Journal articles: 'Anabaena'

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Rosales Loaiza, Néstor, Patricia Vera, Cateryna Aiello-Mazzarri, and Ever Morales. "COMPARATIVE GROWTH AND BIOCHEMICAL COMPOSITION OF FOUR STRAINS OF Nostoc AND Anabaena (CYANOBACTERIA, NOSTOCALES) IN RELATION TO SODIUM NITRATE." Acta Biológica Colombiana 21, no. 2 (April 5, 2016): 347–54. http://dx.doi.org/10.15446/abc.v21n2.48883.

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<p>Nitrogen concentration is an essential parameter in cyanobacterial cultures to produce enriched biomass with agricultural purposes. Growth and biochemical composition of Nostoc LAUN0015,Nostoc UAM206, Anabaena sp.1 and Anabaena sp.2 was compared at 0, 4.25, 8.5 and 17 mM NaNO3. Cultures under laboratory conditions were maintained for 30 days at a volume of 500 mL. Anabaenasp.1 yielded the highest value of dry mass of 0.26 ± 2.49 mg mL-1 at 8.5 mM NaNO3. For chlorophyll, phycocyanin and phycoerythrin were achieved maximum values at 17 mM NaNO3 with 18.09 ± 1.74, 102.90 ± 6.73 and 53.47 ± 2.40 μg mL-1, respectively. Nostoc LAUN0015 produced its maximum value of protein 644.86 ± 19.77 μg mL-1, and 890 mg mL-1 of carbohydrates in the absence of nitrogen. This comparative study shows that the most efficient strain for the production of protein, carbohydrates and lipids in diazotrophic conditions corresponded to Nostoc LAUN0015. However, Anabaena sp.1 and Anabaena sp.2 required high concentrations of nitrogen to achieve higher values of metabolites, comparing with Nostoc strains. Nitrogen dependence for the production of pigments and high protein production in strains of Anabaena and in diazotrophic conditions for Nostoc was demonstrated. Nostoc can be cultured under nitrogen deficiency andAnabaena in sufficiency, for mass production of biomass with good nutritional profile.</p>

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Plazinski, Jacek, Lynn Croft, Rona Taylor, Qi Zheng, Barry G. Rolfe, and Brian E. S. Gunning. "Indigenous plasmids in Anabaena azollae: their taxonomic distribution and existence of regions of homology with symbiotic genes of Rhizobium." Canadian Journal of Microbiology 37, no. 3 (March 1, 1991): 171–81. http://dx.doi.org/10.1139/m91-027.

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The method of horizontal agarose gel electrophoresis was used to demonstrate the presence of indigenous plasmid DNAs in different isolates of the symbiotic cyanobacterium Anabaena azollae. All isolates extracted from seven distinct species of the host fern Azolla were found to possess one to three cryptic plasmids ranging in sizes from 35 to 100 MDa (million daltons). Anabaenas isolated from Azolla caroliniana, Az. nilotica, and Az. pinnata species contained a single plasmid band of molecular mass approximately 60 MDa, whereas other endosymbiotic cyanobacteria extracted from Azolla filiculoides, Az. rubra, Az. mexicana, and Az. microphylla were shown to possess two or three covalently closed circular (CCC) DNAs. Cloned DNA fragments derived from the plasmid sequences of two different An. azollae isolates were used as hybridization probes. Hybridization data indicated that these symbiotic cyanobacteria possess different but related plasmid species and that it is possible to construct specific plasmid DNA probes capable of distinguishing among several strains of the symbiotic anabaenas. Several heterologous DNA probes, including Rhizobium symbiotic genes, were used to seek homologous sequences on the An. azollae plasmids. DNA sequences homologous to the nod box and nodMN genes were present on the Anabaena plasmids. Moreover, homology of a key Rhizobium exopolysaccharide (exoY) gene to the An. azollae CCC DNAs was detected. In addition, the introduction of the An. azollae plasmid clone into Rhizobium Exo− mutant (exoY) resulted in the Exo+ transconjugants. Those findings suggest that some of the An. azollae plasmids may play a role in symbiotic interactions with Azolla fem. Key words: Anabaena azollae, Azolla, symbiosis, cyanobacterium, plasmids.

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Matz, Carlyn J., Michael R. Christensen, Auralee D. Bone, Courtney D. Gress, Scott B. Widenmaier, and Harold G. Weger. "Only iron-limited cells of the cyanobacterium Anabaena flos-aquae inhibit growth of the green alga Chlamydomonas reinhardtii." Canadian Journal of Botany 82, no. 4 (April 1, 2004): 436–42. http://dx.doi.org/10.1139/b04-022.

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Cocultivation of iron-limited cells of the cyanobacterium Anabaena flos-aquae (Lyng.) Brèb. and the green alga Chlamydomonas reinhardtii Dangeard resulted in growth of Anabaena but not Chlamydomonas, even in the presence of excess exogenous iron. This effect was also observed during the cultivation of Chlamydomonas in a medium in which iron-limited Anabaena cells had been growing, but were removed prior to culture of Chlamydomonas. Conversely, iron-limited Chlamydomonas cells grew very well in medium from iron (nutrient)-sufficient, phosphate-limited, and nitrogen-limited Anabaena cultures. Iron-limited Anabaena cultures produced siderophores, while the other types of Anabaena cultures did not. Treatment of Anabaena iron-limited medium with activated charcoal completely removed the inhibitory effect on Chlamydomonas growth, and boiling the medium removed most of the inhibitory effect. Both the charcoal and the boiling treatments also removed siderophores from the medium. Partially purified Anabaena siderophore preparations were also inhibitory to Chlamydomonas growth. The inhibitory effect of iron-limited Anabaena medium could be partially overcome by addition of excess micronutrients (especially cobalt copper) but not by addition of iron. We suggest that Anabaena-derived siderophores, present only in iron-limited Anabaena medium, inhibit the growth of Chlamydomonas cells via a previously uncharacterized toxicity. This effect is different from previously described experiments in which cyanobacterial siderophores suppressed green algal growth via competition for limiting amounts of iron.Key words: Anabaena, Chlamydomonas, cocultivation, iron limitation, micronutrients; siderophores.

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Rajopadhyaya, Ritu, Sangita Joshi, Sabitri Shrestha, and Shiva Kumar Raj. "Some New and Interesting Cyanobacteria from Baghjhoda Pond, Eastern Nepal." Himalayan Journal of Science and Technology 1 (December 1, 2017): 1–8. http://dx.doi.org/10.3126/hijost.v1i0.25814.

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Cyanobacteria of BaghJhoda pond in three different seasons hav been studied. A total of 8 cyanophycean algae under 6 genera viz., Anabaena, Aphanocapsa, Chroococcus, Oscillatoria, Phormidium and Spirulina were recorded. Anabaena, Oscillatoria and Phormidium were dominant genera and occurred in all three seasons. All the 8 taxa were new for the study area and Anabaena affinis and Anabaena subcylindrical were new records for Nepal.

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Patil, Keerthi, and Doris M. Singh. "OPTIMIZATION OF CULTURE MEDIA FOR THE GROWTH OF ANABAENA PCC550, ANABAENA PCC 574, AND CYLINDROSPERMUM PCC518, CYLINDROSPERMUM PCC 567." Journal of Advanced Scientific Research 13, no. 06 (July 31, 2022): 106–10. http://dx.doi.org/10.55218/jasr.202213619.

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In the present study, Anabaena PCC550, Anabaena PCC574 and Cylindrospermum PCC518, Cylindrospermum PCC 567 have been subjected to 7 different inorganic culture media. In order to identify the best growth medium i.e.; optimized medium, the nutrient requirement of these two algae have been evaluated as prime requisite. The present investigation analyzed the growth of wet biomass of the four microalgae. In order to attain optimal growth of Anabaena and Cylindrospermum species, the 7 culture media employed in the current study were (i) BG11 medium (ii) Knoops medium (iii) Cyanophycean agar medium (iv) Modified Bristols medium (v) Prigsheims Medium (vi) Foggs Medium and (vii) Algal culture medium. Highest growth on 60th day was seen in Cylindrospermum PCC 518 (0.134mg/100ml), Anabaena PCC 574 (0123mg/100ml), Cylindrospermum PCC 567 (0.098mg/100ml), Anabaena PCC 550 (0.094mg/100ml) in Algal culture media which shows luxurient growth when compared to BG11, Foggs Media, Modified Bristols media, Knoops media. While, Prigsheims medium did not show any growth of Anabaena PCC550, Anabaena PCC574 and Cylindrospermum PCC518, Cylindrospermum PCC 567.

