| effect of nadp on light-induced cytochrome changes in membrane fragments from a blue-green alga. | the effect of nadp+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragements prepared from the blue-green algae nostoc muscorum (strain 7119) that had high rates of electron transport from water to nadp+ and from an artificial electron donor, reduced dichlorophenolindophenol (dciph2) to ndap+. the membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. with dciph2 as the elec ... | 1976 | 2320 |
| influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in kaneohe bay, hawaii. | nitrogen fixation was investigated in kaneohe bay, oahu, hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. no active, planktonic, n2-fixing blue-green algae or bacteria were observed. however, calothrix and nostoc capable of fixing n2 were cultured from navigational buoys and dead coral heads. nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. experiments demon ... | 1976 | 7198 |
| "synthetical" aiptasia mutabilis rapp (coelenterata) (author's transl). | after being cultivated in the dark for some months and after being fed with food free of carotenoids during the time aiptasia mutabilis (coelenterata) loses its symbiontic algae (rich in brown fucoxanthin) and becomes transparent white. this disarranged symbiosis may be regenerated under light cultivation by adding different species of chlorophyceae (chlorella, dunaliella) and chrysophyceae (ochromonas, cyclotella), but not of cyanophyceae (anabaena, nostoc, oscillatoria, anacystis). - this chan ... | 1976 | 8888 |
| photolysis of water coupled to nitrate reduction by nostoc muscorum subcellular particles. | | 1976 | 9086 |
| spectral effects of denaturation of b- and c-phycoerythrins. | b-phycoerythrin (b-phe) from red alga porphyridium cruentum and c-phycoerythrin (c-phe) from blue-green alga nostoc punctiforma were isolated. their absorption and fluorescence spectra were measured at room and liquid nitrogen temperature. the drastic change of fluorescence and absorption maxima under dissociation of the proteins into subunits was observed. dissociation of the c-phe into two subunits (molecular weight 16 000 and 12 000) was revealed by sds-acrylamide gel electrophoresis in 0.01% ... | 1976 | 10015 |
| effect of physical and chemical agents on the blue-green algal virus n-1. | the stability of the blue-green algal virus n-1, infecting the blue-green alga nostoc muscorum, against temperature, edta and ph was studied. ninety per cent thermal inactivation of virus occured at 55 degrees c in 20 minutes with an average inactivation rate constant of 0.07 per minute; at 60 degrees c the virus was completely inactivated within 5 minutes. 10(-4) m edta inactivated 30 per cent of free virus in 60 minutes; 10(-3) m edta was completely lethal. intracellular virus was comparativel ... | 1977 | 18927 |
| effects of host aging, ions, and ph on the adsorption of the cyanovirus n-1 to nostoc muscorum. | the adsorption rate of the cyanovirus n-1 infecting the nitrogen-fixing blue-green alga nostocmuscorum decreased with aging of algal cultures and the virus failed to adsorb to the dead host cells. the adsorption rate declined in saline magnesium chloride solution compared to that in algal growth medium. the addition of amino acids like l-tryptophan and l-phenylalanine failed to enhance the adsorption rate of the virus. optimal ph of adsorption was 7.6 to 8;1. | 1978 | 25636 |
| effect of ph, light intensity and population on the toxicity of the pesticide carbofuran to the blue-green alga nostoc muscorum. | the effect of ph, light intensity and population on the toxicity of the pesticide furadan (containing 3% carbofuran as the active ingredient) was studied on the nitrogen fixing blue-green alga nostoc muscorum. it was observed that all these factors had effects on the toxicity of the pesticide. the blue-green alga grew better in the ph range of 7.5-10, whereas the acidic ph of 5-6 retarded growth. the pesticide was more toxic to alga in the medium of ph 5-6, whereas reduction in toxicity was noti ... | 1978 | 36544 |
| effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue-green alga nostoc muscorum. | the effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (hch) in growth medium to the n2-fixing blue-green alga nostoc muscorum. it was observed that all these chemicals had some effects on toxicity. the toxicity of both carbofuran and hch was reduced to some extent in the presence of higher concentrations ... | 1979 | 94720 |
