| phylogenetic and gene expression analysis of cyanobacteria and diatoms in the twilight waters of the temperate northeast pacific ocean. | in this study, to explore the microbial community structure and its functionality in the deep-sea environments, we initially performed a 16s ribosomal rna (rrna)-based community structure analyses for microbial communities in the sea water collected from sites of 765-790-ám in depth in the pacific ocean. interestingly, in the clone library we detected the presence of both photoautotrophic bacteria such as cyanobacteria and photoheterotrophic bacteria, such as chloroflexus sp. to further explore ... | 2011 | 21698402 |
| impacts of shading on sponge-cyanobacteria symbioses: a comparison between host-specific and generalist associations. | the marine sponge lamellodysidea chlorea contains large populations of the host-specific, filamentous cyanobacterium oscillatoria spongeliae. other marine sponges, including xestospongia exigua, contain the generalist, unicellular cyanobacterium synechococcus spongiarum. the impact of cyanobacterial photosynthesis on host sponges was manipulated by shading these sponge-cyanobacteria associations. if cyanobacteria benefit their hosts, shading should reduce this benefit. chlorophyll a concentratio ... | 2005 | 21676782 |
| [seasonal variation of chlorophyll a and its potential relationship with various algal species in xiaojiang river backwater area, three gorges reservoir]. | the seasonal variation of chlorophyll a (chla) in xiaojiang river backwater area from may 2007 to april 2008 with 115 water samples was studied. three trophic states i.e. chla < or = 5 microg x l(-1), 5 microg x l(-1) < chla < or = 19 microg x l(-1) and chla >19 microg x l(-1), were applied to represent the potential relationship of chla, algal cell density (celld) and biomass (biom) in xiaojiang river backwater area. the results showed that the algal cell density, biomass and chla had significa ... | 2011 | 21717735 |
| directional rna deep sequencing sheds new light on the transcriptional response of anabaena sp. strain pcc 7120 to combined-nitrogen deprivation. | cyanobacteria are potential sources of renewable chemicals and biofuels and serve as model organisms for bacterial photosynthesis, nitrogen fixation, and responses to environmental changes. anabaena (nostoc) sp. strain pcc 7120 (hereafter anabaena) is a multicellular filamentous cyanobacterium that can "fix" atmospheric nitrogen into ammonia when grown in the absence of a source of combined nitrogen. because the nitrogenase enzyme is oxygen sensitive, anabaena forms specialized cells called hete ... | 2011 | 21711558 |
| identification of trichotoxin, a novel chlorinated compound associated with the bloom forming cyanobacterium, trichodesmium thiebautii. | trichodesmium is a suspected toxin-producing nonheterocystous cyanobacteria ubiquitous in tropical, subtropical, and temperate seas. the genus is known for its ability to fix nitrogen and form massive blooms. in oligotrophic seas, it can dominate the biomass and be a major component of oceanic primary production and global nitrogen cycling. numerous reports suggest trichodesmium-derived toxins are a cause of death of fish, crabs, and bivalves. laboratory studies have demonstrated neurotoxic effe ... | 2011 | 21740025 |
| clock genes and sleep. | in most species-from cyanobacteria to humans-endogenous clocks have evolved that drive 24-h rhythms of behavior and physiology. in mammals, these circadian rhythms are regulated by a hierarchical network of cellular oscillators controlled by a set of clock genes organized in a system of interlocked transcriptional feedback loops. one of the most prominent outputs of the circadian system is the synchronization of the sleep-wake cycle with external (day-) time. clock genes also have a strong impac ... | 2011 | 21833490 |
| use of marfey's reagent and analogs for chiral amino acid analysis: assessment and applications to natural products and biological systems. | the present paper describes an updated knowledge and status on marfey's reagent (mr), 1-fluoro-2,4-dinitrophenyl-5-l-alanine amide (fdnp-l-ala-nh(2)). the reagent is used for pre-column derivatization of amino acids followed by hplc separation of the diastereomers so formed. emphasis is put on the design and application of structural variants which are synthesized by introducing different (other than l-ala-nh(2)) l- and d-amino acid amides and amino acids in the 1,5-difluoro-2,4-dinitro benzene ... | 2011 | 21737363 |
| dynamics of gene duplication in the genomes of chlorophyll d-producing cyanobacteria: implications for the ecological niche. | gene duplication may be an important mechanism for the evolution of new functions and for the adaptive modulation of gene expression via dosage effects. here, we analyzed the fate of gene duplicates for two strains of a novel group of cyanobacteria (genus acaryochloris) that produces the far-red light absorbing chlorophyll d as its main photosynthetic pigment. the genomes of both strains contain an unusually high number of gene duplicates for bacteria. as has been observed for eukaryotic genomes ... | 2011 | 21697100 |
| crystal structure of the eukaryotic light-driven proton-pumping rhodopsin, acetabularia rhodopsin ii, from marine alga. | acetabularia rhodopsin (ar) is a rhodopsin from the marine plant acetabularia acetabulum. the opsin-encoding gene from a. acetabulum, arii, was cloned and found to be novel but homologous to that reported previously. arii is a light-driven proton pump, as demonstrated by the existence of a photo-induced current through xenopus oocytes expressing arii. the photochemical reaction of arii prepared by cell-free protein synthesis was similar to that of bacteriorhodopsin (br), except for the lack of l ... | 2011 | 21726566 |
| efficiency of photosynthesis in a chl d-utilizing cyanobacterium is comparable to or higher than that in chl a-utilizing oxygenic species. | the cyanobacterium acaryochloris marina uses chlorophyll d to carry out oxygenic photosynthesis in environments depleted in visible and enhanced in lower-energy, far-red light. however, the extent to which low photon energies limit the efficiency of oxygenic photochemistry in a. marina is not known. here, we report the first direct measurements of the energy-storage efficiency of the photosynthetic light reactions in a. marina whole cells, and find it is comparable to or higher than that in typi ... | 2011 | 21708123 |
| composition and diversity of nifh genes of nitrogen-fixing cyanobacteria associated with boreal forest feather mosses. | ôçó recent studies have revealed that nitrogen fixation by cyanobacteria living in association with feather mosses is a major input of nitrogen to boreal forests. we characterized the community composition and diversity of cyanobacterial nifh phylotypes associated with each of two feather moss species (pleurozium schreberi and hylocomium splendens) on each of 30 lake islands varying in ecosystem properties in northern sweden. ôçó nitrogen fixation was measured using acetylene reduction, and nifh ... | 2011 | 21714790 |
