| direct analysis of phycobilisomal antenna proteins and metabolites in small cyanobacterial populations by laser ablation electrospray ionization mass spectrometry. | due to their significance in energy and environmental and natural product research, as well as their large genetic diversity, rapid in situ analysis of cyanobacteria is of increasing interest. metabolic profiles and the composition of energy harvesting antenna protein complexes are needed to understand how environmental factors affect the functioning of these microorganisms. here, we show that laser ablation electrospray ionization (laesi) mass spectrometry enables the direct analysis of phycobi ... | 2011 | 22141353 |
| An integrated method for removal of harmful cyanobacterial blooms in eutrophic lakes. | As the eutrophication of lakes becomes an increasingly widespread phenomenon, cyanobacterial blooms are occurring in many countries. Although some research has been reported, there is currently no good method for bloom removal. We propose here a new two-step integrated approach to resolve this problem. The first step is the inactivation of the cyanobacteria via the addition of H(2)O(2). We found 60 mg/L was the lowest effective dose for a cyanobacterial concentration corresponding to 100 µg/L ch ... | 2012 | 22035923 |
| nitrogen conversion under rapid pyrolysis of two types of aquatic biomass and corresponding blends with coal. | rapid pyrolysis of two types of aquatic biomass (blue-green algae and water hyacinth), and their blends with two coals (bituminous and anthracite) was carried out in a high-frequency furnace. nitrogen conversions during rapid pyrolysis of the two biomass and the interactions between the biomass and coals on nitrogen conversions were investigated. results show that little nitrogen retained in char after the biomass pyrolysis, and nh(3) yields were higher than hcn. during co-pyrolysis of biomass a ... | 2011 | 21903383 |
| Phylogenetic, chemical and morphological diversity of cyanobacteria from Portuguese temperate estuaries. | Cyanobacteria from estuarine habitats have been poorly studied regarding diversity and potential bioactive compounds production compared with their fresh and marine waters' congeners. In this work, 44 cyanobacteria isolates characterised from three Portuguese estuarine environments. Identification was performed based on diacritical morphological features of the isolates (e.g. cell shape, cell size, presence/absence of sheaths) and on 16S rRNA gene sequences phylogenetic analysis. Diversity of pr ... | 2012 | 22093261 |
| analysis of the bacterial diversity in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. | the aim of this study was to determine the bacteria present in the fecal material of the endangered yangtze finless porpoise, neophocaena phocaenoides asiaeorientalis. fecal samples were collected from 12 yangtze finless porpoises living in the wild at poyang lake, located in jiangxi province, china. to determine the bacterial diversity, a 16s rrna gene clone library using the bacterial pcr primers fd1 and rp2, was prepared. a total of 138 near-full-length sequences were analyzed and 39 operatio ... | 2011 | 22201021 |
| oxygen-independent alkane formation by non-heme iron-dependent cyanobacterial aldehyde decarbonylase: investigation of kinetics and requirement for an external electron donor. | cyanobacterial aldehyde decarbonylase (cad) is, structurally, a member of the di-iron carboxylate family of oxygenases. we previously reported that cad from prochlorococcus marinus catalyzes the unusual hydrolysis of aldehydes to produce alkanes and formate in a reaction that requires an external reducing system but does not require oxygen [das et al. (2011) angew. chem. 50, 7148-7152]. here we demonstrate that cads from divergent cyanobacterial classes, including the enzyme from n. puntiformes ... | 2011 | 22074177 |
| circular micro-proteins and mechanisms of cyclization. | transpeptidation reactions result in the formation of new peptide bonds and this can occur between two separate peptides or within the one peptide. these reactions are catalyzed by enzymes and when the n- and c-terminus of the one peptide are joined it results in the formation of cyclic proteins. cyclization via head-to-tail linkage of the termini of a peptide chain occurs in only a small percentage of proteins but gives the resultant cyclic proteins exceptional stability. the mechanisms are not ... | 2011 | 22204430 |
| establishment of a real-time pcr method for quantification of geosmin-producing streptomyces spp. in recirculating aquaculture systems. | geosmin and 2-methylisoborneol (mib) have been associated with off-flavour problems in fish and seafood products, generating a strong negative impact for aquaculture industries. although most of the producers of geosmin and mib have been identified as streptomyces species or cyanobacteria, streptomyces spp. are thought to be responsible for the synthesis of these compounds in indoor recirculating aquaculture systems (ras). the detection of genes involved in the synthesis of geosmin and mib can b ... | 2011 | 22060964 |
| microbial response to limited nutrients in shallow water immediately after the end-permian mass extinction. | previous work indicates that a variety of microbes bloomed in the oceans after the end-permian faunal mass extinction, but evidence is sporadically documented. thus, the nature and geographic distribution of such microbes and their associations are unclear, addressed in this study using a series of biomarker groups. on the basis of microbial biomarker records of the 2-methylhopane index, evidence is presented for cyanobacterial blooms in both the western and eastern tethys sea and in both shallo ... | 2012 | 22168223 |
| computational study of the covalent bonding of microcystins to cysteine residues - a reaction involved in the inhibition of the ppp family of protein phosphatases. | microcystins (mcs) are cyclic peptides, produced by cyanobacteria, that are hepatotoxic to mammals. the toxicity mechanism involves the potent inhibition of protein phosphatases, as the toxins bind the catalytic subunits of five enzymes of the phosphoprotein phosphatase (ppp) family of serine/threonine-specific phosphatases: ppp1 (aka pp1), ppp2 (aka pp2a), ppp4, ppp5 and ppp6. the interaction with the proteins includes the formation of a covalent bond with a cysteine residue. although this reac ... | 2011 | 22177231 |
| photophysical diversity of two novel cyanobacteriochromes with phycocyanobilin chromophores: photochemistry and dark reversion kinetics. | cyanobacteriochromes are phytochrome homologues in cyanobacteria that act as sensory photoreceptors. we compare two cyanobacteriochromes, rgs (coded by slr1393) from synechocystis sp. pcc 6803 and aphc (coded by all2699) from nostoc sp. pcc 7120. both contain three gaf (cgmp phosphodiesterase, adenylyl cyclase and fhla protein) domains (gaf1, gaf2 and gaf3). the respective full-length, truncated and cysteine point-mutated genes were expressed in escherichia coli together with genes for chromopho ... | 2012 | 22008418 |
| membrane proteins in four acts: function precedes structure determination. | studies on four membrane protein systems, which combine information derived from crystal structures and biophysical studies have emphasized, as a precursor to crystallization, demonstration of functional activity. these assays have relied on sensitive spectrophotometric, electrophysiological, and microbiological assays of activity to select purification procedures that lead to functional complexes and with greater likelihood to successful crystallization: (i), hetero-oligomeric proteins involved ... | 2011 | 22079407 |