| isolation of a sulphate reductase-less mutant of the blue-green alga nostoc muscorum. | the wild type nostoc muscorum (uw strain) has yielded various physiological mutants altered in utilization of sulphate, following mutagenic treatments with n-methyl, n'-nitro n-nitrosoguanidine (ntg). one of the mutant strains designated as sat-20 failed to grow in a medium containing sulphate (mgso4.7 h2o). however, the mutant strain could grow when supplemented with thiosulphate (na2s2o3.5 h2o), while methionine could fulfil the sulphur requirement only partially. on comparative reasons, the w ... | 1978 | 96618 |
| comparative studies on two ferredoxins from the cyanobacterium nostoc strain mac. | two ferredoxins were isolated from the cyanobacterium nostoc strain mac grown autotrophically in the light or heterotrophically in the dark. in either case approximately three times as much ferredoxin i as ferredoxin ii was obtained. both ferredoxins had absorption maxima at 276, 282 (shoulder), 330, 423 and 465 nm in the oxidized state, and each possessed a single 2 fe-2s active centre. their isoelectric points were approx. 3.2. the midpoint redox potentials of the ferredoxins differed markedly ... | 1978 | 99139 |
| dark hexose metabolism by photoautotrophically and heterotrophically grown cells of the blue-green alga (cyanobacterium) nostoc sp. strain mac. | photoautotrophically grown cells of the blue-green alga (cyanobacterium) nostoc sp. strain mac assimilated and oxidized both glucose and fructose in the dark at different rates. the rate of fructose metabolism in these cells could be stimulated by casein hydrolysate, the effect being most pronounced at low sugar concentrations. this stimulation was not seen in cells grown heterotrophically in the dark, suggesting that it is a transitory phenomenon which disappears during the autotrophy-heterotro ... | 1978 | 99438 |
| reversed phase chromatographic analysis of nostoc and euglena isoleucyl-trnas aminoacylated in vitro in homologous and heterologous systems. | | 1978 | 102350 |
| effects of some inorganic elements on nitrogen-fixation in blue-green algae and some ecological aspects of pollution. | nitrogen-fixation by two species of nostoc, one of them a lichen phycobiont, was generally stimulated by low concentrations of arsenic, cadmium, nickel, lead, palladium, and zinc. higher concentrations (0.025 to 0.125 ppm) of arsenic, nickel, and palladium were also stimulatory; however, higher concentrations of cadmium, lead, and zinc tended to inhibit fixation. with the exception of palladium and zinc at low concentrations these six tested elements tended to inhibit nitrogen-fixation in chloro ... | 1978 | 104450 |
| toxicity of carbofuran to blue-green alga nostoc muscorum. | effect of commercial grade pesticide furadan (3% a.i. as carbofuran) was studied on the survival, growth and nitrogen fixation of blue-green alga nostoc muscorum. the lower concentration of furadan i.e. 25 microgram/ml enhanced survival, growth and nitrogen fixation in the alga whereas these were gradually inhibited in higher concentrations (50--1000 microgram/ml) and the presence of more than 1200 microgram/ml was algicidal. the preliminary observations revelaed that pesticide is biodegraded by ... | 1978 | 104755 |
| histidine sensitive variant of the blue-green alga nostoc muscorum: response to corepressors of histidine biosynthesis. | a model has been proposed to account for growth inhibition by l-histidine in a variant strain of nostoc muscorum. this strain has been characterized for its response to 3-amino-1,2,4-triazole and 1,2,4-triazole-3-alanine known to act as false core-pressors of the histidine biosynthesis genes. the histidine sensitive strain retained its sensitivity to triazole alanine while the inhibitory effects of aminotriazole were much reduced indicating a change in regulation of his genes. the probable inter ... | 1979 | 108514 |
| cyanobacterial evolution: results of 16s ribosomal ribonucleic acid sequence analyses. | we report here the sequences of oligonucleotides released by t1-ribonuclease digestion of the 16s ribosomal rna's (rrna's) of unicellular cyanobacteria agmenellum quadruplicatum (strain bg-1) and synechococcus 7502. we compare them with sequences previously obtained for the 16s rna's of six other cyanobacteria and two chloroplasts, and conclude that: (i) synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes agmenelium quadruplicatum, usually considered to be ... | 1979 | 113061 |
