to cyanobacteria and their toxins in recreational waters. The epidemiological data to date are limited; we sought to improve on the design of some previously conducted studies in order to facilitate revision and refinement of guidelines for exposure to cyanobacteria in recreational waters. Methods A prospective cohort study was conducted to investigate the incidence of acute symptoms in individuals exposed, through recreational activities, to low (cell surface area 2/mL, medium (2.4–12.0 mm2/mL and high (>12.0 mm2/mL levels of cyanobacteria in lakes and rivers in southeast Queensland, the central coast area of New South Wales, and northeast and central Florida. Multivariable logistic regression analyses were employed; models adjusted for region, age, smoking, prior history of asthma, hay fever or skin disease (eczema or dermatitis and clustering by household. Results Of individuals approached, 3,595 met the eligibility criteria, 3,193 (89% agreed to participate and 1,331 (37% completed both the questionnaire and follow-up interview. Respiratory symptoms were 2.1 (95%CI: 1.1–4.0 times more likely to be reported by subjects exposed to high levels of cyanobacteria than by those exposed to low levels. Similarly, when grouping all reported symptoms, individuals exposed to high levels of cyanobacteria were 1.7 (95%CI: 1.0–2.8 times more likely to report symptoms than their low-level cyanobacteria-exposed counterparts. Conclusion A significant increase in reporting of minor self-limiting symptoms, particularly respiratory symptoms, was associated with exposure to higher levels of cyanobacteria of mixed genera. We suggest that exposure to cyanobacteria based on total cell surface area above 12 mm2/mL could result in increased incidence of symptoms. The potential for severe, life-threatening cyanobacteria-related illness is

  8. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    International Nuclear Information System (INIS)

    Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Sassi, Roberto; Farias, Natanael Dantas; Santana, Lucas Nunes

    2017-01-01

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  9. Evidence for a novel marine harmful algal bloom: cyanotoxin (microcystin transfer from land to sea otters.

    Directory of Open Access Journals (Sweden)

    Melissa A Miller

    Full Text Available "Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine

  10. Evidence for a novel marine harmful algal bloom: Cyanotoxin (Microcystin) transfer from land to sea otters

    Science.gov (United States)

    Miller, Melissa A.; Kudela, Raphael M.; Mekebri, Abdu; Crane, Dave; Oates, Stori C.; Tinker, M. Timothy; Staedler, Michelle; Miller, Woutrina A.; Toy-Choutka, Sharon; Dominik, Clare; Hardin, Dane; Langlois, Gregg; Murray, Michael; Ward, Kim; Jessup, David A.

    2010-01-01

    "Super-blooms" of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine "harmful algal

  11. Cyanobacteria, algae and microfungi present in biofilm from Božana Cave (Serbia

    Directory of Open Access Journals (Sweden)

    Slađana Popović

    2015-05-01

    Full Text Available Phototrophic microorganisms (cyanobacteria and algae and microfungi, were identified from biofilm on the walls of the entrance of BožanaCavein west Serbia. Temperature, relative humidity and light intensity were measured, and chlorophyll a content determined. Light intensity differed from the entrance inwards. However, Chl a content was not proportional to light intensity, instead it was positively correlated to biofilm weight. Biofilm samples from two sites were also observed using a scanning electron microscope. Coccoid forms of cyanobacteria were abundant at the sampling site with the lowest light intensity, while members of the order Nostocales were predominant at the sampling site with the highest light intensity measured. Cyanobacteria were the dominant group of phototrophs colonizing cave walls (29 taxa, with the order Chroococcales prevailing (21 taxa. The most frequently documented cyanobacteria were species from genera Gloeocapsa, Scytonema, Aphanocapsa and Chroococcus. Desmococcus olivaceus and Trentepohlia aurea were the only green algae documented on cave walls. Ascomycetes were common (e.g. Alternaria, Aspergillus, Cladosporium, Epicoccum, Penicillum and Trichoderma, while zygomycetes and oomycetes were less frequent. The different color of each biofilm sample was ascribed to the presence of various different species of cyanobacteria and algae.

  12. Cyanobacteria: A Precious Bio-resource in Agriculture, Ecosystem, and Environmental Sustainability

    Science.gov (United States)

    Singh, Jay Shankar; Kumar, Arun; Rai, Amar N.; Singh, Devendra P.

    2016-01-01

    Keeping in view, the challenges concerning agro-ecosystem and environment, the recent developments in biotechnology offers a more reliable approach to address the food security for future generations and also resolve the complex environmental problems. Several unique features of cyanobacteria such as oxygenic photosynthesis, high biomass yield, growth on non-arable lands and a wide variety of water sources (contaminated and polluted waters), generation of useful by-products and bio-fuels, enhancing the soil fertility and reducing green house gas emissions, have collectively offered these bio-agents as the precious bio-resource for sustainable development. Cyanobacterial biomass is the effective bio-fertilizer source to improve soil physico-chemical characteristics such as water-holding capacity and mineral nutrient status of the degraded lands. The unique characteristics of cyanobacteria include their ubiquity presence, short generation time and capability to fix the atmospheric N2. Similar to other prokaryotic bacteria, the cyanobacteria are increasingly applied as bio-inoculants for improving soil fertility and environmental quality. Genetically engineered cyanobacteria have been devised with the novel genes for the production of a number of bio-fuels such as bio-diesel, bio-hydrogen, bio-methane, synga, and therefore, open new avenues for the generation of bio-fuels in the economically sustainable manner. This review is an effort to enlist the valuable information about the qualities of cyanobacteria and their potential role in solving the agricultural and environmental problems for the future welfare of the planet. PMID:27148218

  13. Discovery of a super-strong promoter enables efficient production of heterologous proteins in cyanobacteria.

    Science.gov (United States)

    Zhou, Jie; Zhang, Haifeng; Meng, Hengkai; Zhu, Yan; Bao, Guanhui; Zhang, Yanping; Li, Yin; Ma, Yanhe

    2014-03-28

    Cyanobacteria are oxygenic photosynthetic prokaryotes that play important roles in the global carbon cycle. Recently, engineered cyanobacteria capable of producing various small molecules from CO2 have been developed. However, cyanobacteria are seldom considered as factories for producing proteins, mainly because of the lack of efficient strong promoters. Here, we report the discovery and verification of a super-strong promoter P(cpc560), which contains two predicted promoters and 14 predicted transcription factor binding sites (TFBSs). Using P(cpc560), functional proteins were produced at a level of up to 15% of total soluble protein in the cyanobacterium Synechocystis sp. 6803, a level comparable to that produced in Escherichia coli. We demonstrated that the presence of multiple TFBSs in P(cpc560) is crucial for its promoter strength. Genetically transformable cyanobacteria neither have endotoxins nor form inclusion bodies; therefore, P(cpc560) opens the possibility to use cyanobacteria as alternative hosts for producing heterogeneous proteins from CO2 and inorganic nutrients.

  14. Chytrid parasitism facilitates trophic transfer between bloom-forming cyanobacteria and zooplankton (Daphnia).

    Science.gov (United States)

    Agha, Ramsy; Saebelfeld, Manja; Manthey, Christin; Rohrlack, Thomas; Wolinska, Justyna

    2016-10-13

    Parasites are rarely included in food web studies, although they can strongly alter trophic interactions. In aquatic ecosystems, poorly grazed cyanobacteria often dominate phytoplankton communities, leading to the decoupling of primary and secondary production. Here, we addressed the interface between predator-prey and host-parasite interactions by conducting a life-table experiment, in which four Daphnia galeata genotypes were maintained on quantitatively comparable diets consisting of healthy cyanobacteria or cyanobacteria infected by a fungal (chytrid) parasite. In four out of five fitness parameters, at least one Daphnia genotype performed better on parasitised cyanobacteria than in the absence of infection. Further treatments consisting of purified chytrid zoospores and heterotrophic bacteria suspensions established the causes of improved fitness. First, Daphnia feed on chytrid zoospores which trophically upgrade cyanobacterial carbon. Second, an increase in heterotrophic bacterial biomass, promoted by cyanobacterial decay, provides an additional food source for Daphnia. In addition, chytrid infection induces fragmentation of cyanobacterial filaments, which could render cyanobacteria more edible. Our results demonstrate that chytrid parasitism can sustain zooplankton under cyanobacterial bloom conditions, and exemplify the potential of parasites to alter interactions between trophic levels.

  15. Feathermoss and epiphytic Nostoc cooperate differently: expanding the spectrum of plant-cyanobacteria symbiosis.

    Science.gov (United States)

    Warshan, Denis; Espinoza, Josh L; Stuart, Rhona K; Richter, R Alexander; Kim, Sea-Yong; Shapiro, Nicole; Woyke, Tanja; C Kyrpides, Nikos; Barry, Kerrie; Singan, Vasanth; Lindquist, Erika; Ansong, Charles; Purvine, Samuel O; M Brewer, Heather; Weyman, Philip D; Dupont, Christopher L; Rasmussen, Ulla

    2017-12-01

    Dinitrogen (N 2 )-fixation by cyanobacteria in symbiosis with feathermosses is the primary pathway of biological nitrogen (N) input into boreal forests. Despite its significance, little is known about the cyanobacterial gene repertoire and regulatory rewiring needed for the establishment and maintenance of the symbiosis. To determine gene acquisitions and regulatory changes allowing cyanobacteria to form and maintain this symbiosis, we compared genomically closely related symbiotic-competent and -incompetent Nostoc strains using a proteogenomics approach and an experimental set up allowing for controlled chemical and physical contact between partners. Thirty-two gene families were found only in the genomes of symbiotic strains, including some never before associated with cyanobacterial symbiosis. We identified conserved orthologs that were differentially expressed in symbiotic strains, including protein families involved in chemotaxis and motility, NO regulation, sulfate/phosphate transport, and glycosyl-modifying and oxidative stress-mediating exoenzymes. The physical moss-cyanobacteria epiphytic symbiosis is distinct from other cyanobacteria-plant symbioses, with Nostoc retaining motility, and lacking modulation of N 2 -fixation, photosynthesis, GS-GOGAT cycle and heterocyst formation. The results expand our knowledge base of plant-cyanobacterial symbioses, provide a model of information and material exchange in this ecologically significant symbiosis, and suggest new currencies, namely nitric oxide and aliphatic sulfonates, may be involved in establishing and maintaining the cyanobacteria-feathermoss symbiosis.