| structure of the rubisco chaperone rbcx from the thermophilic cyanobacterium thermosynechococcus elongatus. | the crystal structure of terbcx, a rubisco assembly chaperone from the cyanobacterium thermosynechococcus elongatus, a thermophilic organism, has been determined at 1.7ôçà+à resolution. terbcx has an unusual cysteine residue at-áposition 103 that is not found in rbcx proteins from mesophilic organisms. unlike wild-type terbcx, a mutant protein with cys103 replaced by ala (terbcx-c103a) could be readily crystallized. the structure revealed that the-áoverall fold of the terbcx homodimer is similar ... | 2011 | 21821880 |
| the use of cyanobacteria as filler in nitrocellulose capillaries improves ultrastructural preservation of immature barley pollen upon high pressure freezing. | the high pressure freezing (hpf) followed by freeze substitution technique has advantages over chemical fixation in the context of preserving sample ultrastructure. however, when hpf is applied to cultured pollen grains, the large intercellular spaces present lead to a poor level of ultrastructure preservation. we report here that the mixing of cyanobacteria with immature barley pollen grains succeeded in greatly reducing the volume of liquid present between the large pollen grains, and so impro ... | 2011 | 21711458 |
| microbial community structure of arctic multiyear sea ice and surface seawater by 454 sequencing of the 16s rna gene. | dramatic decreases in the extent of arctic multiyear ice (myi) suggest this environment may disappear as early as 2100, replaced by ecologically different first-year ice. to better understand the implications of this loss on microbial biodiversity, we undertook a detailed census of the microbial community in myi at two sites near the geographic north pole using parallel tag sequencing of the 16s rrna gene. although the composition of the myi microbial community has been characterized by previous ... | 2011 | 21716307 |
| the study of biochemical and histopathological effects of spirulina in rats with tnbs-induced colitis. | to evaluate the beneficial effects of spirulina on the treatment of experimental colitis. | 2011 | 21682075 |
| a synthetic route to the saxitoxin skeleton: synthesis of decarbamoyl +¦-saxitoxinol, an analogue of saxitoxin produced by the cyanobacterium lyngbya wollei. | | 2011 | 21688378 |
| cyanobacterial lactate oxidases serve as essential partners in n2 fixation and evolved into photorespiratory glycolate oxidases in plants. | glycolate oxidase (gox) is an essential enzyme involved in photorespiratory metabolism in plants. in cyanobacteria and green algae, the corresponding reaction is catalyzed by glycolate dehydrogenases (glcd). the genomes of n(2)-fixing cyanobacteria, such as nostoc pcc 7120 and green algae, appear to harbor genes for both glcd and gox proteins. the gox-like proteins from nostoc (no-lox) and from chlamydomonas reinhardtii showed high l-lactate oxidase (lox) and low gox activities, whereas glycolat ... | 2011 | 21828292 |
| genome of the cyanobacterium microcoleus vaginatusfgp-2, a photosynthetic ecosystem engineer of arid land soil biocrusts worldwide. | the filamentous cyanobacterium microcoleus vaginatusis found in arid land soils worldwide. the genome of m. vaginatusstrain fgp-2 allows exploration of genes involved in photosynthesis, desiccation tolerance, alkane production, and other features contributing to this organism's ability to function as a major component of biological soil crusts in arid lands. | 2011 | 21705610 |
| gene expression profiles in liver of zebrafish treated with microcystin-lr. | microcystin-lr (mc-lr) is the most frequently studied cyclic heptatoxin produced by cyanobacteria, which has tremendous negative impacts on fish, while its molecular mechanism behind remained unclear at present. here, affymetrix zebrafish genechip was used to identify alterations in gene expression of zebrafish (danio rerio) after mc-lr exposure. among the 14,900 transcripts in the microarray, 273 genes were differentially expressed, in which 243 genes were elevated and 30 were decreased. accord ... | 2008 | 21783881 |
| plasma biochemical responses of the planktivorous filter-feeding silver carp (hypophthalmichthys molitrix) and bighead carp (aristichthys nobilis) to prolonged toxic cyanobacterial blooms in natural waters. | the planktivorous filter-feeding silver carp (hypophthalmichthys molitrix) and bighead carp (aristichthys nobilis) are the attractive candidates for bio-control of plankton communities to eliminate odorous populations of cyanobacteria. however, few studies focused on the health of such fishes in natural water body with vigorous toxic blooms. blood parameters are useful and sensitive for diagnosis of diseases and monitoring of the physiological status of fish exposed to toxicants. to evaluate the ... | 2009 | 21783964 |
| genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits. | 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. | 2011 | 21718514 |
| biselyngbyaside, isolated from marine cyanobacteria, inhibits osteoclastogenesis and induces apoptosis in mature osteoclasts. | the mass and function of bones depend on the maintenance of a complicated balance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. an inhibitor of osteoclast differentiation and/or function is expected to be useful for treatment of bone lytic diseases such as osteoporosis, rheumatoid arthritis and tumor metastasis into bone. biselyngbyaside is a recently isolated macrolide compound from marine cyanobacteria lyngbya sp. that shows wide-spectrum cytotoxicity towa ... | 2011 | 21678460 |
| environmental impacts of cultured meat production. | cultured meat (i.e., meat produced in vitro using tissue engineering techniques) is being developed as a potentially healthier and more efficient alternative to conventional meat. life cycle assessment (lca) research method was used for assessing environmental impacts of large-scale cultured meat production. cyanobacteria hydrolysate was assumed to be used as the nutrient and energy source for muscle cell growth. the results showed that production of 1000 kg cultured meat requires 26-33 gj energ ... | 2011 | 21682287 |
| biostrome communities and mercury and selenium bioaccumulation in the great salt lake (utah, usa). | the great salt lake has a salinity near 150g/l and is habitat for over 200 species of migratory birds. the diet of many of these birds is dependent on the food web of carbonaceous biostromes (stromatolites) that cover 260km(2) of the lake's littoral zone. we investigated the biostrome community to understand their production processes and to assess whether they are a potential vector for bioconcentration of high mercury and selenium levels in the lake. the periphyton community of the biostromes ... | 2011 | 21835437 |
| [cyanobacterial genome transposable element mining and analysis based on 454 deep-sequencing data set]. | researches on the next generation sequencing (ngs) and the comparative genome analysis have recently been concerned. the analyses on transposable element composition and abundance are important parts for genome studies. generally, the analyses of transposable element system were based on the complete spliced genomes; however, the post-processing and sequence splicing of the huge amount of short sequences from the 454 sequencer always encounter problems. moreover, the occasion that large amount o ... | 2011 | 21684872 |
