| cyanobacterial evolution: results of 16s ribosomal ribonucleic acid sequence analyses. | we report here the sequences of oligonucleotides released by t1-ribonuclease digestion of the 16s ribosomal rna's (rrna's) of unicellular cyanobacteria agmenellum quadruplicatum (strain bg-1) and synechococcus 7502. we compare them with sequences previously obtained for the 16s rna's of six other cyanobacteria and two chloroplasts, and conclude that: (i) synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes agmenelium quadruplicatum, usually considered to be ... | 1979 | 113061 |
| photoreactivation of uv-irradiated blue-green algae and algal virus lpp-1. | ultraviolet (uv) sensitivity and photoreactivation of blue-green algae cylindrospermum sp., plectonema boryanum, spores of fischerella muscicola and algal virus (cyanophage) lpp-1 were studied. the survival value after uv irradiation of filaments of cylindrospermum sp. and virus lpp-1 showed exponential trend and these were comparatively sensitive towards uv than f.muscicola and p.boryanum. photoreactivation of uv-induced damage occurred in black, blue, green, yellow, red and white light in cyli ... | 1975 | 807175 |
| basis for the resistance of several algae to microbial decomposition. | the basis for the resistance of certain algae to microbial decomposition in natural waters was investigated using pediastrum duplex, staurastrum sp., and fischerella muscicola as test organisms. enzyme preparations previously found to convert susceptible algae into spheroplasts had no such effect on the resistant species, although glucose and galacturonic acid was released from p. duplex walls. little protein or lipid but considerable carbohydrate was found in the walls of the refractory organis ... | 1975 | 808166 |
| effects of chemicals on fischerella muscicola (thuret) gom. | | 1970 | 4985484 |
| characterization of surfaces involved in adherence of legionella pneumophila to fischerella species. | legionella pneumophila adheres to the slime coat of fischerella spp. this was shown by microscopic examination and by a decline in l. pneumophila cfu in samples removed from coincubation mixtures of both organisms. binding of partially purified fischerella slime by l. pneumophila was most efficient by young, less hydrophobic l. pneumophila cells than by older, more hydrophobic cells. uptake of crystal violet and partitioning into hexadecane were used to measure hydrophobicity of l. pneumophila. ... | 1983 | 6413413 |
| cyanobacterial stimulation of growth and oxygen uptake by legionella pneumophila. | a laboratory-adapted strain of legionella pneumophila grew in coculture with fischerella. insoluble fischerella slime contained carbohydrate and protein and was isolated from cultures on filters. slime-free filtrates separated into three 280-nm absorbance peaks on sephadex g-25. peaks 1 and 2 contained protein and carbohydrate and stimulated legionella respiration. peak 3 and slime had no effect. | 1983 | 6414374 |
| growth of legionella pneumophila in association with blue-green algae (cyanobacteria). | legionella pneumophila (legionnaires disease bacterium) of serogroup 1 was isolated from an algal-bacterial mat community growing at 45 degrees c in a man-made thermal effluent. this isolate was grown in mineral salts medium at 45 degrees c in association with the blue-green alga (cyanobacterium) fischerella sp. over a ph range of 6.9 to 7.6. l. pneumophila was apparently using algal extracellular products as its carbon and energy sources. these observations indicate that the temperature, ph, an ... | 1980 | 6769388 |
| influence of blue-green algae (cyanobacteria) on survival of legionella pneumophila in aerosols. | the fluid in which blue-green algae (cyanobacteria) (fischerella sp.) had been grown (algal extract) was investigated for its effect on aerosols of legionella pneumophila. the bacteria were significantly more stable when suspended in algal extract than in the tryptose-saline solution employed in previously reported experiments. the stabilizing property of the extract disappeared after dialysis, suggesting that a relatively small molecule was involved. the relationship of this observation to the ... | 1981 | 6788701 |
| biological activities of cyanobacteria: evaluation of extracts and pure compounds. | a total of 80 lipophilic and hydrophilic extracts obtained from 20 samples of cultured freshwater and terrestrial cyanobacteria were investigated for their biological activities. of all the extracts, 26% exhibited a significant lethal effect against brine shrimp. out of 54 extracts tested for antimicrobial activity, 78% showed antibacterial and 45% antifungal activities. of 30 extracts tested for cytotoxicity against kb cells, none was found to be active. bioassay-guided fractionation of the lip ... | 1995 | 7480178 |