| electron paramagentic resonance studies of photosynthetic electron transport: photoreduction of ferredoxinand membrane-bound iron-sulfur centers. | electron paramagnetic resonance spectrometry was used to investigate, at physiological temperatures, light-induced electron transport from membrane-bound iron-sulfur components (bound ferredoxin) to soluble ferredoxin and nadp(+) in membrane fragments (from the blue-green alga, nostoc muscorum) that had high rates of electron transport from water to nadp(+) and from an artificial electron donor, reduced dichlorophenolindophenol (dciph(2)) to nadp(+). illumination at 20 degrees resulted in the ph ... | 1977 | 198808 |
| midpoint redox potentials of plant and algal ferredoxins. | midpoint potentials of plant-type ferredoxins from a range of sources were measured by redox titrations combined with electron-paramagnetic-resonance spectroscopy. for ferredoxins from higher plants, green algae and most red algae, the midpoint potentials (at ph 8.0) were between --390 and --425 mv. values for the major ferredoxin fractions from blue-green algae were less negative (between --325 and --390 mv). in addition, spirulina maxima and nostoc strain mac contain second minor ferredoxin co ... | 1977 | 202262 |
| paracrystalline inclusions in various isolates of the blue-green bacteria nostoc and anabaena. | a number of different crystalline inclusions were observed in various isolates of anabaena and nostoc. membrane-limited crystalline bodies were observed in 7 of 20 isolates of anabaena and 19 of 29 isolates of nostoc. these are spherical, single membrane-limited bodies from 0.6 to 0.1 micron in diameter. in most of the isolates they contained needle-like crystals 20 a in thickness and up to 80 nm in length. in 9 of the isolates the inclusions contained granular and fibrillar material. the number ... | 1978 | 223816 |
| epr spectra of photosystem i and other iron protein components in intact cells of cyanobacteria. | electron paramagnetic resonance (epr) spectra were recorded of whole filaments of the cyanobacteria nostoc muscorum and anabaena cylindrica. signals due to manganese were removed by freezing and thawing the cells in edta. epr spectra were assigned on the basis of their g values, linewidths, temperature dependence and response to dithionite and light treatments. the principal components identified were: (i) rhombic fe3+ (signal at g = 4.3), probably a soluble storage form of iron; (ii) iron-sulfu ... | 1979 | 228708 |
| two plant-type ferredoxins in light-grown and dark-grown cells of the blue-green bacterium nostoc strain mac. | | 1975 | 236956 |
| isolation and characterization of gas vesicles from microcyclus aquaticus. | intact gas vesicles of microcyclus aquaticus s1 were isolated by using centrifugally accelerated flotation of vesicles and molecular sieve chromatography. isolated gas vesicles were cylindrical organelles with biconical ends and measured 250x100nm. the gas vesicle membrane was composed almost entirely of protein; neither lipid nor carbohydrate was detected, although one mole of phosphate per mole of protein was found. amino acid analysis indicated that the protein contained 54.6% hydrophobic ami ... | 1977 | 403898 |
| evidence for two types of p-700 in membrane fragments from a blue-green alga. | the mathematical analysis described in the preceding paper (biochim. biophys. acta (1977) 460, 65-75), in which the steady-state photooxidation of p-700 was compared with overall electron flux in photosystem i chloroplast fragments, was applied to membrane fragments from the blue-gree alga nostoc muscorum (strain 7119) noted for their high activity of both photosystem i and photosystem ii. the same analysis, which gave good agreement between the photooxidation of p-700 and the overall light-indu ... | 1977 | 403940 |
| two plant-type ferredoxins from a blue-green alga, nostoc verrucosum. | two plant-type ferredoxins were isolated and purified from a blue-green alga, nostoc verrucosum. they were separable by chromatography on a deae-cellulose column. the slow-moving band was designated ferredoxin i (fd i) and the fast-moving band was ferredoxin ii (fd ii). the ratio of the yield of ferredoxins i and ii was about 1 : 0.84. both ferredoxins had absorption spectra similar to those of plant-type ferredoxins. two atoms of non-heme iron and two of labile sulfur were found per mol of both ... | 1977 | 403941 |