  16. Growth of cyanobacteria on Martian Regolith Simulant after exposure to vacuum

    Science.gov (United States)

    Arai, Mayumi; Sato, Seigo; Ohmori, Masayuki; Tomita-Yokotani, Kaori; Hashimoto, Hirofumi; Yamashita, Masamichi

    Habitation on Mars is one of our challenges in this century. The growth of cyanobacteria on Martian Regolith Simulant (MRS) was studied with two species of terrestrial cyanobacteria, Nostoc, and one species of other cyanobacterium, Synechosystis. Their vacuum tolerances was examined in order to judge feasibility of the use of cyanobacteria to creat habitable environment on a distant planet. The viability of cyanobacteria tested was evaluated by the microscopic observation after staining by FDA (fluorescein diacetate). A part of them were also re-incubated again in a liquid culture medium, and viability and the chlorophyll production were examined in detail. Nostoc was found to grow for over 140 days with their having normal function of chlorophyll synthesis on the MRS. After the exposure to high vacuum environment (10-5 Pa) for a year, Nostoc sp. started growth. Chlorophyll was produced after this vacuum exposure as well. The A'MED (Arai's Mars Ecosystem Dome, A'MED) is designed to install on Mars for conducting agricultural production in it. We performed the fundamental experiment with MRS. These results show a possibility that cyanobacteria could adapt to MRS, and grow under the low pressure environment expected on Mars.

  17. Biodiversity of cyanobacteria and green algae on monuments in the Mediterranean Basin: an overview.

    Science.gov (United States)

    Macedo, Maria Filomena; Miller, Ana Zélia; Dionísio, Amélia; Saiz-Jimenez, Cesareo

    2009-11-01

    The presence and deteriorating action of micro-organisms on monuments and stone works of art have received considerable attention in the last few years. Knowledge of the microbial populations living on stone materials is the starting point for successful conservation treatment and control. This paper reviews the literature on cyanobacteria and chlorophyta that cause deterioration of stone cultural heritage (outdoor monuments and stone works of art) in European countries of the Mediterranean Basin. Some 45 case studies from 32 scientific papers published between 1976 and 2009 were analysed. Six lithotypes were considered: marble, limestone, travertine, dolomite, sandstone and granite. A wide range of stone monuments in the Mediterranean Basin support considerable colonization of cyanobacteria and chlorophyta, showing notable biodiversity. About 172 taxa have been described by different authors, including 37 genera of cyanobacteria and 48 genera of chlorophyta. The most widespread and commonly reported taxa on the stone cultural heritage in the Mediterranean Basin are, among cyanobacteria, Gloeocapsa, Phormidium and Chroococcus and, among chlorophyta, Chlorella, Stichococcus and Chlorococcum. The results suggest that cyanobacteria and chlorophyta colonize a wide variety of substrata and that this is related primarily to the physical characteristics of the stone surface, microclimate and environmental conditions and secondarily to the lithotype.

  18. Deciphering the factors associated with the colonization of rice plants by cyanobacteria.

    Science.gov (United States)

    Bidyarani, Ngangom; Prasanna, Radha; Chawla, Gautam; Babu, Santosh; Singh, Rajendra

    2015-04-01

    Cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. The activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ARA), and DNA fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. Microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and shoot tissues. Among the six cyanobacterial strains employed, Calothrix sp. (RPC1), Anabaena laxa (RPAN8), and Anabaena azollae (C16) were the best performing strains, in terms of colonization in roots and stem. These strains also enhanced nitrogen fixation and stimulated the activity of plant defense/cell wall-degrading enzymes. A significantly high correlation was also recorded between the elicited plant enzymes, growth, and ARA. DNA fingerprinting using highly iterated palindromic sequences (HIP-TG) further helped in proving the establishment of inoculated organisms in the roots/shoots of rice plants. This study illustrated that the colonization of cyanobacteria in the plant tissues is facilitated by increased elicitation of plant enzymes, leading to improved plant growth, nutrient mobilization, and enhanced plant fitness. Such strains can be promising candidates for developing "cyanobacteria colonized-nitrogen-fixing rice plants" in the future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Evolution of multicellularity coincided with increased diversification of cyanobacteria and the Great Oxidation Event

    Science.gov (United States)

    Schirrmeister, Bettina E.; de Vos, Jurriaan M.; Antonelli, Alexandre; Bagheri, Homayoun C.

    2013-01-01

    Cyanobacteria are among the most diverse prokaryotic phyla, with morphotypes ranging from unicellular to multicellular filamentous forms, including those able to terminally (i.e., irreversibly) differentiate in form and function. It has been suggested that cyanobacteria raised oxygen levels in the atmosphere around 2.45–2.32 billion y ago during the Great Oxidation Event (GOE), hence dramatically changing life on the planet. However, little is known about the temporal evolution of cyanobacterial lineages, and possible interplay between the origin of multicellularity, diversification of cyanobacteria, and the rise of atmospheric oxygen. We estimated divergence times of extant cyanobacterial lineages under Bayesian relaxed clocks for a dataset of 16S rRNA sequences representing the entire known diversity of this phylum. We tested whether the evolution of multicellularity overlaps with the GOE, and whether multicellularity is associated with significant shifts in diversification rates in cyanobacteria. Our results indicate an origin of cyanobacteria before the rise of atmospheric oxygen. The evolution of multicellular forms coincides with the onset of the GOE and an increase in diversification rates. These results suggest that multicellularity could have played a key role in triggering cyanobacterial evolution around the GOE. PMID:23319632

  20. What distinguishes cyanobacteria able to revive after desiccation from those that cannot: the genome aspect.

    Science.gov (United States)

    Murik, Omer; Oren, Nadav; Shotland, Yoram; Raanan, Hagai; Treves, Haim; Kedem, Isaac; Keren, Nir; Hagemann, Martin; Pade, Nadin; Kaplan, Aaron

    2017-02-01

    Filamentous cyanobacteria are the main founders and primary producers in biological desert soil crusts (BSCs) and are likely equipped to cope with one of the harshest environmental conditions on earth including daily hydration/dehydration cycles, high irradiance and extreme temperatures. Here, we resolved and report on the genome sequence of Leptolyngbya ohadii, an important constituent of the BSC. Comparative genomics identified a set of genes present in desiccation-tolerant but not in dehydration-sensitive cyanobacteria. RT qPCR analyses showed that the transcript abundance of many of them is upregulated during desiccation in L. ohadii. In addition, we identified genes where the orthologs detected in desiccation-tolerant cyanobacteria differs substantially from that found in desiccation-sensitive cells. We present two examples, treS and fbpA (encoding trehalose synthase and fructose 1,6-bisphosphate aldolase respectively) where, in addition to the orthologs present in the desiccation-sensitive strains, the resistant cyanobacteria also possess genes with different predicted structures. We show that in both cases the two orthologs are transcribed during controlled dehydration of L. ohadii and discuss the genetic basis for the acclimation of cyanobacteria to the desiccation conditions in desert BSC. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. Variety of DNA Replication Activity Among Cyanobacteria Correlates with Distinct Respiration Activity in the Dark.

    Science.gov (United States)

    Ohbayashi, Ryudo; Yamamoto, Jun-Ya; Watanabe, Satoru; Kanesaki, Yu; Chibazakura, Taku; Miyagishima, Shin-Ya; Yoshikawa, Hirofumi

    2017-02-01

    Cyanobacteria exhibit light-dependent cell growth since most of their cellular energy is obtained by photosynthesis. In Synechococcus elongatus PCC 7942, one of the model cyanobacteria, DNA replication depends on photosynthetic electron transport. However, the critical signal for the regulatory mechanism of DNA replication has not been identified. In addition, conservation of this regulatory mechanism has not been investigated among cyanobacteria. To understand this regulatory signal and its dependence on light, we examined the regulation of DNA replication under both light and dark conditions among three model cyanobacteria, S. elongatus PCC 7942, Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120. Interestingly, DNA replication activity in Synechocystis and Anabaena was retained when cells were transferred to the dark, although it was drastically decreased in S. elongatus. Glycogen metabolism and respiration were higher in Synechocystis and Anabaena than in S. elongatus in the dark. Moreover, DNA replication activity in Synechocystis and Anabaena was reduced to the same level as that in S. elongatus by inhibition of respiratory electron transport after transfer to the dark. These results demonstrate that there is disparity in DNA replication occurring in the dark among cyanobacteria, which is caused by the difference in activity of respiratory electron transport. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Effect of Cyanobacteria Isolates on Rice Seeds Germination in Saline Soil

    Directory of Open Access Journals (Sweden)

    Mostafa M. El -Sheekh

    2018-03-01

    Full Text Available Cyanobacteria are prokaryotic photosynthetic communities which are used in biofertilization of many plants especially rice plant. Cyanobacteria play a vital role to increase the plant's ability for salinity tolerance. Salinity is a worldwide problem which affects the growth and productivity of crops. In this work three cyanobacteria strains (Nostoc calcicola, Anabaena variabilis, and Nostoc linkia were isolated from saline soil at Kafr El-Sheikh Governorate; North Egypt. The propagated cyanobacteria strains were used to withstand salinity of the soil and increase rice plant growth (Giza 178. The length of roots and shoot seedlings was measured for seven and forty days of cultivation, respectively. The results of this investigation showed that the inoculation with Nostoc calcicola, Anabaena variabilis, and Nostoc linkia increased root length by 27.0, 4.0, 3.0 % and 39, 20, 19 % in EC5 and 10 (ds/m, respectively. Similarly, they increased shoot length by 121, 70, 55 %, 116, 88, 82 % in EC5 and 10 (ds/m, respectively. In EC15and more concentrations, control rice plants could not grow while those to which cyanobacteria were inoculated could withstand only EC15 but not other elevated concentrations. These results encourage using Nostoc calcicola,Anabaena variabilis, and Nostoc linkia as biofertilizer for rice plant in the saline soil for increasing growth and decrease soil electrical conductivity.