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Peters, G. A., D. Kaplan, and H. E. Calvert. "Solar-powered N2 fixation in ferns: the Azolla-Anabaena symbioses." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 86 (1985): 169–77. http://dx.doi.org/10.1017/s0269727000008101.

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SynopsisThe heterosporous aquatic ferns in the genus Azolla contain a heterocystous cyanobacterium, Anabaena azollae, as a symbiont. The Anabaena occupies cavities formed in the aerial dorsal leaf lobes of the ferns and can provide the symbiotic associations with their total N requirement via the fixation of atmospheric nitrogen. The photosynthetic pigments of the fern and cyanobacterium are complementary. Photosynthesis is of course the source of energy for growth and the ultimate source of the ATP and reductant required for N2 fixation in the light or dark. However, nitrogen fixation is maximal in the light and the phycobili-proteins of the Anabaena are as effective as its chlorophyll in driving this photosystem I-linked process.The partners exhibit a coordinated pattern of development with the Azolla exerting a control over the Anabaena, affecting both its metabolism and differentiation. Anabaena filaments associated with the fern apices lack heterocysts. As cavities are formed and occupied by the Anabaena, it differentiates a high proportion of heterocysts and exhibits nitrogenase activity. In mature cavities, the Anabaena receives fixed carbon from the Azolla and releases fixed N2 as ammonium. The ammonium is assimilated and/or transported by the Azolla toward its stem apices. Special epidermal cavity trichomes, which are intimately associated with the Anabaena at all stages in the ontogeny of the association, may facilitate metabolite exchange between the fern and cyanobacterium.

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Chen, Pei-Chung. "Physiology of Nitrogen Fixation in Two New Strains of Anabaena." Zeitschrift für Naturforschung C 40, no. 5-6 (June 1, 1985): 406–8. http://dx.doi.org/10.1515/znc-1985-5-620.

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Abstract Two different cyanobacteria, Anabaena CH 1 and CH2, were isolated from Taiwan paddy soils. Both strains can grow well with daily dilution method. Anabaena CH1 shows a blue-green color and Anabaena CH2 a green brownish one. Nitrogenase activity decreased as cultures were transferred from light to dark. When a darkened culture was placed again into the light, nitrogenase activity recovered within two hours, but not in the presence of chloramphenicol. Energy supply for nitrogenase within both strains was different. Nitrogenase activity of Anabaena CH1 was light-dependent and oxygen in heterocyst was exhausted through oxyhydrogen reaction. Except photosynthesis, respiration may be used as energy source for nitrogenase in Anabaena CH2. Respiration was the major one to protect nitrogenase against oxygen.

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Qian, Kuimei, Martin Dokulil, and Yuwei Chen. "Do the regular annual extreme water level changes affect the seasonal appearance of Anabaena in Poyang Lake?" PeerJ 7 (April 12, 2019): e6608. http://dx.doi.org/10.7717/peerj.6608.

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Background Poyang Lake is an ecosystem experiencing annual variations in water level of up to 14 m. Water level changes were 8.03 and 11.22 m, respectively, in the years 2013 and 2014. The biomass and heterocyst frequency of Anabaena increased in the summers of recent years. Methods A weekly to bi-weekly monitoring from June to November 2013 and 2014 was set up to explain the variations of Anabaena appearance in different phases of the water level. Results Anabaena was present in the lake throughout the year. The average relative biomass of Anabaena in the present study was over 40%, being most abundant in summer. The average heterocyst frequency was 0.23% in 2013 and 0.76% in 2014. Correlation analysis indicated a positive trend of Anabaena biomass with water temperature and water level and a negative one with total nitrogen (TN), which is the reason for the increase of heterocyst frequency in 2013 and 2014. Heterocyst frequency of Anabaena was positively correlated with water temperature, water level and PO4-P, and negatively with dissolved inorganic nitrogen (DIN/DIP), NO3-N and TN. Moreover, water temperature and DIN/DIP were significantly correlated with water level, indicating that water level changes have a direct effect on Anabaena and heterocyst formation in Poyang Lake. Conclusions The results of this study support the hypothesis that increasing biomass and heterocyst formation of Anabaena can be primarily caused by seasonal changes of the water level in Poyang Lake.

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Liengen, Turid. "Environmental factors influencing the nitrogen fixation activity of free-living terrestrial cyanobacteria from a high arctic area, Spitsbergen." Canadian Journal of Microbiology 45, no. 7 (August 1, 1999): 573–81. http://dx.doi.org/10.1139/w99-040.

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The influence of environmental factors on the nitrogen fixation activity of free-living, terrestrial cyanobacteria from a high arctic area were investigated using experimental manipulations with two different types of field samples, including macroscopic sheets of Nostoc commune and soil samples with a cyanobacterial crust from a Puccinellia salt marsh. In addition, a cultured Anabaena sp. previously isolated from the salt marsh was examined. Nitrogen fixation activity was measured using the acetylene reduction method. The nitrogen fixation mainly took place in the light, but even after 12 h incubation in darkness, low activities were maintained. Phosphorus fertilization stimulated the nitrogen fixation activity, and the highest activities were obtained with about 300 μM phosphate, both in the field samples and the cultured Anabaena sp. Ammonium (28 mM) immediately inhibited the nitrogen fixation activity of the cultured Anabaena sp, whereas 14 mM urea and 540 μM glutamate led to a weaker and slower inhibition of the nitrogen fixation activity, showing that the cultured Anabaena sp. was able to assimilate these combined nitrogen sources. Nitrate did not have any inhibitory effect on nitrogen fixation activity, either in the field samples or in the cultured Anabaena sp. Both the field samples and the cultured Anabaena sp. showed tolerance against sodium chloride concentrations corresponding to the concentration in seawater. The temperature optimum of the nitrogen fixation activity of the cultured Anabaena sp. was about 20°C. Key words: nitrogen fixation, cyanobacteria, Nostoc commune, Anabaena sp., high arctic.

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Kirjakov, Ivan Kirilov, and Katya Naneva Velichkova. "A new cyanobacterial species of Anabaena genus (Nostocales, Cyanobacteria) from Bulgaria." Anales de Biología, no. 38 (May 17, 2016): 69–72. http://dx.doi.org/10.6018/analesbio.38.06.

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Se describe una nueva especie del género de Cyanobacterias, Anabaena Bory ex Born. et Flah. (Nostocales) de las montañas Ródope de Bulgaria. Anabaena rhodopensis sp. nova. tiene acinetas con paredes celulares esculpidas. Se dan los datos biométricos para el tamaño de las células vegetativas, heterocistos y acinetos.A new species of cyanobacterial genus Anabaena Bory ex Born. et Flah. (Nostocales) from Rhodope Mountains in Bulgaria is described. Anabaena rhodopensis sp. nova. has akinetes with sculptured cell walls. Biometrical data for size of vegetative cells, heterocytes and akinetes are given.

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Halinen, Katrianna, Jouni Jokela, David P. Fewer, Matti Wahlsten, and Kaarina Sivonen. "Direct Evidence for Production of Microcystins by Anabaena Strains from the Baltic Sea." Applied and Environmental Microbiology 73, no. 20 (August 31, 2007): 6543–50. http://dx.doi.org/10.1128/aem.01377-07.

