Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| siderophore production in two species of nostoc as influenced by the toxicity of nitrophenolics. | 1997 | 9211704 | |
| discovery of cyanovirin-n, a novel human immunodeficiency virus-inactivating protein that binds viral surface envelope glycoprotein gp120: potential applications to microbicide development. | we have isolated and sequenced a novel 11-kda virucidal protein, named cyanovirin-n (cv-n), from cultures of the cyanobacterium (blue-green alga) nostoc ellipsosporum. we also have produced cv-n recombinantly by expression of a corresponding dna sequence in escherichia coli. low nanomolar concentrations of either natural or recombinant cv-n irreversibly inactivate diverse laboratory strains and primary isolates of human immunodeficiency virus (hiv) type 1 as well as strains of hiv type 2 and sim ... | 1997 | 9210678 |
| dechlorination of lindane by the cyanobacterium anabaena sp. strain pcc7120 depends on the function of the nir operon. | nitrate is essential for lindane dechlorination by the cyanobacteria anabaena sp. strain pcc7120 and nostoc ellipsosporum, as it is for dechlorination of other organic compounds by heterotrophic microorganisms. based on analyses of mutants and effects of environmental factors, we conclude that lindane dechlorination by anabaena sp. requires a functional nir operon that encodes the enzymes for nitrate utilization. | 1997 | 9150239 |
| three new cryptophycins from nostoc sp. gsv 224. | cryptophycin 46 (2), -175 (3), and -176(4) have been identified as three new trace constituents of nostoc sp. gsv 224. cryptophycin-46 is an epimer of cryptophycin-3 (5) and to date is the only naturally occurring analogue having the s configuration at c-10 (c-2 in unit b). cryptophycins-175 and -176 also differ in unit b where 3 is the o-methyl analogue of cryptophycin-45 (6) and 4 is the o-desmethyl analogue of cryptophycin-21 (8). the relative and absolute stereochemistries of the three new a ... | 1997 | 9090872 |
| protein tyrosine phosphorylation in the cyanobacterium anabaena sp. strain pcc 7120. | components of a protein tyrosine phosphorylation/dephosphorylation network were identified in the cyanobacterium anabaena sp. strain pcc 7120. three phosphotyrosine (p-tyr) proteins of 27, 36, and 52 kda were identified through their conspicuous immunoreactions with rc20h monoclonal antibodies specific for p-tyr. these immunoreactions were outcompeted completely by free p-tyr (5 mm) but not by phosphoserine or phosphothreonine. the p-tyr content of the three major p-tyr proteins and several mino ... | 1997 | 9079918 |
| a polyketide-synthase-like gene is involved in the synthesis of heterocyst glycolipids in nostoc punctiforme strain atcc 29133. | a tn5-1063-derived mutant of nostoc punctiforme strain atcc 29133 was unable to fix n2 in air although it reduced acetylene in the absence of o2. mutant strain ucd 307 formed cells morphologically similar to heterocysts, but it failed to synthesize the characteristic heterocyst glycolipids. sequence analysis around the site of insertion revealed an orf of 3,159 base pairs, termed hgle. hgle putatively encodes a 115.4-kda protein containing two domains with conserved amino acid sequences identifi ... | 1997 | 9075624 |
| uv-b-induced synthesis of photoprotective pigments and extracellular polysaccharides in the terrestrial cyanobacterium nostoc commune. | liquid cultures of the terrestrial cyanobacterium nostoc commune derived from field material were treated with artificial uv-b and uv-a irradiation. we studied the induction of various pigments which are though to provide protection against damaging uv-b irradiation. first, uv-b irradiation induced an increase in carotenoids, especially echinenone and myxoxanthophyll, but did not influence production of chlorophyll a. second, an increase of an extracellular, water-soluble uv-a/b-absorbing mycosp ... | 1997 | 9068639 |
| effect of cadmium on the bioelement composition of nostoc uam208: interaction with calcium. | 1997 | 9060371 | |
| a hormogonium regulating locus, hrmua, of the cyanobacterium nostoc punctiforme strain atcc 29133 and its response to an extract of a symbiotic plant partner anthoceros punctatus. | transposon-generated mutant strain ucd 328 of nostoc punctiforme strain atcc 29133 has a phenotype of an increased sensitivity to a hormogonium-inducing factor exuded by a symbiotic plant partner, anthoceros punctatus, and an initial increased hormogonium-dependent infection of the plant. sequence analysis showed that the transposition site in strain ucd 328 lies within a 1,251-bp open reading frame (orf), designated hrma, that displays no significant similarity to known database sequences. a se ... | 1997 | 9057333 |
| purification and spectroscopic characterization of a recombinant chloroplastic hemoglobin from the green unicellular alga chlamydomonas eugametos. | hemoglobins (hb), which have the important task of delivering molecular oxygen by facilitating its reversible binding to the heme, are now thought to have evolved in all groups of organisms including prokaryotes, fungi, plants and animals. our recent finding of a light-inducible chloroplastic hb in the green unicellular alga chlamydomonas eugametos has further extend this idea, while raising questions about the function that an hb could play in a high oxygen environment such as in the chloroplas ... | 1996 | 9022709 |
| 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 |
| heterocyst formation. | heterocysts are microaerobic, n2-fixing cells that form in a patterned array within o2-producing filamentous cyanobacteria. structural features of heterocysts can be predicted from consideration of their physiology. this review focuses on the spacing mechanism that determines which cells will differentiate, and on the regulation of the progression of the differentiation process. applicable genetic tools, developed primarily using anabaena pcc 7120, but employed also with nostoc spp., are reviewe ... | 1996 | 8982449 |
| effective concentrations of nitrophenolics toward growth yield of selected microalgae and cyanobacteria isolated from soil. | the effective concentrations (ec), which cause a certain percentage of inhibition in growth yield, of four nitrophenolics (o-nitrophenol, m-nitrophenol, p-nitrophenol (pnp), and 2,4-dinitrophenol) and the major metabolites of pnp reduction (p-nitrosophenol and p-aminophenol) toward growth of two microalgae (chlorella vulgaris and scenedesmus bijugatus) and two cyanobacteria (nostoc muscorum and nostoc linckia), all isolated from soil, were determined following linear regression analysis. the ec5 ... | 1995 | 8964245 |
| reconstitution of the 2fe-2s center and g = 1.89 electron paramagnetic resonance signal into overproduced nostoc sp. pcc 7906 rieske protein. | the rieske 2fe-2s protein is a distinguishing subunit of the photosynthetic electron transport cytochrome b6f complex in chloroplast and cyanobacterial thylakoid membranes. we have constructed plasmids for overproduction in escherichia coli of fusion, full-length, and truncated forms of the rieske (petc) protein from the cyanobacterium nostoc sp. pcc 7906. a glutathione s-transferase/rieske fusion protein was used to prepare specific chicken egg-yolk antibodies against the rieske protein. expres ... | 1996 | 8952502 |