  3. Fate of cyanobacteria and their metabolites during water treatment sludge management processes.

    Science.gov (United States)

    Ho, Lionel; Dreyfus, Jennifer; Boyer, Justine; Lowe, Todd; Bustamante, Heriberto; Duker, Phil; Meli, Tass; Newcombe, Gayle

    2012-05-01

    Cyanobacteria and their metabolites are an issue for water authorities; however, little is known as to the fate of coagulated cyanobacterial-laden sludge during waste management processes in water treatment plants (WTPs). This paper provides information on the cell integrity of Anabaena circinalis and Cylindrospermopsis raciborskii during: laboratory-scale coagulation/sedimentation processes; direct filtration and backwashing procedures; and cyanobacterial-laden sludge management practices. In addition, the metabolites produced by A. circinalis (geosmin and saxitoxins) and C. raciborskii (cylindrospermopsin) were investigated with respect to their release (and possible degradation) during each of the studied processes. Where sedimentation was used, coagulation effectively removed cyanobacteria (and intracellular metabolites) without any considerable exertion on coagulant demand. During direct filtration experiments, cyanobacteria released intracellular metabolites through a stagnation period, suggesting that more frequent backwashing of filters may be required to prevent floc build-up and metabolite release. Cyanobacteria appeared to be protected within the flocs, with minimal damage during backwashing of the filters. Within coagulant sludge, cyanobacteria released intracellular metabolites into the supernatant after 3d, even though cells remained viable up to 7d. This work has improved the understanding of cyanobacterial metabolite risks associated with management of backwash water and sludge and is likely to facilitate improvements at WTPs, including increased monitoring and the application of treatment strategies and operational practices, with respect to cyanobacterial-laden sludge and/or supernatant recycle management. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Report on approaches to predicting probability of cyanobacteria blooms or related indices based on nutrient inputs and other ecosystem attributes in lakes

    Science.gov (United States)

    Despite a lengthy history of research on cyanobacteria, many important questions about this diverse group of aquatic, photosynthetic “blue-green algae” remain unanswered. For example, how can we more accurately predict cyanobacteria blooms in freshwater systems? Whi...

  5. Spatial and seasonal variation in diversity and structure of microbial biofilms on marine plastics in Northern European waters.

    Science.gov (United States)

    Oberbeckmann, Sonja; Loeder, Martin G J; Gerdts, Gunnar; Osborn, A Mark

    2014-11-01

    Plastic pollution is now recognised as a major threat to marine environments and marine biota. Recent research highlights that diverse microbial species are found to colonise plastic surfaces (the plastisphere) within marine waters. Here, we investigate how the structure and diversity of marine plastisphere microbial community vary with respect to season, location and plastic substrate type. We performed a 6-week exposure experiment with polyethylene terephthalate (PET) bottles in the North Sea (UK) as well as sea surface sampling of plastic polymers in Northern European waters. Scanning electron microscopy revealed diverse plastisphere communities comprising prokaryotic and eukaryotic microorganisms. Denaturing gradient gel electrophoresis (DGGE) and sequencing analysis revealed that plastisphere microbial communities on PET fragments varied both with season and location and comprised of bacteria belonging to Bacteroidetes, Proteobacteria, Cyanobacteria and members of the eukaryotes Bacillariophyceae and Phaeophyceae. Polymers sampled from the sea surface mainly comprised polyethylene, polystyrene and polypropylene particles. Variation within plastisphere communities on different polymer types was observed, but communities were primarily dominated by Cyanobacteria. This research reveals that the composition of plastisphere microbial communities in marine waters varies with season, geographical location and plastic substrate type. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Harmful Freshwater Algal Blooms, With an Emphasis on Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Hans W. Paerl

    2001-01-01

    Full Text Available Suspended algae, or phytoplankton, are the prime source of organic matter supporting food webs in freshwater ecosystems. Phytoplankton productivity is reliant on adequate nutrient supplies; however, increasing rates of nutrient supply, much of it manmade, fuels accelerating primary production or eutrophication. An obvious and problematic symptom of eutrophication is rapid growth and accumulations of phytoplankton, leading to discoloration of affected waters. These events are termed blooms. Blooms are a prime agent of water quality deterioration, including foul odors and tastes, deoxygenation of bottom waters (hypoxia and anoxia, toxicity, fish kills, and food web alterations. Toxins produced by blooms can adversely affect animal (including human health in waters used for recreational and drinking purposes. Numerous freshwater genera within the diverse phyla comprising the phytoplankton are capable of forming blooms; however, the blue-green algae (or cyanobacteria are the most notorious bloom formers. This is especially true for harmful toxic, surface-dwelling, scum-forming genera (e.g., Anabaena, Aphanizomenon, Nodularia, Microcystis and some subsurface bloom-formers (Cylindrospermopsis, Oscillatoria that are adept at exploiting nutrient-enriched conditions. They thrive in highly productive waters by being able to rapidly migrate between radiance-rich surface waters and nutrient-rich bottom waters. Furthermore, many harmful species are tolerant of extreme environmental conditions, including very high light levels, high temperatures, various degrees of desiccation, and periodic nutrient deprivation. Some of the most noxious cyanobacterial bloom genera (e.g., Anabaena, Aphanizomenon, Cylindrospermopsis, Nodularia are capable of fixing atmospheric nitrogen (N2, enabling them to periodically dominate under nitrogen-limited conditions. Cyanobacteria produce a range of organic compounds, including those that are toxic to higher-ranked consumers, from

  7. Phylogenetic position of Geitleribactron purpureum (Synechococcales, Cyanobacteria/Cyanophyceae) and its implications for the taxonomy of Chamaesiphonaceae and Leptolyngbyaceae.

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jan; Cantonati, M.

    2016-01-01

    Roč. 16, č. 1 (2016), s. 104-111 ISSN 1802-5439 Institutional support: RVO:60077344 Keywords : Alps * carbonate lakes * Geitleribactron * heteropolar cyanobacteria * single-colony sequencing * unicellular cyanobacteria Subject RIV: EF - Botanics Impact factor: 1.350, year: 2016

  8. Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

    Science.gov (United States)

    da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall'Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves; Gonçalves, Evonnildo Costa

    2016-05-19

    Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here. Copyright © 2016 da Silva et al.

  9. Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria

    OpenAIRE

    da Silva, F?bio Daniel Flor?ncio; Lima, Alex Ranieri Jer?nimo; Moraes, Pablo Henrique Gon?alves; Siqueira, Andrei Santos; Dall?Agnol, Leonardo Teixeira; Bara?na, Anna Rafaella Ferreira; Martins, Luisa Car?cio; Oliveira, Karol Guimar?es; de Lima, Clayton Pereira Silva; Nunes, M?rcio Roberto Teixeira; Vianez-J?nior, Jo?o L?dio Silva Gon?alves; Gon?alves, Evonnildo Costa

    2016-01-01

    Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here.

  10. Grazing on colonial and filamentous, toxic and non-toxic cyanobacteria by the zebra mussel Dreissena polymorpha

    NARCIS (Netherlands)

    Pires, L.M.D.; Bontes, B.M.; Van Donk, E.; Ibelings, B.W.

    2005-01-01

    Colony forming and toxic cyanobacteria form a problem in surface waters of shallow lakes, both for recreation and wildlife. Zebra mussels, Dreissena polymorpha, have been employed to help to restore shallow lakes in the Netherlands, dominated by cyanobacteria, to their former clear state. Zebra

  11. Phenotypic and genetic diversification of Pseudanabaena spp. (cyanobacteria).

    Science.gov (United States)

    Acinas, Silvia G; Haverkamp, Thomas H A; Huisman, Jef; Stal, Lucas J

    2009-01-01

    Pseudanabaena species are poorly known filamentous bloom-forming cyanobacteria closely related to Limnothrix. We isolated 28 Pseudanabaena strains from the Baltic Sea (BS) and the Albufera de Valencia (AV; Spain). By combining phenotypic and genotypic approaches, the phylogeny, diversity and evolutionary diversification of these isolates were explored. Analysis of the in vivo absorption spectra of the Pseudanabaena strains revealed two coexisting pigmentation phenotypes: (i) phycocyanin-rich (PC-rich) strains and (ii) strains containing both PC and phycoerythrin (PE). Strains of the latter phenotype were all capable of complementary chromatic adaptation (CCA). About 65 kb of the Pseudanabaena genomes were sequenced through a multilocus sequencing approach including the sequencing of the16 and 23S rRNA genes, the ribosomal intergenic spacer (IGS), internal transcribed spacer 1 (ITS-1), the cpcBA operon encoding PC and the IGS between cpcA and cpcB. In addition, the presence of nifH, one of the structural genes of nitrogenase, was investigated. Sequence analysis of ITS and cpcBA-IGS allowed the differentiation between Pseudanabaena isolates exhibiting high levels of microdiversity. This multilocus sequencing approach revealed specific clusters for the BS, the AV and a mixed cluster with strains from both ecosystems. The latter comprised exclusively CCA phenotypes. The phylogenies of the 16 and 23S rRNA genes are consistent, but analysis of other loci indicated the loss of substructure, suggesting that the recombination between these loci has occurred. Our preliminary results on population genetic analyses of the PC genes suggest an evolutionary diversification of Pseudanabaena through purifying selection.

  12. Desert Cyanobacteria under simulated space and Martian conditions

    Science.gov (United States)

    Billi, D.; Ghelardini, P.; Onofri, S.; Cockell, C. S.; Rabbow, E.; Horneck, G.

    2008-09-01

    The environment in space and on planets such as Mars, can be lethal to living organisms and high levels of tolerance to desiccation, cold and radiation are needed for survival: rock-inhabiting cyanobacteria belonging to the genus Chroococcidiopsis can fulfil these requirements [1]. These cyanobacteria constantly appear in the most extreme and dry habitats on Earth, including the McMurdo Dry Valleys (Antarctica) and the Atacama Desert (Chile), which are considered the closest terrestrial analogs of two Mars environmental extremes: cold and aridity. In their natural environment, these cyanobacteria occupy the last refuges for life inside porous rocks or at the stone-soil interfaces, where they survive in a dry, dormant state for prolonged periods. How desert strains of Chroococcidiopsis can dry without dying is only partially understood, even though experimental evidences support the existence of an interplay between mechanisms to avoid (or limit) DNA damage and repair it: i) desert strains of Chroococcidiopsis mend genome fragmentation induced by ionizing radiation [2]; ii) desiccation-survivors protect their genome from complete fragmentation; iii) in the dry state they show a survival to an unattenuated Martian UV flux greater than that of Bacillus subtilis spores [3], and even though they die following atmospheric entry after having orbited the Earth for 16 days [4], they survive to simulated shock pressures up to 10 GPa [5]. Recently additional experiments were carried out at the German Aerospace Center (DLR) of Cologne (Germany) in order to identify suitable biomarkers to investigate the survival of Chroococcidiopsis cells present in lichen-dominated communities, in view of their direct and long term space exposition on the International Space Station (ISS) in the framework of the LIchens and Fungi Experiments (LIFE, EXPOSEEuTEF, ESA). Multilayers of dried cells of strains CCMEE 134 (Beacon Valley, Antarctica), and CCMEE 123 (costal desert, Chile ), shielded by

  13. Genome Engineering of the 2,3-Butanediol Biosynthetic Pathway for Tight Regulation in Cyanobacteria.

    Science.gov (United States)

    Nozzi, Nicole E; Atsumi, Shota

    2015-11-20

    Cyanobacteria have gained popularity among the metabolic engineering community as a tractable photosynthetic host for renewable chemical production. However, though a number of successfully engineered production systems have been reported, long-term genetic stability remains an issue for cyanobacterial systems. The genetic engineering toolbox for cyanobacteria is largely lacking inducible systems for expression control. The characterization of tight regulation systems for use in cyanobacteria may help to alleviate this problem. In this work we explore the function of the IPTG inducible promoter P(L)lacO1 in the model cyanobacterium Synechococcus elongatus PCC 7942 as well as the effect of gene order within an operon on pathway expression. According to our experiments, P(L)lacO1 functions well as an inducible promoter in S. elongatus. Additionally, we found that gene order within an operon can strongly influence control of expression of each gene.