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ABSTRACT Anabaena is a filamentous, N2-fixing, and morphologically diverse genus of cyanobacteria found in freshwater and brackish water environments worldwide. It contributes to the formation of toxic blooms in freshwater bodies through the production of a range of hepatotoxins or neurotoxins. In the Baltic Sea, Anabaena spp. form late summer blooms, together with Nodularia spumigena and Aphanizomenon flos-aquae. It has been long suspected that Baltic Sea Anabaena may produce microcystins. The presence of microcystins has been reported for the coastal regions of the Baltic proper, and a recent report also indicated the presence of the toxin in the open Gulf of Finland. However, at present there is no direct evidence linking Baltic Sea Anabaena spp. to microcystin production. Here we report on the isolation of microcystin-producing strains of the genus Anabaena in the open Gulf of Finland. The dominant microcystin variants produced by these strains included the highly toxic MCYST-LR as well as [d-Asp3]MCYST-LR, [d-Asp3]MCYST-HtyR, MCYST-HtyR, [d-Asp3,Dha7]MCYST-HtyR, and [Dha7]MCYST-HtyR variants. Toxic strains were isolated from the coastal Gulf of Finland as well as from the easternmost open-sea sampling station, where there were lower salinities than at other stations. This result suggests that lower salinity may favor microcystin-producing Anabaena strains. Furthermore, we sequenced 16S rRNA genes and found evidence for pronounced genetic heterogeneity of the microcystin-producing Anabaena strains. Future studies should take into account the potential presence of microcystin-producing Anabaena sp. in the Gulf of Finland.

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Du, Jian Fen, Yu Lin Tang, and Qian Li. "The Effect of Nano-ZnO on the Photosynthetic Capacity and Survival of Anabaena sp. and M. aeruginosa." Advanced Materials Research 1073-1076 (December 2014): 77–80. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.77.

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Anabaena sp. and M. aeruginosa were used to examine the toxic mechanism of nanoZnO to them, as well as the toxicity. Typical chlorophyll fluorescence parameters, including effective quantum yield, photosynthetic efficiency and maximum electron transport rate, were measured by a pulse amplitude modulated fluorometer. Results showed that nanoZnO could inhibit Anabaena sp. and M.aeruginosa growth with the EC50 (concentration for 50% of maximal effect) of 0.74±0.01 and 1.68±0.01 mg/L respectively. The toxicity of nanoZnO to Anabaena sp. is higher than that to M.aeruginosa, which can be proved by the malondialdehyde content in Anabaena sp. and M.aeruginosa cells.

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Chow-Fraser, Patricia, and W. Gary Sprules. "Inhibitory effect of Anabaena sp. on in situ filtering rate of Daphnia." Canadian Journal of Zoology 64, no. 9 (September 1, 1986): 1831–34. http://dx.doi.org/10.1139/z86-273.

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We found that in situ filtering rates of Daphnia spp. measured in a lake containing Anabaena were significantly lower than those measured in a filament-free lake. Even after accounting for the depressing effects of high nannoplankton biomass concentration, filtering rates in the lake with Anabaena were 64% lower than those from the filament-free lake. We also found that filtering rates for Daphnia pulex in laboratory experiments were lower when Anabaena was present in experimental beakers than when Chlorella was present. When Anabaena was removed from Three Mile Lake water, filtering rates compared closely with predicted rates based on nannoplankton concentration and carapace length alone. Our analysis indicates that the presence of Anabaena filaments depresses Daphnia grazing rates in general, and that the filaments themselves are ingested at a lower rate than algae such as Chlorella.

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ISLAM, M. S., M. M. GOLDAR, M. G. MORSHED, H. B. M. BAKHT, M. S. ISLAM, and D. A. SACK. "Chemotaxis between Vibrio cholerae O1 and a blue-green alga, Anabaena sp." Epidemiology and Infection 134, no. 3 (October 5, 2005): 645–48. http://dx.doi.org/10.1017/s0950268805005297.

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The chemotactic response of Vibrio cholerae O1 towards the mucilaginous sheath of Anabaena sp. was investigated by capillary tube method using a virulent strain of V. cholerae O1, El Tor, Ogawa (3083-T) and its isogenic mutant (HAP-1-T) that lacks the hap gene, which codes for mucinase (HA/protease). Homogenates of Anabaena sp. and purified mucin were used in this study as chemoattractants. Results showed 5·7% bacterial accumulation of wild-type V. cholerae O1 towards 4% homogenates of Anabaena sp. whereas, its mutant (hap−) showed 2·9% accumulation after 90 min. The higher percentage of attraction of wild-type V. cholerae O1 than the mutant (hap−) towards mucin and the homogenates of Anabaena sp. might be due to the activity of mucinase. These results indicate the role of mucinase in the chemotactic motility of V. cholerae O1 towards Anabaena sp.

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Meeks, John C., Nisan A. Steinberg, Carol S. Enderlin, Cecillia M. Joseph, and Gerald A. Peters. "Azolla-Anabaena Relationship." Plant Physiology 84, no. 3 (July 1, 1987): 883–86. http://dx.doi.org/10.1104/pp.84.3.883.

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Agnihotri, Vijai K. "Anabaena flos-aquae." Critical Reviews in Environmental Science and Technology 44, no. 18 (July 28, 2014): 1995–2037. http://dx.doi.org/10.1080/10643389.2013.803797.

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Rajaniemi, Pirjo, Pavel Hrouzek, Klára Kaštovská, Raphaël Willame, Anne Rantala, Lucien Hoffmann, Jiří Komárek, and Kaarina Sivonen. "Phylogenetic and morphological evaluation of the genera Anabaena, Aphanizomenon, Trichormus and Nostoc (Nostocales, Cyanobacteria)." International Journal of Systematic and Evolutionary Microbiology 55, no. 1 (January 1, 2005): 11–26. http://dx.doi.org/10.1099/ijs.0.63276-0.

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The heterocytous cyanobacteria form a monophyletic group according to 16S rRNA gene sequence data. Within this group, phylogenetic and morphological studies have shown that genera such as Anabaena and Aphanizomenon are intermixed. Moreover, the phylogeny of the genus Trichormus, which was recently separated from Anabaena, has not been investigated. The aim was to study the taxonomy of the genera Anabaena, Aphanizomenon, Nostoc and Trichormus belonging to the family Nostocaceae (subsection IV.I) by morphological and phylogenetic analyses of 16S rRNA gene, rpoB and rbcLX sequences. New strains were isolated to avoid identification problems caused by morphological changes of strains during cultivation. Morphological and phylogenetic data showed that benthic and planktic Anabaena strains were intermixed. In addition, the present study confirmed that Anabaena and Aphanizomenon strains were not monophyletic, as previously demonstrated. The evolutionary distances between the strains indicated that the planktic Anabaena and Aphanizomenon strains as well as five benthic Anabaena strains in cluster 1 could be assigned to a single genus. On the basis of the 16S rRNA, rpoB and rbcLX gene sequences, the Anabaena/Aphanizomenon strains (cluster 1) were divided into nine supported subclusters which could also be separated morphologically, and which therefore might represent different species. Trichormus strains were morphologically and phylogenetically heterogeneous and did not form a monophyletic cluster. These Trichormus strains, which were representatives of three distinct species, might actually belong to three genera according to the evolutionary distances. Nostoc strains were also heterogeneous and seemed to form a monophyletic cluster, which may contain more than one genus. It was found that certain morphological features were stable and could be used to separate different phylogenetic clusters. For example, the width and the length of akinetes were useful features for classification of the Anabaena/Aphanizomenon strains in cluster 1. This morphological and phylogenetic study with fresh isolates showed that the current classification of these anabaenoid genera needs to be revised.

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Mishbach, Imam, Nila Suci Permatasari, M. Zainuri, Hermin Pancasakti Kusumaningrum, and Endah Dwi Hastuti. "Potensi Mikroalga Anabaena sp. Sebagai Bahan Utama Bioetanol." EKOTONIA: Jurnal Penelitian Biologi, Botani, Zoologi dan Mikrobiologi 7, no. 1 (July 6, 2022): 69–76. http://dx.doi.org/10.33019/ekotonia.v7i1.3144.

