| penicillinase (beta-lactamase) formation by blue-green algae. | beta-lactamase (penicillinase) activity was found in a number of strains of blue-green algea. in some cases, this enzyme permitted algae to overcome the inhibitory effects of penicillin. production and localization of beta-lactamase were studied in a unicellular species, coccochloris elabens (strain 7003), and in a filamentous, nitrogen-fixing anabaena species (strain 7120). when cells were grown in a neutral medium with nano3 as n source, the ph rose during growth; at a ph of about 10, most of ... | 1977 | 15530 |
| crystallization and a 5 a x-ray diffraction study of aphanothece sacrum ferredoxin. | a chloroplast-type ferredoxin containing two non-heme iron and two labile sulfur atoms per molecule was prepared from aphanothece sacrum. crystals were obtained by dialysis against 75% saturated a-monium sulfate solution, and belong to the tetragonal system with cell dimensions a = b = 92.2 a and c = 47.6 a, containing four molecules in an asymmetric unit. the electron density map at 5 a resolution was calculated by using the best phase angles determined by the single isomorphous replacement met ... | 1978 | 101536 |
| sulfide inhibition of photosystem ii in cyanobacteria (blue-green algae) and tobacco chloroplasts. | the present study shows that in the presence of 600 nm light, sulfide acts as a specific inhibitor of photosynthetic electron transport between water and photosystem ii in the cyanobacteria aphanothece halophytica and synechococcus 6311 as well as in tobacco chloroplasts. in the presence of 600 nm light sulfied affects the fast fluorescence transients as does a low concentration (10 mm) of hydroxylamine; the fluorescence yield decreases in the presence of either chemical and can be restored by t ... | 1979 | 109120 |
| occurrence of facultative anoxygenic photosynthesis among filamentous and unicellular cyanobacteria. | eleven of 21 cyanobacteria strains examined are capable of facultative anoxygenic photosynthesis, as shown by their ability to photoassimilate co2 in the presence of na2s, 3-(3,4-dichlorophenyl)-1,1-dimethylurea and 703-nm light. these include different cyanobacterial types (filamentous and unicellular) of different growth histories (aerobic, anaerobic, and marine and freshwater). oscillatoria limnetica, aphanothece halophytica (7418), and lyngbya (7104) have different optimal concentrations of ... | 1977 | 402355 |
| hydrogen metabolism in the facultative anoxygenic cyanobacteria (blue-green algae) oscillatoria limnetica and aphanothece halophytica. | two facultative anoxygenic photoautotrophic cyanobacteria, oscillatoria limnetica and aphanothece halophytica were found capable of co2 photoassimilation using molecular hydrogen as electron donor in a photosystem i driven reaction. a. halophytica was also capable of evolving hydrogen from na-dithionite reduced methylviologen in a light independent reaction. | 1978 | 414684 |
| amino acid sequence of aphanothece sacrum ferredoxin ii (minor component). structural characteristics and evolutionary implications. | | 1978 | 417074 |
| halophilic-blue-green algae. | the isolation of a halophilic blue-green alga, aphanothece halophytica, from great salt lake is described. the organism was cultured from waters with salinities up to saturated nac1 (about 30% w/v). it has an optimum salinity for growth of about 16% nac1, but can grow very slowly even in saturated nac1. based on the study of the great salt lake organism, and on a review of the earlier literature, it is concluded that despite recent reports to the contrary, true halophilic blue-green algae do exi ... | 1976 | 814875 |
| a minor component of ferredoxin from aphanothece sacrum cells. | about 20% of the total extractable ferredoxin from a blue-green alga, aphanothece sacrum, was separated as a minor component on a deae-cellulose column during the preparation of the major component of the cells. it was always found in cells collected in three different seasons. the chemical properties of the minor component was different from those of the major one. the enzymatic activity and spectral properties were those of typical chloroplast-type ferredoxins. the significance of isozymes in ... | 1975 | 818075 |
| evolutionary information involved in primary structures of chloroplast-type ferredoxins. | the complete amino acid sequence of a chloroplast-type ferredoxin from a fresh water prokaryote, aphanothece sacrum, was determined. the sequence consisted of 96 amino acid residues and was homologous to those of ferredoxins of higher plants. comparison of eight ferredoxins, including one from a green alga and three from blue-green algae, suggested that the sequences of algal ferredoxins were as different from one another as from those of higher plants. the relationship between the numbers of di ... | 1975 | 818076 |
| amino acid sequence of the major component of aphanothece sacrum ferredoxin. | the amino acid sequence of the major ferredoxin component isolated from a blue-green alga, aphanothece sacrum, has been fully determined. chymotryptic and tryptic peptides of carboxymethyl-ferredoxin and chymotryptic peptides of oxidized ferredoxin were prepared and their sequences were analyzed... | 1976 | 818078 |
| amino acid sequence of the major component of nostoc muscorum ferredoxin. | the amino acid sequence of the major component of ferredoxin isolated from a blue-green alga, nostoc muscorum, grown under n2 as the sole nitrogen source has been studied. the use of a combination of sequence analyzer, carboxypeptidases, and manual edman degradations on tryptic and chymotryptic peptides of carboxymethylferredoxin has established the amino acid seuqence, which consists of 98 amino acid residues. only four cysteine residues were present, located at positions 41, 46, 49, and 79. th ... | 1976 | 826526 |
| ion metabolism in a halophilic blue-green alga, aphanothece halophytica. | the intracellular ion content of the halophilic blue-green alga, aphanthece halophytica was studied as a function of age, external sodium and external potassium concentration. intracellular na+ was found to be about 0.38 millimoles/g dry mass. intracellular k+ concentrations were as high as 1 m and varied directly with external salinity. intracellular ca++ and mg++ were in the range previously reported for fresh water blue-green algae despite their extremely high extracellular concentrations. av ... | 1976 | 828029 |