| transcriptional regulation of zwf, encoding glucose-6-phosphate dehydrogenase, from the cyanobacterium nostoc punctiforme strain atcc 29133. | the gene encoding glucose-6-phosphate dehydrogenase (g6pd), zwf, in nostoc punctiforme strain atcc 29133 is part of a four-gene operon that also encodes fructose bisphosphatase (fbp), transaldolase (tal) and a gene product termed opca, which is contranscribed with zwf and essential for g6pd activity. the effect of exogenous nitrogen and carbon sources on transcription of these genes was investigated. growth in the presence of ammonium yielded low levels of transcripts encoding all genes of the o ... | 1996 | 8939431 |
| glbn (cyanoglobin) is a peripheral membrane protein that is restricted to certain nostoc spp. | the glbn gene of nostoc commune utex 584 is juxtaposed to nifu and nifh, and it encodes a 12-kda monomeric hemoglobin that binds oxygen with high affinity. in n. commune utex 584, maximum accumulation of glbn occurred in both the heterocysts and vegetative cells of nitrogen-fixing cultures when the rate of oxygen evolution was repressed to less than 25 micromol of o2 mg of chlorophyll a(-1) h(-1). accumulation of glbn coincided with maximum synthesis of nifh and ferredoxin nadp+ oxidoreductase ( ... | 1996 | 8932316 |
| regulation of photosynthetic enzymes in light- or dark-grown cyanobacterium nostoc sp. mac. | 1996 | 8878946 | |
| promiscuity of heme groups in the cyanobacterial cytochrome-c oxidase. | the cyanobacteria nostoc sp. strain mac, anabaena 7937, synechocystis 6803, and anacystis nidulans (synechococcus 6301) were grown and incubated in the light under three different oxygen regimes: phase-a cells were harvested from photoautotrophically growing cultures at a cell density of 2.8-3.2 microliter packed cell mass/ml and an oxygen concentration of approx. 350 microm (corresponding to > 150% air saturation). phase-b cells were harvested 24 hrs after 20 microm 3-(3,4-dichlorophyl)-1,1-dim ... | 1995 | 8747548 |
| cyclic peptides and depsipeptides from cyanobacteria: a review. | an elaborate array of structurally-novel and biologically-active cyclic peptides and depsipeptides are found in blue-green algae (cyanobacteria). several of these compounds possess structures that are similar to those of natural products from marine invertebrates. most of these cyclic peptides and depsipeptides, such as the microcystins and the lyngbyatoxins, will probably only be useful as biochemical research tools. a few, however, have the potential for development into useful commercial prod ... | 1996 | 8730577 |
| impact of aluminium, fluoride and fluoroaluminate complex on atpase activity of nostoc linckia and chlorella vulgaris. | this study demonstrates a ph-dependent inhibition of mg(2+)- and ca(2+)-atpase activities of nostoc linckia and chlorella vulgaris exposed to alcl3, alf3, naf and alcl3+naf together. alf3 and the combination of alcl3+naf were more inhibitory to both the enzymes as compared with alcl3 and naf. toxicity of the test compounds increased with increasing acidity. interaction of alcl3+naf was additive on n. linckia and c. vulgaris, respectively, at ph 7.5 and 6.8, and synergistic at ph 6.0 and 4.5. in ... | 1996 | 8696079 |
| ca2+ uptake and its regulation in the cyanobacterium nostoc mac | the uptake of ca2+ and its regulation in the cyanobacterium nostoc mac were investigated. cation uptake pattern was found to be biphasic, consisting of (a) rapid binding of cations to the negatively charged cell surface and (b) its metabolism dependent on intracellular import at least up to 60 min with the saturation at 2 mm ca2+ (km, 1.5 mm, vmax 42.1 nmol ca2+ mg-1 protein min-1 ). the cellular ca2+ uptake was light and atp dependent, and the addition of 3(3,4-dichlorophenyl)-1,1-dimethyl urea ... | 1996 | 8661678 |
| geosiphon pyriforme, a fungus forming endocytobiosis with nostoc (cyanobacteria), is an ancestral member of the glomales: evidence by ssu rrna analysis. | geosiphon pyriforme inhabiting the surface of humid soils represents the only known example of endocytobiosis between a fungus (zygomycotina; macrosymbiont) and cyanobacteria (nostoc; endosymbiont). in order to elucidate the taxonomical and evolutionary relationship of geosiphon pyriforme to fungi forming arbuscular mycorrhiza (am fungi), the small-subunit (ssu) ribosomal rna genes of geosiphon pyriforme and glomus versiforme (glomales; a typical am fungus) were analyzed and aligned with ssu rrn ... | 1996 | 8660431 |
| transaldolase genes from the cyanobacteria anabaena variabilis and synechocystis sp. pcc 6803: comparison with other eubacterial and eukaryotic homologues. | we have sequenced and analysed the transaldolase (tal) genes from two cyanobacteria, anabaena variabilis (atcc 29413) and synechocystis sp. pcc 6803, which are filamentous heterocyst-forming and unicellular organisms, respectively. the deduced amino acid sequences of the two cyanobacterial tal genes are 78% identical and are highly homologous to both eubacterial and eukaryotic transaldolases (escherichia coli, two yeasts, and man) with values ranging from 54 to 60% amino acid identity. in contra ... | 1996 | 8616240 |
| the devr gene product is characteristic of receivers of two-component regulatory systems and is essential for heterocyst development in the filamentous cyanobacterium nostoc sp. strain atcc 29133. | strain ucd 311 is a transposon-induced mutant of nostoc sp. strain atc c 29133 that is unable to fix nitrogen in air but does so under anoxic conditions and is able to establish a functional symbiotic association with the hornwort anthoceros punctatus. these properties of strain ucd 311 are consistent with previous observations that protection against oxygen inactivation of nitrogenase is physiologically provided within a. punctatus tissue. upon deprivation of combined nitrogen, strain ucd 311 c ... | 1996 | 8606181 |
| disintegration of phycobilisomes in a rice field cyanobacterium nostoc sp. following uv irradiation. | the effects of ultraviolet-b (uv-b, 280-315 nm) irradiation on survival, growth and phycobilisome assembly have been studied in the n2-fixing cyanobacterium nostoc sp. survival and growth were virtually arrested after 120 min of uv irradiation. the phycobiliprotein fractions showed a decrease in absorption and fluorescence as well as a shift towards shorter wavelengths indicating the impairment of energy transfer from phycobiliproteins to the photosynthetic reaction centers. this was further sup ... | 1995 | 8589643 |
| factors regulating methyl mercury uptake in a cyanobacterium. | the simultaneous addition of dithiothreitol (dtt), mercaptoethanol, and glutathione (30 microm each) and ch3hg+ to nostoc calcicola cells reduced ch3hg+ uptake in the order gsh > dtt > mercaptoethanol. however, the preexposure of cyanobacterial cells to similar thiols resulted in different pattern of ch3hg+ uptake in the sequence: gsh > mercaptoethanol > dtt. light-grown cyanobacterial cells demonstrated a faster initial uptake of ch3hg+ (rate 0.619 mumol ch3hg+ mg-1 protein min-1, 10 min) with ... | 1995 | 8565882 |