| general distribution of the nitrogen control gene ntca in cyanobacteria. | the ntca gene from synechococcus sp. strain pcc 7942 encodes a regulatory protein which is required for the expression of all of the genes known to be subject to repression by ammonium in that cyanobacterium. homologs to ntca have now been cloned by hybridization from the cyanobacteria synechocystis sp. strain pcc 6803 and anabaena sp. strain pcc 7120. sequence analysis has shown that these ntca genes would encode polypeptides strongly similar (77 to 79% identity) to the synechococcus ntca prote ... | 1993 | 8366058 |
| amino acid transport in taxonomically diverse cyanobacteria and identification of two genes encoding elements of a neutral amino acid permease putatively involved in recapture of leaked hydrophobic amino acids. | the activities of uptake of thirteen 14c-labeled amino acids were determined in nine cyanobacteria, including the unicellular strains synechococcus sp. strain pcc 7942 and synechocystis sp. strain pcc 6803; the filamentous strain pseudanabaena sp. strain pcc 6903, and the filamentous, heterocyst-forming strains anabaena sp. strains pcc 7120 and pcc 7937; nostoc sp. strains pcc 7413 and pcc 7107; calothrix sp. strain pcc 7601 (which is a mutant unable to develop heterocysts); and fischerella musc ... | 1997 | 9006043 |
| action of the allelochemical, fischerellin a, on photosystem ii. | the cyanobacterium, fischerella muscicola, produces a secondary metabolite named fischerellin a (fs) that strongly inhibits the growth of cyanobacteria and other photosynthetic organisms. the compound exhibits a unique structure and is composed of two cyclic amines and a c15 substituent that contains a double bond in the (z) configuration and two triple bonds [l. hagmann, f. jüttner, tetrahedron lett., 37 (1996) 6539-6542]. the site of fs action is located in photosystem ii (psii). the chlorophy ... | 1998 | 9630706 |
| inhibitory metabolites production by the cyanobacterium fischerella muscicola. | broad-spectrum inhibitory metabolites were produced by a benthic cyanobacterium fischerella muscicola (utex 1829) in batch culture. these metabolites inhibited the growth of eukaryotic algae, cyanobacteria and eubacteria. the effect of culture age on the production and leakage of these inhibitory metabolites from the cyanobacterium was studied. confirmation of the presence of an allelochemical, possibly fischerellin was achieved using high performance liquid chromatography (hplc). the cyanobacte ... | 1999 | 10052156 |
| oxidized welwitindolinones from terrestrial fischerella spp | 3-hydroxy-n-methylwelwitindolinone c isonitrile (3), 3-hydroxy-n-methylwelwitindolinone c isothiocyanate (4), and the novel cyclic ether n-methylwelwitindolinone d isonitrile (6) are three new alkaloids from two terrestrial fischerella spp. belonging to the stigonemataceae. photooxidation of n-methylwelwitindolinone c isonitrile (1) leads to isonitriles 3 and 6. isonitrile 3 is readily hydrated to 3-hydroxy-n-methylwelwitindolinone c formamide (5), an artifact produced during the isolation proce ... | 1999 | 10217710 |
| oxidized welwitindolinones from terrestrial fischerella spp | | 1999 | 10395527 |
| structural interactions among epilithic cyanobacteria and heterotrophic microorganisms in roman hypogea. | abstract phototrophic microbial communities present in the roman catacombs were characterized and different species of terrestrial epilithic cyanobacteria were found to occur as dominant organisms. eucapsis, leptolyngbya, scytonema, and fischerella were the most frequently encountered cyanobacterial taxa, while a few species of green algae and the diatom diadesmis gallica occurred in minor amounts. streptomyces strains, a few genera of eubacteria, and to a lesser extent fungi were always present ... | 1999 | 10541786 |
| inhibition of bacterial rna polymerase by the cyanobacterial metabolites 12-epi-hapalindole e isonitrile and calothrixin a. | the alkaloid 12-epi-hapalindole e isonitrile, from a cyanobacterial fischerella species, and the indolophenanthridine calothrixin a, from calothrix, inhibited escherichia coli rna polymerase competitively with respect to atp, and non-competitively with respect to utp. the inhibition was dependent on the order of addition of the inhibitors. the k(i) values, with atp as the variable substrate, were 1.3+/-0.2 mm and 0.23+/-0.11 mm, respectively. based on comparisons with the sensitivity of whole ce ... | 2001 | 11267769 |
| the iron-regulated isia gene of fischerella muscicola strain pcc 73103 is linked to a likewise regulated gene encoding a pcb-like chlorophyll-binding protein. | the expression of the chlorophyll a-binding, iron stress-induced protein isia is part of the cyanobacterial response to iron deficiency. a new isia gene from the filamentous heterocystous cyanobacterial strain, fischerella muscicola pcc 73103, was identified using standard and inverse pcr. while in unicellular cyanobacterial strains isia is organized in an operon with isib (encoding flavodoxin), in fischerella not an isib gene but another chlorophyll-binding protein encoding gene was identified ... | 2001 | 11287157 |