| absorption of color additives and settling volume in water of blue-green alga, ishikurage (nostoc commune). | the properties of ishikurage (nostoc commune) and other algae were compared. ishikurage and suizenji nori (aphanothece sacrum) absorbed much more amaranth than others. they have a high settling volume (sv) in water. the high sv of ishikurage is attributable to its neutral detergent fiber (ndf). the acid detergent fiber (adf) from the alga had a high amaranth absorption. however the absorption by the adf did not explain the absorption by ishikurage. the results suggest that ishikurage may have a ... | 1992 | 1312238 |
| distribution of phototrophic microbes in the flat laminated microbial mat at laguna figueroa, baja california, mexico. | the microbial mat community in the saltmarsh/evaporate flat interface at laguna figueroa involved in the deposition of laminated sediments was investigated. pigment analysis, light microscopy and transmission electron microscopy were used to determine the relative abundance and distribution of phototrophic species. the community is vertically stratified into four distinct phototrophic populations. the layering could be distinguished by pigment and species composition. the two layers closest to t ... | 1990 | 2108737 |
| structure of the [2fe-2s] ferredoxin i from the blue-green alga aphanothece sacrum at 2.2 a resolution. | crystals of a [2fe-2s] ferredoxin (fd) i with a relative molecular mass of 10,480 were obtained from the blue-green alga aphanothece sacrum. each asymmetric unit of the crystal contains four molecules. an electron density map calculated by the single isomorphous replacement method with the anomalous dispersion at 2.5 a resolution was refined by averaging the four molecules in the asymmetric unit. positional and isotropic thermal parameters for the non-hydrogen atoms of the four molecules and 158 ... | 1990 | 2123937 |
| a simple and rapid method for screening bacteria for type ii restriction endonucleases: enzymes in aphanothece halophytica. | a method is described which allows a large number of bacterial strains to be rapidly and easily screened for the presence of site-specific endonucleases. the method involves selective permeabilization of the bacterial cell and analysis of the exuded material. type ii restriction endonucleases from cyanobacteria and gram-negative eubacteria have been detected and new enzymes have been found. the method should be widely applicable and easy to modify for use in genera other than those tested. three ... | 1985 | 2986568 |
| role of the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase in the activation process. | the large (a) and small (b) subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (ec 4.1.1.39) from the cyanobacterium aphanothece halophytica and from the purple sulfur photosynthetic bacterium chromatium vinosum (strain d) were separated by sucrose density gradient centrifugation at low ionic strength and alkaline ph (9.3), respectively. it was found that subunit b enhances the extent of activation by co2 and mg2+ at equilibrium of the two homologous enzymes consisting of aphanothece la ... | 1986 | 3089168 |
| purification and characterization of phosphoenolpyruvate carboxylase from a cyanobacterium. | phosphoenolpyruvate (pep) carboxylase (ec 4.1.1.31) was purified 100-fold from the cyanobacterium coccochloris peniocystis with a yield of 10%. a single isozyme was found at all stages of purification, and activity of other beta-carboxylase enzymes was not detected. the apparent molecular weight of the native enzyme was 560,000. optimal activity was observed at ph 8.0 and 40 degrees c, yielding a vmax of 8.84 mumol/mg of protein per min. the enzyme was not protected from heat inactivation by asp ... | 1986 | 3093461 |
| isolation of the catalytically competent small subunit of ribulose bisphosphate carboxylase/oxygenase from spinach under an extremely alkaline condition. | a method for isolating the small subunit (b) of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from spinach leaf using an alkaline buffer (ph 11.2) in combination with sucrose gradient centrifugation is described. although the yield of isolated subunit b (ca. 20%) was comparable to that previously described (ca. 25%) using the acid precipitation method [andrews, t.j. and lorimer, g.h. (1985) j. biol. chem. 260: 4632-4636], the isolated subunit b in this report suffered less denaturati ... | 1986 | 3461783 |
| factors affecting the dissociation and reconstitution of ribulose-1,5-bisphosphate carboxylase/oxygenase from aphanothece halophytica. | factors affecting the mutual interaction between the catalytic core [octamer of large subunit (a)] and the small subunit (b) comprising ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from the superhalophilic cyanobacterium, aphanothece halophytica, were investigated. the enzyme molecule dissociated into the catalytic core highly depleted of subunit b and the monomeric form of subunit b during density gradient centrifugation (15 h, 4 degrees c) in a sucrose solution of low ionic streng ... | 1985 | 3919647 |
| heterologous hybridization of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) restores the enzyme activities. | the catalytic core (a8) and small subunit (b) of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) were isolated from two species of cyanobacteria (aphanothece halophytica and synechococcus acmm 323) as well as from the photosynthetic purple sulfur bacterium, chromatium vinosum. the subunit b is essential for the activity of all three enzymes. the heterologous hybridization of rubisco molecules from the three organisms was attempted and the reconstitution of the catalytically active hybr ... | 1985 | 3919715 |
| ferredoxin from a blue-green alga, aphanothece sacrum (suringar) okada. | | 1974 | 4156362 |
| loss of photosynthetic activity in two blue-green algae as a result of osmotic stress. | a progressive loss of photosynthetic activity occurred when cells of anacystis nidulans and coccochloris peniocystis were incubated in increasing concentrations of osmotica from 0.2 to 0.7 m, and there was a release of pteridine from the cells proportional to the loss of photosynthetic activity. | 1973 | 4197908 |
| the characterization of c-phycocyanin from an extremely halo-tolerant blue-green alga, coccochloris elabens. | c-phycocyanin was isolated and purified from a uni-algal culture of an extremely halo-tolerant blue-green alga, coccochloris elabens. this alga can be grown under laboratory conditions in 25% (w/v) nacl. purified halophile phycocyanin was characterized by amino acid analysis and the measurement of sedimentation velocity, fluorescence polarization and immunodiffusion as a function of protein concentration, ph and ionic strength. the results were compared with those of studies of phycocyanin isola ... | 1973 | 4198583 |