| reconstruction and verification of a genome-scale metabolic model for synechocystis sp. pcc6803. | in terms of generating sustainable energy resources, the prospect of producing energy and other useful materials using cyanobacteria has been attracting increasing attention since these processes require only carbon dioxide and solar energy. to establish production processes with a high productivity, in silico models to predict the metabolic activity of cyanobacteria are highly desired. in this study, we reconstructed a genome-scale metabolic model of the cyanobacterium synechocystis sp. pcc6803 ... | 2011 | 21881889 |
| unravelling the conformational plasticity of the extracellular domain of a prokaryotic nachr homologue in solution by nmr. | pentameric ligand-gated ion channels (plgics) of the cys loop family are transmembrane glycoproteins implicated in a variety of biological functions. here, we present a solution nmr study of the extracellular domain of a prokaryotic plgic homologue from the bacterium gloeobacter violaceus that is found to be a monomer in solution. | 2011 | 22007668 |
| characterization of microcystin-lr removal process in the presence of probiotic bacteria. | toxic cyanobacteria have been reported in lakes and reservoirs in several countries. the presence of toxins in drinking water creates a potential risk of toxin transference for water consumers. besides chemical and physical methods of cyanotoxin removal from water, biodegradation methods would be useful. the aim of the current study was to identify bacterial removal mechanisms of the hepatotoxin microcystin-lr. this was studied by testing the hypothesis of enzymatic degradation of microcystin-lr ... | 2011 | 22115989 |
| protein-protein interactions by molecular modeling and biochemical characterization of psi-lhci supercomplexes from chlamydomonas reinhardtii. | the physiological function of photosystem i (psi) is a sunlight energy converter, catalyzing one of the initial steps in driving oxygenic photosynthesis in cyanobacteria, algae and higher plants. the chlamydomonas reinhardtii psi structure was not known since it contains a unique structure having additional light harvesting complex i (lhci) subunits, which play a major role in the transfer of sunlight energy to the reaction center. here, individual subunits of lhc and core subunits are built bas ... | 2011 | 21915394 |
| [phytoplankton community structure in shijiuyang constructed wetland of jiaxing, zhejiang province of east china in winter]. | aimed to explore the purification effect of constructed wetland on phytoplankton community structure, an investigation was conducted on the species composition, biomass, and community diversity of phytoplankton in the water body of shijiuyang constructed drinking water source wetland of jiaxing, zhejiang province of east china in winter, 2010. a total of 77 phytoplankton species were identified, belonging to 39 genera of 7 phyla. the main phylum was bacillariophyta, with 33 species of 14 genera. ... | 2011 | 22126059 |
| cyanobacterial metallochaperone inhibits deleterious side reactions of copper. | copper metallochaperones supply copper to cupro-proteins through copper-mediated protein-protein-interactions and it has been hypothesized that metallochaperones thereby inhibit copper from causing damage en route. evidence is presented in support of this latter role for cyanobacterial metallochaperone, atx1. in cyanobacteria atx1 contributes towards the supply of copper to plastocyanin inside thylakoids but it is shown here that in copper-replete medium, copper can reach plastocyanin without at ... | 2011 | 22198771 |
| the management of undesirable cyanobacteria blooms in channel catfish ponds using a constructed wetland: contribution to the control of off-flavor occurrences. | an exploratory study on the management of undesirable cyanobacteria blooms with respect to off-flavor problems using an integrated vertical-flow constructed wetland (cw) was performed at a small commercial-scale channel catfish farm from 2004 to 2007. the results of the three-year experiment indicated that water treatment by the cw could reduce the possibility of dominance by undesirable cyanobacteria species that often cause off-flavor problems. a detailed investigation in 2007, showed that the ... | 2011 | 22000715 |
| massive multiplication of genome and ribosomes in dormant cells (akinetes) of aphanizomenon ovalisporum (cyanobacteria). | akinetes are dormancy cells commonly found among filamentous cyanobacteria, many of which are toxic and/or nuisance, bloom-forming species. development of akinetes from vegetative cells is a process that involves morphological and biochemical modifications. here, we applied a single-cell approach to quantify genome and ribosome content of akinetes and vegetative cells in aphanizomenon ovalisporum (cyanobacteria). vegetative cells of a. ovalisporum were naturally polyploid and contained, on avera ... | 2011 | 21975597 |
| morphological, phylogenetic and physiological studies of pico-cyanobacteria isolated from the halocline of a saline meromictic lake, lake suigetsu, japan. | small cyanobacteria (<2 µm, pico-cyanobacteria) are abundant in waters deeper than the oxic-anoxic zone in the halocline of a saline meromictic lake, lake suigetsu, fukui, japan. we have isolated 101 strains that were grouped into six groups by means of the phycobiliprotein composition and sequence homology of the intergenic spacer between the 16s and 23s rrna genes. significant growth was observed under weak green light (1.5 µmol m(-2) s(-1), approx. 460 to 600 nm), whereas the cells died under ... | 2011 | 22200643 |
| crystal structure of the n-terminal domain of linker l(r) and the assembly of cyanobacterial phycobilisome rods. | phycobilisomes are light-harvesting supramolecular complexes in cyanobacteria and red algae. linkers play a pivotal role in the assembly and energy transfer modulation of phycobilisomes. however, how linkers function remains unclear due to the lack of structural and biochemical studies of linkers, especially the n-terminal domain of l(r) (pfam00427). here, we report the crystal structure of the pfam00427 domain of the linker l(r) (30) from synechocystis sp. pcc 6803 at 1.9 å. the pfam00427 prese ... | 2011 | 21923764 |
| microcystin-lr induces cytoskeleton system reorganization through hyperphosphorylation of tau and hsp27 via pp2a inhibition and subsequent activation of the p38 mapk signaling pathway in neuroendocrine (pc12) cells. | cyanobacteria-derived microcystin-lr (mc-lr) commonly characterized as a hepatotoxin has recently been documented to show potential neurotoxicity, but the detailed neurotoxic effects of mc-lr and its mechanisms are unclear. in the present study, the neuroendocrine pc12 cell line was used to investigate whether mc-lr causes alterations of neuronal morphology and abnormalities in the phosphorylation status of cytoskeletal-associated proteins, and to elucidate the underlying mechanisms. the results ... | 2011 | 22000993 |