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Bioethanol is an energy source that can be used to reduce the use of fossil fuels. It has some advantages such as biodegradable, and non-toxic because the main ingredients come from biomass and produce fewer pollutants. Anabaena sp. is Cyanobacteria that can be used as the main ingredient of bioethanol, its advantages are that it does not compete with food, its growth is fast and it contains carbohydrates. The purpose of this study was to analyze the carbohydrate content of Anabaena sp. The stages of the research carried out were Anabaena sp. cultivated for 30 days in freshwater using Walne media, then harvested. The collected biomass was then tested using proximate analysis with two replications. In this study, the data obtained in the form of growth of Anabaena sp. and carbohydrate content was presented in the form of tables and graphs. The results showed that Anabaena sp. which was cultivated for 30 days and harvested biomass was carried out in an exponential phase (day 14), had a carbohydrate content of 25.43 %, protein of 53.70 %, and lipid of 2.40 %. Based on the results of the study, it can be concluded that the biomass of Anabaena sp. has a carbohydrate content of 25.43 % and has the potential as the main ingredient of bioethanol.

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Wang, Kangjie, Beijuan Hu, Chuangang Zheng, Zhiyi Deng, Jian Duan, Kangxi Qin, Xinwei Cui, and Shifeng Li. "Application of Anabaena azotica- and Chlorella pyrenoidosa-Based Algal Biotechnology in Green Production of Algae-Rich Crataegi fructus." Journal of Healthcare Engineering 2022 (March 30, 2022): 1–7. http://dx.doi.org/10.1155/2022/8424890.

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Nitrogen-fixing Anabaena and Chlorella pyrenoidosa algal biotechnology are known as new agricultural inputs due to their characteristics and are widely used in the field of agricultural planting. This paper discusses the application of algal biotechnology based on nitrogen-fixing Anabaena sp. The advantages of algal biotechnology based on nitrogen-fixing Anabaena and Chlorella pyrenoidosa in terms of yield, sugar content, polyunsaturated fatty acid content, and high-quality yield of hawthorn were compared.

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Ballal, Anand, Marc Bramkamp, Hema Rajaram, Petra Zimmann, Shree Kumar Apte, and Karlheinz Altendorf. "An Atypical KdpD Homologue from the Cyanobacterium Anabaena sp. Strain L-31: Cloning, In Vivo Expression, and Interaction with Escherichia coli KdpD-CTD." Journal of Bacteriology 187, no. 14 (July 2005): 4921–27. http://dx.doi.org/10.1128/jb.187.14.4921-4927.2005.

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ABSTRACT The kdpFABC operon of Escherichia coli, coding for the high-affinity K+ transport system KdpFABC, is transcriptionally regulated by the products of the adjacently located kdpDE genes. The KdpD protein is a membrane-bound sensor kinase consisting of a large N-terminal domain and a C-terminal transmitter domain interconnected by four transmembrane segments (the transmembrane segments together with the C-terminal transmitter domain of KdpD are referred to as CTD), while KdpE is a cytosolic response regulator. We have cloned and sequenced the kdp operon from a nitrogen-fixing, filamentous cyanobacterium, Anabaena sp. strain L-31 (GenBank accession. number AF213466 ). The kdpABC genes are similar in size to those of E. coli, but the kdpD gene is short (coding only for 365 amino acids), showing homology only to the N-terminal domain of E. coli KdpD. A kdpE-like gene is absent in the vicinity of this operon. Anabaena KdpD with six C-terminal histidines was overproduced in E. coli and purified by Ni2+-nitrilotriacetic acid affinity chromatography. With antisera raised against the purified Anabaena KdpD, the protein was detected in Anabaena sp. strain L-31 membranes. The membrane-associated or soluble form of the Anabaena KdpD(6His) could be photoaffinity labeled with the ATP analog 8-azido-ATP, indicating the presence of an ATP binding site. The coproduction of Anabaena KdpD with E. coli KdpD-CTD decreased E. coli kdpFABC expression in response to K+ limitation in vivo relative to the wild-type KdpD-CTD protein. In vitro experiments revealed that the kinase activity of the E. coli KdpD-CTD was unaffected, but its phosphatase activity increased in the presence of Anabaena KdpD(6His). To our knowledge this is the first report where a heterologous N-terminal domain (Anabaena KdpD) is shown to affect in trans KdpD-CTD (E. coli) activity, which is just opposite to that observed for the KdpD-N-terminal domain of E. coli.

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Fiedler, Gabriele, Alicia M. Muro-Pastor, Enrique Flores, and Iris Maldener. "NtcA-Dependent Expression of the devBCAOperon, Encoding a Heterocyst-Specific ATP-Binding Cassette Transporter in Anabaena spp." Journal of Bacteriology 183, no. 12 (June 15, 2001): 3795–99. http://dx.doi.org/10.1128/jb.183.12.3795-3799.2001.

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ABSTRACT The devBCA operon, encoding subunits of an ATP-binding cassette exporter, is essential for differentiation of N2-fixing heterocysts in Anabaena spp. Nitrogen deficiency-dependent transcription of the operon and the use of its transcriptional start point, located 762 (Anabaena variabilis strain ATCC 29413-FD) or 704 (Anabaena sp. strain PCC 7120) bp upstream of the translation start site, were found to require the global nitrogen transcriptional regulator NtcA. Furthermore, NtcA was shown to bind in vitro to the promoter ofdevBCA.

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Vaitomaa, Jaana, Anne Rantala, Katrianna Halinen, Leo Rouhiainen, Petra Tallberg, Lena Mokelke, and Kaarina Sivonen. "Quantitative Real-Time PCR for Determination of Microcystin Synthetase E Copy Numbers for Microcystis and Anabaena in Lakes." Applied and Environmental Microbiology 69, no. 12 (December 2003): 7289–97. http://dx.doi.org/10.1128/aem.69.12.7289-7297.2003.

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ABSTRACT Cyanobacterial mass occurrences in freshwater lakes are generally formed by Anabaena, Microcystis, and Planktothrix, which may produce cyclic heptapeptide hepatotoxins, microcystins. Thus far, identification of the most potent microcystin producer in a lake has not been possible due to a lack of quantitative methods. The aim of this study was to identify the microcystin-producing genera and to determine the copy numbers of microcystin synthetase gene E (mcyE) in Lake Tuusulanjärvi and Lake Hiidenvesi in Finland by quantitative real-time PCR. The microcystin concentrations and cyanobacterial cell densities of these lakes were also determined. The microcystin concentrations correlated positively with the sum of Microcystis and Anabaena mcyE copy numbers from both Lake Tuusulanjärvi and Lake Hiidenvesi, indicating that mcyE gene copy numbers can be used as surrogates for hepatotoxic Microcystis and Anabaena. The main microcystin producer in Lake Tuusulanjärvi was Microcystis spp., since average Microcystis mcyE copy numbers were >30 times more abundant than those of Anabaena. Lake Hiidenvesi seemed to contain both nontoxic and toxic Anabaena as well as toxic Microcystis strains. Identifying the most potent microcystin producer in a lake could be valuable for designing lake restoration strategies, among other uses.

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Galmozzi, Carla V., Lorena Saelices, Francisco J. Florencio, and M. Isabel Muro-Pastor. "Posttranscriptional Regulation of Glutamine Synthetase in the Filamentous Cyanobacterium Anabaena sp. PCC 7120: Differential Expression between Vegetative Cells and Heterocysts." Journal of Bacteriology 192, no. 18 (July 16, 2010): 4701–11. http://dx.doi.org/10.1128/jb.00222-10.

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ABSTRACT Genes homologous to those implicated in glutamine synthetase (GS) regulation by protein-protein interaction in the cyanobacterium Synechocystis sp. strain PCC 6803 are conserved in several cyanobacterial sequenced genomes. We investigated this GS regulatory mechanism in Anabaena sp. strain PCC 7120. In this strain the system operates with only one GS inactivation factor (inactivation factor 7A [IF7A]), encoded by open reading frame (ORF) asl2329 (gifA). Following addition of ammonium, expression of gifA is derepressed, leading to the synthesis of IF7A, and consequently, GS is inactivated. Upon ammonium removal, the GS activity returns to the initial level and IF7A becomes undetectable. The global nitrogen control protein NtcA binds to the gifA promoter. Constitutive high expression levels of gifA were found in an Anabaena ntcA mutant (CSE2), indicating a repressor role for NtcA. In vitro studies demonstrate that Anabaena GS is not inactivated by Synechocystis IFs (IF7 and IF17), indicating the specificity of the system. We constructed an Anabaena strain expressing a second inactivating factor, containing the amino-terminal part of IF17 from Synechocystis fused to IF7A. GS inactivation in this strain is more effective than that in the wild type (WT) and resembles that observed in Synechocystis. Finally we found differential expression of the IF system between heterocysts and vegetative cells of Anabaena.