| spectroscopical and functional characterization of the hemoglobin of nostoc commune (utex 584 (cyanobacterial). | structural analysis of a monomeric hemoglobin from the cyanobacterium nostoc commune strain utex 584, cyanoglobin (potts et al. (1992) science 256, 1690-1692), is presented. cyanoglobin binds molecular oxygen reversibly, with high oxygen affinity and non-cooperativity. there was no evidence for decreased stability of the pigment at 37 degrees c. cyanoglobin-specific antibodies showed no cross-reactivity with two reference hemoglobins, leghemoglobin a and sperm whale myoglobin. the absorption spe ... | 1996 | 8547335 |
| interaction of cryptophycin 1 with tubulin and microtubules. | the cryptophycins are newly discovered antimitotic agents isolated from the cyanobacterium nostoc. previous studies using cultured cells demonstrated that microtubules are the target of these compounds. we have studied the interaction of cryptophycin 1 with tubulin and microtubules in vitro. cryptophycin 1 is an effective inhibitor of tubulin polymerization, causes tubulin to aggregate, and depolymerizes microtubules to linear polymers somewhat similar to the spiral-like structures produced by t ... | 1995 | 8543019 |
| rehydration induces rapid onset of lipid biosynthesis in desiccated nostoc commune (cyanobacteria). | water, which contained [1,3-3h]glycerol, [35s]sodium sulfate, or [32p]sodium orthophosphate, was used to rehydrate air-dried cells of the desiccation-tolerant filamentous cyanobacterium nostoc commune. the cells retained their capacities for the uptake and transport of all three compounds and, in response to rewetting, they mobilized the radiolabels into lipid precursors and initiated complex lipid biosynthesis. the onset of these events, measured in short-term, long-term and pulse-chase labelin ... | 1993 | 8504158 |
| multisensory activation of the phosphorelay initiating sporulation in bacillus subtilis: identification and sequence of the protein kinase of the alternate pathway. | the phosphorelay is the signal-transduction system recognizing and integrating environmental signals to initiate sporulation. the major signal input to the phosphorelay is an atp-dependent kinase, kina, responsible for phosphorylating the spoof protein. mutants lacking kina, however, still sporulate, suggesting that other kinases can fulfil its role. in order to identify these kinases, genes for kinases were isolated by hybridization using a degenerate oligonucleotide probe designed for common r ... | 1993 | 8497199 |
| recovery of nostoc muscorum previously exposed to some triazine and phenylurea herbicides. | 1993 | 8490271 | |
| the rubisco activase (rca) gene is located downstream from rbcs in anabaena sp. strain ca and is detected in other anabaena/nostoc strains. | a gene encoding ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activase (rca) was found downstream from the rbclrbcs operon in the heterocystous cyanobacterium anabaena sp. strain ca. two unknown open reading frames were shown to be located between rbcs and rca in strain ca and all the genes, rbclrbcs, orf1, orf2, and rca were in the same transcriptional orientation. the deduced amino acid sequence of the anabaena rubisco activase showed both similarities and differences to the plant ... | 1993 | 8467074 |
| the patb gene product, required for growth of the cyanobacterium anabaena sp. strain pcc 7120 under nitrogen-limiting conditions, contains ferredoxin and helix-turn-helix domains. | a mutant of anabaena sp. strain pcc 7120, called pat-2, that grows poorly under nitrogen-fixing conditions, has been isolated. the heterocysts of the mutant strain develop much more slowly than those of the wild type and are spaced more closely in an older culture of the mutant than in the wild type. the wild-type gene that complements the mutation in pat-2, called patb, was isolated and characterized. the predicted 529-amino-acid patb protein contains a region very similar to the fe4s4 bacteria ... | 1993 | 8449877 |
| copper toxicity and phosphate utilization in the cyanobacterium nostoc calcicola. | 1993 | 8422521 | |
| characterization of genes for an alternative nitrogenase in the cyanobacterium anabaena variabilis. | anabaena variabilis atcc 29413 is a heterotrophic, nitrogen-fixing cyanobacterium that has been reported to fix nitrogen and reduce acetylene to ethane in the absence of molybdenum. dna from this strain hybridized well at low stringency to the nitrogenase 2 (vnfdgk) genes of azotobacter vinelandii. the hybridizing region was cloned from a lambda embl3 genomic library of a. variabilis, mapped, and sequenced. the deduced amino acid sequences of the vnfd and vnfk genes of a. variabilis showed only ... | 1993 | 8407800 |
| characterization of a cta/cde operon-like genomic region encoding subunits i-iii of the cytochrome c oxidase of the cyanobacterium synechocystis pcc 6803. | strong heterologous hybridization of a synthetic oligonucleotide probe of 17 bp originally used to clone subunit i of the paracoccus denitrificans cytochrome c oxidase (m. raitio, t. jalli and m. saraste (1987) embo j. 6, 2825-2833) to a single band was observed on southern blots of anacystis nidulans r2 (synechococcus pcc 7942), synechocystis pcc 6803, and nostoc mac pcc 8002 chromosomal dna digests. six pooled gene banks prepared from synechocystis pcc 6803 contained regions that hybridized to ... | 1993 | 8387368 |
| cloning and expression of the nspv restriction-modification genes of nostoc sp. strain pcc7524. | 1993 | 8367311 | |
| 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 |
| plasmids from two morphologically distinct cyanobacterial strains share a novel replication origin. | a 2.9-kbp replication origin from a plasmid endogenous to the filamentous cyanobacterium fremyella diplosiphon utex 481 was genetically characterized and sequenced. deletion analysis of the 2.9-kbp dna fragment delimited the minimum region necessary for replication in f. diplosiphon fd33 to approximately 2.5 kbp. dna sequence analysis revealed that the f. diplosiphon plasmid replication origin is structurally very similar to and shares significant identity with the 1.75-kbp replication origin re ... | 1993 | 8366056 |
| mutational replacement of molybdenum by vanadium in assimilation of n2 or no3- as nitrogen source in the cyanobacterium nostoc muscorum. | tungsten resistant (wr) mutants of het+nif+nia+, het+nif-nia+ and het+nif+nia- strains of nostoc muscorum were isolated with severely defective molybdate transport activity. all such mutants showed vanadium (v)-dependent nitrogenase activity and/or nitrate reductase activity and v-dependent growth on n2-nitrogen and/or no3(-)-nitrogen and v-dependent no3(-)-repression of heterocyst formation and nitrogenase activity. none of them grew with molybdenum (mo) under parallel growth condition. results ... | 1993 | 8330016 |