| the [nife]-hydrogenase of the cyanobacterium synechocystis sp. pcc 6803 works bidirectionally with a bias to h2 production. | protein film electrochemistry (pfe) was utilized to characterize the catalytic activity and oxidative inactivation of a bidirectional [nife]-hydrogenase (hoxefuyh) from the cyanobacterium synechocystis sp. pcc 6803. pfe provides precise control of the redox potential of the adsorbed enzyme so that its activity can be monitored under changing experimental conditions as current. the properties of hoxefuyh are different from those of both the standard uptake and the "oxygen-tolerant" [nife]-hydroge ... | 2011 | 21675712 |
| effects on growth and oxidative stress status of rice plants (oryza sativa) exposed to two extracts of toxin-producing cyanobacteria (aphanizomenon ovalisporum and microcystis aeruginosa). | toxic cyanobacteria are considered emerging world threats, being responsible for the degradation of the aquatic ecosystems. aphanizomenon ovalisporum produces the toxin cylindrospermopsin (cyn) being a concern in fresh water habitats. this work aims to increase our knowledge on the effects of this toxic cyanobacterium in plants by studying the alterations in growth parameters and oxidative stress status of rice (oriza sativa) exposed to the cyanobacteria cell extracts containing cyn. significant ... | 2011 | 21723604 |
| nitrogen fixation in denitrified marine waters. | nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria), whereas nitrogen losses occur in oxygen-depleted intermediate waters ... | 2011 | 21687726 |
| moorea producta gen. nov., sp. nov. and moorea bouillonii comb. nov., tropical marine cyanobacteria rich in bioactive secondary metabolites. | 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. moorea is photosynthetic (containing phycocyanin, phycoerythrin, allophycocyanin, and chlorophyll a), but non-diazotrophic (lacks heterocysts and nitrogenase reductase genes). the cells (discoid and 25-80 -ám wide) are arranged in long filaments (<10 cm in length) and often form extensi ... | 2011 | 21724952 |
| edaphic and phytochemical factors as predictors of equine grass sickness cases in the uk. | background: equine dysautonomia or equine grass sickness (egs), as it is more commonly known, is a usually fatal disease of equids of uncertain etiology, although associated with grazing, that affects the autonomic and enteric nervous system. lowered gastrointestinal motility, leading to paralysis of the gut, is one of the main symptoms of egs. previous studies have implicated anaerobic bacteria, notably clostridium botulinum, but what triggers the severe bacterial infestations remains enigmatic ... | 2010 | 21833167 |
| metatranscriptomic analyses of chlorophototrophs of a hot-spring microbial mat. | the phototrophic microbial mat community of mushroom spring, an alkaline siliceous hot spring in yellowstone national park, was studied by metatranscriptomic methods. rna was extracted from mat specimens collected at four timepoints during light-to-dark and dark-to-light transitions in one diel cycle, and these rna samples were analyzed by both pyrosequencing and solid technologies. pyrosequencing was used to assess the community composition, which showed that ~84% of the rrna was derived from m ... | 2011 | 21697962 |
| phage auxiliary metabolic genes and the redirection of cyanobacterial host carbon metabolism. | cyanophages infecting the marine cyanobacteria prochlorococcus and synechococcus encode and express genes for the photosynthetic light reactions. sequenced cyanophage genomes lack calvin cycle genes, however, suggesting that photosynthetic energy harvested via phage proteins is not used for carbon fixation. we report here that cyanophages carry and express a calvin cycle inhibitor, cp12, whose host homologue directs carbon flux from the calvin cycle to the pentose phosphate pathway (ppp). phage ... | 2011 | 21844365 |
| archaeal and bacterial diversity in hot springs on the tibetan plateau, china. | the diversity of archaea and bacteria was investigated in ten hot springs (elevation >4600-ám above sea level) in central and central-eastern tibet using 16s rrna gene phylogenetic analysis. the temperature and ph of these hot springs were 26-81-¦c and close to neutral, respectively. a total of 959 (415 and 544 for bacteria and archaea, respectively) clone sequences were obtained. phylogenetic analysis showed that bacteria were more diverse than archaea and that these clone sequences were classi ... | 2011 | 21695489 |
| [application of molecular genetics and mirobiological methods to ecology and biotechnology of cyanobacteria]. | | 2010 | 21774152 |
| pathological modifications following sub-chronic exposure of medaka fish (oryzias latipes) to microcystin-lr. | microcystins (mcs) are toxic monocyclic heptapeptides produced by many cyanobacteria. mcs, especially mc-lr, cause toxic effects in animals and are a recognized potent cause of environmental stress and health hazard in aquatic ecosystems when heavy blooms of cyanobacteria appear. consequently, one of the major problems is the chronic exposure of fish to cyanotoxins in their natural environment. the present experiment involving chronic exposure confirmed initial findings on acute exposure to mc c ... | 2011 | 21839164 |
| cyanobacteria cultivation in industrial wastewaters and biodiesel production from their biomass: a review. | as an alternative fuel biodiesel has become increasingly important due to diminishing petroleum reserves and adverse environmental consequences of exhaust gases from petroleum-fueled engines. recently, research interest has focused on the production of biofuel from microalgae. cyanobacteria appeared to be suitable candidates for cultivation in wastes and wastewaters because they produce biomass in satisfactory quantity and can be harvested relatively easily due to their size and structure. in ad ... | 2011 | 21838795 |
| probing the in vivo biosynthesis of scytonemin, a cyanobacterial ultraviolet radiation sunscreen, through small scale stable isotope incubation studies and maldi-tof mass spectrometry. | scytonemin is a dimeric indole phenolic pigment found in the sheaths of many cyanobacteria. this pigment absorbs uv radiation protecting subtending cyanobacterial cells from harmful effects. based on scytonemin's unique chemical structure, the pathway to its biosynthesis is uncertain, thus motivating the current investigation. herein, we report the incorporation of both tyrosine and tryptophan into scytonemin, and provide in vivo data supporting the tryptophan origin of the ketone carbon involve ... | 2011 | 21742508 |
| acute toxicity assessment of perfluorinated carboxylic acids towards the baltic microalgae. | the presence of high-energy carbon-fluorine bonds in perfluoro compounds lends them great stability and causes them to be environmentally persistent. relatively little is known about the acute toxicity of perfluorinated carboxylic acids (pfcas) to ecotoxicological markers such as aquatic plants and animals. this study tested the toxicity of these compounds to the green alga chlorella vulgaris, the diatom skeletonema marinoi and the blue-green alga geitlerinema amphibium, which are species repres ... | 2009 | 21783999 |
| total synthesis of (-)-n-methylwelwitindolinone c isothiocyanate. | we report the first total synthesis of (-)-n-methylwelwitindolinone c isothiocyanate. our route features a number of key transformations, including an indolyne cyclization to assemble the [4.3.1]-bicyclic scaffold, as well as a late-stage intramolecular nitrene insertion to functionalize the c11 bridgehead carbon en route to the natural product. | 2011 | 21819133 |