| effects of herbivory, nutrients, and reef protection on algal proliferation and coral growth on a tropical reef. | maintaining coral reef resilience against increasing anthropogenic disturbance is critical for effective reef management. resilience is partially determined by how processes, such as herbivory and nutrient supply, affect coral recovery versus macroalgal proliferation following disturbances. however, the relative effects of herbivory versus nutrient enrichment on algal proliferation remain debated. here, we manipulated herbivory and nutrients on a coral-dominated reef protected from fishing, and ... | 2011 | 22038059 |
| Codon usage patterns and adaptive evolution of marine unicellular cyanobacteria Synechococcus and Prochlorococcus. | Marine unicellular cyanobacteria, represented by Synechococcus and Prochlorococcus, dominate the total phytoplankton biomass and production in oligotrophic ocean. In this study, we employed comparative genomics approaches to extensively investigate synonymous codon usage bias and evolutionary rates in a large number of closely related species of marine unicellular cyanobacteria. Although these two groups of marine cyanobacteria have a close phylogenetic relationship, we find that they are highly ... | 2012 | 22040764 |
| biodiversity, abundance, and activity of nitrogen-fixing bacteria during primary succession on a copper mine tailings. | microorganisms are important in soil development, inputs and biogeochemical cycling of nutrients and organic matter during early stages of ecosystem development, but little is known about their diversity, distribution, and function in relation to the chemical and physical changes associated with the progress of succession. in this study, we characterized the community structure and activity of nitrogen-fixing microbes during primary succession on a copper tailings. terminal fragment length polym ... | 2011 | 22066852 |
| Effects of microcystin-LR on the metal bioaccumulation and toxicity in Chlamydomonas reinhardtii. | Microcystin-LR (MC-LR) is one of the most notorious toxins liberated from cyanobacteria in eutrophicated freshwater ecosystems. Its effects on the bioaccumulation and toxicity of Cd(2+), CrO(4)(2-), Cu(2+), and Zn(2+) in a green alga Chlamydomonas reinhardtii were investigated in the present study. The metal bioaccumulation in the alga was unaffected by MC-LR. The surface-adsorbed and intracellular metal concentrations in the treatments with and without the addition of MC-LR could be well simula ... | 2012 | 22078256 |
| effects of cd, cu, ni, and zn on brown tide alga aureococcus anophagefferens growth and metal accumulation. | trace metals play important roles in regulating phytoplankton growth and could influence algal bloom development. laboratory studies were conducted to evaluate the influence of environmentally relevant concentrations of cd, cu, ni, and zn on aureococcus anophagefferens bloom (brown tide) development. results show that the elevated ni2+ concentrations, e.g. those of brown tide waters in the northeastern us, greatly stimulated a. anophagefferens growth (as compared to the control without ni addit ... | 2011 | 22103320 |
| microbial ultraviolet sunscreens. | exposure to the shortest wavelengths in sunlight, ultraviolet light, constitutes a deleterious ecological factor for many microorganisms. the use of secondary metabolites as sunscreens has emerged as an important photoprotective mechanism in certain groups of large-celled microorganisms, such as cyanobacteria, fungi and many protists. in this review, we describe our current understanding of microbial 'sunscreen' compounds, including scytonemin, the mycosporines and the naphthalene-based melanins ... | 2011 | 21963801 |
| towards models of the oxygen-evolving complex (oec) of photosystem ii: a mn4ca cluster of relevance to low oxidation states of the oec. | synthetic access has been achieved into high oxidation state mn/ca chemistry with the 4 : 1 mn : ca stoichiometry of the oxygen-evolving complex (oec) of plants and cyanobacteria; the anion of (et(3)nh)(2)[mn(iii)(4)ca(o(2)cph)(4)(shi)(4)] has a square pyramidal metal topology and an s = 0 ground state. | 2011 | 21904743 |
| increasing oxygen radicals and water temperature select for toxic microcystis sp. | pronounced rises in frequency of toxic cyanobacterial blooms are recently observed worldwide, particularly when temperatures increase. different strains of cyanobacterial species vary in their potential to produce toxins but driving forces are still obscure. our study examines effects of hydrogen peroxide on toxic and non-toxic (including a non-toxic mutant) strains of m. aeruginosa. here we show that hydrogen peroxide diminishes chlorophyll a content and growth of cyanobacteria and that this re ... | 2011 | 21980492 |
| critical review of actually available chemical compounds for prevention and management of cyanobacterial blooms. | cyanobacteria proliferation is among the most threatening consequences of freshwater pollution. health risks from human and other-organism exposure to cyanobacteria have led to an effort to find practical methods for cyanobacterial water-bloom reduction. hence, methods and techniques have been developed in order to reduce the amount of phosphorus or to decrease the abundance of nuisance phytoplankton species directly in the water bodies (in-lake measures). although these "acute" methods do not s ... | 2011 | 21925702 |
| novel cytotoxicity associated with anabaena circinalis 131c. | the production of secondary metabolites by cyanobacteria is extensively varied. anabaena spp. have been shown to produce the toxins saxitoxin, anatoxin-a, anatoxin-a(s), cylindrospermopsin and microcystin. in this study we show cytotoxicity associated with anabaena circinalis 131c that could not be attributed to its high saxitoxin content. analytical, elisa and enzymatic methods excluded the presence of other known cyanobacterial toxins leading to the suggestion of novel toxicity. | 2011 | 21964631 |
| the hydrogenase chip: a tiling oligonucleotide dna microarray technique for characterizing hydrogen-producing and -consuming microbes in microbial communities. | we developed a broad-ranging method for identifying key hydrogen-producing and consuming microorganisms through analysis of hydrogenase gene content and expression in complex anaerobic microbial communities. the method is based on a tiling hydrogenase gene oligonucleotide dna microarray (hydrogenase chip), which implements a high number of probes per gene by tiling probe sequences across genes of interest at 1.67 × -2 × coverage. this design favors the avoidance of false positive gene identifica ... | 2011 | 21993396 |
| identification of substrain-specific mutations by massively parallel whole-genome resequencing of synechocystis sp. pcc 6803. | the cyanobacterium, synechocystis sp. pcc 6803, was the first photosynthetic organism whose genome sequence was determined in 1996 (kazusa strain). it thus plays an important role in basic research on the mechanism, evolution, and molecular genetics of the photosynthetic machinery. there are many substrains or laboratory strains derived from the original berkeley strain including glucose-tolerant (gt) strains. to establish reliable genomic sequence data of this cyanobacterium, we performed reseq ... | 2011 | 22193367 |
| a quorum-sensing molecule acts as a morphogen controlling gas vesicle organelle biogenesis and adaptive flotation in an enterobacterium. | gas vesicles are hollow intracellular proteinaceous organelles produced by aquatic eubacteria and archaea, including cyanobacteria and halobacteria. gas vesicles increase buoyancy and allow taxis toward air-liquid interfaces, enabling subsequent niche colonization. here we report a unique example of gas vesicle-mediated flotation in an enterobacterium; serratia sp. strain atcc39006. this strain is a member of the enterobacteriaceae previously studied for its production of prodigiosin and carbape ... | 2011 | 21873216 |