| a small plasmid, pca2.4, from the cyanobacterium synechocystis sp. strain pcc 6803 encodes a rep protein and replicates by a rolling circle mechanism. | different cryptic plasmids are widely distributed in many strains of cyanobacteria. a small cryptic plasmid, pca2.4, from synechocystis strain pcc 6803 was completely sequenced, and its replication mode was determined. pca2.4 contained 2,378 bp and encoded a replication (rep) protein, designated repa. an analysis of the deduced amino acid sequence revealed that repa of pca2.4 has significant homology with rep proteins of pkym from shigella sonnei, a pub110 plasmid family from gram-positive bacte ... | 1993 | 8320214 |
| an osmotic stress protein of cyanobacteria is immunologically related to plant dehydrins. | dehydrins are a family of desiccation proteins that were identified originally in plants (t.j. close, a.a. kortt, p.m. chandler [1989] plant mol biol 13: 95-108; g. galau, t.j. close [1992] plant physiol 98: 1523-1525). dehydrins are characterized by the consensus amino acid sequence domain ekkgimdkikeklpg found at or near the carboxy terminus; the core of this domain (kikeklpg) may be repeated from one to many times within the complete polypeptide. dehydrins generally accumulate in plants in re ... | 1993 | 8310057 |
| structure, composition, and assembly of paracrystalline phycobiliproteins in synechocystis sp. strain bo 8402 and of phycobilisomes in the derivative strain bo 9201. | the phycobiliproteins of the unicellular cyanobacterium synechocystis sp. strain bo 8402 and its derivative strain bo 9201 are compared. the biliproteins of strain bo 8402 are organized in paracrystalline inclusion bodies showing an intense autofluorescence in vivo. these protein-pigment aggregates have been isolated. the highly purified complexes contain phycocyanin with traces of phycoerythrin, corresponding linker polypeptides lr35pc and lr33pe (the latter in a small amount), and a unique col ... | 1994 | 8300542 |
| characterization of a restriction barrier and electrotransformation of the cyanobacterium nostoc pcc 7121. | we have investigated host restriction as a barrier to transformation and developed a method for gene transfer into the previously untransformable, heterotrophic cyanobacterium nostoc pcc 7121. a restriction endonuclease, designated nsp 7121i, has been partially purified by phosphocellulose chromatography of nostoc cell extracts. comparisons of nsp 7121i digests of bacteriophage lambda and plasmid dnas with computer-generated restriction fragment profiles showed that nsp 7121i is an isoschizomer ... | 1993 | 8215799 |
| common nitrogen control of caesium uptake, caesium toxicity and ammonium (methylammonium) uptake in the cyanobacterium nostoc muscorum. | studies were carried out to examine the role of ammonium transport activity in the control of caesium uptake and toxicity in nostoc muscorum. the results showed a definite specific role of the ammonium-repressible/derepressible ammonium transport system of the cyanobacterium in caesium uptake, accumulation and toxicity. furthermore, the results showed that n. muscorum can acquire resistance against diazotrophically-associated caesium toxicity when supplied with ammonium as a nitrogen source. in ... | 1994 | 8200501 |
| nuclear genes encoding chloroplast hemoglobins in the unicellular green alga chlamydomonas eugametos. | when the green unicellular alga chlamydomonas eugametos is grown under light/dark regimes, nuclear genes are periodically activated in response to the changes in light conditions. these genetic responses are dependent upon the activation of genes associated with photosynthesis (li616 and li637), nonphotosynthetic photoreceptors (li410 and li818) and the biological clock (li818). we report here that the li410 and li637 genes are part of a small gene family encoding hemoglobins (hbs) related to th ... | 1994 | 8177215 |
| detection and characterization of cyanobacterial nifh genes. | the dna sequence of a 359-bp fragment of nifh was determined for the heterocystous strains anabaena sp. strain ca (atcc 33047), nostoc muscorum utex 1933, a nostoc sp., gloeothece sp. strain atcc 27152, lyngbya lagerheimii utex 1930, and plectonema boryanum iu 594. results confirmed that the dna sequence of the 359-bp segment is sufficiently variable to distinguish cyanobacterial nifh genes from other eubacterial and arachaeobacterial nifh genes, as well as to distinguish heterocystous from nonh ... | 1994 | 8161180 |
| hypocholesterolemic effect of blue-green alga, ishikurage (nostoc commune) in rats fed atherogenic diet. | blue-green alga, nostoc commune is rich in dietary fiber. to examine the hypocholesterolemic effect, the alga or the dietary fibers were given to the rats fed cholesterol diet. serum cholesterol elevation was significantly depressed in those rats. cholesterol increased in the liver of rats given the alga and the fiber. the content of fecal cholesterol and bile acid unchanged. of the dietary fibers, oxalate-oxalic acid soluble substance (ooss) found abundant in the alga was most effective in lowe ... | 1994 | 8146104 |
| water stress proteins of nostoc commune (cyanobacteria) are secreted with uv-a/b-absorbing pigments and associate with 1,4-beta-d-xylanxylanohydrolase activity. | acidic water stress polypeptides (wsp) with molecular masses of 33, 37 and 39 kda are the most abundant soluble proteins in the cyanobacterium nostoc commune. wsp polypeptides and uv-a/b-absorbing pigments are secreted by cells, accumulate in the extracellular glycan sheath, and are released from desiccated colonies upon rehydration. no evidence was obtained for either glycosylation, phosphorylation, or acylation of wsp polypeptides. nh2-terminal amino acid sequences of the 33-, 37-, and 39-kda ... | 1994 | 8125999 |
| the gene encoding cytochrome-c oxidase subunit i from synechocystis pcc6803. | the gene (coxi or coxa) encoding subunit i (coi) of cytochrome-c oxidase (cytochrome aa3) of synechocystis pcc6803, synechococcus pcc7942 (anacystis nidulans r2) and nostoc pcc8002 (nostoc mac), was identified by heterologous hybridization of chromosomal digests with a 17-bp oligodeoxyribonucleotide (probe c) derived from the coxi of paracoccus denitrificans. a single genomic fragment was found to bind to probe c in all chromosomal digests. due to its favorable signal-to-noise ratio, the genome ... | 1994 | 8125290 |
| energetics of cyanophage n-1 multiplication in the diazotrophic cyanobacterium nostoc muscorum. | cyanophage n-1 multiplication was investigated during the latent period of the virus, when 14co2 fixation was inhibited whereas respiratory o2 uptake increased approximately 67% at 4 h after infection. a simultaneous decrease (70%) in the glycogen content of infected cells indicated its catabolic involvement. a chloramphenicol-sensitive rise in glucose-6-phosphate dehydrogenase activity as a result of n-1 infection partly explained the increase in aerobic respiration. the total atp pool declined ... | 1994 | 8078415 |