| nitrate regulation of heterocyst differentiation and nitrogen fixation in a chlorate-resistant mutant of the blue-green alga, nostoc muscorum. | | 1977 | 404549 |
| inactivation by ammonia of the photosynthetic reduction of nitrate in nostoc muscorum particles. | | 1977 | 405010 |
| isolation and characterization of chlorate-resistant mutants of the blue-green alga nosoc muscorum. | spontaneous chlorate-resistant (clr) mutants of three classes were isolated from nostoc muscorum under three different selective conditions. a clr-n2 class of mutants lacked nitrate reductase and showed nitrate inhibition of nitrogen fixation. a clr-no3 group of het+ nif- mutants formed heterocysts, but lacked nitrogen fixation and active nitrogenase enzyme. the clr-no2 class included those mutants deficient in both active nitrogenase and nitrate reductase, as they were unable to grow at the exp ... | 1977 | 405580 |
| isolation of sulphate reductaseless mutants of the blue-green alga nostoc muscorum. | | 1977 | 408673 |
| metabolic interconversion of ferredoxin-nitrate reductase and nadp reductase of nostoc muscorum. | | 1977 | 410410 |
| effect of temperature on the adsorption and one-step growth of the nostoc virus n-1. | this study was an attempt to observe the effects of temperature on adsorption and one-step growth of the virus n-1 infecting the nitrogen-fixing cyanobacterium nostoc muscorum. adsorption rate was found to maximum at 40 degrees c whereas no adsorption occurred at 10 degrees c. the q10 value was about 2.03 and the energy of activation, ea was 16.3 kcal/mole for the adsorption process. the development cycle of the virus was temperature sensitive. with increase in temperature, a gradual increase in ... | 1977 | 413522 |
| transport of d-glucose and 3-o-methyl-d-glucose in the cyanobacteria aphanocapsa 6714 and nostoc strain mac. | 1. the cyanobacterium aphanocapsa 6714 which grow in the dark on d-glucose, will take up d-glucose and the analogue 3-o-methyl-d-glucose; uptake of each of these compounds was inhibited competitively by the other and by 6-deoxy-d-glucose. 2. this cyanobacterium accumulated 3-o-methyl-d-glucose up to 100-fold relative to the medium but did not modify or metabolize it to a significant degree. 3. intracellular 3-o-methyl-d-glucose was rapidly displaced from aphanocapsa 6714 by exogenous d-glucose a ... | 1978 | 413715 |
| some characteristics of two morphological mutants of nostoc linckia induced by nitrosoguanidine. | the blue-green alga nostoc linckia was treated with nitrosoguanidine and two classes of morphological mutant clones were isolated. one class shows certain abnormal phenotypic features of vegetative cells, spores, and heterocysts. it has increased heterocyst frequency and impaired growth rate. the other class exhibits an altered heterocyst spacing pattern. both classes of mutants have reduced nitrogenase activity. | 1977 | 414465 |
| ribosomal rna homologies and the evolution of the filamentous blue-green bacteria. | ribosomal rna (rrna) sequence homology (as determined by comparisons of t1 oligonucleotide catalogs of 32p-labeled 16s rrnas) has been used to assess phylogenetic relationships within the filamentous and unicellular blue-green bacteria, and to identify regions of evolutionary conservatism within blue-green bacterial 16s rrnas. nostoc and fishcherella, representatives of two morphologically distinct and highly differentiated orders, are shown to be as closely related (on the basis of rna sequence ... | 1978 | 416225 |
| variability of nitrogen fixation in some isolates of nostoc linckia. | four clonal isolates of nostoc linckia isolated from different localities were compared with respect to growth, nitrogen content (cellular and extracellular), and pigment composition. a considerable range of variation was observed among these isolates. this indicates the existence of genetically distinct clonal populations of the alga in natural habitats. | 1977 | 416603 |
| evidence for the involvement of a genetic determinant controlling functional specificity of group vi b elements in the metabolism of n2 and no-3 in the blue-green alga nostoc muscorum. | | 1978 | 418780 |