| main chain fold of a [2fe-2s]ferredoxin i from aphanothece sacrum at 2.5 a resolution. | crystal structure analysis of a [2fe-2s]ferredoxin i from aphanothece sacrum, a blue green alga, was carried out at 2.5 a resolution. the phase angle of each reflection was determined by the single isomorphous replacement method coupled with the anomalous dispersion effect for the uranium derivative. the four molecules in an asymmetric unit were clearly seen in a 3.9 a electron density map. the main chains of three molecules were traced at 2.5 a resolution. the structure of the remaining one mol ... | 1983 | 6413499 |
| ribulose 1,5-bisphosphate carboxylase from the halophilic cyanobacterium aphanothece halophytica. | various structural and functional properties of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) isolated from the halophilic cyanobacterium (blue-green alga) aphanothece halophytica were reexamined. the ready dissociation of this algal rubisco during sedimentation in a linear sucrose density gradient was observed. low nacl concentrations promote the dissociation of small subunit (b) from the original native enzyme molecule as evidenced by the sucrose density gradient centrifugation and ... | 1983 | 6414378 |
| ferredoxin from aphanothece halophitica, a unicellular blue-green alga: close relationship to ferredoxins from filamentous blue-green algae and phylogenetic implications. | the amino acid sequence of a ferredoxin from a unicellular blue-green alga, aphanothece halophitica, was established by the conventional methods. total number of residues was 98 lacking only tryptophan. a most probable phylogenetic tree was constructed for 19 algal ferredoxins on the basis of an amino acid difference matrix made from the sequence comparison. a. halophitica has been classified as a unicellular blue-green alga in the same genus to which aphanothece sacrum belongs, but the tree ind ... | 1983 | 6418732 |
| interaction of constituent subunits in ribulose 1,5-bisphosphate carboxylase from aphanothece halophytica. | ribulose 1,5-bisphosphate carboxylase-oxygenase (rubisco) from the halophilic cyanobacterium, aphanothece halophytica, dissociates into catalytic core (large subunit a oligomer) and small subunit b under low ionic strength during sucrose density gradient centrifugation. supplementation of kcl, nacl, or k2so4 ( [i] = 0.3 m) partly prevents the dissociation, the preventive effect of divalent cation salts such as mgcl2 and cacl2 being more effective than monovalent cation salts. rubisco with its hi ... | 1984 | 6422849 |
| essentiality of the small subunit (b) in the catalysis of rubp carboxylase/oxygenase is not related to substrate-binding in the large subunit (a). | the small subunit (b) of ribulose 1,5-bisphosphate (rubp) carboxylase/oxygenase from aphanothece halophytica is absolutely required for the catalysis, but depletion of subunit b does not significantly affect the formation of the quaternary complex-[enzyme.activator co2.mg.carboxyarabinitol bisphosphate] in the catalytic core. the inhibition of rubp carboxylase activity by the reaction of the epsilon-amino group of a lysine in the rubp-binding site with pyridoxal 5-p is the same whether subunit b ... | 1984 | 6431974 |
| gliding motility in aphanothece halophytica: analysis of wall proteins in mot mutants. | the unicellular cyanobacterium aphanothece halophytica (pcc 7418) is motile, and spontaneous nonmotile (mot) mutants accumulate when the organism is subcultured. analysis of mot mutants suggests that a glycoprotein in the cell wall is involved in the motility mechanism. proteins from the wall fraction of the wild type and five mot clones were analyzed by gradient sodium dodecyl sulfate-acrylamide gel electrophoresis. four clones were similar to the wild type, and one clone, mot-3, was missing a ... | 1981 | 6793555 |
| [hygienic and microbiological influences exerted on natural water biotopes by algae and the growth of water plants. 1. communication: antibacterial properties of three water algae (hydrodictyon reticulatum, chlorella vulgaris, aphanothece nidulans) in vitro (author's transl)]. | the growth-inhibiting behaviour of abacterial, liquid pure cultures made up of three water algae (hydrodictyon reticulatum, chlorella vulgaris, aphanothece nidulans) which were made to grow profusely in special culture containers under constant exposure to light and ventilation was examined in ten different species of microorganisms during a period of contact of 4 days both in the light and in the dark. subjected to the test were the 5 pathogenic species staphylococcus aureus, klebsiella aerogen ... | 1981 | 6805159 |
| amino acid sequence of synechocystis 6714 ferredoxin: a unique structural feature of unicellular blue-green algal ferredoxin. | the amino acid sequence of ferredoxin from synechocystis 6714, a unicellular blue-green alga, was determined by a combination of conventional methods. the ferredoxin was composed of 96 amino acid residues and lacked methionine and tryptophan. the sequence was as follows: ala-ser-tyr-thr-val-lys-leu-ile-thr- pro-asp-gly-glu-asn-ser-ile-glu-cys-ser-asp-asp-thr-tyr-ile-leu-asp-ala-ala- glu-glu-ala-gly-leu-asp-leu-pro-tyr-ser-cys-arg-ala-gly-ala-cys-ser-thr-cys- ala-gly-lys-ile-thr-ala-gly-ser-val-a ... | 1982 | 6818221 |
| native-like beta-hairpin structure in an isolated fragment from ferredoxin: nmr and cd studies of solvent effects on the n-terminal 20 residues. | the conformational properties of protein fragments have been widely studied as models of the earliest initiation events in protein folding. while native-like alpha-helices and beta-turns have been identified, less is known about the factors that underly beta-sheet formation, in particular beta-hairpins, where considerably greater long-range order is required. the n-terminal 20 residue sequence of native ferredoxin i (from the blue-green alga aphanothece sacrum) forms a beta-hairpin in the native ... | 1996 | 8844827 |
| isolation and characterization of a dnak genomic locus in a halotolerant cyanobacterium aphanothece halophytica. | we cloned and characterized a genomic locus encoding a distinct member of the dnak/hsp70 family of molecular chaperones, dnak1, from the halotolerant cyanobacterium aphanothece halophytica. co-expression of dnak1 with a plant plastocyanin precursor in escherichia coli resulted in a dramatic increase in the solubility of the plant protein. this indicates that a. halophytica dnak1 encodes a functional protein possessing functions assigned to dnak/hsp70 chaperone members. the a. halophytica dnak1 l ... | 1997 | 9426597 |
| molecular characterization of dnak from the halotolerant cyanobacterium aphanothece halophytica for atpase, protein folding, and copper binding under various salinity conditions. | previously, it was found that the dnak1 gene of the halotolerant cyanobacterium aphanothece halophytica encodes a polypeptide of 721 amino acids which has a long c-terminal region rich in acidic amino acid residues. to understand whether the a. halophytica dnak1 possesses chaperone activity at high salinity and to clarify the role of the extra c-terminal amino acids, a comparative study examined three kinds of dnak molecules for atpase activity as well as the refolding activity of other urea-den ... | 1999 | 10437825 |