| isolation and characterization of temperature-sensitive mutants of cyanophage n-1. | optimal conditions for the induction of temperature-sensitive (ts) mutants of cyanophage n-1 were established after mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine (mnng). a treatment with mnng (400 micrograms/ml) for 2 hrs at ph 8.0 induced ts-mutants at a maximum frequency of 1.46 x 10(-3). a characterization of 10 such ts-mutants with regard to adsorption, one-step growth and temperature-shift experiments with nostoc muscorum as host bacterium led to the identification of temperature-se ... | 1994 | 8067307 |
| analysis of the sequences within and flanking the cyanoglobin-encoding gene, glbn, of the cyanobacterium nostoc commune utex 584. | a 3.5-kb segment of dna containing nifu glbn nifh nifd was cloned from a gene library of nostoc 584 and sequenced. the nifu-glbn intergenic region contains short tandemly repeated repetitive sequences (5'-aattacg). a sequence corresponding to a nifa-like upstream activator sequence (with the consensus recognition sequence for bifa in anabaena 7120), elements of a nifh promoter and a sequence that may function as a transcription terminator, were identified downstream from glbn. glbn, unique to ce ... | 1994 | 8063099 |
| athermal physiological effects of microwaves on a cynobacterium nostoc muscorum: evidence for em-memory bits in water. | athermal physiological effects of continuous wave and modulated microwaves were studied on a cynobacterium nostoc muscorum. the study shows that different microwave frequencies in continuous wave and modulated modes produced significantly different physiological effects on the algae. water-mediated bioeffects further present additional proof that water has the capability to remember the imposed electromagnetic field characteristics for an extended period of time. | 1994 | 8022214 |
| mutational analysis of the nh4+-nitrogen controls that regulate ammonium transport activity, heterocyst differentiation, nitrogenase activity and the heterocyst-spacing pattern in the cyanobacterium nostoc muscorum. | mutational analysis of the genetic determinants mediating nh(4+)-nitrogen regulating effects on nh(4+)-transport activity, heterocyst differentiation, nitrogenase activity and heterocyst pattern formation was carried out in nostoc muscorum. evidence suggested the operation of three separate genetic determinants in such nitrogen control; one mediating nh(4+)-repression control on both heterocyst formation and nh(4+)-transport activity, a second (nif-r) mediating nh(4+)-repression control on nitro ... | 1994 | 8019441 |
| two mutations that block heterocyst differentiation have different effects on akinete differentiation in nostoc ellipsosporum. | evident differentiation of vegetative cells into heterocysts in anabaena sp. strain pcc 7120 is prevented by insertions in genes hetr and hetp. nostoc ellipsosporum possesses single copies of genes that hybridize with hetr and hetp. in mutant ne2 of n. ellipsosporum, in which hetr is interrupted by an insert, and in a double recombinant of wild-type n. ellipsosporum with a plasmid that bears an interrupted copy of hetr, neither heterocysts nor akinetes are formed. when an intact copy of hetr fro ... | 1994 | 7934891 |
| cloning and nucleotide sequence of the gene encoding dinitrogenase reductase (nifh) from the cyanobacterium nostoc 6720. | the nucleotide sequence of the 3' end of the nifu coding sequence, the complete coding sequence of nifh and a substantial part of the 5' end of nifd coding sequence from nostoc 6720 is presented. the coding sequences are highly conserved with those of anabaena 7120 and anabaena sp. l31. however the intergenic region between nifu and nifh contains two segments of short tandemly repetitive repeat sequences (strrs) that differ from the strr that is common to both anabaena7120 and anabaenasp. l31. v ... | 1994 | 7918657 |
| cryptophycin: a new antimicrotubule agent active against drug-resistant cells. | cryptophycin is a cytotoxic dioxadiazacyclohexadecenetetrone isolated from cyanobacteria of the genus nostoc. incubation of l1210 leukemia cells with cryptophycin resulted in dose-dependent inhibition of cell proliferation in parallel with increases in the percentage of cells in mitosis (half-maximal effects at < 10 pm). indirect immunofluorescence studies demonstrated that treatment of a-10 vascular smooth muscle cells with cryptophycin results in marked depletion of cellular microtubules and r ... | 1994 | 7913408 |
| biochemical effects of carbaryl on nitrogen assimilating enzymes of cyanobacteria nostoc muscorum. | 1994 | 7912573 | |
| sequence of a 2.6-kb cryptic plasmid from a marine cyanobacterium synechococcus sp. | we have shown previously that the copy number of plasmid psy10 from the marine cyanobacterium synechococcus sp. nkbg 042902 is dependent on the salinity of the growth medium. we report here the complete nucleotide sequence (2561 bp) of this plasmid. the longest open reading frame, orf-b (1.08 kb), occurs on a 1.6-kb ecori fragment. this orf encodes a putative protein which is 360 aa residues in length and is 37.8% homologous to the replication protein of plasmid pca2.4 from synechocystis sp. str ... | 1994 | 7899510 |
| transposon mutagenesis of nostoc sp. strain atcc 29133, a filamentous cyanobacterium with multiple cellular differentiation alternatives. | nostoc sp. strain atcc 29133 (pcc 73102; nostoc 29133) is a symbiotically-competent, facultatively heterotrophic, diazotrophic cyanobacterium with the capacity to differentiate specialized cells such as heterocysts, akinetes and hormogonial filaments. we have optimized several methods for physiological and molecular genetic analysis of nostoc 29133. by use of a tn5 derivative, tn5-1063 (km(r)bm(r)sm(r)), delivered by conjugation from escherichia coli, antibiotic-resistant mutants of nostoc 29133 ... | 1994 | 7881544 |
| nucleotide sequence of an operon in nostoc sp. strain atcc 29133 encoding four genes of the oxidative pentose phosphate cycle. | 1995 | 7870816 | |
| cadmium mediated control of nitrogenase activity and other enzymes in a nitrogen fixing cyanobacterium. | cadmium decreased the specific growth rate and total cell mass at concentrations > 0.001 micrograms ml-1. it also reduced heterocyst frequency, total cell protein, nitrogenase activity (acetylene reduction) and decreased glutamine synthetase (gs) and glutamate synthase (gogat) activities. however, cells grown under low concentration of cadmium (0.001 microgram ml-1) had enhanced nitrogenase as well as gs activity besides showing increased growth rate and heterocyst frequency. cadmium has apparen ... | 1994 | 7866728 |
| desiccation tolerance of prokaryotes. | the removal of cell-bound water through air drying and the addition of water to air-dried cells are forces that have played a pivotal role in the evolution of the prokaryotes. in bacterial cells that have been subjected to air drying, the evaporation of free cytoplasmic water (vf) can be instantaneous, and an equilibrium between cell-bound water (vb) and the environmental water (vapor) potential (psi wv) may be achieved rapidly. in the air-dried state some bacteria survive only for seconds where ... | 1994 | 7854254 |