| interactions between histidine kinase nbls and the response regulators rpab and srra are involved in the bleaching process of the cyanobacterium synechococcus elongatus pcc 7942. | cyanobacteria have developed a light-harvesting antenna complex known as the phycobilisome. when cells are starved for nutrients or exposed to high light, the phycobilisome is rapidly degraded (bleaching). it has been suggested that in the cyanobacterium synechococcus elongatus pcc 7942, the bleaching process is regulated by a two-component histidine kinase, nbls. to clarify the signaling pathway involving nbls, we identified the nbls-interacting response regulators rpab and srra. in vitro assay ... | 2011 | 22021405 |
| dynamics of transcriptional start site selection during nitrogen stress-induced cell differentiation in anabaena sp. pcc7120. | the fixation of atmospheric n(2) by cyanobacteria is a major source of nitrogen in the biosphere. in nostocales, such as anabaena, this process is spatially separated from oxygenic photosynthesis and occurs in heterocysts. upon nitrogen step-down, these specialized cells differentiate from vegetative cells in a process controlled by two major regulators: ntca and hetr. however, the regulon controlled by these two factors is only partially defined, and several aspects of the differentiation proce ... | 2011 | 22135468 |
| composition and function of cytochrome c biogenesis system ii. | organisms employ one of several different enzyme systems to mature cytochromes c. the biosynthetic process involves the periplasmic reduction of cysteine residues in the heme c attachment motif of the apocytochrome, transmembrane transport of heme b and stereospecific covalent heme attachment via thioether bonds. the biogenesis system ii (or ccs system) is employed by β-, δ- and ε-proteobacteria, gram-positive bacteria, aquificales and cyanobacteria, as well as by algal and plant chloroplasts. s ... | 2011 | 21955752 |
| bacterial community composition in low-flowing river water with different sources of pollutants. | pollution of water resources is a major risk to human health and water quality throughout the world. the purpose of this study was to determine the influence of pollutant sources from agricultural activities, urban runoffs, and runoffs from wastewater treatment plants (wwtps) on bacterial communities in a low-flowing river. bacterial community structure was monitored using terminal restriction fragment length polymorphism (t-rflp) and 16s rrna gene clone library. the results were analyzed using ... | 2011 | 22066546 |
| the impact of cyanobacteria on growth and death of opportunistic pathogenic bacteria. | climate change may cause increased microbial growth in water sources and more knowledge is required on how this may affect the hygienic water quality, i.e., whether increased occurrence of cyanobacteria and algae may stimulate the growth rate of opportunistic pathogenic bacteria. laboratory experiments were performed to investigate if the presence of the cyanobacteria anabanea lemmermannii and microcystis aeruginosa affected the survival and growth rate of the opportunistic pathogenic bacteria a ... | 2011 | 22097011 |
| novel metabolic attributes of the genus cyanothece, comprising a group of unicellular nitrogen-fixing cyanothece. | the genus cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. system-level studies of cyanothece sp. atcc 51142, a prototypic member of this group, revealed many interesting metabolic attributes. to identify the metabolic traits that define this class of cyanobac ... | 2011 | 21972240 |
| biochemical and ultrastructural changes in the hepatopancreas of bellamya aeruginosa (gastropoda) fed with toxic cyanobacteria. | this study was conducted to investigate ultrastructural alterations and biochemical responses in the hepatopancreas of the freshwater snail bellamya aeruginosa after exposure to two treatments: toxic cyanobacterium (microcystis aeruginosa) and toxic cyanobacterial cells mixed with a non-toxic green alga (scendesmus quadricauda) for a period of 15 days of intoxication, followed by a 15-day detoxification period. the toxic algal suspension induced a very pronounced increase of the activities of ac ... | 2011 | 22125458 |
| impairment of the mitochondrial oxidative phosphorylation system and oxidative stress in liver of crucian carp (carassius auratus l.) exposed to microcystins. | hepatotoxic microcystins (mcs) are produced by cyanobacteria in diverse water bodies and the pathophysiology includes induction of reactive oxygen species and adenosine triphosphate (atp) depletion in cells. in this study, we evaluated mcs induced changes in the oxidative phosphorylation (oxphos) system in mitochondria of crucian carp liver. fish were subdivided into two groups that were intraperitoneally injected with two doses of mcs (50 and 200 mc-lreq μg/kg bw) and were sacrificed at 1, 3, 1 ... | 2011 | 21913302 |
| a deletion mutation in the spacing within the psaa core promoter enhances transcription in a cyanobacterium synechocystis sp. pcc 6803. | transcriptional regulation of psi reaction center psaa is one of the important physiological responses to changing environments. we previously reported that the rrf2-type transcriptional regulator slr0846 activates transcription of psaa in synechocystis sp. pcc 6803. in the δslr0846 mutant, transcripts from two promoters, p1 and p2, were downshifted and, as a result, a lower chl content and slower growth were observed. here, we report spontaneous suppressors which recovered chl accumulation and ... | 2011 | 22102696 |
| microbiology. closing the cycle. | | 2011 | 22174240 |
| biogeography of pelagic bacterioplankton across an antagonistic temperature-salinity gradient in the red sea. | the red sea is a unique marine ecosystem with contrasting gradients of temperature and salinity along its north-to-south axis. it is an extremely oligotrophic environment that is characterized by perpetual year-round water column stratification, high annual solar irradiation, and negligible riverine and precipitation inputs. in this study, we investigated whether the contemporary environmental conditions shape community assemblages by pyrosequencing 16s rrna genes of bacteria in surface water sa ... | 2011 | 22133021 |
| cylindrospermopsin induced dna damage and alteration in the expression of genes involved in the response to dna damage, apoptosis and oxidative stress. | cylindrospermopsin (cyn), a potent cyanobacterial cytototoxin produced by certain freshwater cyanobacteria, is regularly found in water supplies in many parts of the world, and has been associated with the intoxication of humans and livestock. the few genotoxicity studies available indicate that cyn is genotoxic, generally implying that it is pro-genotoxic. in human peripheral blood lymphocytes (hpbls) cyn (0, 0.05, 0.1 and 0.5 μg/ml) induced the formation of dna single strand breaks, applying t ... | 2011 | 21867723 |
| the role of reduction in iron uptake processes in a unicellular, planktonic cyanobacterium. | in many aquatic environments the essential micronutrient iron is predominantly complexed by a heterogeneous pool of strong organic chelators. research on iron uptake mechanisms of cyanobacteria inhabiting these environments has focused on endogenous siderophore production and internalization. however, as many cyanobacterial species do not produce siderophores, alternative fe acquisition mechanisms must exist. here we present a study of the iron uptake pathways in the unicellular, planktonic, non ... | 2011 | 21906223 |