| genomic island variability facilitates prochlorococcus-virus coexistence. | prochlorococcus cyanobacteria are extremely abundant in the oceans, as are the viruses that infect them. how hosts and viruses coexist in nature remains unclear, although the presence of both susceptible and resistant cells may allow this coexistence. combined whole-genome sequencing and pcr screening technology now enables us to investigate the effect of resistance on genome evolution and the genomic mechanisms behind the long-term coexistence of prochlorococcus and their viruses. here we prese ... | 2011 | 21720364 |
| planktonic microbes in the gulf of maine area. | in the gulf of maine area (goma), as elsewhere in the ocean, the organisms of greatest numerical abundance are microbes. viruses in goma are largely cyanophages and bacteriophages, including podoviruses which lack tails. there is also evidence of mimivirus and chlorovirus in the metagenome. bacteria in goma comprise the dominant sar11 phylotype cluster, and other abundant phylotypes such as sar86-like cluster, sar116-like cluster, roseobacter, rhodospirillaceae, acidomicrobidae, flavobacteriales ... | 2011 | 21698243 |
| characterizing the feeding habits of the testate amoebae hyalosphenia papilio and nebela tincta along a narrow "fen-bog" gradient using digestive vacuole content and (13)c and (15)n isotopic analyses. | population dynamics and feeding habits of the testate amoebae nebela tincta and hyalosphenia papilio were studied along a short "fen" to "bog" gradient in a sphagnum-dominated mire (jura, france). samples were collected in living "top segments" (0-3cm) and early declining "bottom segments" (3-6cm) of sphagnum fallax peat. observations of digestive vacuole content and stable isotope analyses ((13)c and (15)n) were used to establish the feeding behavior of both testate amoeba species. owing to the ... | 2011 | 21840255 |
| phylogenetic diversity of bacteria associated with the marine sponge gelliodes carnosa collected from the hainan island coastal waters of the south china sea. | several molecular techniques were employed to document the bacterial diversity associated with the marine sponge gelliodes carnosa. cultivation-dependent and cultivation-independent methods were used to obtain the 16s rrna gene sequences of the bacteria. phylogenetic analysis based on the 16s rrna gene sequences showed that the bacterial community structure was highly diverse with representatives of the high gôçë+ôçëc gram-positive bacteria, cyanobacteria, low gôçë+ôçëc gram-positive bacteria, a ... | 2011 | 21728038 |
| construction and analysis of liver suppression subtractive hybridization library of silver carp (hypophthalmichthys molitrix) intraperitoneally injected with microcystin-lr. | microcystin-lr (mc-lr) is the most frequently studied cyclic heptapeptide hepatotoxin produced by cyanobacteria. the toxin accumulates rapidly in the liver where it exerts most of its damage, but the molecular mechanisms behind its toxicity remain unclear. here, suppression subtractive hybridization (ssh) was used to identify alterations in gene transcription of the silver carp (hypophthalmichthys molitrix) after exposure to mc-lr. after hybridization and cloning, the forward and reverse subtrac ... | 2011 | 21718658 |
| the bradyrhizobium japonicum frcb gene encodes a diheme ferric reductase. | iron utilization by bacteria in aerobic environments involves uptake as a ferric chelate from the environment, followed by reduction to the ferrous form. ferric iron reduction is poorly understood in most bacterial species. here, we identified bradyrhizobium japonicum frcb (bll3557) as a gene adjacent to, and coregulated with, the pyor gene (blr3555) encoding the outer membrane receptor for transport of a ferric pyoverdine. frcb is a membrane-bound, diheme protein, characteristic of eukaryotic f ... | 2011 | 21705608 |
| oxygen evolving complex in photosystem ii: better than excellent. | the oxygen evolving complex in photosystem ii, which is responsible for the oxidation of water to oxygen in plants, algae and cyanobacteria, contains a cluster of one calcium and four manganese atoms. this cluster serves as a model for the splitting of water by energy obtained from sunlight. the recent published data on the mechanism and the structure of photosystem ii provide a detailed architecture of the oxygen-evolving complex and the surrounding amino acids. biomimetically, we expect to lea ... | 2011 | 21735020 |
| phytoplankton as bioindicator for waste stabilization ponds. | waste stabilization ponds are an appropriate technology for domestic onsite wastewater treatment. it is a low-cost technology, requires low maintenance, is highly efficient, mostly natural and remarkablably sustainable. in facultative ponds, the existence of an algal population is very important for the stability of the symbiotic relation with aerobic bacteria. the aim of this work is to determine the pattern of microalgae in the facultative and maturation ponds to obtain information for the ope ... | 2011 | 21820796 |
| genetic diversity of cyanobacteria in four eutrophic lakes. | recent studies indicate genetic diversity of cyanobacteria in eutrophic lakes is not represented well by culture collections or morphology. yet, few studies have investigated genetic richness and evenness of cyanobacteria using culture-independent methods. we compared the genetic structure of cyanobacteria supported by four neighboring eutrophic lakes during the ice-free season. the partial phycobilincpcb/a genes plus intergenic spacer (pc-igs) was used as a genetic marker.sequences were phyloge ... | 2011 | 21707672 |
| diverse two-cysteine photocycles in phytochromes and cyanobacteriochromes. | phytochromes are well-known as photoactive red- and near ir-absorbing chromoproteins with cysteine-linked linear tetrapyrrole (bilin) prosthetic groups. phytochrome photoswitching regulates adaptive responses to light in both photosynthetic and nonphotosynthetic organisms. exclusively found in cyanobacteria, the related cyanobacteriochrome (cbcr) sensors extend the photosensory range of the phytochrome superfamily to shorter wavelengths of visible light. blue/green light sensing by a well-studie ... | 2011 | 21712441 |
| evidence for direct binding of glycerol to photosystem i. | the interaction between glycerol and photosystem i (psi) was investigated using low temperature single-molecule spectroscopy. psi complexes were dissolved in three different solutions: in buffer solution, in 66% glycerol/buffer solution, and in 66% glycerol/buffer solution that was afterwards diluted by buffer; the final glycerol concentration was <1ôç¦. mean fluorescence spectra and intercomplex heterogeneity of psi complexes in 66% glycerol/buffer solution and in the re-diluted solution show h ... | 2011 | 21722637 |
| nitrogen starvation of cyanobacteria results in the production of-á+¦-n-methylamino-l-alanine. | +¦-n-methylamino-l-alanine, an unusual amino acid implicated in neurodegenerative disease, has been detected in cultures of nearly all genera of environmentally ubiquitous cyanobacteria tested. the compound is present within cyanobacterial cells in free and protein-associated forms, with large variations occurring in the concentration of these pools between species as well as within single strains. with a lack of knowledge and supporting data on the regulation of bmaa production and the role of ... | 2011 | 21704054 |