| plasmid and chromosomal dna recovery by electroextraction of cyanobacteria. | high voltage electroporation has been investigated as a method for rapid recovery of plasmid and chromosomal dna from the cyanobacteria nostoc pcc 7121, synechococcus pcc 7002, and anabaena pcc 7120. pulses of 18 kv/cm and higher applied to concentrated nostoc cells carrying a shuttle plasmid (prl25) resulted in copious release of nucleic acids and phycobiliproteins into the suspending medium. small portions of these supernatants, when electroporated with escherichia coli, gave rise to hundreds ... | 1995 | 7781980 |
| multiple metal resistance in the cyanobacterium nostoc muscorum. | 1995 | 7767039 | |
| growth and some physiological aspects of nostoc muscorum in response to mixtures of two triazine herbicides. | 1995 | 7742636 | |
| structure of a novel oligosaccharide-mycosporine-amino acid ultraviolet a/b sunscreen pigment from the terrestrial cyanobacterium nostoc commune. | water-soluble uv-a/b-absorbing pigments are secreted by cells of the cosmopolitan terrestrial cyanobacterium nostoc commune. the pigments constitute a complex mixture of monomers with molecular masses of up to 1801 da. two different chromophores with absorption maxima at 312 and 335 nm are linked to different amino acids and to oligosaccharides consisting of galactose, glucose, xylose, glucuronic acid, and glucosamine. the 335 nm chromophore is a 1,3-diaminocyclohexen derivative, while the chrom ... | 1995 | 7721752 |
| a protein-tyrosine/serine phosphatase encoded by the genome of the cyanobacterium nostoc commune utex 584. | protein-tyrosine phosphorylation has long been regarded as an exclusively eukaryotic phenomenon. although some non-eukaryotes, mainly viruses, possess genes encoding protein-tyrosine kinases or protein-tyrosine phosphatases, these were probably appropriated from the eukaryotic hosts that constitute the sites of action of these enzymes. herein we identify a gene, iphp, from the chromosome of the cyanobacterium nostoc commune utex 584 that contains the his-cys-xaa-ala-gly-xaa-xaa-arg sequence char ... | 1993 | 7681825 |
| characterization of ts-mutants of cyanophage n-1 by their inactivation by physical and chemical agents. | the effect of temperature, ultraviolet (uv) light and ethylenediaminetetraacetic acid (edta) on the stability of cyanophage n-1, infecting the cyanobacterium nostoc muscorum was studied. complete inactivation of the phage occurred at 60 degrees c in 6 mins. all the temperature-sensitive (ts) mutants exhibited faster inactivation at 50 degrees c than the wild type. uv light readily inactivated the particles of the wild giving a survival of 3.44% at a dose of 60 secs. all the ts-mutants were found ... | 1995 | 7676938 |
| genetic evidence of a major role for glucose-6-phosphate dehydrogenase in nitrogen fixation and dark growth of the cyanobacterium nostoc sp. strain atcc 29133. | heterocysts, sites of nitrogen fixation in certain filamentous cyanobacteria, are limited to a heterotrophic metabolism, rather than the photoautotrophic metabolism characteristic of cyanobacterial vegetative cells. the metabolic route of carbon catabolism in the supply of reductant to nitrogenase and for respiratory electron transport in heterocysts is unresolved. the gene (zwf) encoding glucose-6-phosphate dehydrogenase (g6pd), the initial enzyme of the oxidative pentose phosphate pathway, was ... | 1995 | 7592384 |
| characterization of toxin-producing cyanobacteria by using an oligonucleotide probe containing a tandemly repeated heptamer. | cyanobacteria produce toxins that kill animals. the two main classes of cyanobacterial toxins are cyclic peptides that cause liver damage and alkaloids that block nerve transmission. many toxin-producing strains from finnish lakes were brought into axenic culture, and their toxins were characterized. restriction fragment length polymorphism analysis, probing with a short tandemly repeated dna sequence found at many locations in the chromosome of anabaena sp. strain pcc 7120, distinguishes hepato ... | 1995 | 7592362 |
| two heterocyst-specific dna rearrangements of nif operons in anabaena cylindrica and nostoc sp. strain mac. | two site-specific dna rearrangements occur during heterocyst differentiation in the cyanobacterium anabaena sp. strain pcc 7120: the deletion of an 11 kb element from within the nifd gene and the deletion of a 55 kb element from within the fdxn gene. three nostoc and six anabaena strains were screened for the presence of the nifd and fdxn elements by southern hybridization with anabaena pcc 7120 dna probes. eight of the nine strains contained dna sequences that were similar to the nifd element. ... | 1995 | 7582007 |
| structure and evolution of paramecium hemoglobin genes. | hemoglobin (hb) genes have been cloned from three different species of ciliated protists, p. multimicronucleatum, p. triaurelia and p. jenningsi. southern blotting of the genomic dnas using the p. caudatum hb cdna showed both intraspecies variation in different stocks of p. caudatum and interspecies variation within the genus paramecium. the isolated hb genes were composed of 118, 117 and 117 codons, and interrupted by a short intron with 27, 29 and 29 bp at the same position, in p. multimicronu ... | 1995 | 7578257 |
| a gene encoding a protein related to eukaryotic protein kinases from the filamentous heterocystous cyanobacterium anabaena pcc 7120. | protein kinases play essential roles in the development of eukaryotic cells. these enzymes display various degrees of sequence similarity in their catalytic domains. this conservation has allowed the identification of protein kinases in a variety of organisms, including the gram-negative bacterium myxococcus xanthus. in this study, sequences related to those encoding eukaryotic protein kinases were amplified by pcr from dna of anabaena pcc 7120, a filamentous cyanobacterium that differentiates c ... | 1993 | 7505448 |
| allophycocyanin from nostoc sp. phycobilisomes. properties and amino acid sequence at the nh2 terminus of the alpha and beta subunits of allophycocyanins i, ii, and iii. | allophycocyanin from nostoc sp. phycobilisomes was separated into four spectrally distinct components designated allophycocyanin i, b, ii, and iii by adsorption chromatography on brushite columns. allophycocyanins i and b had red-shifted fluorescence emission maxima, and on this basis, may function in transfer of excitation energy from phycobilisomes to chlorophyll a. allophycyanins ii and iii, which together comprise 70% of the total allophycocyanin, have absorption maxima at 648 nm and 650 nm, ... | 1980 | 7410430 |
| efficiency of ferredoxins and flavodoxins as mediators in systems for hydrogen evolution. | 1. the efficiencies of ferredoxins and flavodoxins from a range of sources as mediators in systems for hydrogen evolution were assessed. 2. in supporting electron transfer from dithionite to hydrogenase of the bacterium clostridium pasteurianum, highest activity was shown by the ferredoxin from the cyanobacterium chlorogloeopsis fritschii and flavodoxin from the bacterium megasphaera elsdenii. the latter was some twenty times as active as comparable concentrations of methyl viologen. ferredoxins ... | 1980 | 7016115 |