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24

Chaurasia, Akhilesh Kumar, and Shree Kumar Apte. "Overexpression of the groESL Operon Enhances the Heat and Salinity Stress Tolerance of the Nitrogen-Fixing Cyanobacterium Anabaena sp. Strain PCC7120." Applied and Environmental Microbiology 75, no. 18 (July 24, 2009): 6008–12. http://dx.doi.org/10.1128/aem.00838-09.

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ABSTRACT The bicistronic groESL operon, encoding the Hsp60 and Hsp10 chaperonins, was cloned into an integrative expression vector, pFPN, and incorporated at an innocuous site in the Anabaena sp. strain PCC7120 genome. In the recombinant Anabaena strain, the additional groESL operon was expressed from a strong cyanobacterial P psbA1 promoter without hampering the stress-responsive expression of the native groESL operon. The net expression of the two groESL operons promoted better growth, supported the vital activities of nitrogen fixation and photosynthesis at ambient conditions, and enhanced the tolerance of the recombinant Anabaena strain to heat and salinity stresses.

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25

De Nobel, W. T. (Pim), N. Staats, and L. R. Mur. "Competition between nitrogen-fixing cyanobacteria during phosphorus-limited growth." Water Science and Technology 32, no. 4 (August 1, 1995): 99–101. http://dx.doi.org/10.2166/wst.1995.0170.

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The phosphorus-limited growth of cultures of the nitrogen-fixing cyanobacteria Aphanizomenon and Anabaena was investigated. In conditions of nutrient and light excess Anabaena has a competitive advantage. The lower the light intensity conditions at which Aphanizomenon populations dominate are indicated for future study.

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26

van Hove, C., and A. Lejeune. "The Azolla: Anabaena Symbiosis." Biology and Environment: Proceedings of the Royal Irish Academy 102B, no. 1 (2002): 23–26. http://dx.doi.org/10.1353/bae.2002.0036.

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Golden, James W., and Ho-Sung Yoon. "Heterocyst formation in Anabaena." Current Opinion in Microbiology 1, no. 6 (December 1998): 623–29. http://dx.doi.org/10.1016/s1369-5274(98)80106-9.

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Golden, James W., and Ho-Sung Yoon. "Heterocyst development in Anabaena." Current Opinion in Microbiology 6, no. 6 (December 2003): 557–63. http://dx.doi.org/10.1016/j.mib.2003.10.004.

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29

Isono, Takahiro, and Tetzuya Katoh. "Subparticles of Anabaena phycobilisomes." Archives of Biochemistry and Biophysics 256, no. 1 (July 1987): 317–24. http://dx.doi.org/10.1016/0003-9861(87)90452-8.

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30

Parthiban, Jeevitha, and Ranjitha Jambulingam. "Enhancing the Biodiesel Production Potential of Synechococcus elongatus and Anabaena Cyanobacterial Strain Isolated from Saline Water Using Different Media Composition and Organic Carbon Sources." Sustainability 15, no. 1 (January 3, 2023): 870. http://dx.doi.org/10.3390/su15010870.

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In the present study, Synechococcus elongatus and Anabaena, two cyanobacterial species were cultured using different media conditions such as ASN III, modified ASN III, BG-11, and BBM for the enrichment of biomass and lipid productivity. The experimental result clearly shows that BG 11 was the efficient and cost-effective medium for both the isolated cyanobacterial species such as Synechococcus elongatus and Anabaena. The influence of organic carbon sources on biomass and lipid productivity of the selected cyanobacterial species were studied when cultivated in a BG-11 medium using different organic carbon sources such as sucrose, glucose, sodium acetate and glycerol under mixotrophic conditions. Based on the experimental results, the isolated cyanobacterial strain Synechococcus elongatus and Anabaena showed an enriching effect on lipid production under mixotrophic conditions, but whereas Synechococcus elongatus showed a significant effect three times greater lipid productivity compared with Anabaena cyanobacterial strain, by the addition of glycerol as a supplement to the culture media.

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COSSAR, J. D., A. J. DARLING, S. M. IP, P. ROWELL, and W. D. P. STEWART. "Immunocytochemical Localization of Thioredoxins in the Cyanobacteria Anabaena cylindrica and Anabaena variabilis." Microbiology 131, no. 11 (November 1, 1985): 3029–35. http://dx.doi.org/10.1099/00221287-131-11-3029.

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32

Jones, Gary J., and Wolfgang Korth. "In situ production of volatile odour compounds by river and reservoir phytoplankton populations in Australia." Water Science and Technology 31, no. 11 (June 1, 1995): 145–51. http://dx.doi.org/10.2166/wst.1995.0424.

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The production of volatile odour compounds by freshwater phytoplankton was monitored weekly from November to April (summer period) 1990/91 at two sites: (1) Hay Weir pool on the Murrumbidgee River, NSW and (2) Carcoar Dam, near Blayney, NSW. During this period, the phytoplankton of the Murrumbidgee River was dominated by two species of the diatom Melosira, and the cyanobacterium Anabaena sp. Carcoar Dam was mostly dominated by the cyanobacteria Microcystis aeruginosa and Anabaena sp. The major odour compounds detected were geosmin, β-cyclocitral, β-ionone, geranylacetone, and 6-methylhept-5-en-2-one. Clmparison of multivariate statistical analyses of the volatile odour compound profiles and algal population data provided strong evidence for the hypothesis that the major source of many of these odour compounds was the phytoplankton. Total (intra+extracellular) geosmin concentration was strongly correlated with Anabaena abundance with no significant difference in geosmin production between sites. From the overall average of 10 fg geosmin cell−1 it is possible to predict that taste and odour problems, due to geosmin, may be experienced at Anabaena abundances of > 1,000-2,000 cells ml−1 in temperate Australian waters. β-cyclocitral concentration was correlated with Microcystis abundance at Carcoar Dam (10 fg β-cyclocitral cell−1), but with Anabaena sp. abundance at Hay Weir (2 fg cell−1).

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Ballal, Anand, and Shree K. Apte. "Differential Expression of the Two kdp Operons in the Nitrogen-Fixing Cyanobacterium Anabaena sp. Strain L-31." Applied and Environmental Microbiology 71, no. 9 (September 2005): 5297–303. http://dx.doi.org/10.1128/aem.71.9.5297-5303.2005.

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ABSTRACT In several types of bacteria, the Kdp ATPase (comprising of the KdpABC complex) is an inducible, high-affinity potassium transporter that scavenges K+ from the environment. The cyanobacterium Anabaena sp. strain L-31 showed the presence of not one but two distinct kdp operons in its genome. The kdp1 consisted of kdpA1B1G1C1D genes, whereas the kdp2 contained the kdpA2B2G2C2 genes. Among the regulatory genes, the kdpD open reading frame of Anabaena sp. strain L-31 was truncated compared to the kdpD of other bacteria, whereas a kdpE-like gene was absent in the vicinity of the two kdp operons. In response to K+ limitation (<0.05 mM external K+), only kdp2 (and not kdp1) expression could be detected as a 5.3-kb transcript on Northern blots, indicating that kdpA2B2G2C2 genes constitute a polycystronic operon. Unlike E. coli, addition of osmolytes like NaCl, or a change in pH of the medium did not enhance the kdp expression in Anabaena sp. strain L-31. Interestingly, the Anabaena sp. strain L-31 kdp2 operon was strongly induced in response to desiccation stress. The addition of K+ to K+-starved cultures resulted in repression and degradation of kdp2 transcripts. Our results clearly show that kdp2 is the major kdp operon expressed in Anabaena sp. strain L-31 and may play an important role in adaptation to K+ limitation and desiccation stress.