| generation of transplastomic lettuce with enhanced growth and high yield. | we generated transplastomic lettuce plants expressing cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase (fbp/sbpase) in chloroplasts.-átheir photosynthetic capacity and productivity were increased 1.3-fold and 1.6-fold, respectively, compared with control plants transformed with prl200, indicating that the introduction of the enzyme affects the photosynthetic capacity and growth of lettuce plants at ambient co 2 levels (360 ppm).-á | 2010 | 21844689 |
| freshwater cyanobacterium microcystis aeruginosa (utex 2385) induced dna damage in vivo and in vitro. | microcystins are a family of potent hepatotoxins and liver tumor promoters produced by several genera of cyanobacteria including microcystis, nodularia, anabena, nostoc, etc. they are chemically very stable and represent a public health threat when they occur in water used for human consumption. we investigated the dna damage effects of m. aeruginosa utex 2385 in mouse liver in vivo and also in mammalian cells in vitro. the dna damage effect is compared with purified toxin microcystin-lr (mclr) ... | 1998 | 21781844 |
| emerging patterns of marine nitrogen fixation. | biological n(2) fixation is an important part of the marine nitrogen cycle as it provides a source of new nitrogen that can support biological carbon export and sequestration. research in the past decade has focused on determining the patterns of distribution and abundance of diazotrophs, defining the environmental features leading to these patterns and characterizing the factors that constrain marine n(2) fixation overall. in this review, we describe how variations in the deposition of iron fro ... | 2011 | 21677685 |
| evolution of time-keeping mechanisms: early emergence and adaptation to photoperiod. | virtually all species have developed cellular oscillations and mechanisms that synchronize these cellular oscillations to environmental cycles. such environmental cycles in biotic (e.g. food availability and predation risk) or abiotic (e.g. temperature and light) factors may occur on a daily, annual or tidal time scale. internal timing mechanisms may facilitate behavioural or physiological adaptation to such changes in environmental conditions. these timing mechanisms commonly involve an interna ... | 2011 | 21690131 |
| modulation of cyanobacterial photosystem i deposition properties on alkanethiolate au substrate by various experimental conditions. | we present results from atomic force microscopy (afm) images indicating various experimental conditions, which alter the morphological characteristics of self-assembled cyanobacterial ps i on hydroxyl-terminated self-assembled alkanethiolate monolayers (sam/au) substrates. afm topographical images of sam/au substrates incubated in solutions containing different ps i concentrations solubilized with triton x-100 as the detergent reveal large columnar aggregates (ôê+100nm and hence, much taller tha ... | 2011 | 21820281 |
| theoretical study of the excited states of the photosynthetic reaction center in photosystem ii: electronic structure, interactions, and their origin. | the excited states of the chlorophyll 6-mer in the photosystem ii (psii) reaction center (rc) were investigated theoretically using ab initio quantum chemical calculations, and the results are compared with those of the bacterial reaction center (brc). a significant difference in the peak at the lowest energy in the absorption spectra arises from the structural asymmetry of the special pair (sp). the origin can be traced back to the structural difference in the cd helix. the low-lying excited st ... | 2011 | 21816534 |
| a heme oxygenase isoform is essential for aerobic growth in the cyanobacterium synechocystis sp. pcc 6803: modes of differential operation of two isoforms/enzymes to adapt to low oxygen environments in cyanobacteria. | heme oxygenase (ho) catalyzes the oxygen-dependent cleavage of heme to produce biliverdin ix+¦ in phycobilin biosynthesis. in the genome of the cyanobacterium synechocystis sp. pcc 6803 there are two genes, ho1 (sll1184) and ho2 (sll1875), encoding ho isoforms. reverse-transcription pcr indicated that ho1 is constitutively expressed, and ho2 is induced under micro-oxic conditions. a mutant lacking ho1 ( +öho1) failed to grow under aerobic conditions while it did grow at a significantly slower ra ... | 2011 | 21828104 |
| use of qpcr for the study of hepatotoxic cyanobacteria population dynamics. | toxic cyanobacteria blooms are increasingly frequent and object of greater concern due to its ecological and health impacts. one important lack in the toxic cyanobacteria research field is to understand which parameters influence most and how they operate to regulate the overall levels of cyanotoxins in a body of water. mc concentration is believed to be influenced by changes in several seasonal environmental factors that influence the succession of toxic cyanobacteria. in the last years, qpcr ( ... | 2011 | 21735229 |
| a cyanolichen from the lower devonian rhynie chert. | the 400 million-year-old rhynie chert has provided a wealth of information about various types of fungal interactions that existed in this early devonian paleoecosystem. in this paper we report the first unequivocal evidence of a lichen symbiosis from the rhynie chert. specimens of a new genus, winfrenatia, consist of a thallus of superimposed layers of aseptate hyphae and, on the upper surface, numerous uniform depressions. extending into the base of each depression are hyphae that form a three ... | 1997 | 21708654 |
| underwater application of quantitative pcr on an ocean mooring. | the environmental sample processor (esp) is a device that allows for the underwater, autonomous application of dna and protein probe array technologies as a means to remotely identify and quantify, in situ, marine microorganisms and substances they produce. here, we added functionality to the esp through the development and incorporation of a module capable of solid-phase nucleic acid extraction and quantitative pcr (qpcr). samples collected by the instrument were homogenized in a chaotropic buf ... | 2011 | 21829630 |
| taxonomic and functional prokaryote diversity in mildly arsenic-contaminated sediments. | arsenic-resistant prokaryote diversity is far from being exhaustively explored. in this study, the arsenic-adapted prokaryotic community present in a moderately arsenic-contaminated site near sainte-marie-aux-mines (france) was characterized, using metaproteomic and 16s rrna-encoding gene amplification. high prokaryotic diversity was observed, with a majority of proteobacteria, acidobacteria and bacteroidetes, and a large archaeal community comprising euryarchaeaota and thaumarchaeota. metaprote ... | 2011 | 21704701 |
| chemoenzymatic synthesis of cryptophycin anticancer agents by an ester bond-forming non-ribosomal peptide synthetase module. | cryptophycins (crp) are a group of cyanobacterial depsipeptides with activity against drug-resistant tumors. although they have been shown to be promising, further efforts are required to return these highly potent compounds to the clinic through a new generation of analogues with improved medicinal properties. herein, we report a chemosynthetic route relying on the multifunctional enzyme crpd-m2 that incorporates a 2-hydroxy acid moiety (unit d) into crp analogues. crpd-m2 is a unique non-ribos ... | 2011 | 21823639 |