| chromophore attachment to biliproteins: specificity of pece/pecf, a lyase-isomerase for the photoactive 3(1)-cys-alpha 84-phycoviolobilin chromophore of phycoerythrocyanin. | pece and pecf, the products of two phycoerythrocyanin lyase genes (pece and pecf) of mastigocladus laminosus (fischerella), catalyze two reactions: (1) the regiospecific addition of phycocyanobilin (pcb) to cys-alpha 84 of the phycoerythrocyanin alpha-subunit (peca), and (2) the delta 4-->delta 2 isomerization of the pcb to the phycoviolobilin (pvb)-chromophore [zhao et al. (2000) febs lett. 469, 9-13]. the alpha-apoprotein (peca) as well pece and pecf were overexpressed from two strains of m. l ... | 2001 | 11591166 |
| [associative cyanobacteria isolated from the roots of epiphytic orchids]. | associative cyanobacteria were isolated from the rhizoplane and velamen of the aerial roots of the epiphytic orchids acampe papillosa, phalaenopsis amabilis, and dendrobium moschatum and from the substrate roots of acampe papillosa and dendrobium moschatum. cyanobacteria were isolated on complete and nitrogen-free variants of bg-11 medium. on all media and in all samples, cyanobacteria of the genus nostoc predominated. nostoc, anabaena, and calothrix were isolated from the surface of the a. papi ... | 2003 | 12698800 |
| polyphyly of true branching cyanobacteria (stigonematales). | cyanobacteria with true branching are classified in subsection v (formerly order stigonematales) in the phylum cyanobacteria: they exhibit a high degree of morphological complexity and are known from particular biotopes. only a few stigonematalean morphotypes have been cultured, and therefore the high variability of morphotypes found in nature is under-represented in culture. axenic cultures of chlorogloeopsis and fischerella sensu rippka et al. were, to date, the only representatives of this su ... | 2004 | 15023942 |
| ambigol c and 2,4-dichlorobenzoic acid, natural products produced by the terrestrial cyanobacterium fischerella ambigua. | the new natural products 3,5-bis(2,4-dichlorophenoxy)-2,6-dichlorophenol (ambigol c, 1), a highly chlorinated aromatic compound, and 2,4-dichlorobenzoic acid (2) were isolated from the terrestrial cyanobacterium fischerella ambigua together with the known compounds ambigol a (3) and tjipanazole d (4). all structures were secured by extensive spectroscopic analysis (1d and 2d nmr, ms, uv, ir). ambigol c has moderate activity against trypanosoma rhodesiense. | 2005 | 15787461 |
| insecticidal compounds of the biofilm-forming cyanobacterium fischerella sp. (atcc 43239). | cyanobacterial biofilms are grazed by many different benthic invertebrates. in particular, larvae of insects are often present in great numbers and exert strong grazing pressure on cyanobacteria. along with morphological adaptations, allelochemicals may have been developed as defense mechanisms against insect larvae. to investigate the chemical defense of biofilm-forming cyanobacteria, larvae of chironomus sp., a widely distributed genus in this habitat, were used. ten artificial biofilms of axe ... | 2005 | 15892037 |
| community phylogenetic analysis of moderately thermophilic cyanobacterial mats from china, the philippines and thailand. | most community molecular studies of thermophilic cyanobacterial mats to date have focused on synechococcus occurring at temperatures of approximately 50-65 degrees c. these reveal that molecular diversity exceeds that indicated by morphology, and that phylogeographic lineages exist. the moderately thermophilic and generally filamentous cyanobacterial mat communities occurring at lower temperatures have not previously been investigated at the community molecular level. here we report community di ... | 2005 | 15970994 |
| fresh water blue green algae from three agro-climatic zones of uttar pradesh, india: distribution pattern with seasonal variation. | the paper deals with 45 species of 21 genera of fresh water blue green algae (bga) from three different agro-climatic zones of uttar pradesh. samples were collected from different habitats varying in physico-chemical properties. out of 45 species, 13 species belonged to order chroococcales, 31 to order nostocales, while only 1 species belonged to order stigonimatales i.e. fischerella mucicola. the physico-chemical parameters like ph, temperature, dissolved oxygen, electrical conductivity, nitrat ... | 2005 | 16114457 |
| community structure of free-floating filamentous cyanobacterial mats from the wonder lake geothermal springs in the philippines. | cyanobacterial mats were characterized from pools of 45-60 degrees c in near-neutral ph, low-sulphide geothermal springs in the philippines. mat structure did not vary with temperature. all mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. upper mat layers supported biomass with elevated carotenoid:chlorophyll a ratios and an as yet uncharacterized waxy layer on the dorsal surface ... | 2005 | 16175207 |