| genome sequences of siphoviruses infecting marine synechococcus unveil a diverse cyanophage group and extensive phage-host genetic exchanges. | investigating the interactions between marine cyanobacteria and their viruses (phages) is important towards understanding the dynamic of ocean's primary productivity. genome sequencing of marine cyanophages has greatly advanced our understanding about their ecology and evolution. among 24 reported genomes of cyanophages that infect marine picocyanobacteria, 17 are from cyanomyoviruses and six from cyanopodoviruses, and only one from cyanosiphovirus (prochlorococcus phage p-ss2). here we present ... | 2011 | 22188618 |
| molecular genetic and chemotaxonomic characterization of the terrestrial cyanobacterium nostoc commune and its neighboring species. | the phylogeny of the terrestrial cyanobacterium nostoc commune and its neighboring nostoc species was studied using molecular genetic and chemotaxonomic approaches. at least eight genotypes of n. commune were characterized by the differences among 16s rrna gene sequences and the peth gene encoding ferredoxin-nadp(+) oxidoreductase and by random amplified polymorphic dna analysis. the genotypes of n. commune were distributed in japan without regional specificity. the nrtp gene encoding nrtp-type ... | 2011 | 22066798 |
| to bloom or not to bloom: contrasting responses of cyanobacteria to recent heat waves explained by critical thresholds of abiotic drivers. | past heat waves are considered harbingers of future climate change. in this study, we have evaluated the effects of two recent central european summer heat waves (2003 and 2006) on cyanobacterial blooms in a eutrophic, shallow lake. while a bloom of cyanobacteria developed in 2006, consistent with our expectations, cyanobacterial biomass surprisingly remained at a record-low during the entire summer of 2003. critical thresholds of abiotic drivers extracted from the long-term (1993-2007) data set ... | 2011 | 22120704 |
| cyanobacteria and microalgae: a positive prospect for biofuels. | biofuel-bioenergy production has generated intensive interest due to increased concern regarding limited petroleum-based fuel supplies and their contribution to atmospheric co2 levels. biofuel research is not just a matter of finding the right type of biomass and converting it to fuel, but it must also be economically sustainable on large-scale. several aspects of cyanobacteria and microalgae such as oxygenic photosynthesis, high per-acre productivity, non-food based feedstock, growth on non-pro ... | 2011 | 21924898 |
| dynamic proteomic profiling of a unicellular cyanobacterium cyanothece atcc51142 across light-dark diurnal cycles. | abstract: | 2011 | 22133144 |
| similar uptake profiles of microcystin-lr and -rr in an in vitro human intestinal model. | microcystins (mcs) are cyclic hepatotoxins produced by various species of cyanobacteria. their structure includes two variable amino acids (aa) leading to more than 80 mc variants. in this study, we focused on the most common variant, microcystin-lr (mc-lr), and microcystin-rr (mc-rr), a variant differing by only one aa. despite their structural similarity, mc-lr elicits higher liver toxicity than mc-rr partly due to a discrepancy in their uptake by hepatic organic anion transporters (oatp 1b1 a ... | 2011 | 21872638 |
| [increasing reductant nadph content via metabolic engineering of phb synthesis pathway in synechocystis sp. pcc 6803]. | cyanobacteria have become attractive hosts for renewable chemicals production. the low productivity, however, prevents it from industrial application. reductant nad(p)h availability is a chief hurdle for the production of reductive metabolites in microbes. to increase nadph content in synechocystis sp. pcc 6803, phb synthase encoding gene phac and phae in synechocystis was inactivated by replacing phac&e genes with chloromycetin resistance cassette via homologous recombination. pcr analysis show ... | 2011 | 22016983 |
| microbial biofilms on the sandstone monuments of the angkor wat complex, cambodia. | discoloring biofilms from cambodian temples angkor wat, preah khan, and the bayon and west prasat in angkor thom contained a microbial community dominated by coccoid cyanobacteria. molecular analysis identified chroococcidiopsis as major colonizer, but low similarity values (<95%) suggested a similar genus or species not present in the databases. in only two of the six sites sampled were filamentous cyanobacteria, microcoleus, leptolyngbya, and scytonema, found; the first two detected by sequenc ... | 2011 | 22006074 |
| bacterial community associated with the intestinal tract of p. monodon in commercial farms. | the potentially important roles of intestinal bacteria on immune response, disease resistance, and nutrition for the black tiger shrimp penaeus monodon have been increasingly investigated. however, so far, little is known about the intestinal bacterial community of the shrimp in the commercial aquaculture settings. in this study, the intestinal bacterial communities of juvenile p. monodon (70 individuals) from eight commercial farms in thailand were examined using 16s rdna pcr-dgge, and seven 16 ... | 2011 | 21915632 |
| arsenate resistance in the unicellular marine diazotroph crocosphaera watsonii. | the toxic arsenate ion can behave as a phosphate analog, and this can result in arsenate toxicity especially in areas with elevated arsenate to phosphate ratios like the surface waters of the ocean gyres. in these systems, cellular arsenate resistance strategies would allow phytoplankton to ameliorate the effects of arsenate transport into the cell. despite the potential coupling between arsenate and phosphate cycling in oligotrophic marine waters, relatively little is known about arsenate resis ... | 2011 | 22046174 |
| removal of metal ions by phormidium bigranulatum (cyanobacteria)-dominated mat in batch and continuous flow systems. | live phormidium bigranulatum-dominated mat successfully removed pb(ii), cu(ii) and cd(ii) from aqueous solution. percent metal removal approached equilibrium within 4h, independent of mat thickness (0.2-1.6mm), in batch system. but % metal removal increased with increase in mat thickness due to enhancement of biomass, which provided more metal binding sites. metal accumulation decreased with increase in mat thickness due to lessened metal availability vis-à-vis biomass. metal removal (%) increas ... | 2012 | 22119430 |
| estimating cyanobacterial bloom transport by coupling remotely sensed imagery and a hydrodynamic model. | the ability to forecast the transport of harmful cyanobacterial blooms in the laurentian great lakes is beneficial to natural resource managers concerned with public health. this manuscript describes a method that improves the prediction of cyanobacterial bloom transport with the use of a preoperational hydrodynamic model and high temporal resolution satellite imagery. two scenarios were examined from separate cyanobacterial blooms in western lake erie, usa. the first scenario modeled bloom posi ... | 2011 | 22073654 |