| removal of pb (ii) by immobilized and free filaments of marine oscillatoria sp. ntms01 and phormidium sp. ntms02. | pb(2+) removal ability of the immobilized and free filaments of marine cyanobacteria oscillatoria sp. ntms01 and phormidium sp. ntms02 was studied using batch experiments. biosorption of lead by immobilized filaments was studied as a function of ph (2, 4, 6, 8, 10), contact time (5-180-ámin) and initial lead concentration (1, 3, 5, 7-ámg/l) and the removal efficiency of free filaments was studied by culturing in the marine medium with the initial concentration (1, 3, 5, 7-ámg/l) at ph 7 and incu ... | 2011 | 21720797 |
| microbiology: arms race in a drop of sea water. | | 2011 | 21720356 |
| effects of carbaryl and 1-naphthol on soil population of cyanobacteria and microalgae and select cultures of diazotrophic cyanobacteria. | carbaryl application to soil collected from a rice fallow field was relatively less toxic to viable estimates of cyanobacteria and microalgae under nonflooded conditions than under flooded conditions. application of 1-naphthol, the hydrolysis product of carbaryl, to soil under both the regimes increased the population of both cyanobacteria and microalgae. soil application of carbaryl and 1-naphthol in combination, up to 1.0-ákg-áha(-1), was nontoxic to the viable population. the toxicity exerted ... | 2011 | 21706293 |
| apparent bioaccumulation of cylindrospermopsin and paralytic shellfish toxins by finfish in lake catemaco (veracruz, mexico). | compared to the well-characterized health threats associated with contamination of fish and shellfish by algal toxins in marine fisheries, the toxicological relevance of the bioaccumulation of toxins from cyanobacteria (blue-green algae), as the primary toxigenic algae in freshwater systems, remains relatively unknown. lake catemaco (veracruz, mexico) is a small, tropical lake system specifically characterized by a year-round dominance of the known toxigenic cyanobacterial genus, cylindrospermop ... | 2011 | 21838624 |
| production of a novel bioflocculant mnxy1 by klebsiella pneumoniae strain ny1 and application in precipitation of cyanobacteria and municipal wastewater treatment. | aims:ôçé to isolate and characterize the novel bioflocculant-producing bacteria, to optimize the bioflocculant production and to evaluate its potential applications. methods and results:ôçé klebsiella pneumoniae strain ny1, a bacterium that produces a novel bioflocculant (mnxy1), was selected on the chemically defined media. it was classified according to the 16s rrna gene sequence, morphological and microscopic characteristics. mnxy1 was characterized to contain 26% protein and 66% total sugar. ... | 2011 | 21679283 |
| biosensors for secondary metabolites, two case studies: ochratoxin a and microcystin. | secondary metabolites are chemical compounds that are not directly involved in the normal growth, development or reproduction of organisms. due to the toxicity shown by some of these compounds, their presence can represent a threat to human health. reliable detection systems able to control their presence are required, as a tool to ensure public health. this chapter offers an overview of different techniques developed for the detection of toxic secondary metabolites, taking ochratoxin a and micr ... | 2011 | 21706442 |
| mycosporine-like amino acids are multifunctional molecules in sea hares and their marine community. | molecules of keystone significance are relatively rare, yet mediate a variety of interactions between organisms. they influence the distribution and abundance of species, the transfer of energy across multiple trophic levels, and thus they play significant roles in structuring ecosystems. despite their potential importance in facilitating our understanding of ecological systems, only three molecules thus far have been proposed as molecules of keystone significance: saxitoxin and dimethyl sulfide ... | 2011 | 21709250 |
| cyanobacterial genomics for ecology and biotechnology. | cyanobacteria are the only prokaryotes that directly convert solar energy and co(2) into organic matter by oxygenic photosynthesis, explaining their relevance for primary production in many ecosystems and the increasing interest for biotechnology. at present, there are more than 60 cyanobacteria for which a total genome sequence is publicly available. these cyanobacteria belong to different lifestyles and origins, coming from marine and freshwater aquatic environments, as well as terrestrial and ... | 2011 | 21840247 |
| the effect of light intensity on the relative dominance of toxigenic and nontoxigenic strains of microcystis aeruginosa. | in aquatic ecosystems, the factors that regulate the dominance of toxin-producing cyanobacteria over non-toxin producing strains of the same species are largely unknown. one possible hypothesis is that limiting resources leads to the dominance of the latter because of the metabolic costs associated with toxin production. in this study, we tested the effect of light intensity on the performance of a microcystin producing strain of microcystis aeruginosa (utcc 300) when grown in mixed cultures wit ... | 2011 | 21841026 |
| circadian clock proteins in prokaryotes: hidden rhythms? | circadian clock genes are vital features of eukaryotes that have evolved such that organisms can adapt to our planet's rotation in order to anticipate the coming day or night as well as unfavorable seasons. this circadian clock uses oscillation as a timekeeping element. however, circadian clock mechanisms exist also in prokaryotes. the circadian clock of cyanobacteria is well studied. it is regulated by a cluster of three genes: kaia, kaib, and kaic. in this review, we will discuss the circadian ... | 2010 | 21687756 |
| antibiotic production by the cyanobacteria oscillatoria angustissima and calothrix parietina. | the accumulation of antibiotic in the medium is temperature dependent and not in direct proportion to growth parameters. the cyanobacterial product suppressed growth of some natural isolates of cyanobacteria and green algae. it inhibits the growth rate and oxygen evolution of the green alga, chlorella fusca. the antibiotic also inhibits the growth of bacteria and some fungi, especially the dermatophytes. generally eukaryotic organisms were less sensitive than prokaryotic. experimental mice were ... | 1999 | 21781939 |
| molecular enumeration of a cyanophage in a laurentian great lake: quantitative evidence for ecological importance. | considerable research has shown that cyanobacteria and the viruses that infect them (cyanophage) are pervasive and diverse in global lake populations. few studies have seasonally analyzed freshwater systems, and little is known about the bacterial and viral communities that coexist during the harsh winters of the laurentian great lakes. here, we employed quantitative pcr to estimate the abundance of cyanomyoviruses in this system, using the portal vertex g20 gene as a proxy for cyanophage abunda ... | 2011 | 21841023 |
| diffusion-based process for carbon dioxide uptake and isoprene emission in gaseous/aqueous two-phase photobioreactors by photosynthetic microorganisms. | photosynthesis for the generation of fuels and chemicals from cyanobacteria and microalgae offers the promise of a single host organism acting both as photocatalyst and processor, performing sunlight absorption and utilization, as well as co(2) assimilation and conversion into product. however, there is a need to develop methods for generating, sequestering and trapping such bio-products in an efficient and cost-effective manner that is suitable for industrial scale-up and exploitation. a sealed ... | 2011 | 21830206 |