| cyanobacterial sulfide-quinone reductase: cloning and heterologous expression. | the gene encoding sulfide-quinone reductase (sqr; e.c.1.8.5.'), the enzyme catalyzing the first step of anoxygenic photosynthesis in the filamentous cyanobacterium oscillatoria limnetica, was cloned by use of amino acid sequences of tryptic peptides as well as sequences conserved in the rhodobacter capsulatus sqr and in an open reading frame found in the genome of aquifex aeolicus. sqr activity was also detected in the unicellular cyanobacterium aphanothece halophytica following sulfide inductio ... | 2000 | 10852862 |
| degradation of glycinebetaine by betaine-homocysteine methyltransferase in aphanothece halophytica: effect of salt downshock and starvation. | we have investigated conditions leading to the degradation of glycinebetaine in aphanothece halophytica and have shown the activity of betaine-homocysteine methyltransferase (bhmt). the intracellular glycinebetaine level was decreased approximately 50% after 36 h salt downshock from 2.0 m nacl medium to 0.5 m nacl medium. a slight additional decrease of glycinebetaine occurred when salt downshock was combined with dark treatment. the omission of carbon and nitrogen sources in the growth medium f ... | 2000 | 10977887 |
| overexpression of dnak from a halotolerant cyanobacterium aphanothece halophytica enhances the high-temperatue tolerance of tobacco during germination and early growth. | dnak1 from a halotolerant cyanobacterium aphanothece halophytica, was overexpressed in the cytosol of tobacco. when the control and transgenic tobacco seeds were incubated at 27 degrees c, more than 95% of the control and transgenic tobacco seeds germinated. however, at a high incubation temperature, 40 degrees c, only 27% of the control seeds germinated whereas 82% of the transgenic seeds germinated. high temperature treatment during the imbibition of seeds delayed germination more in the contr ... | 2001 | 11166432 |
| purification and kinetic properties of betaine-homocysteine methyltransferase from aphanothece halophytica. | betaine-homocysteine methyl transferase (bhmt) from aphanothece halophytica was purified to homogeneity by hydroxyapatite, deae-sepharose cl-6b and sephadex g-200 column chromatography. a 24-fold purification and 11% overall yield were achieved with a specific activity of 595 nmol h(-1) mg(-1). the subunit molecular weight was determined to be 45 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), and the native enzyme was found to have a molecular weight of 350 kda, sug ... | 2001 | 11391473 |
| halotolerant cyanobacterium aphanothece halophytica contains an na(+)/h(+) antiporter, homologous to eukaryotic ones, with novel ion specificity affected by c-terminal tail. | recently, a cyanobacterium synechocystis sp. pcc 6803 has been shown to contain an na(+)/h(+) antiporter gene homologous to plants (sos1 and atnhx1 from arabidopsis) and mammalians (nhes from human) but not to escherichia coli (nhaa and nhab). here, we examined whether a halotolerant cyanobacterium aphanothece halophytica has homologous genes. it turned out that a. halophytica contains an na(+)/h(+) antiporter homologous to plants, mammalians, and some bacteria (nhap from pseudomonas and synnhap ... | 2001 | 11479290 |
| molecular characterization of a phosphoenolpyruvate carboxylase from a thermophilic cyanobacterium, synechococcus vulcanus with unusual allosteric properties. | a gene for phosphoenolpyruvate carboxylase (pepc) was isolated from a thermophilic cyanobacterium, synechococcus vulcanus, by screening a genomic dna library using the coding region of anacystis nidulans 6301 pepc as a probe. the s. vulcanus pepc gene (svpepc) had an open reading frame for a polypeptide of 1,011 amino acid residues with a calculated molecular mass of 116.4 kda. svpepc was expressed in e. coli bl21 codonplus (de3), using pet32a as a vector. the purified recombinant svpepc protein ... | 2002 | 11867695 |
| zinc biosorption from aqueous solution by a halotolerant cyanobacterium aphanothece halophytica. | we have investigated the characteristics of zinc biosorption by aphanothece halophytica. zinc could be rapidly taken up from aqueous solution by the cells with an equilibrium being reached within 15 min of incubation with 100 mg l(-1) zncl(2). the adsorbed zinc was desorbed by treatment with 10 mm edta. the presence of glucose, carbonyl cyanide m-chlorophenylhydrazone (cccp), and n,n'-dicyclohexylcarbodiimide (dccd) did not affect the uptake of zinc. the specific uptake of zinc increased at low ... | 2002 | 12192523 |
| isolation and functional characterization of n-methyltransferases that catalyze betaine synthesis from glycine in a halotolerant photosynthetic organism aphanothece halophytica. | glycine betaine (n,n,n-trimethylglycine) is an important osmoprotectant and is synthesized in response to abiotic stresses. although almost all known biosynthetic pathways of betaine are two-step oxidation of choline, here we isolated two n-methyltransferase genes from a halotolerant cyanobacterium aphanothece halophytica. one of gene products (orf1) catalyzed the methylation reactions of glycine and sarcosine with s-adenosylmethionine acting as the methyl donor. the other one (orf2) specificall ... | 2003 | 12466265 |
| salt stress enhances choline uptake in the halotolerant cyanobacterium aphanothece halophytica. | the uptake of [14c]choline by a suspension of exponential-phase aphanothece halophytica under various conditions has been studied. salt stress was found to enhance the uptake of choline. the kinetics of choline transport followed the michaelis-menten relationship with apparent k(m) values of 272 and 286 microm, maximum rates of transport (v(max)) of 18 and 37 nmol/min/mg protein for unstressed and salt-stressed cells, respectively. choline uptake under salt stress was significantly reduced in ch ... | 2003 | 12667616 |
| food quality controls reproduction of the zebra mussel (dreissena polymorpha). | species such as dreissena polymorpha sometimes contribute substantially in the transfer of primary to secondary production. during the ontogenetic cycle, the reproductive investment of adult mussels is one of the main parameters that affect recruitment success. we studied how food quality and temperature affect the reproductive investment in term of egg mass of d. polymorpha in a lake by sampling mussels monthly from 4 m and 15 m depths. temperature affected reproduction directly and also indire ... | 2003 | 12721821 |