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34

Islam, M. S., M. M. Goldar, M. G. Morshed, M. N. H. Khan, M. R. Islam, and R. B. Sack. "Involvement of thehapgene (mucinase) in the survival ofVibrio choleraeO1 in association with the blue-green alga,Anabaenasp." Canadian Journal of Microbiology 48, no. 9 (September 1, 2002): 793–800. http://dx.doi.org/10.1139/w02-073.

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Mucinase is a soluble haemagglutinin protease, which may be important for the survival of Vibrio cholerae in association with mucilaginous blue-green algae (cyanobacteria). A comparative survival study was carried out with an Anabaena sp. and a wild-type V. cholerae O1 strain hap+gene (haemagglutinin-protease), together with its isogenic mutant hap (hap-deleted gene). A simple spread plate technique was followed to count culturable V. cholerae O1 on taurocholate tellurite gelatin agar plate. The fluorescent antibody technique of Kogure et al. (1979) was used for the microscopical viable count of V. cholerae O1. Polymerase chain reaction (PCR) and Southern blot hybridization were carried out to detect a lower number of viable but nonculturable (VBNC) V. cholerae O1 from the laboratory-based experiments. The wild and mutant V. cholerae O1 strains survived in culturable form for 22 and 10 days, respectively, in association with the Anabaena sp., with the difference being statistically significant (P < 0.01). The fluorescent antibody technique, PCR, and hybridization results also showed that the wild strain survived better in the VBNC state than did the mutant VBNC strain in association with an Anabaena sp. These results indicate that the enzyme mucinase may play an important role in the association and long-term survival of V. cholerae O1 with a mucilaginous blue-green alga, Anabaena sp.Key words: Vibrio cholerae, Anabaena, mucinase, reservoir.

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35

Serrano, A. "Purification, characterization and function of dihydrolipoamide dehydrogenase from the cyanobacterium Anabaena sp. strain P.C.C. 7119." Biochemical Journal 288, no. 3 (December 15, 1992): 823–30. http://dx.doi.org/10.1042/bj2880823.

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A dihydrolipoamide dehydrogenase (dihydrolipoamide: NAD+ oxidoreductase, EC 1.8.1.4) (DLD) has been found in the soluble fraction of cells of both unicellular (Synechococcus sp. strain P.C.C. 6301) and filamentous (Calothrix sp. strain P.C.C. 7601 and Anabaena sp. strain P.C.C. 7119) cyanobacteria. DLD from Anabaena sp. was purified 3000-fold to electrophoretic homogeneity. The purified enzyme exhibited a specific activity of 190 units/mg and was characterized as a dimeric FAD-containing protein with a native molecular mass of 104 kDa, a Stokes' radius of 4.28 nm and a very acidic pI value of about 3.7. As is the case with the same enzyme from other sources, cyanobacterial DLD showed specificity for NADH and lipoamide, or lipoic acid, as substrates. Nevertheless, the strong acidic character of the Anabaena DLD is a distinctive feature with respect to the same enzyme from other organisms. The presence of essential thiol groups was suggested by the inactivation produced by thiol-group-reactive reagents and heavy-metal ions, with lipoamide, but not NAD+, behaving as a protective agent. The function and physiological significance of Anabaena DLD are discussed in relation to the fact that 2-oxoacid dehydrogenase complexes have not been detected so far in filamentous cyanobacteria. Glycine decarboxylase activity, which might be involved in photorespiratory metabolism, has been found, however, in cell extracts of Anabaena sp. strain P.C.C. 7119 as the present study demonstrates.

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36

Mochimaru, Mari, Hajime Masukawa, Takashi Maoka, Hatem E. Mohamed, Wim F. J. Vermaas, and Shinichi Takaichi. "Substrate Specificities and Availability of Fucosyltransferase and β-Carotene Hydroxylase for Myxol 2′-Fucoside Synthesis in Anabaena sp. Strain PCC 7120 Compared with Synechocystis sp. Strain PCC 6803." Journal of Bacteriology 190, no. 20 (August 15, 2008): 6726–33. http://dx.doi.org/10.1128/jb.01881-07.

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

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37

Liu, Jinxin, Qinghao Jin, Junfeng Geng, Jianxin Xia, Yanhong Wu, and Huiying Chen. "Fast Capture and Efficient Removal of Bloom Algae Based on Improved Dielectrophoresis Process." International Journal of Environmental Research and Public Health 20, no. 1 (January 1, 2023): 832. http://dx.doi.org/10.3390/ijerph20010832.

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A dielectrophoresis (DEP) method for direct capture and fast removal of Anabaena was established in this work. The factors affecting the removal efficiency of Anabaena were investigated systematically, leading to optimized experimental conditions and improved DEP process equipment. The experimental results showed that our improved DEP method could directly capture Anabaena in eutrophic water with much enhanced removal efficiency of Anabaena from high-concentration algal bloom-eutrophication-simulated solution. The removal rate could increase by more than 20% after applying DEP at 15 V compared with a pure filtration process. Moreover, the removal rate could increase from 38.76% to 80.18% in optimized experimental conditions (the initial concentration of 615 μg/L, a flow rate of 0.168 L/h, an AC voltage of 15 V, and frequency of 100 kHz). Optical microscopic images showed that the structure of the captured algae cells was intact, indicating that the DEP method could avoid the secondary pollution caused by the addition of reagents and the release of phycotoxins, providing a new practical method for emergent treatment of water bloom outbreaks.

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38

Pereira, Ana L., and Vitor Vasconcelos. "Classification and phylogeny of the cyanobiont Anabaena azollae Strasburger: an answered question?" International Journal of Systematic and Evolutionary Microbiology 64, Pt_6 (June 1, 2014): 1830–40. http://dx.doi.org/10.1099/ijs.0.059238-0.

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The symbiosis Azolla–Anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. The cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). The classification and phylogeny of the cyanobiont is very controversial: from its morphology, it has been named Nostoc azollae, Anabaena azollae, Anabaena variabilis status azollae and recently Trichormus azollae, but, from its 16S rRNA gene sequence, it has been assigned to Nostoc and/or Anabaena , and from its phycocyanin gene sequence, it has been assigned as non-Nostoc and non-Anabaena. The literature also points to a possible co-evolution between the cyanobiont and the Azolla host, since dendrograms and phylogenetic trees of fatty acids, short tandemly repeated repetitive (STRR) analysis and restriction fragment length polymorphism (RFLP) analysis of nif genes and the 16S rRNA gene give a two-cluster association that matches the two-section ranking of the host (Azolla). Another controversy surrounds the possible existence of more than one genus or more than one species strain. The use of freshly isolated or cultured cyanobionts is an additional problem, since their morphology and protein profiles are different. This review gives an overview of how morphological, chemical and genetic analyses influence the classification and phylogeny of the cyanobiont and future research.

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39

Koksharova, Olga A., and C. Peter Wolk. "Novel DNA-Binding Proteins in the Cyanobacterium Anabaena sp. Strain PCC 7120." Journal of Bacteriology 184, no. 14 (July 15, 2002): 3931–40. http://dx.doi.org/10.1128/jb.184.14.3931-3940.2002.

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ABSTRACT As an approach towards elucidation of the biochemical regulation of the progression of heterocyst differentiation in Anabaena sp. strain PCC 7120, we have identified proteins that bind to a 150-bp sequence upstream from hepC, a gene that plays a role in the synthesis of heterocyst envelope polysaccharide. Such proteins were purified in four steps from extracts of vegetative cells of Anabaena sp. Two of these proteins (Abp1 and Abp2) are encoded by neighboring genes in the Anabaena sp. chromosome. The genes that encode the third (Abp3) and fourth (Abp4) proteins are situated at two other loci in that chromosome. Insertional mutagenesis of abp2 and abp3 blocked expression of hepC and hepA and prevented heterocyst maturation and aerobic fixation of N2.

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40

Ge, Xin, Karen Cain, and Rona Hirschberg. "Urea metabolism and urease regulation in the cyanobacterium Anabaena variabilis." Canadian Journal of Microbiology 36, no. 3 (March 1, 1990): 218–22. http://dx.doi.org/10.1139/m90-037.