| transfer of nitrogen-fixing (nif) genes in the blue-green alga nostoc muscorum. | | 1975 | 803368 |
| spectral properties of phycobilisomes and phycobiliproteins from the blue-green alga-nostoc sp. | | 1975 | 806082 |
| effect of pesticides on blue-green algae and nitrogen-fixation. | the effects of the pesticides, amitrol, a derivative of amitrol (viz. 3,5-diamino-1,2,4-triazole), diquat, paraquat, linuron, mcpa, malathion, and monuron, were studied on the nitrogen-fixing algae, anabaena cylindrica, aulosira sp., calothrix elenkenii. chlorogloeae frischii, cylindrospermum muscicola, nostoc sp. from collema tenax, nostoc muscorum tolypothrix tenuis, and westiellopsis sp. in general, two types of response were discernible; an initial period of depression succeeded by an increa ... | 1975 | 808179 |
| carbon dioxide assimilation in blue-green algae: initial studies on the structure of ribulose 1,5-bisphosphate carboxylase. | d-ribulose 1,5-bisphosphate carboxylase was purified from the blue-green alga anabaena cylindrica (lemm) by procedures involving acid precipitation, ammonium sulfate fractionation, and sephadex g-200 gel filtration. the enzyme was homogeneous by the criterion of polyacrylamide disc gel electrophoresis and was a multimer of a single-size polypeptide chain of 54,000 daltons. the carboxylases from four species of blue-green algae (anabaena, nostoc strain mac, agmenellum quadruplicatum strain pr-6, ... | 1976 | 812868 |
| [growth inhibition by antibiotics and the production of resistance to them in a population of nostoc linckia]. | increasing concentrations of penicillin and streptomycin inhibited the growth of the blue-green alga nostoc linckia. although the alga could build up resistance to higher concentrations of penicillin (1000 mcg/ml), it was very sensitive to streptomycin beyond a concentration of 0.02 mcg/ml. two stable mutants, one resistant to 1000 mcg penicillin/ml and another to 0.02 mcg streptomycin/ml were isolated, of which the latter had lost its nitrogen fixing capacity. drug resistance seems to be due to ... | 1975 | 813088 |
| effects of magnesium and chloride ions on light-induced electron transport in membrane fragments from a blue-green alga. | the effects of magnesium and chloride ions on photosynthetic electron transport were investigated in membrane fragments of a blue-green alga, nostoc muscorum (strain 7119), noted for their stability and high rates of electron transport from water or reduced dichlorophenolindophenol to nadp+. magnesium ions were required not only for light-induced electron transport from water to nadp+ but also for protection in the dark of the integrity of the water-photooxidizing system (photosystem ii). membra ... | 1976 | 813781 |
| mutation to resistance for virus n-1 in the blue-green alga nostoc muscorum. | the spontaneous and nitrosoguanidine induced n-1 virus resistant mutants of the blue-green alga nostoc muscorum were isolated with the average mutation frequency of 3.55 x 10(-5) and 6.08 x 10(-4) respectively. of the surviving colonies 8 per cent became virus sensitive,whereas out of the remaining 92 per cent 9.3 per cent showed lysogenic behaviour and 13.3 per cent showed poor or no nitrogen fixing ability. mutation to virus-resistance was independent of the presence of the virus.spontaneous h ... | 1976 | 826239 |
| 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 |
| viability of lyophilized cyanobacteria (blue-green algae). | lyophilizatin of 13 cyanobacterial cultures belonging to seven genera was attempted in a variety of suspending substances. all organisms survived lyophilization when suspended in lamb serum. some of the organisms could be successfully lyophilized in horse serum, beef serum, fetal bovine serum, or human ascites fluid. with the exception of nostoc muscorium, none of the organisms survived lyophilization in skim milk medium, egg albumin medium, or jansen salts medium. | 1976 | 827240 |
| p-32 uptake the letic algae. | a study of the flat creek embayment of lake sidney lanier near gainesville, georgia revealed three genera of algae, chlorococcum, fragillaria and nostoc, to be prominent in this eutrophic region of the lake. the algae was grown in phosphate-rich media and subsequently labelled with p-32. all species incorporated luxury amounts of phosphorus as determined by the uptake of p-32. the results indicate that the p-32 uptake is proportional to the surface-per-volume ratio. the higher surface-per-volume ... | 1975 | 1183413 |