| viability of dried vegetative cells or filaments, survivability and/or reproduction under water and light stress, and following heat and uv exposure in some blue-green and green algae. | vegetative cells in dried, mucilagenous mass of gloeocapsa aeruginosa and aphanothece nidulans, reticulum of hydrodictyon reticulatum, mucilagenous mass of chroococcus minor, and filaments of oedogonium sp. and scytonema hofmanni died within 1/2, 1/2, 1/2, 1, 3 and 6 h, respectively, while dried vegetative filaments of phormidium foveolarum retained under similar storage conditions viability for 4 d. p. foveolarum tolerated 1 mol/l nacl. the resistance to desiccation in p. foveolarum exhibited s ... | 2003 | 14533482 |
| isolation and functional characterization of ca2+/h+ antiporters from cyanobacteria. | genome sequences of cyanobacteria, synechocystis sp. pcc 6803, anabaena sp. pcc 7120, and thermosynechococcus elongatus bp-1 revealed the presence of a single ca2+/h+ antiporter in these organisms. here, we isolated the putative ca2+/h+ antiporter gene from synechocystis sp. pcc 6803 (syncax) as well as a homologous gene from a halotolerant cyanobacterium aphanothece halophytica (apcax). in contrast to plant vacuolar caxs, the full-length apcax and syncax genes complemented the ca2+-sensitive ph ... | 2004 | 14559898 |
| nitrate uptake by the halotolerant cyanobacterium aphanothece halophytica grown under non-stress and salt-stress conditions. | we have compared the characteristics of nitrate uptake by aphanothece halophytica grown under non-stress and salt-stress conditions. both cell types showed essentially similar patterns of nitrate uptake toward ammonium, nitrite, and dl-glyceraldehyde. although the affinities of nitrate to non-stress cells and salt-stress cells were not significantly different, i.e., ks = 416 and 450 microm, respectively, the v(max) value for non-stress cells was about twofold of that for salt-stress cells (9.1 v ... | 2003 | 14570279 |
| phytoplankton diversity and cyanobacterial dominance in a hypereutrophic shallow lake with biologically produced alkaline ph. | in this work, we have characterized the diversity of phytoplanktonic species in a highly alkaline and hypereutrophic shallow lake, santa olalla (southwestern spain), the evolution of their relative abundances, and that of several physicochemical parameters over 2 years. in the absence of an external input of alkaline water, santa olalla's stable high ph (average ph 9.52, with several maxima >10.5) is explained by an extremely high photosynthetic primary productivity. a variety of phytoplankton s ... | 2004 | 15064977 |
| establishment of a pure culture of the hitherto uncultured unicellular cyanobacterium aphanothece sacrum, and phylogenetic position of the organism. | aphanothece sacrum, an edible freshwater unicellular cyanobacterium, was isolated by using novel synthetic media (designated ast and ast-5xnp). the media were designed on the basis of the ratio of inorganic elements contained in a. sacrum cells cultured in a natural pond. the isolated strain exhibits unicellular rod-shaped cells approximately 6 microm in length that are scattered in an exopolysaccharide matrix, a feature similar to that of natural a. sacrum. dna analysis of the isolated strain r ... | 2004 | 15184129 |
| structure of [2fe-2s] ferredoxin i from equisetum arvense at 1.8 a resolution. | ferredoxin i (fd i) from equisetum arvense is an iron-sulfur protein composed of 95 amino-acid residues and one [2fe-2s] cluster. it crystallized in the space group p2(1), a = 30.4, b = 57.4, c = 47.5 a and beta = 78.7 degrees with two molecules per asymmetric unit. x-ray diffraction data up to 1.8 a resolution were collected by using a rigaku four-circle diffractometer. the initial model of fd i, which was derived by the molecular replacement method using a structure of the fd i from the blue-g ... | 1994 | 15299454 |
| neuro-apoptogenic and blood platelet targeting toxins in benthic marine cyanobacteria from the portuguese coast. | six strains of marine cyanobacteria, of which five benthic, were isolated from an area of the portuguese coast with no known apparent toxic microbial bloom. five strains were lethal for mice. four of them produced lethargy and four lead to bleeding. one of the toxic strains was from a genus (aphanothece) not previously associated with toxin production. extracts from four isolates induced sh-sy5y-neuroblastoma cell apoptosis without affecting the viability of hepatocytes, nrk kidney cells, or fib ... | 2005 | 16039729 |
| nitrate uptake in the halotolerant cyanobacterium aphanothece halophytica is energy-dependent driven by deltaph. | the energetics of nitrate uptake by intact cells of the halotolerant cyanobacterium aphanothece halophytica were investigated. nitrate uptake was inhibited by various protonophores suggesting the coupling of nitrate uptake to the proton motive force. an artificially-generated ph gradient across the membrane (deltaph) caused an increase of nitrate uptake. in contrast, the suppression of deltaph resulted in a decrease of nitrate uptake. the increase of external ph also resulted in an enhancement o ... | 2005 | 16053714 |
| functional differences between cyanobacterial dnak1 chaperones from the halophyte aphanothece halophytica and the freshwater species synechococcus elongatus expressed in escherichia coli. | dnak chaperones participate in essential cellular processes including the assistance of the folding, structural maintenance, trafficking, and degradation of proteins, the control of stress responses, and so on. in contrast to the situation found in most other bacterial groups, the cyanobacteria contain multiple dnak homolog genes whose cellular roles remain ambiguous. we compared in this work the in vivo chaperone capabilities of the dnak1 members from the halophyte aphanothece halophytica and t ... | 2005 | 16059771 |
| halotolerant cyanobacterium aphanothece halophytica contains napa-type na+/h+ antiporters with novel ion specificity that are involved in salt tolerance at alkaline ph. | aphanothece halophytica is a halotolerant alkaliphilic cyanobacterium which can grow at nacl concentrations up to 3.0 m and at ph values up to 11. the genome sequence revealed that the cyanobacterium synechocystis sp. strain pcc 6803 contains five putative na+/h+ antiporters, two of which are homologous to nhap of pseudomonas aeruginosa and three of which are homologous to napa of enterococcus hirae. the physiological and functional properties of napa-type antiporters are largely unknown. one of ... | 2005 | 16085800 |