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Anabaena variabilis can use urea as a nitrogen source, which it breaks down via the action of urease. No evidence of urea amidolyase activity was found. Urease synthesis is constitutive; no major difference in enzyme levels was found when cultures were grown with urea, ammonia, or N2. Urea is not required for urease synthesis, and ammonia does not repress urease synthesis. However, urea does repress nitrogenase synthesis at the transcription level, probably by the same mechanism as ammonia. Anabaena variabilis urease is inhibited by phenylphosphorodiamidate, hydroxyurea, and acetohydroxamic acid, which suggests that the enzyme contains nickel. A Km for urea of 46 μM was observed in crude cell free extracts. The enzyme is cytoplasmic and relatively heat resistant. Key words: urea, urease, cyanobacteria, Anabaena variabilis.

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Al-Tebrineh, Jamal, Troco Kaan Mihali, Francesco Pomati, and Brett A. Neilan. "Detection of Saxitoxin-Producing Cyanobacteria and Anabaena circinalis in Environmental Water Blooms by Quantitative PCR." Applied and Environmental Microbiology 76, no. 23 (October 8, 2010): 7836–42. http://dx.doi.org/10.1128/aem.00174-10.

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ABSTRACT Saxitoxins (STXs) are carbamate alkaloid neurotoxins produced by marine “red tide” dinoflagellates and several species of freshwater filamentous cyanobacteria, including Anabaena circinalis, Aphanizomenon spp., Lyngbya wollei, and Cylindrospermopsis raciborskii. A specific quantitative PCR (qPCR) method based on SYBR green chemistry was developed to quantify saxitoxin-producing Anabaena circinalis cyanobacteria, which are major bloom-forming freshwater cyanobacteria. The aim of this study was to infer the potential toxigenicity of samples by determining the copy number of a unique and unusual polyketide synthase (PKS) sequence (sxtA) in the STX biosynthesis gene cluster identified in cyanobacteria. Our qPCR approach was applied to water samples collected from different Australian lakes, dams, and rivers. The STX concentration and cyanobacterial cell density of these blooms were also determined by high-pressure liquid chromatography (HPLC) and microscopic cell counting, respectively. STX concentrations correlated positively with STX gene copy numbers, indicating that the latter can be used as a measure of potential toxigenicity in Anabaena circinalis and possibly other cyanobacterial blooms. The qPCR method targeting STX genes can also be employed for both monitoring and ecophysiological studies of toxic Anabaena circinalis blooms and potentially several other STX-producing cyanobacteria.

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Österholm, Julia, Rafael V. Popin, David P. Fewer, and Kaarina Sivonen. "Phylogenomic Analysis of Secondary Metabolism in the Toxic Cyanobacterial Genera Anabaena, Dolichospermum and Aphanizomenon." Toxins 12, no. 4 (April 11, 2020): 248. http://dx.doi.org/10.3390/toxins12040248.

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Cyanobacteria produce an array of toxins that pose serious health risks to humans and animals. The closely related diazotrophic genera, Anabaena, Dolichospermum and Aphanizomenon, frequently form poisonous blooms in lakes and brackish waters around the world. These genera form a complex now termed the Anabaena, Dolichospermum and Aphanizomenon (ADA) clade and produce a greater array of toxins than any other cyanobacteria group. However, taxonomic confusion masks the distribution of toxin biosynthetic pathways in cyanobacteria. Here we obtained 11 new draft genomes to improve the understanding of toxin production in these genera. Comparison of secondary metabolite pathways in all available 31 genomes for these three genera suggests that the ability to produce microcystin, anatoxin-a, and saxitoxin is associated with specific subgroups. Each toxin gene cluster was concentrated or even limited to a certain subgroup within the ADA clade. Our results indicate that members of the ADA clade encode a variety of secondary metabolites following the phylogenetic clustering of constituent species. The newly sequenced members of the ADA clade show that phylogenetic separation of planktonic Dolichospermum and benthic Anabaena is not complete. This underscores the importance of taxonomic revision of Anabaena, Dolichospermum and Aphanizomenon genera to reflect current phylogenomic understanding.

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Sevilla, Emma, Cristina Sarasa-Buisan, Andrï¿½s Gonzï¿½lez, Rafael Cases, Galyna Kufryk, M. Luisa Peleato, and Marï¿½a F. Fillat. "Regulation by FurC in Anabaena Links the Oxidative Stress Response to Photosynthetic Metabolism." Plant and Cell Physiology 60, no. 8 (May 21, 2019): 1778–89. http://dx.doi.org/10.1093/pcp/pcz094.

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Abstract The FUR (Ferric Uptake Regulator) family in Anabaena sp. PCC 7120 consists of three paralogs named FurA (Fur), FurB (Zur) and FurC (PerR). furC seems to be an essential gene in the filamentous nitrogen-fixing strain Anabaena sp. PCC 7120, suggesting that it plays a fundamental role in this organism. In order to better understand the functions of FurC in Anabaena, the phenotype of a derivative strain that overexpresses this regulator (EB2770FurC) has been characterized. The furC-overexpressing variant presented alterations in growth rate, morphology and ultrastructure, as well as higher sensitivity to peroxide than Anabaena sp. PCC 7120. Interestingly, the overexpression of furC led to reduced photosynthetic O2 evolution, increased respiratory activity, and had a significant influence in the composition and efficiency of both photosystems. Comparative transcriptional analyses, together with electrophoretic mobility shift assays allowed the identification of different genes directly controlled by FurC, and involved in processes not previously related to PerR proteins, such as the cell division gene ftsZ and the major thylakoid membrane protease ftsH. The rise in the transcription of ftsH in EB2770FurC cells correlated with reduced levels of the D1 protein, which is involved in the PSII repair cycle. Deregulation of the oxidative stress response in EB2770FurC cells led to the identification of novel FurC targets involved in the response to H2O2 through different mechanisms. These results, together with the effect of furC overexpression on the composition, stability and efficiency of the photosynthetic machinery of Anabaena, disclose novel links between PerR proteins, cell division and photosynthesis in filamentous cyanobacteria.

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Banerjee, Manisha, Dhiman Chakravarty, and Anand Ballal. "Molecular basis of function and the unusual antioxidant activity of a cyanobacterial cysteine desulfurase." Biochemical Journal 474, no. 14 (July 6, 2017): 2435–47. http://dx.doi.org/10.1042/bcj20170290.

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Cysteine desulfurases, which supply sulfur for iron–sulfur cluster biogenesis, are broadly distributed in all phyla including cyanobacteria, the progenitors of plant chloroplasts. The SUF (sulfur utilization factor) system is responsible for Fe–S cluster biosynthesis under stress. The suf operon from cyanobacterium Anabaena PCC 7120 showed the presence of a cysteine desulfurase, sufS (alr2495), but not the accessory sulfur-accepting protein (SufE). However, an open reading frame (alr3513) encoding a SufE-like protein (termed AsaE, Anabaena sulfur acceptor E) was found at a location distinct from the suf operon. The purified SufS protein existed as a pyridoxal 5' phosphate (PLP)-containing dimer with a relatively low desulfurase activity. Interestingly, in the presence of the AsaE protein, the catalytic efficiency of this reaction increased 10-fold. In particular, for sulfur mobilization, the AsaE protein partnered only SufS and not other cysteine desulfurases from Anabaena. The SufS protein was found to physically interact with the AsaE protein, demonstrating that AsaE was indeed the missing partner of Anabaena SufS. The conserved cysteine of the SufS or the AsaE protein was essential for activity but not for their physical association. Curiously, overexpression of the SufS protein in Anabaena caused reduced formation of reactive oxygen species on exposure to hydrogen peroxide (H2O2), resulting in superior oxidative stress tolerance to the oxidizing agent when compared with the wild-type strain. Overall, the results highlight the functional interaction between the two proteins that mediate sulfur mobilization, in the cyanobacterial SUF pathway, and further reveal that overexpression of SufS can protect cyanobacteria from oxidative stress.