| degradation of cyanobacterial biosignatures by ionizing radiation. | abstract primitive photosynthetic microorganisms, either dormant or dead, may remain today on the martian surface, akin to terrestrial cyanobacteria surviving endolithically in martian analog sites on earth such as the antarctic dry valleys and the atacama desert. potential markers of martian photoautotrophs include the red edge of chlorophyll reflectance spectra or fluorescence emission from systems of light-harvesting pigments. such biosignatures, however, would be modified and degraded by l ... | 2011 | 22149884 |
| cytochrome c6-like protein as a putative donor of electrons to photosystem i in the cyanobacterium nostoc sp. pcc 7119. | most organisms performing oxygenic photosynthesis contain either cytochrome c(6) or plastocyanin, or both, to transfer electrons from cytochrome b(6)-f to photosystem i. even though plastocyanin has superseded cytochrome c(6) along evolution, plants contain a modified cytochrome c(6), the so called cytochrome c(6a), whose function still remains unknown. in this article, we describe a second cytochrome c(6) (the so called cytochrome c(6)-like protein), which is found in some cyanobacteria but is ... | 2011 | 21984388 |
| Validation trial of Japan's zinc water quality standard for aquatic life using field data. | This study sought to validate Japan's zinc water quality standard for aquatic life (algae and benthic invertebrates) based on field survey data. The effects of zinc on aquatic life, especially algae and benthic invertebrates, were investigated mainly in water areas with upstream basins that contain mines. Seven biological indicators (number of cells or individuals, number of taxa, number of EPT taxa, number of collector-gatherer taxa of benthic invertebrates, and Simpson index, Shannon-Weiner in ... | 2011 | 21851980 |
| Adaptation of microalgae to lindane: A new approach for bioremediation. | Lindane is especially worrisome because its persistence in aquatic ecosystems, tendency to bioaccumulation and toxicity. We studied the adaptation of freshwater cyanobacteria and microalgae to resist lindane using an experimental model to distinguish if lindane-resistant cells had their origin in random spontaneous pre-selective mutations (which occur prior to the lindane exposure), or if lindane-resistant cells arose by a mechanism of physiological acclimation during the exposure to the selecti ... | 2011 | 22204986 |
| dynamic proteome analysis of cyanothece sp. atcc 51142 under constant light. | understanding the dynamic nature of protein abundances provides insights into protein turnover not readily apparent from conventional, static mass spectrometry measurements. this level of data is particularly informative when surveying protein abundances in biological systems subjected to large perturbations or alterations in environment such as cyanobacteria. our current analysis expands upon conventional proteomic approaches in cyanobacteria by measuring dynamic changes of the proteome using a ... | 2011 | 22060561 |
| Construction of a chassis for hydrogen production: physiological and molecular characterization of a Synechocystis sp. PCC 6803 mutant lacking a functional bidirectional hydrogenase. | Cyanobacteria are photosynthetic prokaryotes that are promising "low-cost" microbial cell factories due to their simple nutritional requirements, metabolic plasticity, and availability of tools for their genetic manipulation. The unicellular non-nitrogen fixing Synechocystis sp. PCC 6803 is the best studied cyanobacterial strain and its genome was the first to be sequenced. The vast amount of physiological and molecular data available, together with a relative small genome, makes Synechocystis s ... | 2011 | 22096147 |
| Cultivable bacteria from ancient algal mats from the McMurdo Dry Valleys, Antarctica. | The McMurdo Dry Valleys in Antarctica are a favorable location for preservation of dormant microbes due to their persistent cold and dry climate. In this study, we examined cultivable bacteria in a series of algal mat samples ranging from 8 to 26539 years old. Cultivable bacteria were found in all samples except one (12303 years old), but abundance and diversity of cultivable bacteria decreased with increasing sample age. Only members of the Actinobacteria, Bacteroidetes, and Firmicutes were fou ... | 2012 | 22065250 |
| prokaryotic diversity in aran-bidgol salt lake, the largest hypersaline playa in iran. | prokaryotic diversity in aran-bidgol salt lake, a thalasohaline lake in iran, was studied by fluorescence in situ hybridization (fish), cultivation techniques, denaturing gradient gel electrophoresis (dgge) of pcr-amplified fragments of 16s rrna genes and 16s rrna gene clone library analysis. viable counts obtained (2.5-4×10(6) cells ml(-1)) were similar to total cell abundance in the lake determined by dapi direct count (3-4×10(7) cells ml(-1)). the proportion of bacteria to archaea in the comm ... | 2011 | 22185719 |
| cyanohab occurrence and water irrigation cyanotoxin contamination: ecological impacts and potential health risks. | the world-wide occurrence of harmful cyanobacteria blooms "cyanohab" in fresh and brackish waters creates problems for all life forms. during cyanohab events, toxic cyanobacteria produce cyanotoxins at high levels that can cause chronic and sub-chronic toxicities to animals, plants and humans. cyanotoxicity in eukaryotes has been mainly focused on animals, but during these last years, data, related to cyanotoxin (mainly microcystins, mcs) impact on both aquatic and terrestrials crop plants irrig ... | 2009 | 22069535 |
| [Fossilization of the cells of natronophilic endoevaporite cyanobacterium Euhalothece natronophila in a modelling system ]. | | 2011 | 22073554 |
| A Fungus Capable of Degrading Microcystin-LR in the Algal Culture of Microcystis aeruginosa PCC7806. | Microcystins (MCs) are a family of natural toxins produced by cyanobacteria (blue-green algae). Microbial degradation is considered an efficient method for eliminating cyanobacteria and MCs in environmental conditions. This study examines the ability of Trichaptum abietinum 1302BG, a white rot fungus, to degrade microcystin-LR in the harmful algal culture of Microcystis aeruginosa PCC7806. Results showed that microcystin-LR could not be detected by high-performance liquid chromatography after 12 ... | 2011 | 22167691 |
| Algae biofuels: versatility for the future of bioenergy. | The world continues to increase its energy use, brought about by an expanding population and a desire for a greater standard of living. This energy use coupled with the realization of the impact of carbon dioxide on the climate, has led us to reanalyze the potential of plant-based biofuels. Of the potential sources of biofuels the most efficient producers of biomass are the photosynthetic microalgae and cyanobacteria. These versatile organisms can be used for the production of bioethanol, biodie ... | 2011 | 22104720 |
| fast removal of cyanobacterial toxin microcystin-lr by a low-cytotoxic microgel-fe(ⅲ) complex. | eutrophication has become a serious environmental threat throughout the world. in particular, the presence of cyanobacteria toxins, especially microcystins (mcs), has become a severe problem. inhibition of microcystis growth in water resources is the most effective way to reduce mcs, but it is a long-term investment. in the present study, a microgel-fe(ⅲ) complex was developed for the fast removal of mc-lr. the microgel-fe(ⅲ) characteristics and the mc-lr removal dynamics in milli-q water and na ... | 2011 | 22153353 |