| evolutionary roots of iodine and thyroid hormones in cell-cell signaling. | in vertebrates, thyroid hormones (ths, thyroxine, and triiodothyronine) are critical cell signaling molecules. ths regulate and coordinate physiology within and between cells, tissues, and whole organisms, in addition to controlling embryonic growth and development, via dose-dependent regulatory effects on essential genes. while invertebrates and plants do not have thyroid glands, many utilize ths for development, while others store iodine as th derivatives or th precursor molecules (iodotyrosin ... | 2009 | 21669854 |
| cloning and analysis of the ggps gene from cyanobacteria arthrospira spp. involved in the synthesis of an osmolyte glucosylglycerol. | the genus arthrospira is a nonheterocystous filamentous cyanobacterium inhabiting diverse environments including those of high salinity. in the present study, arthrospira strains were isolated from freshwater and brackish lakes in myanmar, and their osmoprotective adaptation was investigated as it was for the genus synechococcus strains. the arthrospira strains showed satisfactory growth up to 1.0 m sodium chloride, suggesting their acclimation to high salinity stress. cloning and phylogenetic a ... | 2011 | 21719990 |
| proximate mechanisms driving circadian control of neuroendocrine function: lessons from the young and old. | circadian rhythms impact a variety of behavioral and physiological functions contributing to longevity and successful reproduction. in their natural environments, individuals of a species are faced with a multitude of challenges and the coordination of internal processes and behavior with external pressures has been hypothesized to be an important target of natural selection. several lines of evidence from cyanobacteria, drosophila, and plants provide strong support for an important role of the ... | 2009 | 21665838 |
| simultaneous detection of nine cyanotoxins in drinking water using dual solid-phase extraction and liquid chromatography-mass spectrometry. | a solid-phase extraction (spe)-liquid chromatography (lc)-mass spectrometry (ms) method was developed to concentrate and detect nine cyanotoxins simultaneously, including six microcystins (mcs) congeners, nodularin (nod), anatoxin-a (atx) and cylindrospermopsin (cyn), in pure and natural waters. a dual cartridge spe assembly was tested for the operating parameters of cyanotoxin extraction. a surrogate standard (ss), 1,9-diaminononane, was spiked in all the samples before the spe extraction, and ... | 2011 | 21699910 |
| renewable energy from cyanobacteria: energy production optimization by metabolic pathway engineering. | 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 possibil ... | 2011 | 21691792 |
| do photobionts influence the ecology of lichens? a case study of environmental preferences in symbiotic green alga asterochloris (trebouxiophyceae). | the distribution patterns of symbiotic algae are thought to be conferred mainly by their hosts, however, they may originate in algal environmental requirements as well. in lichens, predominantly terrestrial associations of fungi with algae or cyanobacteria, the ecological preferences of photobionts have not been directly studied so far. here, we examine the putative environmental requirements in lichenized alga asterochloris, and search for the existence of ecological guilds in asterochloris-ass ... | 2011 | 21699598 |
| circadian timekeeping in neurospora crassa and synechococcus elongatus. | at first, the saprophytic eukaryote neurospora crassa and the photosynthetic prokaryote synechococcus elongatus may seem to have little in common. however, in both organisms a circadian clock organizes cellular biochemistry, and each organism lends itself to classical and molecular genetic investigations that have revealed a detailed picture of the molecular basis of circadian rhythmicity. in the present chapter, an overview of the molecular clockwork in each organism will be described, highligh ... | 2011 | 21819383 |
| l+®vy walks evolve through interaction between movement and environmental complexity. | ecological theory predicts that animal movement is shaped by its efficiency of resource acquisition. focusing solely on efficiency, however, ignores the fact that animal activity can affect resource availability and distribution. here, we show that feedback between individual behavior and environmental complexity can explain movement strategies in mussels. specifically, experiments show that mussels use a l+®vy walk during the formation of spatially patterned beds, and models reveal that this l+ ... | 2011 | 21700872 |
| first evidence of palytoxin and 42-hydroxy-palytoxin in the marine cyanobacterium trichodesmium. | marine pelagic diazotrophic cyanobacteria of the genus trichodesmium (oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of new caledonia. blooms of trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. the toxicity of water-soluble extracts of trichodesmium spp. were analyzed by mouse bioassay and neuroblastoma assay and t ... | 2011 | 21731549 |
| singlet oxygen stress in microorganisms. | singlet oxygen is the primary agent of photooxidative stress in microorganisms. in photosynthetic microorganisms, sensitized generation by pigments of the photosystems is the main source of singlet oxygen and, in nonphotosynthetic microorganisms, cellular cofactors such as flavins, rhodopsins, quinones, and porphyrins serve as photosensitizer. singlet oxygen rapidly reacts with a wide range of cellular macromolecules including proteins, lipids, dna, and rna, and thereby further reactive substanc ... | 2011 | 21722793 |
| investigation of toxin content in cylindrospermopsis raciborski (wo+éoszy+äska) seenaya and subba raju and aphanizomenon ovalisporum (forti) strains isolated from shallow lakes of hungary. | cylindrospermopsin (cyn) is an alkaloid type cytotoxic metabolite produced by several cyanobacterial species, which caused human illnesses. the occurrence of cyn has been mostly associated with tropical and subtropical cyanobacteria, but recently it is appearing in several countries, all over the world. we analyzed cyn concentration and polyketide synthase/peptide synthetase (pks /ps) genes, important parts of the gene cluster responsible for the cyn biosynthesis, in 14 isolated/collected cylind ... | 2010 | 21565779 |
| pathologic findings and toxin identification in cyanobacterial (nodularia spumigena) intoxication in a dog. | a 3-year-old cairn terrier dog that had been in contact with sea water containing cyanobacteria (blue-green algae) was euthanized because of acute hepatic failure and anuria after a 5-day illness. histologic findings included lytic and hemorrhagic centrilobular hepatocellular necrosis and renal tubular necrosis. the cyanotoxin nodularin was detected in liver and kidney by high-performance liquid chromatography-mass spectrometry. nodularin is a potent hepatotoxin produced by the algal species nod ... | 2011 | 21825312 |