  14. Management of toxic cyanobacteria for drinking water production of Ain Zada Dam.

    Science.gov (United States)

    Saoudi, Amel; Brient, Luc; Boucetta, Sabrine; Ouzrout, Rachid; Bormans, Myriam; Bensouilah, Mourad

    2017-07-01

    Blooms of toxic cyanobacteria in Algerian reservoirs represent a potential health problem, mainly from drinking water that supplies the local population of Ain Zada (Bordj Bou Arreridj). The objective of this study is to monitor, detect, and identify the existence of cyanobacteria and microcystins during blooming times. Samples were taken in 2013 from eight stations. The results show that three potentially toxic cyanobacterial genera with the species Planktothrix agardhii were dominant. Cyanobacterial biomass, phycocyanin (PC) concentrations, and microcystin (MC) concentrations were high in the surface layer and at 14 m depth; these values were also high in the treated water. On 11 May 2013, MC concentrations were 6.3 μg/L in MC-LR equivalent in the drinking water. This study shows for the first time the presence of cyanotoxins in raw and treated waters, highlighting that regular monitoring of cyanobacteria and cyanotoxins must be undertaken to avoid potential health problems.

  15. High-throughput detection of ethanol-producing cyanobacteria in a microdroplet platform.

    Science.gov (United States)

    Abalde-Cela, Sara; Gould, Anna; Liu, Xin; Kazamia, Elena; Smith, Alison G; Abell, Chris

    2015-05-06

    Ethanol production by microorganisms is an important renewable energy source. Most processes involve fermentation of sugars from plant feedstock, but there is increasing interest in direct ethanol production by photosynthetic organisms. To facilitate this, a high-throughput screening technique for the detection of ethanol is required. Here, a method for the quantitative detection of ethanol in a microdroplet-based platform is described that can be used for screening cyanobacterial strains to identify those with the highest ethanol productivity levels. The detection of ethanol by enzymatic assay was optimized both in bulk and in microdroplets. In parallel, the encapsulation of engineered ethanol-producing cyanobacteria in microdroplets and their growth dynamics in microdroplet reservoirs were demonstrated. The combination of modular microdroplet operations including droplet generation for cyanobacteria encapsulation, droplet re-injection and pico-injection, and laser-induced fluorescence, were used to create this new platform to screen genetically engineered strains of cyanobacteria with different levels of ethanol production.

  16. Effects of UV-B and heavy metals on nitrogen and phosphorus metabolism in three cyanobacteria.

    Science.gov (United States)

    Yadav, Shivam; Prajapati, Rajesh; Atri, Neelam

    2016-01-01

    Cyanobacteria sp. (diazotrophic and planktonic) hold a major position in ecosystem, former one due to their intrinsic capability of N2-fixation and later because of mineralization of organic matter. Unfortunately, their exposure to variety of abiotic stresses is unavoidable. Comparative analysis of interactive effect of UV-B and heavy metals (Cd/Zn) on nitrogen and phosphorus metabolism of three cyanobacteria (Anabaena, Microcystis, Nostoc) revealed additive inhibition (χ(2) significant p cyanobacteria suggests UV-B-induced structural change(s) in the enzyme/carriers. Metals seem to compete for the binding sites of the enzymes and carriers; as noticed for Anabaena and Microcystis showing change in Km while no change in the Km value of Nostoc suggests non-competitive nutrient uptake. Higher accumulation and more adverse effect on Na(+) and K(+) efflux proposes Cd as more toxic compared to Zn. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Global warming and hepatotoxin production by cyanobacteria: what can we learn from experiments?

    Science.gov (United States)

    El-Shehawy, Rehab; Gorokhova, Elena; Fernández-Piñas, Francisca; del Campo, Francisca F

    2012-04-01

    Global temperature is expected to rise throughout this century, and blooms of cyanobacteria in lakes and estuaries are predicted to increase with the current level of global warming. The potential environmental, economic and sanitation repercussions of these blooms have attracted considerable attention among the world's scientific communities, water management agencies and general public. Of particular concern is the worldwide occurrence of hepatotoxic cyanobacteria posing a serious threat to global public health. Here, we highlight plausible effects of global warming on physiological and molecular changes in these cyanobacteria and resulting effects on hepatotoxin production. We also emphasize the importance of understanding the natural biological function(s) of hepatotoxins, various mechanisms governing their synthesis, and climate-driven changes in food-web interactions, if we are to predict consequences of the current and projected levels of global warming for production and accumulation of hepatotoxins in aquatic ecosystems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Surveying DNA Elements within Functional Genes of Heterocyst-Forming Cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Jason A Hilton

    Full Text Available Some cyanobacteria are capable of differentiating a variety of cell types in response to environmental factors. For instance, in low nitrogen conditions, some cyanobacteria form heterocysts, which are specialized for N2 fixation. Many heterocyst-forming cyanobacteria have DNA elements interrupting key N2 fixation genes, elements that are excised during heterocyst differentiation. While the mechanism for the excision of the element has been well-studied, many questions remain regarding the introduction of the elements into the cyanobacterial lineage and whether they have been retained ever since or have been lost and reintroduced. To examine the evolutionary relationships and possible function of DNA sequences that interrupt genes of heterocyst-forming cyanobacteria, we identified and compared 101 interruption element sequences within genes from 38 heterocyst-forming cyanobacterial genomes. The interruption element lengths ranged from about 1 kb (the minimum able to encode the recombinase responsible for element excision, up to nearly 1 Mb. The recombinase gene sequences served as genetic markers that were common across the interruption elements and were used to track element evolution. Elements were found that interrupted 22 different orthologs, only five of which had been previously observed to be interrupted by an element. Most of the newly identified interrupted orthologs encode proteins that have been shown to have heterocyst-specific activity. However, the presence of interruption elements within genes with no known role in N2 fixation, as well as in three non-heterocyst-forming cyanobacteria, indicates that the processes that trigger the excision of elements may not be limited to heterocyst development or that the elements move randomly within genomes. This comprehensive analysis provides the framework to study the history and behavior of these unique sequences, and offers new insight regarding the frequency and persistence of interruption

  19. Biofilm formation and indole-3-acetic acid production by two rhizospheric unicellular cyanobacteria.

    Science.gov (United States)

    Ahmed, Mehboob; Stal, Lucas J; Hasnain, Shahida

    2014-08-01

    Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant hormone indole-3-acetic acid (IAA) and the potential of biofilm formation on the rhizoplane of pea plants by two cyanobacterial strains, isolated from rice rhizosphere. The unicellular cyanobacteria Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 that were isolated from a rice rhizosphere, were investigated. Production of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 was measured under experimental conditions (pH and light). The bioactivity of the cyanobacterial auxin was demonstrated through the alteration of the rooting pattern of Pisum sativum seedlings. The increase in the concentration of L-tryptophan and the time that this amino acid was present in the medium resulted in a significant enhancement of the synthesis of IAA (r > 0.900 at p = 0.01). There was also a significant correlation between the concentration of IAA in the supernatant of the cyanobacteria cultures and the root length and number of the pea seedlings. Observations made by confocal laser scanning microscopy revealed the presence of cyanobacteria on the surface of the roots and also provided evidence for the penetration of the cyanobacteria in the endorhizosphere. We show that the synthesis of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 occurs under different environmental conditions and that the auxin is important for the development of the seedling roots and for establishing an intimate symbiosis between cyanobacteria and host plants.

  20. An Amoebal Grazer of Cyanobacteria Requires Cobalamin Produced by Heterotrophic Bacteria.

    Science.gov (United States)

    Ma, Amy T; Beld, Joris; Brahamsha, Bianca

    2017-05-15

    Amoebae are unicellular eukaryotes that consume microbial prey through phagocytosis, playing a role in shaping microbial food webs. Many amoebal species can be cultivated axenically in rich media or monoxenically with a single bacterial prey species. Here, we characterize heterolobosean amoeba LPG3, a recent natural isolate, which is unable to grow on unicellular cyanobacteria, its primary food source, in the absence of a heterotrophic bacterium, a Pseudomonas species coisolate. To investigate the molecular basis of this requirement for heterotrophic bacteria, we performed a screen using the defined nonredundant transposon library of Vibrio cholerae , which implicated genes in corrinoid uptake and biosynthesis. Furthermore, cobalamin synthase deletion mutations in V. cholerae and the Pseudomonas species coisolate do not support the growth of amoeba LPG3 on cyanobacteria. While cyanobacteria are robust producers of a corrinoid variant called pseudocobalamin, this variant does not support the growth of amoeba LPG3. Instead, we show that it requires cobalamin that is produced by the Pseudomonas species coisolate. The diversity of eukaryotes utilizing corrinoids is poorly understood, and this amoebal corrinoid auxotroph serves as a model for examining predator-prey interactions and micronutrient transfer in bacterivores underpinning microbial food webs. IMPORTANCE Cyanobacteria are important primary producers in aquatic environments, where they are grazed upon by a variety of phagotrophic protists and, hence, have an impact on nutrient flux at the base of microbial food webs. Here, we characterize amoebal isolate LPG3, which consumes cyanobacteria as its primary food source but also requires heterotrophic bacteria as a source of corrinoid vitamins. Amoeba LPG3 specifically requires the corrinoid variant produced by heterotrophic bacteria and cannot grow on cyanobacteria alone, as they produce a different corrinoid variant. This same corrinoid specificity is also

  1. Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis.