| further evidence for a phycobilisome model from selective dissociation, fluorescence emission, immunoprecipitation, and electron microscopy. | phycobilisomes, isolated in 500 mm sorensen's phosphate buffer ph 6.8 from the red alga, porphyridium cruetum, were analyzed by selective dissociation at various phosphate concentrations. the results are consistent with a structural model consisting of an allophycocyanin core, surrounding by a hemispherical layer of r-phycocyanin, with phycoerythrin being on the periphery. such a structure also allows maximum energy transfer. intact phycobilisomes transfer excitation energy ultimately to a pigme ... | 1976 | 1276188 |
| toxic effects of omega chrome red me and its treatment by adsorption. | toxic effects of omega chrome red me, a popular textile dye, on the nitrogen fixing cyanobacterium nostoc calcicola were studied. the growth of n. calcicola was found to be suppressed at 10 and 20 mg liter-1 initial concentrations of dye, whereas a low initial concentration of 5 mg liter-1 slightly favors growth. removal of the dye was carried out by adsorption using some cheap and unconventional adsorbents like coal, fly ash, wollastonite, and china clay. it has been observed that, in all cases ... | 1992 | 1280581 |
| cyanobiont diversity within and among cycads of one field site. | limited diversity was found among cyanobionts from a cultivated population of cycads at a field site in florida. all isolates were classified as nostoc but were different from the one nostoc species found in the soil. these cyanobacteria were root endophytes of several plants of zamia integrifolia and one of dioon. the isolates were similar morphologically and in their reactions to four fluorescein isothiocyanate conjugated lectins. electrophoretic protein profiles and zymograms distinguished on ... | 1992 | 1288849 |
| 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 |
| elucidation and optimization of the medium constituents controlling antibiotic production by the cyanobacterium nostoc muscorum. | a study has been made to determine which nutrient factors control antibiotic production by the cyanobacterium, nostoc muscorum. a two-phase approach was employed using a factorial method to explore the response surface and a steepest ascent method to climb the response surface to the region of the optimum. it was found that nitrate and iron were the factors significantly affecting antibiotic production; 26.4 mm nitrate and 6 microm iron were the optimal concentrations for maximizing antibiotic p ... | 1991 | 1367529 |
| protective effects of ca2+, mg2+, cu2+, and ni2+ on mercury and methylmercury toxicity to a cyanobacterium. | toxicological investigations of the impact of inorganic mercury (hg2+) and methylmercury (ch3hg+) in terms of growth, nh4+ uptake, in vivo glutamine synthetase (transferase) activity, and regulation of toxicity by ca2+, mg2+, cu2+ and ni2+ in the diazotrophic cyanobacterium nostoc calcicola bréb. have been completed. photoautotrophic growth of the cyanobacterium was extremely sensitive to both mercury compounds, ch3hg+ being 2.5 times more toxic than hg2+. although nh4+ uptake was 6 times more s ... | 1992 | 1375141 |
| abscisic acid and its synthetic analog in relation to growth and nitrogenase activity of azotobacter chroococcum and nostoc muscorum. | the plant hormone abscisic acid as well as its synthetic analog lab 173711 significantly increased the nitrogenase activity of the bacterium azotobacter chroococcum and the cyanobacterium nostoc muscorum. the effect depended on the concentration of the substances (0.001-10 mg/l) and the age of the cultures. the biomass of the organisms was not significantly influenced. | 1992 | 1387101 |
| three new microcystins, cyclic heptapeptide hepatotoxins, from nostoc sp. strain 152. | three new cyclic heptapeptide hepatotoxins, [d-ser1,admadda5]microcystin-lr (1), [d-asp3,-admadda5]microcystin-lhar (2), and [admadda5,mser7]microcystin-lr (3), were isolated from the cyanobacterium (blue-green alga) nostoc sp. strain 152, together with four known microcystins, [admadda5]microcystin-lr (4), [admadda5]microcystin-lhar (5), [d-asp3,-admadda5]microcystin-lr (6), and [dmadda5]microcystin-lr (7). the structures of new microcystins were assigned on the basis of high-resolution fast at ... | 1992 | 1391612 |