| association between biotic and abiotic parameters and the occurrence of cyanobacteria in a brazilian reservoir. | the water reservoir of vargem das flores, brazil, has been subject to eutrophication problems. the occurrence of cyanobacterial blooms in this water body has raised concerns regarding the presence of toxic metabolites. in order to understand the factors that promote the proliferation and distribution of cyanobacteria in the reservoir, physicochemical parameters, species composition, and toxicity of the reservoir water column were analyzed at monthly intervals over a 3-year period (2004-2007) usi ... | 2011 | 21887480 |
| isolation and characterization of the prochlorococcus carboxysome reveal the presence of the novel shell protein csos1d. | cyanobacteria, including members of the genus prochlorococcus, contain icosahedral protein microcompartments known as carboxysomes that encapsulate multiple copies of the co(2)-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) in a thin protein shell that enhances the catalytic performance of the enzyme in part through the action of a shell-associated carbonic anhydrase. however, the exact mechanism by which compartmentation provides a catalytic advantage to the enzyme is n ... | 2011 | 22155772 |
| role of hoxe subunit in synechocystis pcc6803 hydrogenase. | cyanobacterial nad(p)(+)-reducing reversible hydrogenases comprise five subunits. four of them (hoxf, hoxu, hoxy, and hoxh) are also found in the well-described related enzyme from ralstonia eutropha. the fifth one (hoxe) is not encoded in the r. eutropha genome, but shares homology with the n-terminal part of r. eutropha hoxf. however, in cyanobacteria, hoxe contains a 2fe-2s cluster-binding motif that is not found in the related r. eutropha sequence. in order to obtain some insights into the r ... | 2011 | 21848671 |
| Acinetobacter Insertion Sequence ISAba11 Belongs to a Novel Family That Encodes Transposases with a Signature HHEK Motif. | Experimental and in silico PCR analysis targeting ISAba11 and TnAbaR islands in 196 epidemiologically unrelated Acinetobacter strains representative of =19 species were performed. The first two Acinetobacter baumannii ISAba11 elements identified had been found to map to the same site on TnAbaR transposons. However, no further evidence of physical linkage between the two elements was demonstrated. Indeed, examination of 25 definite or putative insertion sites suggested limited sequence specificit ... | 2012 | 22081580 |
| Harnessing the self-harvesting capability of benthic cyanobacteria for use in benthic photobioreactors. | ABSTRACT: Benthic species of algae and cyanobacteria (i.e., those that grow on surfaces), may provide potential advantages over planktonic species for some commercial-scale biotechnological applications. A multitude of different designs of photobioreactor (PBR) are available for growing planktonic species but to date there has been little research on PBR for benthic algae or cyanobacteria. One notable advantage of some benthic cyanobacterial species is that during their growth cycle they become ... | 2011 | 21906375 |
| Thermostability of two cyanobacterial GrpE thermosensors. | GrpE proteins act as co-chaperones for DnaK heat-shock proteins. The dimeric protein unfolds under heat stress conditions, which results in impaired interaction with a DnaK protein. Since interaction of GrpE with DnaK is crucial for the DnaK chaperone activity, GrpE proteins act as a thermosensor in bacteria. Here we have analyzed the thermostability and function of two GrpE homologs of the mesophilic cyanobacterium Synechocystis sp. PCC 6803 and of the thermophilic cyanobacterium Thermosynechoc ... | 2011 | 21865302 |
| the cyanobacteria derived toxin beta-n-methylamino-l-alanine and amyotrophic lateral sclerosis. | there is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like als (amyotrophic lateral sclerosis). the non-protein amino acid beta-n-methylamino-l-alanine (bmaa) was first associated with the high incidence of amyotrophic lateral sclerosis/parkinsonism dementia complex (als/pdc) in guam, and has been implicated as a potential environmental factor in als, alzheimer's disease, and other neurodegenerative diseases. bmaa has ... | 2010 | 22069578 |
| Estrogenic activity in extracts and exudates of cyanobacteria and green algae. | Here is presented some of the first information on interactions of compounds produced by cyanobacteria and green algae with estrogen receptor signaling. Estrogenic potency of aqueous extracts and exudates (culture spent media with extracellular products) of seven species of cyanobacteria (10 different laboratory strains) and two algal species were assessed by use of in vitro trans-activation assays. Compounds produced by cyanobacteria and algae, and in particular those excreted from the cells, w ... | 2012 | 22208753 |
| mutational analysis of photosystem i of synechocystis sp. pcc 6803: the role of four conserved aromatic residues in the j-helix of psab. | photosystem i is the light-driven plastocyanin-ferredoxin oxidoreductase in the photosynthetic electron transfer of cyanobacteria and plants. two histidyl residues in the symmetric transmembrane helices a-j and b-j provide ligands for the p700 chlorophyll molecules of the reaction center of photosystem i. to determine the role of conserved aromatic residues adjacent to the histidyl molecule in the helix of b-j, we generated six site-directed mutants of the psab gene in synechocystis sp. pcc 6803 ... | 2011 | 21931782 |
| characterization of a vii-like phage specific to escherichia coli o157:h7. | phage vb_ecom_cba120 (cba120), isolated against escherichia coli o157:h7 from a cattle feedlot, is morphologically very similar to the classic phage vii of salmonella enterica serovar typhi. until recently, little was known genetically or physiologically about the vii-like phages, and none targeting e. coli have been described in the literature. the genome of cba120 has been fully sequenced and is highly similar to those of both vii and the shigella phage ag3. the core set of structural and repl ... | 2011 | 21899740 |
| the tricarboxylic acid cycle in cyanobacteria. | it is generally accepted that cyanobacteria have an incomplete tricarboxylic acid (tca) cycle because they lack 2-oxoglutarate dehydrogenase and thus cannot convert 2-oxoglutarate to succinyl-coenzyme a (coa). genes encoding a novel 2-oxoglutarate decarboxylase and succinic semialdehyde dehydrogenase were identified in the cyanobacterium synechococcus sp. pcc 7002. together, these two enzymes convert 2-oxoglutarate to succinate and thus functionally replace 2-oxoglutarate dehydrogenase and succi ... | 2011 | 22174252 |
| Untargeted metabolic footprinting reveals a surprising breadth of metabolite uptake and release by Synechococcus sp. PCC 7002. | Cyanobacteria are important primary producers in diverse ecosystems, yet little is known about the extent of their metabolic interactions with the environment. We have used an integrated, untargeted metabolic footprinting approach to systematically evaluate the uptake and release of metabolites between a model marine cyanobacterium Synechococcus sp. PCC 7002 and different growth media. It was found that 47 out of 202 detected metabolites were consumed, and an additional 55 metabolites were relea ... | 2011 | 21935552 |
| selective suppression of harmful cyanobacteria in an entire lake with hydrogen peroxide. | although harmful cyanobacteria form a major threat to water quality, few methods exist for the rapid suppression of cyanobacterial blooms. since laboratory studies indicated that cyanobacteria are more sensitive to hydrogen peroxide (h(2)o(2)) than eukaryotic phytoplankton, we tested the application of h(2)o(2) in natural waters. first, we exposed water samples from a recreational lake dominated by the toxic cyanobacterium planktothrix agardhii to dilute h(2)o(2). this reduced the photosynthetic ... | 2011 | 22112924 |