    Science.gov (United States)

    Mucci, Maíra; Noyma, Natalia Pessoa; de Magalhães, Leonardo; Miranda, Marcela; van Oosterhout, Frank; Guedes, Iamê Alves; Huszar, Vera L M; Marinho, Marcelo Manzi; Lürling, Miquel

    2017-07-01

    Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show that chitosan may rapidly compromise membrane integrity and kill certain cyanobacteria leading to release of cell contents in the water. A strain of Cylindrospermopsis raciborskii and one strain of Planktothrix agardhii were most sensitive. A 1.3 h exposure to a low dose of 0.5 mg l -1 chitosan already almost completely killed these cultures resulting in release of cell contents. After 24 h, reductions in PSII efficiencies of all cyanobacteria tested were observed. EC50 values varied from around 0.5 mg l -1 chitosan for the two sensitive strains, via about 5 mg l -1 chitosan for an Aphanizomenon flos-aquae strain, a toxic P. agardhii strain and two Anabaena cylindrica cultures, to more than 8 mg l -1 chitosan for a Microcystis aeruginosa strain and another A. flos-aquae strain. Differences in sensitivity to chitosan might be related to polymeric substances that surround cyanobacteria. Rapid lysis of toxic strains is likely and when chitosan flocking and sinking of cyanobacteria is considered in lake restoration, flocculation efficacy studies should be complemented with investigation on the effects of chitosan on the cyanobacteria assemblage being targeted. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Environmental influence on cyanobacteria abundance and microcystin toxin production in a shallow temperate lake.

    Science.gov (United States)

    Lee, Tammy A; Rollwagen-Bollens, Gretchen; Bollens, Stephen M; Faber-Hammond, Joshua J

    2015-04-01

    The increasing frequency of harmful cyanobacterial blooms in freshwater systems is a commonly recognized problem due to detrimental effects on water quality. Vancouver Lake, a shallow, tidally influenced lake in the flood plain of the Columbia River within the city of Vancouver, WA, USA, has experienced numerous summertime cyanobacterial blooms, dominated by Aphanizomenon sp. and Anabaena sp. Cyanobacteria abundance and toxin (microcystin) levels have been monitored in this popular urban lake for several years; however, no previous studies have identified which cyanobacteria species produce toxins, nor analyzed how changes in environmental variables contribute to the fluctuations in toxic cyanobacteria populations. We used a suite of molecular techniques to analyze water samples from Vancouver Lake over two summer bloom cycles (2009 and 2010). Both intracellular and extracellular microcystin concentrations were measured using an ELISA kit. Intracellular microcystin concentrations exceeded WHO guidelines for recreational waters several times throughout the sampling period. PCR results demonstrated that Microcystis sp. was the sole microcystin-producing cyanobacteria species present in Vancouver Lake, although Microcystis sp. was rarely detected in microscopical counts. qPCR results indicated that the majority of the Microcystis sp. population contained the toxin-producing gene (mcyE), although Microcystis sp. abundance rarely exceeded 1 percent of overall cyanobacteria abundance. Non-metric multidimensional scaling (NMDS) revealed that PO4-P was the main environmental variable influencing the abundance of toxic and non-toxic cyanobacteria, as well as intracellular microcystin concentrations. Our study underscores the importance of using molecular genetic techniques, in addition to traditional microscopy, to assess the importance of less conspicuous species in the dynamics of harmful algal blooms. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Surveying DNA Elements within Functional Genes of Heterocyst-Forming Cyanobacteria.

    Science.gov (United States)

    Hilton, Jason A; Meeks, John C; Zehr, Jonathan P

    2016-01-01

    Some cyanobacteria are capable of differentiating a variety of cell types in response to environmental factors. For instance, in low nitrogen conditions, some cyanobacteria form heterocysts, which are specialized for N2 fixation. Many heterocyst-forming cyanobacteria have DNA elements interrupting key N2 fixation genes, elements that are excised during heterocyst differentiation. While the mechanism for the excision of the element has been well-studied, many questions remain regarding the introduction of the elements into the cyanobacterial lineage and whether they have been retained ever since or have been lost and reintroduced. To examine the evolutionary relationships and possible function of DNA sequences that interrupt genes of heterocyst-forming cyanobacteria, we identified and compared 101 interruption element sequences within genes from 38 heterocyst-forming cyanobacterial genomes. The interruption element lengths ranged from about 1 kb (the minimum able to encode the recombinase responsible for element excision), up to nearly 1 Mb. The recombinase gene sequences served as genetic markers that were common across the interruption elements and were used to track element evolution. Elements were found that interrupted 22 different orthologs, only five of which had been previously observed to be interrupted by an element. Most of the newly identified interrupted orthologs encode proteins that have been shown to have heterocyst-specific activity. However, the presence of interruption elements within genes with no known role in N2 fixation, as well as in three non-heterocyst-forming cyanobacteria, indicates that the processes that trigger the excision of elements may not be limited to heterocyst development or that the elements move randomly within genomes. This comprehensive analysis provides the framework to study the history and behavior of these unique sequences, and offers new insight regarding the frequency and persistence of interruption elements in

  4. Relationships among cyanobacteria, zooplankton and fish in sub-bloom conditions in the Sulejow Reservoir

    Directory of Open Access Journals (Sweden)

    Zbigniew Kaczkowski

    2017-01-01

    Full Text Available The occurrence of cyanobacteria is particularly characteristic of shallow eutrophic waters, and they often form massive ‘blooms’ that can affect aquatic invertebrates and fish. However, even a low abundance of cyanobacteria can be hazardous to aquatic organisms, due to the production of toxic metabolites. The aim of this study was to investigate the relationship between cyanobacteria and their toxicity (biological activity towards zooplankton and fish communities, when only low concentrations of cyanobacterial chlorophyll a (less than 20 μg L-1 are detected, i.e. in sub-bloom conditions. Measurements were performed in Sulejow Reservoir (Central Poland, a shallow, lowland, eutrophic reservoir, in which cyanobacterial blooms occur regularly. Fish were assessed using echo-sounding (distribution and by gillnetting (species composition. Simultaneously, zooplankton, cyanobacteria and physico-chemical characteristics were studied at 14 stations situated along hydroacoustic transects. Parameters that characterized the cyanobacteria (cyanobacterial chlorophyll a concentration, the number of 16S rRNA and the mcyA gene copies and microcystin (MC concentration were consistently correlated (based on a principal component analysis, and the highest values were found in the downstream region of the study area. This ‘cyano-complex’ was also positively correlated with oxygen concentration, pH and phosphate levels, but was negatively correlated with temperature and the concentrations of nitrates and nitrites. In Sulejow Reservoir in 2013 the biomass of large zooplankton filter feeders decreased along with increasing MC concentration and fish densities, while small filter feeders did not present such relationships with regards to fish densities. Fish abundance tended to decrease at stations with a lower abundance of cyanobacteria and with growing toxic genotype copies and MC concentration.

  5. Biofilm forming cyanobacteria, algae and fungi on two historic monuments in Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica

    2010-01-01

    Full Text Available Biofilm on the sandstone substrata of the bridge 'Brankov most' and on the granite substrata of the 'Monument of the Unknown Hero' contains a complex consortia of cyanobacteria, algae, and fungi. Coccoid and filamentous cyanobacteria, green algae and diatoms make up the photosynthetic part of the biofilm while hyphal fragments, chlamydospores, fruiting bodies and spores take part as fungal components. These structures make a dense layer by intertwining and overlapping the stone surface. Five cyanobacterial, 11 algal and 23 fungal taxa were found. The interaction of the biofilm's constituents results in the bioweathering of the stone substrata through mechanical penetration, acid corrosion and the production of secondary mycogenic biominerals. .

  6. The generation of molecular hydrogen by cyanobacteria. Die Gewinnung von molekularem Wasserstoff durch Cyanobakterien

    Energy Technology Data Exchange (ETDEWEB)

    Kentemich, T.; Haverkamp, G.; Bothe, H. (Koeln Univ. (Germany, F.R.). Botanisches Inst.)

    1990-01-01

    Currently there is renewed interest in projects on solar-energy conversion by microorganisms. Among all organisms, cyanobacteria are first choice for such projects. Hydrogen production by cyanobacteria is light-dependent and catalyzed by the enzyme complex nitrogenase which concomitantly catalyzes the reduction of N{sub 2} to ammonia. The cyanobacterium Anabaena variabilis can express an alternative, vanadium-containing nitrogenase which produces more hydrogen than the conventional, molybdenum-containing enzyme. In intact cells, most of the H{sub 2} produced by nitrogenase is immediatley reutilized by the hydrogenase enzymes. Maximal hydrogen production requires the genetic blockage of H{sub 2} utilization by the hydrogenases. (orig.).

  7. Methods for determining microcystins (peptide hepatotoxins) and microcystin-producing cyanobacteria.

    Science.gov (United States)

    Sangolkar, Lalita N; Maske, Sarika S; Chakrabarti, Tapan

    2006-11-01

    Episodes of cyanobacterial toxic blooms and fatalities to animals and humans due to cyanobacterial toxins (CBT) are known worldwide. The hepatotoxins and neurotoxins (cyanotoxins) produced by bloom-forming cyanobacteria have been the cause of human and animal health hazards and even death. Prevailing concentration of cell bound endotoxin, exotoxin and the toxin variants depend on developmental stages of the bloom and the cyanobacterial (CB) species involved. Toxic and non-toxic strains do not show any predictable morphological difference. The current instrumental, immunological and molecular methods applied for determining microcystins (peptide hepatotoxins) and microcystin-producing cyanobacteria are reviewed.

  8. Marine animal stings or bites

    Science.gov (United States)

    Stings - marine animals; Bites - marine animals ... Things you can do to prevent a marine animal sting or bite include: Swim near a lifeguard. Observe posted signs that may warn of danger from jellyfish or other hazardous marine life. ...

  9. Siderophilic Cyanobacteria for the Development of Extraterrestrial Photoautotrophic Biotechnologies

    Science.gov (United States)

    Brown, I. I.; McKay, D. S.

    2010-01-01

    In-situ production of consumables (mainly oxygen) using local resources (In-Situ Resource Utilization-ISRU) will significantly facilitate current plans for human exploration and settlement of the solar system, starting with the Moon. With few exceptions, nearly all technologies developed to date have employed an approach based on inorganic chemistry. None of these technologies include concepts for integrating the ISRU system with a bioregenerative life support system and a food production system. Therefore, a new concept based on the cultivation of cyanobacteria (CB) in semi-closed biogeoreactor, linking ISRU, a biological life support system, and food production, has been proposed. The key feature of the biogeoreactor is to use lithotrophic CB to extract many needed elements such as Fe directly from the dissolved regolith and direct them to any technological loop at an extraterrestrial outpost. Our studies showed that siderophilic (Fe-loving) CB are capable to corrode lunar regolith stimulants because they secrete chelating agents and can tolerate [Fe] up to 1 mM. However, lunar and Martian environments are very hostile (very high UV and gamma-radiation, extreme temperatures, deficit of water). Thus, the selection of CB species with high potential for extraterrestrial biotechnologies that may be utilized in 15 years must be sponsored by NASA as soon as possible. The study of the genomes of candidate CB species and the metagenomes of the terrestrial environments which they inhabit is critical to make this decision. Here we provide preliminary results about peculiarities of the genomes of siderophilic CB revealed by analyzing the genome of siderophilic cyanobacterium JSC-1 and the metagenome of iron depositing hot spring (IDHS) Chocolate Pots (Yellowstone National Park, Wyoming, USA). It has been found that IDHS are richer with ferrous iron than the majority of hot springs around the world. Fe2+ is known to increase the magnitude of oxidative stress in prokaryotes

  10. Mariners Weather Log

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Mariners Weather Log (MWL) is a publication containing articles, news and information about marine weather events and phenomena, worldwide environmental impact...