| nucleotide sequence of the replication region of the nostoc pcc 7524 plasmid pdu1. | | 1992 | 1408769 |
| cloning and sequencing of the petbd operon from the cyanobacterium synechococcus sp. pcc 7002. | the genes encoding the photosynthetic cytochrome b6 (petb) and subunit 4 (petd) have been cloned and sequenced from the unicellular, photoheterotrophic, transformable cyanobacterium synechococcus sp. pcc 7002, formerly designated agmenellum quadruplicatum. the gene arrangement was found to be similar to that reported in the cyanobacterium nostoc pcc 7906. the dna and derived protein sequences were compared to chloroplast and the other cyanobacterial sequences. by pulsed-field electrophoresis, th ... | 1992 | 1421151 |
| semipreparative isolation of individual cyanobacterial heterocyst-type glycolipids by reverse-phase high-performance liquid chromatography. | procedures are described for the quantitative, semi-preparative isolation of individual cyanobacterial heterocyst-type glycolipids (hgs) by reverse-phase hplc (rp-hplc) and the modifications to conventional techniques necessary to prevent significant hg losses during sample preparation. total lipids are obtained from cultures of nitrogen-fixing cyanobacteria by triplicate extraction with 200 packed-cell volumes of chloroform/methanol (1/1, v/v), filtered, and redissolved in chloroform for loadin ... | 1992 | 1443590 |
| identification of a second psac gene in the cyanobacterium synechocystis sp. pcc6803. | the psac gene encodes the 9 kda protein subunit of photosystem i that carries the iron-sulfur centers fa and fb. the paper describes the sequence and transcription analysis of a second psac gene (psac2) from synechocystis sp. pcc6803. thepsac2 gene is transcribed into an abundant monocistronic mrna. the deduced amino acid sequence of psi-c2 is very similar to the protein sequences from two other cyanobacteria (synechococcus sp. pcc7002 and nostoc sp. pcc8009). in contrast, the recently isolated ... | 1992 | 1463835 |
| differential effect of ultraviolet-b radiation on certain metabolic processes in a chromatically adapting nostoc. | the impact of uv-b radiation on growth, pigmentation and certain physiological processes has been studied in a n2-fixing chromatically adapting cyanobacterium, nostoc spongiaeforme. a brownish form (phycoerythrin rich) was found to be more tolerant to uv-b than the blue-green (phycocyanin rich) form of n. spongiaeforme. continuous exposure to uv-b (5.5 w m-2) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. pigme ... | 1992 | 1561238 |
| differentiation of free-living anabaena and nostoc cyanobacteria on the basis of fatty acid composition. | the cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera anabaena and nostoc were analyzed to differentiate the genera. the fatty acid compositions of 10 anabaena strains and 10 nostoc strains that were grown for 12 days on bg-11o medium were determined by gas-liquid chromatography-mass spectroscopy. of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at l ... | 1992 | 1581185 |
| construction of insertion mutants of synechocystis sp. pcc 6803: evidence for an essential function of subunit iv of the cytochrome b6/f complex. | the gene encoding subunit iv of the cytochrome b6/f complex (petd) has been isolated from a genomic library of the unicellular cyanobacterium synechocystis sp. pcc 6803. the coding region consists of 480 nucleotides and can code for a polypeptide with a molecular weight of 17.5 kda. the deduced amino acid sequence shows high identity with the corresponding sequences of both the photoautotrophic prokaryote nostoc sp. pcc 7906 as well as of lower and higher photoautotrophic eukaryotes (e.g. chlore ... | 1992 | 1590707 |
| molecular cloning and sequencing of the beta-isopropylmalate dehydrogenase gene from the cyanobacterium spirulina platensis. | the gene for beta-isopropylmalate dehydrogenase (ec 1.1.1.85) of spirulina platensis (leub) was cloned from a lambda embl3 genomic library by heterologous hybridization using the nostoc ucd 7801 leub gene as a probe. the sequence of the entire leub coding region was determined as well as 645 bp of 5' flanking region and 956 bp of 3' flanking region. dna sequencing revealed an open reading frame of 1065 nucleotides capable of encoding a polypeptide of 355 amino acids. homologies between the amino ... | 1992 | 1593261 |