| characterization of nitrogen-fixing cyanobacteria in the brazilian amazon floodplain. | the diversity of the free-living nitrogen-fixing cyanobacterial community in the floodplain sediments along the solimões and amazon rivers and some of their tributaries (japurá, negro and madeira) was investigated. five cyanobacterial genera were morphologically identified, four of which (nostoc, calothrix, cylindrospermum and fischerella) have not previously been isolated from the brazilian amazon floodplain. nostoc strains were the most commonly found heterocyst-forming cyanobacteria. five str ... | 2005 | 16289234 |
| effects of cyanobacterium fischerella ambigua isolates and cell free culture media on zebrafish (danio rerio) embryo development. | the toxic effects of several species of fresh water cyanobacteria, notably microcystis species and associated toxins, the microcystins, anabaena species (anatoxin), nodularia sp. (nodularin), and cylindrospermopsis raciborskii (cylindrospermopsin), are well known. little, however, is known about the effects of secondary metabolites other than alkaloids. early life stage tests with zebrafish (danio rerio) were used to detect bioactive properties of compounds released by healthy cyanobacteria (fis ... | 2006 | 16554083 |
| molecular population genetics and phenotypic diversification of two populations of the thermophilic cyanobacterium mastigocladus laminosus. | we investigated the distributions of genetic and phenotypic variation for two yellowstone national park populations of the heterocyst-forming cyanobacterium mastigocladus (fischerella) laminosus that exhibit dramatic phenotypic differences as a result of environmental differences in nitrogen availability. one population develops heterocysts and fixes nitrogen in situ in response to a deficiency of combined nitrogen in its environment, whereas the other population does neither due to the availabi ... | 2006 | 16597984 |
| contiguous organization of nitrogenase genes in a heterocystous cyanobacterium. | the organization of the three structural nitrogen fixation (nif) genes that encode nitrogenase (nif k and nif d) and nitrogenase reductase (nif h) have been examined in a number of cyanobacteria. hybridization of anabaena 7120 nif gene probes to restriction endonuclease-digested genomic dna has shown (a) that cyanobacteria incapable of n(2) fixation have no regions of dna with significant homology to the three nif probes, (b) that pseudanabaena sp., a nonheterocystous cyanobacterium, has a conti ... | 1987 | 16665666 |
| biogenic black crusts on buildings in unpolluted environments. | samples of peeling black crusts from modern and historic buildings in campeche, mexico, from a gravestone on the island of dom khon, lao, and from the anglican cathedral in belize city were analyzed microbiologically, by scanning electron microscopy plus electron dispersive spectroscopy (eds) and for pigment composition. in all cases, the surface was covered by a thick mat of cyanobacteria with dark brown sheaths. these were filamentous organisms of the genera scytonema or fischerella/mastigocla ... | 2007 | 17211538 |
| studies on the glycolipid content of the cyanobacterium fischerella ambigua. | a series of monogalactosyl diacylglycerols was isolated from lipophilic extracts of fischerella ambigua. these glycolipids were identified on the basis of chemical and spectroscopic analyses. | 1995 | 17238107 |
| antimicrobial ambiguines from the cyanobacterium fischerella sp. collected in israel. | bioassay-guided fractionation of the 7:3 meoh/water extract of a cultured cyanobacterium strain identified as fischerella sp. yielded nine isonitrile-containing alkaloids. three of the compounds, ambiguine h isonitrile (1), ambiguine i isonitrile (2), and ambiguine j isonitrile (3), are new, while the other six, 12-epi-hapalindole h, ambiguine a isonitrile, ambiguine b isonitrile, ambiguine d isonitrile, ambiguine e isonitrile, and ambiguine f isonitrile, have been previously isolated from fisch ... | 2007 | 17315959 |
| insecticidal activity of 12-epi-hapalindole j isonitrile. | 12-epi-hapalindole j isonitrile (1) and three previously described hapalindoles, 12-epi-hapalindole c isonitrile (2), hapalindole l (3) and 12-epi-hapalindole e isonitrile (4) were isolated and identified as insecticidal alkaloids of the biofilm-forming freshwater cyanobacterium fischerella atcc 43239 (stigonematales). the structures of the purified compounds were elucidated by esi-fticr-ms, gc-ei-ms and various 2d nmr experiments. at 26 microm hapalindole 1 killed 100% of the larvae of the dipt ... | 2007 | 17686499 |