  11. MarineCadastre.gov

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MarineCadastre.gov is a marine information system that provides authoritative ocean data, offshore planning tools, and technical support to the offshore renewable...

  12. Marine Jurisdiction Boundaries

    Data.gov (United States)

    Department of Homeland Security — The NOAA Coastal Services Center's Marine Jurisdiction dataset was created to assist in marine spatial planning and offshore alternative energy sitting. This is a...

  13. Tsunamis and marine life

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.V.S.; Ingole, B.S.; Tang, D.; Satyanarayan, B.; Zhao, H.

    The 26 December 2004 tsunami in the Indian Ocean exerted far reaching temporal and spatial impacts on marine biota. Our synthesis was based on satellite data acquired by the Laboratory for Tropical Marine Environmental Dynamics (LED) of the South...

  14. Supermarket Marine Biology.

    Science.gov (United States)

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  15. Seashore marine table quiz

    OpenAIRE

    Institute, Marine

    2013-01-01

    Develop an increasing awareness of plants and animals that live in local marine environments including the seashore, seas and oceans of Ireland. After learning all about the seashore and other marine related lessons, this quiz can be used to evaluate the student’s knowledge of the marine related living things and natural environments. The table quiz can be used as a guide, highlighting facts about the marine environment and some of the animals that live there.

  16. Carotenoids in Marine Animals

    OpenAIRE

    Maoka, Takashi

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine a...

  17. Marine Education Knowledge Inventory.

    Science.gov (United States)

    Hounshell, Paul B.; Hampton, Carolyn

    This 35-item, multiple-choice Marine Education Knowledge Inventory was developed for use in upper elementary/middle schools to measure a student's knowledge of marine science. Content of test items is drawn from oceanography, ecology, earth science, navigation, and the biological sciences (focusing on marine animals). Steps in the construction of…

  18. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  19. Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

    DEFF Research Database (Denmark)

    Hammar, Petter; Angermayr, S. Andreas; Sjostrom, Staffan L.

    2015-01-01

    Background: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible.Results: We present a method for high-throughput, single-cell analy...

  20. Competition and facilitation between unicellular nitrogen-fixing cyanobacteria and non-nitrogen-fixing phytoplankton species

    NARCIS (Netherlands)

    Agawin, N.S.; Rabouille, S.; Veldhuis, M.; Servatius, L.; Hol, S.; van Overzee, H.M.J.; Huisman, J.

    2007-01-01

    Abstract: Recent discoveries show that small unicellular nitrogen-fixing cyanobacteria are more widespread than previously thought and can make major contributions to the nitrogen budget of the oceans. We combined theory and experiments to investigate competition for nitrogen and light between these

  1. Areas of distribution in Cyanobacteria; specificity of the cyanoprokaryotic microflora in the Mediterranean region

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří

    2003-01-01

    Roč. 16, č. 1 (2003), s. 341-354 ISSN 1120-4060. [OPTIMA Meeting /10./. Palermo , 13.09.2001-19.09.2001] R&D Projects: GA AV ČR KSK6005114 Keywords : cyanobacteria * Mediterranean region Subject RIV: EF - Botanics

  2. Growth characteristics of selected thermophilic strains of cyanobacteria using crossed gradients of temperature and light

    Czech Academy of Sciences Publication Activity Database

    Hindák, F.; Kvíderová, Jana; Lukavský, Jaromír

    2013-01-01

    Roč. 68, č. 5 (2013), s. 830-837 ISSN 0006-3088 R&D Projects: GA TA ČR TE01020080 Institutional support: RVO:67985939 Keywords : cyanobacteria * thermophiles * growth characteristics Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.696, year: 2013

  3. The effect of peroral administration of toxic cyanobacteria on laboratory rats (Rattus norvegicus var. alba)

    Czech Academy of Sciences Publication Activity Database

    Adamovský, O.; Kopp, Radovan; Ziková, A.; Blaha, L.; Kohoutek, J.; Ondráčková, P.; Paskerová, H.; Mareš, J.; Palíková, M.

    2011-01-01

    Roč. 32, suppl.1 (2011), s. 35-45 ISSN 0172-780X Institutional research plan: CEZ:AV0Z60050516 Keywords : cyanobacteria * microcystin * rat Subject RIV: EF - Botanics Impact factor: 1.296, year: 2011 http://www.nel.edu/Current_issue_0.htm

  4. Sensitization of a child to cyanobacteria after recreational swimming in a lake

    Science.gov (United States)

    We report a case of an 11 year-old white female who developed an allergic reaction after swimming in Lake Ontario, Canada. Specific IgE reactivity to various species of cyanobacteria extracts was found to be increased in the patient’s serum. This case emphasizes the importance of...

  5. Identification of toxigenic Cyanobacteria of the genus Microcystis in the Curonian Lagoon (Baltic Sea)

    Science.gov (United States)

    Belykh, O. I.; Dmitrieva, O. A.; Gladkikh, A. S.; Sorokovikova, E. G.

    2013-02-01

    In 2002-2008, seasonal (April-November) monitoring of the phytoplankton in the Russian part of the Curonian Lagoon at five fixed sites was performed. A total of 91 Cyanobacteria, 100 Bacillariophyta, 280 Chlorophyta, 21 Cryptophyta, and 24 Dinophyta species were found. Six potentially toxic species of cyanobacteria: Aphanizomenon flos-aquae, Anabaena sp., Microcystis aeruginosa, M. viridis, M. wesenbergii, and Planktothrix agardhii dominated the phytoplankton biomass and caused water blooms. The seasonal average phytoplankton biomass ranged from 30 to 137 g/m3. The cyanobacteria's biomass varied from 10 to 113 g/m3 forming 30-82% of the total with a mean of 50%. With the aid of genetic markers (microcystin ( mcy) and nodularin synthetases), six variants of the microcystin-producing gene mcyE from the genus Microcystis were identified. Due to the intensive and lengthy blooms of potentially toxic and toxigenic cyanobacteria, the environmental conditions in the Curonian Lagoon appear unfavorable. The water should be monitored for cyanotoxins with analytical methods in order to determine if the area is safe for recreational use.

  6. The effect of mixotrophic chrysophyte on toxic and colony-forming cyanobacteria

    NARCIS (Netherlands)

    Van Donk, E.; Cerbin, S.; Wilken, S.; Helmsing, N.R.; Ptacnik, R.; Verschoor, A.M.

    2009-01-01

    1. In order to test the effect of Ochromonas sp., a mixotrophic chrysophyte, on cyanobacteria, grazing experiments were performed under controlled conditions. We studied grazing on three Microcystis aeruginosa strains, varying in toxicity and morphology, as well as on one filamentous cyanobacterium,

  7. Cyanobacteria inhabiting biological soil crusts of a polar desert: Sør Rondane Mountains, Antarctica.

    Science.gov (United States)

    Pushkareva, Ekaterina; Pessi, Igor S; Namsaraev, Zorigto; Mano, Marie-Jose; Elster, Josef; Wilmotte, Annick

    2018-02-07

    Molecular and morphological methods were applied to study cyanobacterial community composition in biological soil crusts (BSCs) from four areas (two nunataks and two ridges) in the Sør Rondane Mountains, Antarctica. The sampling sites serve as control areas for open top chambers (OTCs) that were put in place in 2010 at the time of sample collection and will be compared with BSC samples taken from the OTCs in the future. Cyanobacterial cell biovolume was estimated using epifluorescence microscopy, which revealed the dominance of filamentous cyanobacteria in all studied sites except the Utsteinen ridge, where unicellular cyanobacteria were the most abundant. Cyanobacterial diversity was studied by a combination of molecular fingerprinting methods based on the 16S rRNA gene (denaturing gradient gel electrophoresis (DGGE) and 454 pyrosequencing) using cyanobacteria-specific primers. The number of DGGE sequences obtained per site was variable and, therefore, a high-throughput method was subsequently employed to improve the diversity coverage. Consistent with previous surveys in Antarctica, both methods showed that filamentous cyanobacteria, such as Leptolyngbya sp., Phormidium sp. and Microcoleus sp., were dominant in the studied sites. In addition, the studied localities differed in substrate type, climatic conditions and soil parameters, which probably resulted in differences in cyanobacterial community composition. Furthermore, the BSC growing on gneiss pebbles had lower cyanobacterial abundances than BSCs associated with granitic substrates. Copyright © 2018 Elsevier GmbH. All rights reserved.

  8. Diversity of cyanobacteria in man-made solar saltern, Petchaburi Province, Thailand - a pilot study.

    Czech Academy of Sciences Publication Activity Database

    Chatchawan, T.; Peerapornpisal, Y.; Komárek, Jiří

    2011-01-01

    Roč. 11, č. 1 (2011), 203-214 ISSN 1802-5439 R&D Projects: GA ČR GA206/08/0318 Institutional research plan: CEZ:AV0Z60050516 Keywords : biodiversity of cyanobacteria * solar salterns * Thailand Subject RIV: EF - Botanics Impact factor: 1.327, year: 2011

  9. Fate of cyanobacteria in drinking water treatment plant lagoon supernatant and sludge.

    Science.gov (United States)

    Pestana, Carlos J; Reeve, Petra J; Sawade, Emma; Voldoire, Camille F; Newton, Kelly; Praptiwi, Radisti; Collingnon, Lea; Dreyfus, Jennifer; Hobson, Peter; Gaget, Virginie; Newcombe, Gayle

    2016-09-15

    In conventional water treatment processes, where the coagulation and flocculation steps are designed to remove particles from drinking water, cyanobacteria are also concentrated into the resultant sludge. As a consequence, cyanobacteria-laden sludge can act as a reservoir for metabolites such as taste and odour compounds and cyanotoxins. This can pose a significant risk to water quality where supernatant from the sludge treatment facility is returned to the inlet to the plant. In this study the complex processes that can take place in a sludge treatment lagoon were investigated. It was shown that cyanobacteria can proliferate in the conditions manifest in a sludge treatment lagoon, and that cyanobacteria can survive and produce metabolites for at least 10days in sludge. The major processes of metabolite release and degradation are very dependent on the physical, chemical and biological environment in the sludge treatment facility and it was not possible to accurately model the net effect. For the first time evidence is provided to suggest that there is a greater risk associated with recycling sludge supernatant than can be estimated from the raw water quality, as metabolite concentrations increased by up to 500% over several days after coagulation, attributed to increased metabolite production and/or cell proliferation in the sludge. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

    NARCIS (Netherlands)

    Hammar, P.; Angermayr, S.A.; Sjostrom, S.L.; van der Meer, J.; Hellingwerf, K.J.; Hudson, E.P.; Joensson, H.N.