| carboxyl-terminal hydrophilic tail of a nhap type na+/h+ antiporter from cyanobacteria is involved in the apparent affinity for na+ and ph sensitivity. | little information is available on the c-terminal hydrophilic tails of prokaryotic na(+)/h(+) antiporters. to address functional properties of the c-terminal tail, truncation mutants in this domain were constructed. truncation of c-terminal amino acid residues of nhap1 type antiporter from synechocystis pcc6803 (synnhap1) did not change the v(max) values, but increased the k(m) values for na(+) and li(+) about 3 to 15-fold. truncation of c-terminal tail of a halotolerant cyanobacterium aphanothe ... | 2006 | 16616885 |
| evidence for hco(3) transport by the blue-green alga (cyanobacterium) coccochloris peniocystis. | the possibility of hco(3) (-) transport in the blue-green alga (cyanobacterium) coccochloris peniocystis has been investigated. coccochloris photosynthesized most rapidly in the ph range 8 to 10, where most of the inorganic c exists as hco(3) (-). if photosynthesis used only co(2) from the external solution the rate of photosynthesis would be limited by the rate of hco(3) (-) dehydration to co(2). observed rates of photosynthesis at alkaline ph were as much as 48-fold higher than could be suppor ... | 1980 | 16661199 |
| effect of oxygen and temperature on the efficiency of photosynthetic carbon assimilation in two microscopic algae. | the co(2) compensation points of coccochloris peniocystis, a blue-green alga and chlamydomonas reinhardtii, a green alga, were determined at ph 8.0 in a closed system by a gas chromatographic technique. the compensation point of chlamydomonas increased markedly with temperature, rising from 0.79 microliter per liter co(2) at 15 c to 2.5 microliters per liter co(2) at 35 c. in contrast, the compensation point of coccochloris at 20 c was 0.71 microliter per liter co(2) and rose to only 0.95 microl ... | 1980 | 16661319 |
| inorganic carbon accumulation and photosynthesis in a blue-green alga as a function of external ph. | the blue-green alga coccochloris peniocystis photosynthesizes optimally over the ph range of 7.0 to 10.0, but the o(2)-evolution rate is inhibited below ph 7.0 and ceases below ph 5.25. measurement of the inorganic carbon pool in this alga in the light, using the silicone-fluid filtration technique demonstrated that the rate of accumulation of dissolved inorganic carbon remained relatively constant over a wide ph range. at external dissolved inorganic carbon concentrations of 0.56 to 0.89 millim ... | 1981 | 16661792 |
| effect of betaine on enzyme activity and subunit interaction of ribulose-1,5-bisphosphate carboxylase/oxygenase from aphanothece halophytica. | the presence of betaine, a quaternary ammonium compound, at a concentration (0.5 molar) reported to accumulate inside aphanothece halophytica in response to increasing external salinity, slightly promoted ribulose-1,5-bisphosphate (rubp) carboxylase activity. kcl at 0.25 molar inhibited rubp carboxylase about 55%. betaine relieved the inhibition by 0.25 m kcl and the original uninhibited activity was restored at 1 m betaine. other osmoregulatory solutes such as sucrose and glycerol also reduced ... | 1986 | 16664941 |
| co(2) fixation rate and rubisco content increase in the halotolerant cyanobacterium, aphanothece halophytica, grown in high salinities. | the growth of the halotolerant cyanobacterium aphanothece halophytica, previously adapted to 0.5 molar nacl, was optimal when nacl concentration in culture medium was in the range 0.5 to 1.0 molar. the growth was delayed at either too low or too high salinities with lag time of ca. 0.5 day in 0.25 molar nacl and ca. 2 days in 2 molar nacl under the experimental conditions. however, the growth rates at the logarithmic phase were similar in the culture media containing nacl in the range 0.25 to 2. ... | 1988 | 16666431 |
| purification and characterization of phosphoglycolate phosphatase from the cyanobacterium coccochloris peniocystis. | the properties and role of the enzyme phosphoglycolate phosphatase in the cyanobacterium coccochloris peniocystis have been investigated. phosphoglycolate phosphatase was purified 92-fold and had a native molecular mass of approximately 56 kilodaltons. the enzyme demonstrated a broad ph optimum of ph 5.0 to 7.5 and showed a relatively low apparent affinity for substrate (k(m) = 222 micromolar) when compared to that from higher plants. the enzyme required both an anion and divalent cation for act ... | 1991 | 16668041 |
| oral administration of exopolysaccharide from aphanothece halophytica (chroococcales) significantly inhibits influenza virus (h1n1)-induced pneumonia in mice. | the halophilous cyanobacterium aphanothece halophytica releases large sums of single type sulfated exopolysaccharide in late logarithmic growth phase in culture. this polysaccharide contained sulfate up to 34.46% of the total moieties in the molecular. as a sulfated polysaccharide that can be biosynthesized in large quantities, however, its antiviral activity has not yet been reported. in this study, we examined effects of exopolysaccharide from a. halophytica fremy (epah) on influenza virus a f ... | 2006 | 16714212 |
| halotolerant cyanobacterium aphanothece halophytica contains a betaine transporter active at alkaline ph and high salinity. | aphanothece halophytica is a halotolerant alkaliphilic cyanobacterium which can grow in media of up to 3.0 m nacl and ph 11. this cyanobacterium can synthesize betaine from glycine by three-step methylation using s-adenosylmethionine as a methyl donor. to unveil the mechanism of betaine uptake and efflux in this alkaliphile, we isolated and characterized a betaine transporter. a gene encoding a protein (bett(a. halophytica)) that belongs to the betaine-choline-carnitine transporter (bcct) family ... | 2006 | 16957224 |
| the kinetics of the removal of nitrogen and organic matter from parboiled rice effluent by cyanobacteria in a stirred batch reactor. | the aim of this research was to evaluate the kinetics of the removal of nitrogen and organic matter from parboiled rice effluent by the cyanobacteria aphanothece microscopica nägeli. from the results obtained, it was verified that maximum efficiency for the removal of organic matter expressed as cod and total nitrogen (n-tkn) occurred after 15 h of cultivation, being 83.44% and 72.74, respectively. the scale-up process indicated that the volume of the estimated reactor would be 100.2m(3), contai ... | 2007 | 17110102 |