| In vitro modulation of intracellular receptor signaling and cytotoxicity induced by extracts of cyanobacteria, complex water blooms and their fractions. | The biological activity of cyanobacteria and their chemical components have been widely studied due to their blooms in eutrophic waters worldwide. The primary goal of this study was to determine if individual cyanobacterial species and mixtures of cyanobacteria collected from the environment contain compounds with the potential for interaction with signaling pathways of the aryl hydrocarbon receptor (AhR), androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR) and retinoid ... | 2011 | 21903046 |
| virulence genes of aeromonas isolates, bacterial endotoxins and cyanobacterial toxins from recreational water samples associated with human health symptoms. | exposure to cyanobacterial water blooms has been associated with various kinds of adverse health effects. in addition to cyanobacteria and their toxins, the bacteria associated with cyanobacteria could also be the etiological agents. we isolated aeromonas strains (n = 176) from water samples (n = 38) taken from sites where cyanobacteria were suspected to have caused human health symptoms, of which fever and gastrointestinal symptoms were the most common. the isolates were screened by pcr for six ... | 2011 | 22048427 |
| Wewakamide A and guineamide G, cyclic depsipeptides from the marine cyanobacteria Lyngbya semiplena and Lyngbya majuscula. | Two new cyclic depsipeptides wewakamide A (1) and guineamide G (2) have been isolated from the marine cyanobacterium Lyngbya semiplena and Lyngbya majuscula, respectively, collected from Papua New Guinea. The amino and hydroxy acid partial structures of wewakamide A and guineamide G were elucidated through extensive spectroscopic techniques, including HR-FABMS, 1D (1)H and (13)C NMR, as well as 2D COSY, HSQC, HSQCTOCSY, and HMBC spectra. The sequence of the residues of wewakamide A was determine ... | 2011 | 21952369 |
| analysis of growth directions of columnar stromatolites from walker lake, western nevada. | samples of digitate, branching, columnar stromatolites were collected from the steep sides and near horizontal top of four in situ boulders located on the southwestern side of walker lake, nevada, to test the widely held assumption that stromatolite column formation represents a phototropic response. we would predict that the columns on the steeply dipping sides of the boulder would bend upwards toward the light during growth if phototropism was significant during stromatolite morphogenesis. ang ... | 2011 | 21884363 |
| inactivation and degradation of microcystis aeruginosa by uv-c irradiation. | in this study, the mechanisms and factors affecting the inactivation and degradation efficiency during uv-c irradiation of microcystis aeruginosa, a harmful cyanobacteria strain, were investigated. under different experimental conditions, the concentrations of three bioactivity materials, including protein, phycocyanin and chl-a, were measured, and fluorescence regional integration (fri) was used to quantify the results of excitation emission matrix fluorescence spectroscopy. furthermore, any al ... | 2011 | 21872902 |
| dynamic fluctuations lubricate the circadian clock. | | 2011 | 21873208 |
| studies on mineral phosphate solubilization by cyanobacteria westiellopsis and anabaena. | two diazotrophic cyanobacteria, westiellopsis prolifica and anabaena variabilis were evaluated for elucidating the possible mechanism of mineral phosphate solubilization. phosphate starved cyanobacteria evaluated for the presence of organic acids, extracellular compounds or enzymes that might have been produced and promoted the mineral phosphate solubilization with mussorie rock phosphate and tricalcium phosphate as substrates. both the cultures did not reveal production of organic acids through ... | 2011 | 22073557 |
| Antagonistic interactions between filamentous heterotrophs and the cyanobacterium Nostoc muscorum. | ABSTRACT: | 2011 | 21914201 |
| the response of diatom central carbon metabolism to nitrogen starvation is different from that of green algae and higher plants. | the availability of nitrogen varies greatly in the ocean and limits primary productivity over large areas. diatoms, a group of phytoplankton that are responsible for about 20% of global carbon fixation, respond rapidly to influxes of nitrate and are highly successful in upwelling regions. although recent diatom genome projects have highlighted clues to the success of this group, very little is known about their adaptive response to changing environmental conditions. here, we compare the proteome ... | 2011 | 22065419 |
| Phosphate transporters in marine phytoplankton and their viruses: cross-domain commonalities in viral-host gene exchanges. | Phosphate (PO(4) ) is an important limiting nutrient in marine environments. Marine cyanobacteria scavenge PO(4) using the high-affinity periplasmic phosphate binding protein PstS. The pstS gene has recently been identified in genomes of cyanobacterial viruses as well. Here, we analyse genes encoding transporters in genomes from viruses that infect eukaryotic phytoplankton. We identified inorganic PO(4) transporter-encoding genes from the PHO4 superfamily in several virus genomes, along with o ... | 2011 | 21914098 |
| fine-scale distribution patterns of synechococcus ecological diversity in microbial mats of mushroom spring, yellowstone national park. | past analyses of sequence diversity in high-resolution protein-encoding genes have identified putative ecological species of unicellular cyanobacteria in the genus synechococcus, which are specialized to 60°c but not 65°c in mushroom spring microbial mats. because these studies were limited to only two habitats, we studied the distribution of synechococcus sequence variants at 1°c intervals along the effluent flow channel and at 80-μm vertical-depth intervals throughout the upper photic layer of ... | 2011 | 21890675 |
| dynamic gut microbiome across life history of the malaria mosquito anopheles gambiae in kenya. | the mosquito gut represents an ecosystem that accommodates a complex, intimately associated microbiome. it is increasingly clear that the gut microbiome influences a wide variety of host traits, such as fitness and immunity. understanding the microbial community structure and its dynamics across mosquito life is a prerequisite for comprehending the symbiotic relationship between the mosquito and its gut microbial residents. here we characterized gut bacterial communities across larvae, pupae and ... | 2011 | 21957459 |
| What drives the distribution of the bloom-forming cyanobacteria Planktothrix agardhii and Cylindrospermopsis raciborskii? | The cyanobacteria Planktothrix agardhii and Cylindrospermopsis raciborskii are bloom-forming species common in eutrophic freshwaters. These filamentous species share certain physiological traits which imply that they might flourish under similar environmental conditions. We compared the distribution of the two species in a large database (940 samples) covering different climatic regions and the Northern and Southern hemispheres, and carried out laboratory experiments to compare their morphologic ... | 2011 | 22092489 |