    2015-01-01

    BACKGROUND: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible. RESULTS: We present a method for high-throughput, single-cell

  11. Biofilm Formation and Indole-3-Acetic Acid Production by Two Rhizospheric Unicellular Cyanobacteria

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2014-01-01

    Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant

  12. A new photobioreactor concept enabling the production of desiccation induced biotechnological products using terrestrial cyanobacteria.

    Science.gov (United States)

    Kuhne, S; Strieth, D; Lakatos, M; Muffler, K; Ulber, R

    2014-12-20

    Cyanobacteria offer great potential for the production of biotechnological products for pharmaceutical applications. However, these organisms can only be cultivated efficiently using photobioreactors (PBR). Under submerged conditions though, terrestrial cyanobacteria mostly grow in a suboptimal way, which makes this cultivation-technique uneconomic and thus terrestrial cyanobacteria unattractive. Therefore, a novel emersed photobioreactor (ePBR) has been developed, which can provide the natural conditions for these organisms. Proof of concept as well as first efficiency tests are conducted using the terrestrial cyanobacteria Trichocoleus sociatus as a model organism. The initial maximum growth rate of T. sociatus (0.014±0.001h(-1)) in submerged systems could be increased by 35%. Furthermore, it is now possible to control desiccation-correlated product formation and related metabolic processes. This is shown for the production of extracellular polymeric substances (EPS). In this case the yield of 0.068±0.006g of EPS/g DW could be increased by more than seven times. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Biofilm formation and indole-3-acetic acid production by two rhizospheric unicellular cyanobacteria

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2014-01-01

    Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant

  14. A proposal for further integration of the cyanobacteria under the Bacteriological Code.

    Science.gov (United States)

    Oren, Aharon

    2004-09-01

    This taxonomic note reviews the present status of the nomenclature of the cyanobacteria under the Bacteriological Code. No more than 13 names of cyanobacterial species have been proposed so far in the International Journal of Systematic and Evolutionary Microbiology (IJSEM)/International Journal of Systematic Bacteriology (IJSB), and of these only five are validly published. The cyanobacteria (Cyanophyta, blue-green algae) are also named under the Botanical Code, and the dual nomenclature system causes considerable confusion. This note calls for a more intense involvement of the International Committee on Systematics of Prokaryotes (ICSP), its Judicial Commission and its Subcommittee on the Taxonomy of Photosynthetic Prokaryotes in the nomenclature of the cyanobacteria under the Bacteriological Code. The establishment of minimal standards for the description of new species and genera should be encouraged in a way that will be acceptable to the botanical authorities as well. This should be followed by the publication of an 'Approved List of Names of Cyanobacteria' in IJSEM. The ultimate goal is to achieve a consensus nomenclature that is acceptable both to bacteriologists and to botanists, anticipating the future implementation of a universal 'Biocode' that would regulate the nomenclature of all organisms living on Earth.

  15. Temperature induced changes in the heterocyst glycolipid composition of N2-fixing heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bauersachs, T.; Stal, L.J.; Grego, M.; Schwark, L.

    2014-01-01

    We investigated the effect of temperature on the heterocyst glycolipid (HG) composition of the diazotrophic heterocystous cyanobacteria Anabaena sp. strain CCY9613 and Nostoc sp. strain CCY9926 grown at 9, 12, 16, 20 and 24 °C. Both strains contained an overall similar composition of heterocyst

  16. Temperature-dependent effect of filamentous cyanobacteria on Daphnia magna life history traits

    Directory of Open Access Journals (Sweden)

    Piotr DAWIDOWICZ

    2011-08-01

    Full Text Available Filamentous cyanobacteria are unsuitable food for Daphnia due to their poor manageability, poor nutritional value and, in some cases, toxicity. As the strength of harmful effects of cyanobacteria on filter-feeding zooplankton is temperature dependent, the global warming scenarios for eutrophic lakes in temperate zone might include an escalated suppression of Daphnia populations caused by the presence of cyanobacterial filaments. To test this assumption, we conducted life-table experiments with four clones of Daphnia magna fed either a green alga Scenedesmus obliquus or a non-toxic strain of filamentous cyanobacteria Cylindrospermopsis raciborskii in two temperatures (20 °C and 24 °C. Key life history parameters of Daphnia, i.e., age and size at first reproduction, fecundity, and individual growth rate, were measured. Both food and temperature significantly affected Daphnia performance, however, the effect of interaction of these two factors was ambiguous and highly genotype-dependent. We conclude that the temperature increase within the studied range will not necessarily strengthen the suppression of Daphnia growth by filamentous cyanobacteria, but may affect clonal selection within population of Daphnia, thus possibly triggering microevolutionary changes within affected populations.

  17. Feathermoss and epiphytic Nostoc cooperate differently: expanding the spectrum of plant–cyanobacteria symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Warshan, Denis; Espinoza, Josh L.; Stuart, Rhona; Richter, Alexander R.; Kim, Sea-Yong; Shapiro, Nicole; Woyke, Tanja; Kyripides, Nikos; Barry, Kerrie W.; Singan, Vasanth; Lindquist, Erika; Ansong, Charles K.; Purvine, Samuel O.; Brewer, Heather M.; Weyman, Philip D.; Dupont, Chris; Rasmussen, Ulla

    2017-12-31

    Dinitrogen (N2)-fixation by cyanobacteria in symbiosis with feather mosses represents the main pathway of biological N input into boreal forests. Despite its significance, little is known about the gene repertoire needed for the establishment and maintenance of the symbiosis. To determine gene acquisitions or regulatory rewiring allowing cyanobacteria to form this symbiosis, we compared closely related Nostoc strains that were either symbiosis-competent or non-competent, using a proteogenomics approach and a unique experimental setup allowing for controlled chemical and physical contact between partners. Thirty-two protein families were only in the genomes of competent strains, including some never before associated with symbiosis. We identified conserved orthologs that were differentially expressed in competent strains, including gene families involved in chemotaxis and motility, NO regulation, sulfate/phosphate transport, sugar metabolism, and glycosyl-modifying and oxidative stress-mediating exoenzymes. In contrast to other cyanobacteria-plant symbioses, the moss-cyanobacteria epiphytic symbiosis is distinct, with the symbiont retaining motility and chemotaxis, and not modulating N-fixation, photosynthesis, GS-GOGAT cycle, and heterocyst formation. Our work expands our knowledge of plant cyanobacterial symbioses, provides an interaction model of this ecologically significant symbiosis, and suggests new currencies, namely nitric oxide and aliphatic sulfonates, may be involved in establishing and maintaining this symbiosis.

  18. Heavy metals pollution influence the community structure of Cyanobacteria in nutrient rich tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Anas, A.; Jasmin, C.; Sheeba V.A.; Gireeshkumar, T.R; Nair, S.

    , Mn, Fe, Ni, Cu and Zn) on community structure of cyanobacteria in a nutrient rich tropical estuary, Cochin Estuary (CE), across the southwest coast of India. Dissolved heavy metals were higher in CE during dry season, with Zn as major pollutant...

  19. Cyanobacteria blooms cannot be controlled by effective microorganisms (EM) from mud- or Bokashi-balls

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Tolman, Y.; Oosterhout, J.F.X.

    2010-01-01

    In controlled experiments, the ability of ‘‘Effective Microorganisms (EM, in the form of mudballs or Bokashi-balls)’’ was tested for clearing waters from cyanobacteria. We found suspensions of EM-mudballs up to 1 g l-1 to be ineffective in reducing cyanobacterial growth. In all controls and

  20. A giant chlorophyll-protein complex induced by iron deficiency in cyanobacteria

    NARCIS (Netherlands)

    Boekema, E.J.; Hifney, A.; Yakushevska, A.E.; Piotrowski, M.; Keegstra, W.; Berry, S.; Michel, K.-P.; Pistorius, E.K.; Kruip, J.

    2001-01-01

    Cyanobacteria are abundant throughout most of the world's water bodies and contribute significantly to global primary productivity through oxygenic photosynthesis. This reaction is catalysed by two membrane-bound protein complexes, photosystem I (PSI) and photosystem II (PSII), which both contain

  1. A polyphasic approach for the taxonomy of cyanobacteria: principles and applications.

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří

    2016-01-01

    Roč. 51, č. 3 (2016), s. 346-353 ISSN 0967-0262 R&D Projects: GA ČR GA15-00113S; GA ČR GAP506/12/1818 Institutional support: RVO:67985939 Keywords : cyanobacteria * taxonomy * polyphasic approach Subject RIV: EF - Botanics Impact factor: 2.412, year: 2016

  2. Cyanobacteria Assessment Network (CyAN) - 2017 NASA Water Resources PI Presentation

    Science.gov (United States)

    Presentation on the Cyanobacteria Assessment Network (CYAN) and how is supports the environmental management and public use of the U.S. lakes and estuaries by providing a capability of detecting and quantifying algal blooms and related water quality using satellite data records.

  3. The Cyanobacteria Assessment Network - Recent Success in Harmful Algal Bloom Detection

    Science.gov (United States)

    Cyanobacteria blooms, which can become harmful algal blooms (HABs), are a huge environmental problem across the United States. They are capable of producing dangerous toxins that threaten the health of humans and animals, quality of drinking water supplies, and the ecosystem in w...

  4. Macrochaete gen. nov. (Nostocales, Cyanobacteria), a taxon morphologically and molecularly distinct from Calothrix

    Czech Academy of Sciences Publication Activity Database

    Gómez, E. B.; Johansen, J. R.; Kaštovský, J.; Bohunická, Markéta; Čapková, Kateřina

    2016-01-01

    Roč. 52, č. 4 (2016), s. 638-655 ISSN 0022-3646 R&D Projects: GA ČR GA13-13368S; GA ČR(CZ) GA15-11912S Institutional support: RVO:67985939 Keywords : cyanobacteria * polyphasic approach Subject RIV: EF - Botanics Impact factor: 2.608, year: 2016

  5. An open science approach to modeling and visualizing cyanobacteria blooms in lakes and ponds

    Science.gov (United States)

    It is expected that cyanobacteria blooms will increase in frequency, duration, and severity as inputs of nutrients increase and the impacts of climate change are realized. Partly in response to this, federal, state, and local entities have ramped up efforts to better understand b...