| amino acid sequences of nostoc strain mac ferredoxins i and ii. | the amino acid sequences of ferredoxins i and ii from a blue-green alga, nostoc strain mac were determined. this alga is able to grow autotrophically in the light or heterotrophically in the dark. analyses of tryptic peptides of cm-proteins by conventional methods including solid-phase edman degradation gave the complete amino acid sequences. both molecules consisted of 98 amino acid residues and 34 amino acid differences including two deletions were found between the two. comparing these sequen ... | 1982 | 6818220 |
| isolation and preliminary characterization of mutants of the cyanobacterium nostoc muscorum resistant to growth inhibition by methylamine. | the wild-type heterocystous and nitrogen-fixing (het+nif+) n. muscorum and its non-heterocystous non-nitrogen-fixing (het-nif-) mutant strain both fail to grow in different inorganic nitrogen media containing 1 mm methylamine hydrochloride (ma). mutants of the het+nif+ and het-nif- parents resistant to growth inhibition by 5 mm ma and thus designated as mar strains were isolated with a frequency of 2.5(+/- 2.4) x 10(6). a mar strain of the het+nif+ and a mar strain of the het-nif- parent were ch ... | 1981 | 6799749 |
| atp-dependent uptake of nitrate in nostoc muscorum and inhibition by ammonium ions. | a high rate of nitrate uptake was observed in nostoc muscorum when cells were grown on elemental nitrogen as compared to that when they were grown on nitrate or ammonium. the uptake of nitrate was light dependent. however, supplementation with atp (50 microm) stimulated nitrate uptake both in light and darkness. adp, under similar conditions had no effect. 3-(3,4-dichlorophenyl)-1,1-dimethylurea (dcmu), 2-n-heptyl-4-hydroxyquinoline, (hoqno) and kcn inhibited nitrate uptake in light which could ... | 1981 | 6786358 |
| regulation of nitrate reductase levels in the cyanobacteria anacystis nidulans, anabaena sp. strain 7119, and nostoc sp. strain 6719. | the effect of the nitrogen source on the cellular activity of ferredoxin-nitrate reductase in different cyanobacteria was examined. in the unicellular species anacystis nidulans, nitrate reductase was repressed in the presence of ammonium but de novo enzyme synthesis took place in media containing either nitrate or not nitrogen source, indicating that nitrate was not required as an obligate inducer. nitrate reductase in a. nidulans was freed from ammonium repression by l-methionine-d,l-sulfoximi ... | 1981 | 6780511 |
| increase of nitrogenase activity in the blue-green alga nostoc muscorum (cyanobacterium). | preincubation of the blue-green alga (cyanobacterium) nostoc muscorum under hydrogen or argon (nongrowing conditions, neither co(2) nor n(2) or bound nitrogen present) in the light resulted in a two- to fourfold increase of light-induced hydrogen evolution and a 30% increase of acetylene reduction. preincubation under the same gases in the dark led to a decrease of both activities. cultivation of algae under a hydrogen-containing atmosphere (n(2), h(2), co(2)) increased neither hydrogen nor ethy ... | 1980 | 6777364 |
| cell size and heterocyst differentiation in nostocacean blue-green algae. | cell size variations in three heterocystous blue-green algae, viz. nostoc muscorum (isu strain), n. muscorum (uw strain) and n. calcicola (a local isolate) have been surveyed under conditions permissive and non-permissive of heterocyst differentiation. a monomodal distribution pattern was observed for the two strains of n. muscorum under conditions not requiring heterocyst differentiation, while elemental nitrogen grown cultures retained a group of relatively larger cells in addition to this mod ... | 1980 | 6775879 |
| apoflavodoxin aggregation following dissociation of flavin. | flavodoxins were isolated for the cyanobacteria anacystis nidulans and nostoc strain mac, and from the red alga chondrus crispus, and apoflavodoxins prepared by five methods. gel electrophoretic studies showed that whereas the apoproteins of a. nudulans and nostoc strain mac were recovered in monomeric form, the removal of riboflavin 5'-phosphate from c. crispus flavodoxin resulted in extensive aggregation of the apoprotein. in extent and nature this aggregation differed with the dissociating ag ... | 1980 | 6774761 |
| spectral analysis of allophycocyanin i, ii, iii and b from nostoc sp. phycobilisomes. | low temperature (-196c) and room temperature (25c) absorption spectra of a family of allophycocyanin spectral forms isolated from nostoc sp. phycobilisomes as well as of the phycobilisomes themselves have been analyzed by gaussian curve-fitting. allophycocyanin i and b share long wavelength components at 668 and 679 nm, bands that are absent from allophycocyanin ii and iii. these long wavelength absorption components are apparently responsible for the 20 nm difference between the 680 nm fluoresc ... | 1980 | 6773565 |
| components and activity of the photosynthetic electron transport system of intact heterocysts isolated from the blue-green alga nostoc muscorum. | heterocysts of the blue-green alga nostoc muscorum have been isolated by prolonged treatment with lysozyme. quantitative data are presented which show the occurrence of cytochromes c-553, f-557 and b-563 in heterocysts in amounts comparable to vegetative cells. particularly the content of the water-soluble cytochrome c-553 can be used to evaluate the intactness of a heterocyst preparation. cytochrome f-557 has been partially purified and found to be a c-type cytochrome corresponding to cytochrom ... | 1980 | 6772215 |
| regulatory effect of hydrogen on nitrogenase activity of the blue-green alga (cyanobacterium) nostoc muscorum. | preincubation of the blue-green alga (cyanobacterium) nostoc muscorum under an atmosphere of argon plus acetylene in the light led to a greater than fourfold increase of light-induced hydrogen evolution and to a 50% increase of acetylene reduction, as compared to cells that had not been preconditioned. the basic and the increased hydrogen evolution were both due to nitrogenase activity. furthermore, after preincubation the hydrogen uptake, usually observed with unconditional cells, was abolished ... | 1980 | 6767700 |
| powerful mutagenicity of a bipyridylium herbicide in a nitrogen-fixing blue-green alga nostoc muscorum. | the herbicide, paraquat (1,1'-dimethyl-4,4'-bipyridylium ion), was found to be toxic and lytic to nostoc muscorum in n2 (at the expense of elemental nitrogen, i.e. unsupplemented with any combined nitrogen source) and no-3 media, without any apparent inhibitory or stimulatory effect on its nitrogen-fixing apparatus, i.e. heterocyst formation. at a dose of paraquat resulting in 20, 50 and 75% survival, induction of reverse mutations (from het- nif- auxotrophy to het+ nif+ prototrophy), forward mu ... | 1984 | 6436694 |