| presence of a na+-stimulated p-type atpase in the plasma membrane of the alkaliphilic halotolerant cyanobacterium aphanothece halophytica. | aphanothece cells could take up na(+) and this uptake was strongly inhibited by the protonophore, carbonyl cyanide m-chlorophenylhydrazone (cccp). cells preloaded with na(+) exhibited na(+) extrusion ability upon energizing with glucose. na(+) was also taken up by the plasma membranes supplied with atp and the uptake was abolished by gramicidin d, monensin or na(+)-ionophore. orthovanadate and cccp strongly inhibited na(+) uptake, whereas n, n'-dicyclohexylcarbodiimide (dccd) slightly inhibited ... | 2007 | 17302934 |
| growth assays with mixed cultures of cyanobacteria and algae assessed by in vivo fluorescence: one step closer to real ecosystems? | a growth toxicity assay with mixed cultures of cyanobacteria and algae using in vivo fluorescence is presented. test organisms (the green alga pseudokirchneriella subcapitata and the cyanobacterium aphanothece clathrata) growing alone and in a mixture were exposed to selected chemicals. p. subcapitata featured a higher sensitivity to toxicants in the presence of a. clathrata compared to the single species assay. on the other hand, growth of a cyanobacterium was not affected by the presence or ab ... | 2008 | 17845814 |
| metabolic engineering for betaine accumulation in microbes and plants. | plants accumulate a variety of osmoprotectants that improve their ability to combat abiotic stresses. among them, betaine appears to play an important role in conferring resistance to stresses. betaine is synthesized via either choline oxidation or glycine methylation. an increased betaine level in transgenic plants is one of the potential strategies to generate stress-tolerant crop plants. here, we showed that an exogenous supply of serine or glycine to a halotolerant cyanobacterium aphanothece ... | 2007 | 17884813 |
| cyanobacteria as a biosorbent for mercuric ion. | the biosorption of hg(2+) by two strains of cyanobacteria, spirulina platensis and aphanothece flocculosa, was studied under a batch stirred reaction system. essential process parameters, including ph, biomass concentration, initial metal concentration, and presence of co-ions were shown to influence the hg(2+) uptake. hg(2+) uptake was optimal at ph 6.0 for both strains. the maximum loading capacities per gram of dry biomass were found to be 456 mg hg(2+) for a. flocculosa and 428 mg hg(2+) for ... | 2008 | 18158240 |
| survival and reproduction in some algae under stress conditions. | pithophora oedogonia and cladophora glomerata survived lowest 60 and 58%, respectively, in june when the pond diurnal water temperature (pdwt) increased to a maximum of 28 degrees c. the lowering of pdwt only by 1 degrees c in july improved survivability of both algae to their almost maximum level of 100 and 96%, respectively. further lowering of pdwt to 17-22 degrees c in november initiated akinete formation in p. oedogonia. the process of akinete initiation, maturation and germination continue ... | 2007 | 18450223 |
| vegetative survival of some wall and soil blue-green algae under stress conditions. | lyngbya major (a wall alga), survived throughout year, maximally to >80 % at atmospheric temperature (at) of 17-36 degrees c and relative humidity (rh) 60-100 % in rainy and spring seasons, but the survival was 43-64 % in winter when at decreased to 5 degrees c and rh was 65-98 %, and 15-23 % in summer when at reached 48 degrees c and rh was 23-60 %. all soil algae (lyngbya birgei, aphanothece pallida, gloeocapsa atrata, oscillatoria subbrevis, o. animalis) survived >90 % in rainy season when so ... | 2008 | 18759119 |
| competitive exclusion of cyanobacterial species in the great salt lake. | the great salt lake is separated into different salinity regimes by rail and vehicular causeways. cyanobacterial distributions map salinity, with aphanothece halophytica proliferating in the highly saline northern arm (27% saline), while nodularia spumigena occurs in the less saline south (6-10%). we sought to test if cyanobacterial species abundant in the north are competitively excluded from the south, and if southern species are excluded by the high salinity of the north. autoclaved samples f ... | 2009 | 19129967 |
| survival and reproduction of some blue-green and green algae as affected by sewage water, fertilizer factory effluent, brassica oil, phenol, toluene and benzene. | fourteen blue-green and green algae survived for widely different time periods ranging between 22-102 d in control culture medium. irrespective of their long or short survival period in control cultures, their pro- or eukaryotic nature, their different morphological types or natural habitats, they all survived for a short time period ranging between 3-8 d in sewage water, 5-10 d in fertilizer factory effluent, (1/4)-2 d in brassica oil, (1/2)-2 d in phenol, 1-3 d in toluene, and 1-4 d in benzene ... | 2009 | 19330547 |
| a hypersaline microbial mat from the pacific atoll kiritimati: insights into composition and carbon fixation using biomarker analyses and a 13c-labeling approach. | modern microbial mats are widely recognized as useful analogs for the study of biogeochemical processes relevant to paleoenvironmental reconstruction in the precambrian. we combined microscopic observations and investigations of biomarker composition to investigate community structure and function in the upper layers of a thick phototrophic microbial mat system from a hypersaline lake on kiritimati (christmas island) in the northern line islands, republic of kiribati. in particular, an explorato ... | 2009 | 19476506 |
| an mrp-like cluster in the halotolerant cyanobacterium aphanothece halophytica functions as a na+/h+ antiporter. | the mrp homolog gene cluster mrpcd1d2efgab (ap-mrp) was found in a halotolerant cyanobacterium, aphanothece halophytica, amplified, and expressed in escherichia coli mutant to114. ap-mrp complemented the salt-sensitive phenotype of to114 and exhibited na(+)/h(+) and li(+)/h(+) exchange activities, indicating that ap-mrp functions as a na(+)/h(+) antiporter. | 2009 | 19700555 |
| cyanobacterial megamolecule sacran efficiently forms lc gels with very heavy metal ions. | we extracted the megamolecular polysaccharide sacran, which contains carboxylate and sulfate groups, from the jellylike extracellular matrix (ecm) of the cyanobacterium aphanothece sacrum, which has mineral adsorption bioactivity. we investigated the gelation properties of sacran binding with various heavy metal ions. the sacran chain adsorbed heavier metal ions such as indium, rare earth metals, and lead ions more efficiently to form gel beads. in addition, trivalent metal ions adsorbed onto th ... | 2009 | 20050044 |