| critical view on the monochlorodimedone assay utilized to detect haloperoxidase activity. | the current study aimed to identify the halogenating enzymes involved in the biosynthesis of the ambigols a, b, c and tjipanazole d, isolated from the cyanobacterium fischerella ambigua. haloperoxidase (hpo) activity within f. ambigua was therefore assayed spectrophotometrically by using monochlorodimedone (mcd) during protein purification. this strategy revealed the isolation of a protein positive in the mcd-assay, but an involvement in halogenating processes could not be verified. n-terminal s ... | 2008 | 17889043 |
| characterization of true-branching cyanobacteria from geothermal sites and hot springs of costa rica. | costa rica is at the centre of the mesoamerican biodiversity hotspot. little is known about cyanobacteria from this region so far. here, four isolates of the order stigonematales (section v) were characterized in a polyphasic approach. all strains were isolated from geothermal sites and hot springs of costa rica. however, one of them, identified as westiellopsis sp. ar73, did not grow at more than 40 degrees c. based on its identical 16s rrna to several previously isolated westiellopsis sp. and ... | 2008 | 18093164 |
| allelopathic activity among cyanobacteria and microalgae isolated from florida freshwater habitats. | we evaluated allelopathic interactions between strains of cyanobacteria and green algae isolated from south and central florida. allelopathy, including inhibition or stimulation of growth, was assessed by cocultivation of each of the isolated strains, as well as by evaluation of extracts prepared from the isolates. all of the strains of cyanobacteria, and four of the six isolates of green algae, showed some allelopathic activity (i.e. inhibition or stimulation of the growth of other strains). of ... | 2008 | 18266743 |
| microcystin production by a freshwater spring cyanobacterium of the genus fischerella. | we investigated the production of a hepatotoxic, cyclic heptapeptide, microcystin, by a filamentous branched cyanobacterium belonging to the order stigonematales, genus fischerella. the freshwater fischerella sp. strain cena161 was isolated from spring water in a small concrete dam in piracicaba, são paulo state, brazil, and identified by combining a morphological description with 16s rrna gene sequencing and phylogenetic analysis. microcystin (mcyst) analysis performed using an elisa assay on c ... | 2009 | 19233225 |
| antimicrobial ambiguine isonitriles from the cyanobacterium fischerella ambigua. | five new antibacterial ambiguine k-o isonitriles (1-5) and eight previously described indole alkaloids were isolated from the cultured cyanobacterium fischerella ambigua (utex 1903) by bioassay-guided fractionation. the planar structures of the new compounds were determined by spectroscopic analysis including ms and 1d and 2d nmr. x-ray crystallography was used to determine the absolute stereoconfiguration of ambiguine k isonitrile. the isolates were evaluated for their antibacterial activities ... | 2009 | 19371071 |
| non-ribosomal peptides produced by brazilian cyanobacterial isolates with antimicrobial activity. | cyanobacterial strains isolated from terrestrial and freshwater habitats in brazil were evaluated for their antimicrobial and siderophore activities. metabolites of fifty isolates were extracted from the supernatant culture media and cells using ethyl acetate and methanol, respectively. the extracts of 24 isolates showed antimicrobial activity against several pathogenic bacteria and one yeast. these active extracts were characterized by q-tof/ms. the cyanobacterial strains cylindrospermopsis rac ... | 2011 | 20630723 |
| hapalindole-related alkaloids from the cultured cyanobacterium fischerella ambigua. | four hapalindole-related alkaloids, namely fischambiguines a and b, ambiguine p, ambiguine q nitrile as well as ambiguine g nitrile were identified from the cultured cyanobacterium fischerella ambigua (utex 1903). the structures were determined by spectroscopic analysis including ms, 1d and 2d nmr and x-ray crystallography. the alkaloids possessed fused pentacyclic and hexacyclic carbon skeletons. fischambiguine b displayed a strong inhibitory activity against mycobacterium tuberculosis with an ... | 2010 | 20965528 |
| structure of transcription factor hetr required for heterocyst differentiation in cyanobacteria. | hetr is an essential regulator of heterocyst development in cyanobacteria. hetr binds to a dna palindrome upstream of the hetp gene. we report the crystal structure of hetr from fischerella at 3.0 å. the protein is a dimer comprised of a central dna-binding unit containing the n-terminal regions of the two subunits organized with two helix-turn-helix motifs; two globular flaps extending in opposite directions; and a hood over the central core formed from the c-terminal subdomains. the flaps and ... | 2011 | 21628585 |