| [energy migration in phycobilisomes]. | fluorescence emission and polarization spectra of the phycobilisomes (pbs) of the blue-green alga nostoc muscorum were measured at 20, -73 and -196 degrees c while exciting at the absorption maximum of each pigment in the pbs. the emission spectra were deconvoluted into a number of gaussian components and energy migration coefficients and quantum yields of fluorescence for the 8 forms of the phycobilins constituting the pbs were calculated. the overlap integrals and the critical and real distanc ... | 1984 | 6425643 |
| redox potentials of algal and cyanobacterial flavodoxins. | the redox potentials of flavodoxins from the cyanobacteria synechococcus pcc 6301 (formerly anacystis nidulans) and nostoc strain mac, and from the red alga chondrus crispus, were determined by potentiometric titration. for the oxidized-semiquinone interconversion the potentials at ph 7.0 of the three flavodoxins were between -210 and -235 mv, and these were ph-dependent over the range ph 6.9-8.2. for the semiquinone-reduced interconversion the potentials of the cyanobacterial flavodoxins were c ... | 1984 | 6424653 |
| [fractionation of phycobilisomes from the blue-green alga nostoc muscorum]. | phycobilisomes (pbs) isolated from nostoc muscorum contain eight spectral forms of phycobiliproteins. pbs partially dissociated by osmotic or temperature shock, were separated into 42s and 34s particles by centrifugation in sucrose density gradient. the 42s particles are enriched with phycocyanin, the 34s ones--with allophycocyanin. the 42s particles dissociate to free pigments by repeated osmotic or temperature shock and the 34s ones dissociate to subparticles i and ii having the constant pigme ... | 1984 | 6423967 |
| inhibition of photosystem ii of nitrogen-fixing blue-green alga nostoc linckia by the rice-field herbicide benthiocarb. | effects of rice-field herbicide benthiocarb (s(4-chlorobenzyl)-n,n-diethyl thiolcarbamate) was studied on the nitrogen-fixing blue-green alga nostoc linckia. the herbicide caused inhibition of growth and heterocyst formation, an increase in intensity of photoacoustic signals, and a four-fold reduction in oxygen evolution, but did not affect dark o2-uptake. the inhibition of growth and heterocyst formation was relieved by 500 micrograms/ml glucose. a het-nif- mutant of nostoc muscorum failed to s ... | 1983 | 6415936 |
| transfer of nitrate reductase genes of the cyanobacterium nostoc muscorum into rhizobium japonicum. | transformation of rhizobium japonicum cb1809 was studied using dna from the cyanobacterium nostoc muscorum atcc 27893. a spontaneous nitrate reductase deficient (nar-) mutant (nr-6) of r. japonicum cb1809 was isolated with a frequency of 8.4 x 10(-7). streptomycin (sm) and neomycin (neo) resistance markers were introduced into strain nr-6, and the resulting strain was designated nr-6 smr neor. experiments with cyanobacterial dna and live cells of strain nr-6 smr neor indicated transformation of ... | 1983 | 6415231 |
| isolation of polysomes from nostoc sp. mac and translation of messenger rna in a heterologous cell-free system. | a method has been established which isolated polysomes from the lysozyme/edta-shocked cyanobacterium, nostoc sp. mac. in a typical preparation the total recovery of rna as polysomes was 83%, in which 77% of the polysome fraction was present at sizes greater than 5-mers and 23% as 2-4-mers. messenger rna isolated from such a preparation of polysomes produced a 10-fold stimulation in the incorporation of [35s]methionine into polypeptides by a cell-free system of escherichia coli. the in vitro-synt ... | 1983 | 6415228 |
| metabolic activities of isolated akinetes of the cyanobacterium nostoc spongiaeforme. | intact akinetes (spores) of the cyanobacterium nostoc spongiaeforme can be isolated free of vegetative cells and heterocysts. the akinetes remain viable for at least 2 weeks in distilled water. they do not germinate in water but do so readily when transferred subsequently to cyanobacterial growth medium. isolated, nongerminating akinetes incorporated 35s from na235so4 into protein and lipid. similar incorporation was observed when akinetes were isolated from old cultures (containing primarily ak ... | 1983 | 6413494 |
| regulation of nostoc sp. phycobilisome structure by light and temperature. | nostoc sp. strain mac cyanobacteria were green in color when grown in white light at 30 degrees c and contained phycobilisomes that had phycoerythrin and phycocyanin in a molar ratio of 1:1. cells grown for 4 to 5 days in green light at 30 degrees c or white light at 39 degrees c turned brown and contained phycoerythrin and phycocyanin in a molar ratio of greater than 2:1. in addition to the change in pigment composition, phycobilisomes from brown cells were missing a 34.5-kilodalton, rod-associ ... | 1983 | 6411691 |
| the isocitrate dehydrogenase from cyanobacteria. | the present communication describes the properties of isocitrate dehydrogenase in crude extracts from the unicellular anacystis nidulans and from heterocysts and vegetative cells of nostoc muscorum and anabaena cylindrica. the activity levels of this enzyme are much higher in heterocysts than in vegetative cells of n. muscorum and a. cylindrica. isocitrate dehydrogenase is virtually inactive in vegetative cells of a. cylindrica. the enzyme is negatively regulated by the reduction charge and scar ... | 1983 | 6409049 |
| thylakoid morphology of the cyanobacteria anabaena variabilis and nostoc mac grown under light and dark conditions. | anabaena variabilis (atcc 29413) and nostoc sp. strain mac were grown photoautotrophically and chemoheterotrophically. thylakoid morphology of cells from both types of culture was investigated by freeze-etching electron microscopy. peripheral and concentric arrays of thylakoid membranes seen in autotrophic cells were replaced, in heterotrophic cells, by numerous vesicular or tubular structures; the changes were reversible. heterotrophic cells showed a reduced overall content of chlorophyll but s ... | 1983 | 6402604 |
| resistance of dna from filamentous and unicellular cyanobacteria to restriction endonuclease cleavage. | chromosomal dna from nine species of filamentous cyanobacteria as diverse as nostoc, gloeotrichia and plectonema is suggested to be extensively modified (methylated) by its resistance to cleavage by a number of restriction endonucleases. a remarkably similar pattern of dna modification in these species contrasts with the known heterogeneity of their type ii restriction endonuclease content. in particular, nostoc pcc 73102, which lacks detectable sequence-specific endonucleases, is shown to posse ... | 1984 | 6320895 |
| a restriction map of plasmid pdc1 from the filamentous cyanobacterium nostoc sp. mac pcc 8009. | a plasmid designated pdc1 from the cyanobacterium nostoc sp. mac pcc 8009 was incubated with 16 different restriction enzymes, of which 8 cleaved pdc1. plasmid pdc1 has a single site for clai, two sites for each of bgli, ecori, ecorv, and mlui, three sites for hpai, and four for hindiii. a restriction map of pdc1 for these 7 enzymes was constructed. | 1983 | 6314412 |