| screening a novel na+/h+ antiporter gene from a metagenomic library of halophiles colonizing in the dagong ancient brine well in china. | metagenomic dna libraries constructed from the dagong ancient brine well were screened for genes with na(+)/h(+) antiporter activity on the antiporter-deficient escherichia coli knabc strain. one clone with a stable na(+)-resistant phenotype was obtained and its na(+)/h(+) antiporter gene was sequenced and designated as m-nha. the deduced amino acid sequence of m-nha protein consists of 523 residues with a calculated molecular weight of 58 147 da and a pi of 5.50, which is homologous with nhah f ... | 2010 | 20337714 |
| heterologous expression of apgsmt2 and apdmt2 genes from aphanothece halophytica enhanced drought tolerance in transgenic tobacco. | the glycine-methylation biosynthetic pathway of glycinebetaine (gb) has been investigated, but only a few studies on gb accumulation in transgenic higher plants have utilized this pathway. in this study, two methyltransferase genes named apgsmt2 and apdmt2, encoding proteins catalyzing gb biosynthesis from glycine, were cloned from a relative strain of aphanothece halophytica. the potential roles of apgsmt2 and apdmt2 in gb synthesis were first examined in transgenic escherichia coli, which had ... | 2011 | 20364325 |
| nutritional evaluation of single-cell protein produced by aphanothece microscopica nägeli. | the aim of this research was to evaluate the nutritional characteristics of aphanothece microscopica nägeli microalgae developed in the effluent of parboiled rice. the biomass was biologically evaluated by rat growth, during 10 days for nitrogen balance studies and 28 days for blood analysis. the feeding of aphanothece biomass diets resulted in a nitrogen balance of 1.42 g/rat/day, an apparent biological value of 73.33%, an apparent digestibility of 82.12%, an apparent net protein utilization of ... | 2010 | 20417094 |
| the microbe-mineral environment and gypsum neogenesis in a weathered polar evaporite. | evaporitic deposits are a globally widespread habitat for micro-organisms. the microbe-mineral environment in weathered and remobilized gypsum from exposed mid-ordovician marine evaporite beds in the polar desert of devon island, nunavut, canadian high arctic was examined. the gypsum is characterized by internal green zones of cyanobacterial colonization (dominated by gloeocapsa/aphanothece and chroococcidiopsis spp. morphotypes) and abundant black zones, visible from the surface, that contain p ... | 2010 | 20456500 |
| cyanobacterial polysaccharide gels with efficient rare-earth-metal sorption. | the cyanobacterial polysaccharide sacran, which contains carboxylate and sulfate groups, was extracted from aphanothece sacrum , and the metal sorption behavior of sacran was investigated. heterogels, where the sacran chains were trapped by polyvinyl alcohol networks, were prepared and immersed in ndcl3 solutions to shrink and cloud due to nd binding. these heterogels had the ability to sorb excessive amounts of nd ions, more than the stoichiometric ratio of 1:3 (sacran anion/nd). furthermore, t ... | 2010 | 20560613 |
| na+-stimulated atpase of alkaliphilic halotolerant cyanobacterium aphanothece halophytica translocates na+ into proteoliposomes via na+ uniport mechanism. | when cells are exposed to high salinity conditions, they develop a mechanism to extrude excess na+ from cells to maintain the cytoplasmic na+ concentration. until now, the atpase involved in na+ transport in cyanobacteria has not been characterized. here, the characterization of atpase and its role in na+ transport of alkaliphilic halotolerant aphanothece halophytica were investigated to understand the survival mechanism of a. halophytica under high salinity conditions. | 2010 | 20691102 |
| evaluation of an edible blue-green alga, aphanothece sacrum, for its inhibitory effect on replication of herpes simplex virus type 2 and influenza virus type a. | a hot-water extract of aphanothece sacrum, an edible aquacultured blue-green alga, was found to show a remarkable inhibitory effect on the replication of enveloped viruses including herpes simplex virus type 2 (hsv-2) and influenza virus type a (ifv-a, h1n1) in vitro. the main active components were suggested to be sulfated polysaccharides in non-dialyzable portion (aswph). aswph was found to inhibit the viral adsorption to the receptor of the host cells involved in the replication process of hs ... | 2010 | 20699552 |
| gelation behavior by the lanthanoid adsorption of the cyanobacterial extracellular polysaccharide. | the self-organization behavior of an extracellular polysaccharide (sacran) extracted from the cyanobacterium aphanothece sacrum in response to lanthanoid ion adsorption was investigated. consequently, cryogenic tem images revealed that sacran could be cross-linked by nd(3+) trivalent ions and formed a fibrous nanostructural network containing water. furthermore, sacran adsorbed trivalent metal ions at a 3:1 ratio, which was the theoretical ionic adsorption and showed more efficient adsorption th ... | 2010 | 20923217 |
| halotolerant cyanobacterium aphanothece halophytica contains an na+-dependent f1f0-atp synthase with a potential role in salt-stress tolerance. | aphanothece halophytica is a halotolerant alkaliphilic cyanobacterium that can grow in media of up to 3.0 m nacl and ph 11. here, we show that in addition to a typical h(+)-atp synthase, aphanothece halophytica contains a putative f(1)f(0)-type na(+)-atp synthase (apna(+)-atpase) operon (apna(+)-atp). the operon consists of nine genes organized in the order of putative subunits ß, e, i, hypothetical protein, a, c, b, a, and ?. homologous operons could also be found in some cyanobacteria such as ... | 2011 | 21262962 |
| an alkaline phosphatase/phosphodiesterase, phod, induced by salt stress and secreted out of the cells of aphanothece halophytica, a halotolerant cyanobacterium. | alkaline phosphatases (apases) are important enzymes in organophosphate utilization. three prokaryotic apase gene families, phoa, phox, and phod, are known; however, their functional characterization in cyanobacteria largely remains to be clarified. in this study, we cloned the phod gene from a halotolerant cyanobacterium, aphanothece halophytica (phod(ap)). the deduced protein, phod(ap), contains tat consensus motifs and a peptidase cleavage site at the n terminus. the phod(ap) enzyme was activ ... | 2011 | 21666012 |
| mapping of protein-protein interaction sites in the plant-type [2fe-2s] ferredoxin. | knowing the manner of protein-protein interactions is vital for understanding biological events. the plant-type [2fe-2s] ferredoxin (fd), a well-known small iron-sulfur protein with low redox potential, partitions electrons to a variety of fd-dependent enzymes via specific protein-protein interactions. here we have refined the crystal structure of a recombinant plant-type fd i from the blue green alga aphanothece sacrum (asfd-i) at 1.46 å resolution on the basis of the synchrotron radiation data ... | 2011 | 21760931 |