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Sklenar, K. S., and A. J. Horne. "Horizontal Distribution of Geosmin in a Reservoir before and after Copper Treatment." Water Science and Technology 40, no. 6 (September 1, 1999): 229–37. http://dx.doi.org/10.2166/wst.1999.0303.

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Extracellular geosmin, chlorophyll a, and Anabaena circinalis filament density were measured at several stations on the surface of Lake Perris, a 1.62 × 108 m3 (131,450 acre-ft) reservoir in southern California, before and after the reservoir was treated with copper sulfate. Samples were collected from 22 stations within three hours the day before copper was applied by helicopter to the reservoir, which was undergoing an odorous Anabaena bloom. The day after the copper application, 19 stations were sampled over the same short period of time to see how the copper application affected parameter distribution on the reservoir surface. The presence of higher geosmin concentrations in some areas of the lake after copper treatment suggests that additional geosmin was released into the water when Anabaena cells were lysed by the copper.

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Swapnil, Prashant, Mukesh Meena, and Ashwani K. Rai. "Molecular interaction of nitrate transporter proteins with recombinant glycinebetaine results in efficient nitrate uptake in the cyanobacterium Anabaena PCC 7120." PLOS ONE 16, no. 11 (November 18, 2021): e0257870. http://dx.doi.org/10.1371/journal.pone.0257870.

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Nitrate transport in cyanobacteria is mediated by ABC-transporter, which consists of a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). Under salt stress, recombinant glycinebetaine (GB) not only protected the rate of nitrate transport in transgenic Anabaena PCC 7120, rather stimulated the rate by interacting with the ABC-transporter proteins. In silico analyses revealed that nrtA protein consisted of 427 amino acids, the majority of which were hydrophobic and contained a Tat (twin-arginine translocation) signal profile of 34 amino acids (1–34). The nrtC subunit of 657 amino acids contained two hydrophobic distinct domains; the N-terminal (5–228 amino acids), which was 59% identical to nrtD (the ATP-binding subunit) and the C-terminal (268–591), 28.2% identical to nrtA, suggesting C-terminal as a solute binding domain and N-terminal as ATP binding domain. Subunit nrtD consisted of 277 amino acids and its N-terminal (21–254) was an ATP binding motif. Phylogenetic analysis revealed that nitrate-ABC-transporter proteins are highly conserved among the cyanobacterial species, though variation existed in sequences resulting in several subclades. Nostoc PCC 7120 was very close to Anabaena variabilis ATCC 29413, Anabaena sp. 4–3 and Anabaena sp. CA = ATCC 33047. On the other, Nostoc spp. NIES-3756 and PCC 7524 were often found in the same subclade suggesting more work before referring it to Anabaena PCC 7120 or Nostoc PCC 7120. The molecular interaction of nitrate with nrtA was hydrophilic, while hydrophobic with nrtC and nrtD. GB interaction with nrtACD was hydrophobic and showed higher affinity compared to nitrate.

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Bhargava, Poonam, Arvind Kumar, Yogesh Mishra, and Lal Chand Rai. "Copper pretreatment augments ultraviolet B toxicity in the cyanobacterium Anabaena doliolum: a proteomic analysis of cell death." Functional Plant Biology 35, no. 5 (2008): 360. http://dx.doi.org/10.1071/fp07267.

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This study provides first-hand proteomic characterisation of Cu-pretreatment-induced augmentation of ultraviolet B toxicity in the cyanobacterium Anabaena doliolum Bharadwaja. Of the three treatments (i.e. Cu, UV-B and Cu + UV-B) tested, the UV-B treatment of Cu-pretreated Anabaena produced a greater inhibition of oxygen evolution, 14C fixation, ATP and NADPH contents than UV-B alone. Proteomic analysis using two-dimensional gel electrophoresis (2DE), MALDI-TOF MS/MS and reverse transcription polymerase chain reaction (RT–PCR) of Cu, UV-B, and Cu + UV-B treated Anabaena exhibited significant and reproducible alterations in 12 proteins. Of these, manganese superoxide dismutase (Mn-SOD), iron superoxide dismutase (Fe-SOD) and peroxiredoxin (PER) are antioxidative enzymes; ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo), phosphoribulokinase (PRK), flavodoxin (Flv), plastocyanin (PLC), phosphoglycerate kinase (PGK), phycocyanin (PC) and phycoerythrocyanin α-chain (PC α-chain) are linked with photosynthesis and respiration; and DnaK and nucleoside diphosphate kinase (NDPK) are associated with cellular processes and light signalling, respectively. However, when subjected to a high dose of UV-B, Cu-pretreated Anabaena depicted a severe down-regulation of DnaK, NDPK and Flv, probably because of inevitable oxidative stress. Thus, the augmentation of UV-B toxicity by Cu can be attributed to the down-regulation of DnaK, NDPK and Flv.

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Zhou, Yin, Wen-Li Chen, Li Wang, and Cheng-Cai Zhang. "Identification of the oriC region and its influence on heterocyst development in the filamentous cyanobacterium Anabaena sp. strain PCC 7120." Microbiology 157, no. 7 (July 1, 2011): 1910–19. http://dx.doi.org/10.1099/mic.0.047241-0.

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Anabaena sp. strain PCC 7120 (Anabaena PCC 7120) is a filamentous, nitrogen-fixing cyanobacterium. Upon deprivation of combined nitrogen, about 5–10 % of the cells become heterocysts, i.e. cells devoted to N2 fixation. Heterocysts are intercalated among vegetative cells and distributed in a semi-regular pattern, and adjacent heterocysts are rarely observed. Previously, we showed that the cell cycle could play a regulatory function during heterocyst development, although the mechanism involved remains unknown. As a further step to understand this phenomenon, we identified the oriC region for chromosomal DNA replication, located between dnaA and dnaN. The oriC region of Anabaena PCC 7120 was able to support the self-replication of a plasmid in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Surprisingly, integration of the oriC region into the chromosome of Anabaena PCC 7120 through homologous recombination led to much slower cell growth in the absence of a combined-nitrogen source and to multiple contiguous proheterocysts after prolonged incubation. Real-time RT-PCR showed that expression of two heterocyst-related genes, hetR and hetN, was altered in these strains: hetR expression remained high 48 h after induction, and hetN increased to high levels after induction for 12 h. These results suggest that the balance between oriC and DnaA could be important for heterocyst development.

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Kundu, Karishma, Roberta Teta, Germana Esposito, Mariano Stornaiuolo, and Valeria Costantino. "A Four-Step Platform to Optimize Growth Conditions for High-Yield Production of Siderophores in Cyanobacteria." Metabolites 13, no. 2 (January 20, 2023): 154. http://dx.doi.org/10.3390/metabo13020154.

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In response to Iron deprivation and in specific environmental conditions, the cyanobacteria Anabaena flos aquae produce siderophores, iron-chelating molecules that in virtue of their interesting environmental and clinical applications, are recently gaining the interest of the pharmaceutical industry. Yields of siderophore recovery from in vitro producing cyanobacterial cultures are, unfortunately, very low and reach most of the times only analytical quantities. We here propose a four-step experimental pipeline for a rapid and inexpensive identification and optimization of growth parameters influencing, at the transcriptional level, siderophore production in Anabaena flos aquae. The four-steps pipeline consists of: (1) identification of the promoter region of the operon of interest in the genome of Anabaena flos aquae; (2) cloning of the promoter in a recombinant DNA vector, upstream the cDNA coding for the Green Fluorescent Protein (GFP) followed by its stable transformation in Escherichia Coli; (3) identification of the environmental parameters affecting expression of the gene in Escherichia coli and their application to the cultivation of the Anabaena strain; (4) identification of siderophores by the combined use of high-resolution tandem mass spectrometry and molecular networking. This multidisciplinary, sustainable, and green pipeline is amenable to automation and is virtually applicable to any cyanobacteria, or more in general, to any microorganisms.

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Kaplan, Drora, Harry E. Calvert, and Gerald A. Peters. "The Azolla-Anabaena azollae Relationship." Plant Physiology 80, no. 4 (April 1, 1986): 884–90. http://dx.doi.org/10.1104/pp.80.4.884.

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Journal articles on the topic 'Anabaena'

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