| development of bacterial community during spontaneous succession on spoil heaps after brown coal mining. | changes in the abundance of bacteria and fungi and in the composition of bacterial communities during primary succession were investigated in a brown coal mine deposit area near sokolov, the czech republic, using phospholipid fatty acids analysis, microarray and 16s rrna gene sequencing. the study considered a chronosequence of sites undergoing spontaneous succession: 6-, 12-, 21- and 45-year-old and a 21-year-old site revegetated with alnus glutinosa. during succession, organic carbon and the t ... | 2011 | 21707674 |
| comparison of the structure of key variants of microcystin to vasopressin. | microcystins (mcs) are cyclic heptapeptide compounds [where x(2) (position 2) and z(4) (position 4) are variable l-aminoacids] produced by cyanobacteria and responsible for severe liver damage in animals ingesting acute doses of the toxic compounds. certain variants of microcystins are more toxic than others, the differences being commonly ascribed to the hydrophobic nature of the variant. microcystin-lr (mclr) [x = l-leucine (l); z = l-arginine (r); r1 = r2 = ch(3)] is the most toxic of all the ... | 2005 | 21783489 |
| fate of toxic cyanobacterial cells and disinfection by-products formation after chlorination. | drinking water sources in many regions are subject to proliferation of toxic cyanobacteria (cb). chlorination of source water containing toxic cyanobacterial cells for diverse treatment purposes might cause cell damage, toxin release and disinfection by-products (dbp) formation. there is limited information available on chlorination of different toxic cb cells and dbp formation potentials. this work: (1) determines the extent of lysis and toxins/taste and odor compound release in chlorinated nat ... | 2011 | 21820143 |
| influence of cultivation parameters on growth and microcystin production of microcystis aeruginosa (cyanophyceae) isolated from lake chao (china). | microcystis aeruginosa isolated in 2005 from the shallow eutrophic lake chao (anhui, china) was investigated in terms of growth parameters and microcystin production under varying nutrient concentrations (p, n) and ph values (abiotic factors) as well as under the influence of spent medium of the non-toxic cyanobacterium synechocystis sp. (biotic factors). stimulating effects on growth were observed at the alkaline ph value (10.5), whereas toxin production was significantly increased under phosph ... | 2011 | 21710225 |
| Role of Novel Dimeric Photosystem II (PSII)-Psb27 Protein Complex in PSII Repair. | The multisubunit membrane protein complex Photosystem II (PSII) catalyzes one of the key reactions in photosynthesis: the light-driven oxidation of water. Here, we focus on the role of the Psb27 assembly factor, which is involved in biogenesis and repair after light-induced damage of the complex. We show that Psb27 is essential for the survival of cyanobacterial cells grown under stress conditions. The combination of cold stress (30 -¦C) and high light stress (1000 ++mol of photons +ù m(-2) +ù s ... | 2011 | 21737447 |
| Low-parachor solvents extraction and thermostated micro-thin-layer chromatography separation for fast screening and classification of spirulina from pharmaceutical formulations and food samples. | The goal of this paper is to demonstrate the separation and detection capability of eco-friendly micro-TLC technique for the classification of spirulina and selected herbs from pharmaceutical and food products. Target compounds were extracted using relatively low-parachor liquids. A number of the spirulina samples which originated from pharmaceutical formulations and food products, were isolated using a simple one step extraction with small volume of methanol, acetone or tetrahydrofuran. Herb sa ... | 2011 | 21741048 |
| Cyanobacteria-mediated phenylpropanoids and phytohormones in rice (Oryza sativa) enhance plant growth and stress tolerance. | Phenylpropanoids, flavonoids and plant growth regulators in rice (Oryza sativa) variety (UPR 1823) inoculated with different cyanobacterial strains namely Anabaena oryzae, Anabaena doliolum, Phormidium fragile, Calothrix geitonos, Hapalosiphon intricatus, Aulosira fertilissima, Tolypothrix tenuis, Oscillatoria acuta and Plectonema boryanum were quantified using HPLC in pot conditions after 15 and 30-ádays. Qualitative analysis of the induced compounds using reverse phase HPLC and further confirm ... | 2011 | 21732035 |
| production of cyanophycin in rhizopus oryzae through the expression of a cyanophycin synthetase encoding gene. | cyanophycin or cyanophycin granule peptide is a protein that results from non-ribosomal protein synthesis in microorganisms such as cyanobacteria. the amino acids in cyanophycin can be used as a feedstock in the production of a wide range of chemicals such as acrylonitrile, polyacrylic acid, 1,4-butanediamine, and urea. in this study, an auxotrophic mutant (rhizopus oryzae m16) of the filamentous fungus r. oryzae 99-880 was selected to express cyanophycin synthetase encoding genes. these genes o ... | 2011 | 21972133 |
| Light-dependent attenuation of phycoerythrin gene expression reveals convergent evolution of green light sensing in cyanobacteria. | The colorful process of chromatic acclimation allows many cyanobacteria to change their pigmentation in response to ambient light color changes. In red light, cells produce red-absorbing phycocyanin (PC), whereas in green light, green-absorbing phycoerythrin (PE) is made. Controlling these pigment levels increases fitness by optimizing photosynthetic activity in different light color environments. The light color sensory system controlling PC expression is well understood, but PE regulation has ... | 2011 | 22042852 |
| Adaptation of freshwater mussels to cyanobacterial toxins: Response of the biotransformation and antioxidant enzymes. | Freshwater mussels such as the invasive Dreissena polymorpha and the indigenous Unio tumidus nourish by high filtration rates and may accumulate cyanobacteria and their toxins during cyanobacterial blooms. Physiological adaptations to cyanotoxins enable organisms to endure cyanobacterial blooms but may differ between species. Biotransformation and excretion capacities for cyanobacteria and anthropogenic pollutants have been demonstrated for Dreissena polymorpha but less for unionid species. This ... | 2011 | 22172521 |
| formation of disinfection byproducts from chlor(am)ination of algal organic matter. | algal cells and extracellular organic matter (eom) of two algae species, microcystis aeruginosa (blue-green algae) and chlorella vulgaris (green algae), were characterized. the low specific uv absorbance (suva) values of eom and cells from both algae species indicated the very hydrophilic nature of algal materials. fluorescence excitation-emission matrix showed that algal eom and cells were enriched with protein-like and soluble microbial by-product-like matters. the formation potential of a var ... | 2011 | 22019108 |
| reduction of exogenous ketones depends upon nadph generated photosynthetically in cells of the cyanobacterium synechococcus pcc 7942. | abstract: effective utilization of photosynthetic microorganisms as potential biocatalysts is favorable for the production of useful biomaterials and the reduction of atmospheric co2. for example, biocatalytic transformations are used in the synthesis of optically active alcohols. we previously found that ketone reduction in cells of the cyanobacterium synechococcus pcc 7942 is highly enantioselective and remarkably enhanced under light illumination. in this study, the mechanism of light-enhance ... | 2011 | 21906270 |