  6. The relative importance of water temperature and residence time in predicting cyanobacteria abundance in regulated rivers.

    Science.gov (United States)

    Cha, YoonKyung; Cho, Kyung Hwa; Lee, Hyuk; Kang, Taegu; Kim, Joon Ha

    2017-11-01

    Despite a growing awareness of the problems associated with cyanobacterial blooms in rivers, and particularly in regulated rivers, the drivers of bloom formation and abundance in rivers are not well understood. We developed a Bayesian hierarchical model to assess the relative importance of predictors of summer cyanobacteria abundance, and to test whether the relative importance of each predictor varies by site, using monitoring data from 16 sites in the four major rivers of South Korea. The results suggested that temperature and residence time, but not nutrient levels, are important predictors of summer cyanobacteria abundance in rivers. Although the two predictors were of similar significance across the sites, the residence time was marginally better in accounting for the variation in cyanobacteria abundance. The model with spatial hierarchy demonstrated that temperature played a consistently significant role at all sites, and showed no effect from site-specific factors. In contrast, the importance of residence time varied significantly from site to site. This variation was shown to depend on the trophic state, indicated by the chlorophyll-a and total phosphorus levels. Our results also suggested that the magnitude of weir inflow is a key factor determining the cyanobacteria abundance under baseline conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. CyAN satellite-derived Cyanobacteria products in support of Public Health Protection

    Science.gov (United States)

    The timely distribution of satellite-derived cyanoHAB data is necessary for adaptive water quality management decision-making and for targeted deployment of existing government and non-government water quality monitoring resources. The Cyanobacteria Assessment Network (CyAN) is a...

  8. Great Lake beach-goer behavior during a retrospectively detected bloom of cyanobacteria

    Science.gov (United States)

    Cyanobacteria blooms pose a potential health risk to beachgoers. We conducted a prospective study of weekend beachgoers at a public Great Lake site during July – September 2003. We recorded each person’s health status and activity during their beach visit. We measured...

  9. Autofluorescence imaging system to discriminate and quantify the distribution of benthic cyanobacteria and diatoms

    NARCIS (Netherlands)

    Carreira, C.; Staal, M.; Middelboe, M.; Brussaard, C.P.D.

    2015-01-01

    Observation of benthic photoautotrophs on sediment surfaces shows a single algal layer without distinction between photosynthetic groups. Until now it has not been possible to distinguish between benthic photosynthetic microorganisms, i.e. cyanobacteria and diatoms, at μm to mm scales using a single

  10. Morphological and phylogenetic diversity of thermophilic cyanobacteria in Algerian hot springs.

    Science.gov (United States)

    Amarouche-Yala, Samia; Benouadah, Ali; El Ouahab Bentabet, Abd; López-García, Purificación

    2014-11-01

    Geothermal springs in Algeria have been known since the Roman Empire. They mainly locate in Eastern Algeria and are inhabited by thermophilic organisms, which include cyanobacteria forming mats and concretions. In this work, we have investigated the cyanobacterial diversity of these springs. Cyanobacteria were collected from water, concretions and mats in nine hot springs with water temperatures ranging from 39 to 93 °C. Samples were collected for isolation in culture, microscopic morphological examination, and molecular diversity analysis based on 16S rRNA gene sequences. Nineteen different cyanobacterial morphotypes were identified, the most abundant of which were three species of Leptolyngbya, accompanied by members of the genera Gloeocapsa, Gloeocapsopsis, Stigonema, Fischerella, Synechocystis, Microcoleus, Cyanobacterium, Chroococcus and Geitlerinema. Molecular diversity analyses were in good general agreement with classical identification and allowed the detection of additional species in three springs with temperatures higher than 50 °C. They corresponded to a Synechococcus clade and to relatives of the intracellularly calcifying Candidatus Gloeomargarita lithophora. The hottest springs were dominated by members of Leptolyngbya, Synechococcus-like cyanobacteria and Gloeomargarita, whereas Oscillatoriales other than Leptolyngbya, Chroococcales and Stigonematales dominated lower temperature springs. The isolation of some of these strains sets the ground for future studies on the biology of thermophilic cyanobacteria.

  11. Benthic cyanobacteria: A source of cylindrospermopsin and microcystin in Australian drinking water reservoirs.

    Science.gov (United States)

    Gaget, Virginie; Humpage, Andrew R; Huang, Qiong; Monis, Paul; Brookes, Justin D

    2017-11-01

    Cyanobacteria represent a health hazard worldwide due to their production of a range of highly potent toxins in diverse aquatic environments. While planktonic species have been the subject of many investigations in terms of risk assessment, little is known about benthic forms and their impact on water quality or human and animal health. This study aimed to purify isolates from environmental benthic biofilms sampled from three different drinking water reservoirs and to assess their toxin production by using the following methods: Enzyme-Linked Immunosorbent Assay (ELISA), High-Performance Liquid Chromatography (HPLC), Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and quantitative PCR (qPCR). Microscopic observation of the isolates allowed the identification of various filamentous cyanobacterial genera: Anabaena (benthic form), Calothrix and Nostoc from the Nostocales and Geitlerinema, Leptolyngbya, Limnothrix, Lyngbya, Oxynema, Phormidium and Pseudanabaena representing non-heterocystous filamentous cyanobacteria. The Phormidium ambiguum strain AWQC-PHO021 was found to produce 739 ng/mg of dry weight (d/w) of cylindrospermopsin and 107 ng/mg (d/w) of deoxy-cylindrospermopsin. The Nostoc linckia strain AWQC-NOS001 produced 400 ng/mg (d/w) of a microcystin analogue. This is the first report of hepatotoxin production by benthic cyanobacteria in temperate Australian drinking water reservoirs. These findings indicate that water quality monitoring programs need to consider benthic cyanobacteria as a potential source of toxins. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Estrogenic activity in extracts and exudates of cyanobacteria and green algae

    Czech Academy of Sciences Publication Activity Database

    Sychrová, E.; Štěpánkdová, T.; Nováková, K.; Bláha, Luděk; Giesy, J.P.; Hilscherová, K.

    2012-01-01

    Roč. 39, č. 1 (2012), s. 134-140 ISSN 0160-4120 R&D Projects: GA ČR GA524/08/0496 Institutional support: RVO:67985939 Keywords : cyanobacteria * endocrine disruption * estrogenicity * algae * phytoplankton Subject RIV: EF - Botanics Impact factor: 6.248, year: 2012

  13. Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis

    NARCIS (Netherlands)

    Nunes Teixeira Mucci, Maira; Noyma, Natalia Pessoa; Magalhães, de Leonardo; Miranda, Marcela; Oosterhout, van Frank; Guedes, Iamê Alves; Huszar, Vera L.M.; Marinho, Marcelo Manzi; Lürling, Miquel

    2017-01-01

    Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show

  14. Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis

    NARCIS (Netherlands)

    Mucci, Maira; Noyma, Natalia Pessoa; de Magalhaes, Leonardo; Miranda, Marcela; van Oosterhout, Frank; Guedes, Iame Alves; Huszar, Vera L. M.; Marinho, Marcelo Manzi; Lürling, Miquel

    2017-01-01

    Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show

  15. Dataset exploited for the development and validation of automated cyanobacteria quantification algorithm, ACQUA

    Directory of Open Access Journals (Sweden)

    Emanuele Gandola

    2016-09-01

    Full Text Available The estimation and quantification of potentially toxic cyanobacteria in lakes and reservoirs are often used as a proxy of risk for water intended for human consumption and recreational activities. Here, we present data sets collected from three volcanic Italian lakes (Albano, Vico, Nemi that present filamentous cyanobacteria strains at different environments. Presented data sets were used to estimate abundance and morphometric characteristics of potentially toxic cyanobacteria comparing manual Vs. automated estimation performed by ACQUA (“ACQUA: Automated Cyanobacterial Quantification Algorithm for toxic filamentous genera using spline curves, pattern recognition and machine learning” (Gandola et al., 2016 [1]. This strategy was used to assess the algorithm performance and to set up the denoising algorithm. Abundance and total length estimations were used for software development, to this aim we evaluated the efficiency of statistical tools and mathematical algorithms, here described. The image convolution with the Sobel filter has been chosen to denoise input images from background signals, then spline curves and least square method were used to parameterize detected filaments and to recombine crossing and interrupted sections aimed at performing precise abundances estimations and morphometric measurements. Keywords: Comparing data, Filamentous cyanobacteria, Algorithm, Deoising, Natural sample

  16. Proposal for unified nomenclatural rules for Cyanobacteria vs. Cyanophytes: “Cyano-Guide”

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří; Golubić, S.

    2005-01-01

    Roč. 158, č. 117 (2005), s. 17-18 ISSN 0342-1120. [Symposium of the International Association for Cyanophyte Research /16./. Luxembourg, 30.08.2004-03.09.2004] R&D Projects: GA AV ČR(CZ) KSK6005114 Institutional research plan: CEZ:AV0Z6005908 Keywords : cyanobacteria * nomenclature * nomenclatoric Code Subject RIV: EF - Botanics

  17. Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean

    NARCIS (Netherlands)

    Agawin, N.S.R.; Benavides, M.; Busquets, A.; Ferriol, P.; Stal, L.J.; Aristegui, J.

    2014-01-01

    ABSTRACT: The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic

  18. Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean

    NARCIS (Netherlands)

    Agawin, N.S.R.; Benavides, M.; Busquets, A.; Ferriol, P.; Stal, L.J.; Arístegui, J.

    2014-01-01

    The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to

  19. Several rare freshwater planktic cyanobacteria (Cyanoprokaryotes) from reservoirs in South America

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří; Komárková, Jaroslava

    2007-01-01

    Roč. 34, č. 1 (2007), s. 49-58 ISSN 0073-2877 R&D Projects: GA AV ČR KSK6005114; GA AV ČR IAA6005704 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60170517 Keywords : cyanobacteria * plancton * tropical reservoars Subject RIV: EF - Botanics

  20. Adaptability in diversification processes of cyanobacteria; the example of Synechococcus bigranulatus

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří; Kaštovský, J.

    2003-01-01

    Roč. 148, č. 109 (2003), s. 299-304 ISSN 0342-1120. [Symposium of the International Association for Cyanophyte Research /15./. Barcelona, 03.09.2001-07.09.2001] R&D Projects: GA AV ČR KSK6005114 Keywords : cyanobacteria * adaptation * ecophysiology Subject RIV: EF - Botanics