| myoglobin in a cyanobacterium. | myoglobin was found in the nitrogen-fixing cyanobacterium nostoc commune. this cyanobacterial myoglobin, referred to as cyanoglobin, was shown to be a soluble hemoprotein of 12.5 kilodaltons with an amino acid sequence that is related to that of myoglobins from two lower eukaryotes, the ciliated protozoa paramecium caudatum and tetrahymena pyriformis. cyanoglobin is encoded by the glbn gene, which is positioned between nifu and nifh-two genes essential for nitrogen fixation-in the genome of nost ... | 1992 | 1609281 |
| [2 site-specific endonucleases of the cyanobacterium nostoc linckia]. | two restrictases nli387/7 i and nli387/7 ii have been isolated from cyanobacterium nostoc linckia using chromatography on phosphocellulose, "mono q" column, and heparin sepharose 4b. the preparations are described by the method of electrophoresis in polyacrylamide gel under denaturing conditions. catalytic properties of restrictases are determined: optimal ph of the action--9.0--9.5, optimal concentration of na+--5 mm, that of mg2+--6 mm, optimal temperature--37 degrees c. the isolated enzymes a ... | 1991 | 1650423 |
| psad is required for the stable binding of psac to the photosystem i core protein of synechococcus sp. pcc 6301. | the psac gene product from synechococcus sp. pcc 7002 and the psad gene product from nostoc sp. pcc 8009 were synthesized in escherichia coli and purified to homogeneity. incubation of the psac apoprotein with the synechoccus sp. pcc 6301 photosystem i core protein in the presence of fecl3, na2s, and beta-mercaptoethanol resulted in a time-dependent transition in the flash-induced absorption change from a 1.2-ms, p700+ fx- back-reaction to a long-lived, p700+ [fa/fb]- back-reaction. esr studies ... | 1991 | 1651109 |
| influence of different forms of nitrogen on uptake of ammonium, glutamate and glutamine in the cyanobacterium nostoc muscorum. | effect of various types of nitrogen nutrition was studied on the uptake of ammonium, glutamate and glutamine by nostoc muscorum and its het-nif- mutant. ammonium nitrogen acted as a potent inhibitor/repressor of ammonium, glutamate and glutamine transport. nitrate nitrogen was found to be a strong inhibitor/repressor of ammonium transport, a partial inhibitor/repressor of glutamate transport but, caused a partial stimulation of glutamine transport. | 1991 | 1684351 |
| evidence for a role of glutamine synthetase in assimilation of amino acids as nitrogen source in the cyanobacterium nostoc muscorum. | methylammonium/ammonium ion, glutamine, glutamate, arginine and proline uptake, and their assimilation as nitrogen sources, was studied in nostoc muscorum and its glutamine synthetase-deficient mutant. glutamine served as nitrogen source independent of glutamine synthetase activity. glutamate was not metabolised as a nitrogen source but still inhibited nitrogenase activity and diazotrophic growth. glutamine synthetase activity was essential for the assimilation of n2, ammonia, arginine and proli ... | 1991 | 1687107 |
| evidence for energy-dependent copper efflux as a mechanism of cu2+ resistance in the cyanobacterium nostoc calcicola. | wild-type nostoc calcicola carried out oxygenic photosynthesis extremely sensitive to copper. a cu(2+)-resistant mutant (cu-r1) of the cyanobacterium grew normally at high concentrations of cu2+. its ability to grow under such conditions was found to be due to mutational acquisition of an energy-dependent efficient system of cu(2+)-efflux, which rendered cu(2+)-inhibited oxygenic photosynthesis fully reversible. | 1991 | 1804762 |
| effect of lead on nitrogenase and enzymes of nitrogen assimilation in a cyanobacterium nostoc muscorum. | lead decreased the growth rates, total cell mass, heterocyst frequency, total cell protein, nitrogenase activity, glutamine synthetase (gs) and glutamate synthase (gogat) activities in n:muscorum. however, lead at 0.01 and 10 micrograms ml-1 conc. enhanced nitrogenase as well as gs activity of the cells. on transfer to excess lead (100 micrograms ml-1), nitrogenase and gs activities ceased almost after 24 hr in the cyanobacterium. it is deduced that lead has a two step effect on stimulation and ... | 1991 | 1816095 |
| [production of the antibiotic-algicide cyanobacterin lu-2 by a filamentous cyanobacterium nostoc sp]. | a strain of cyanobacterium of nostoc has been isolated, and found to produce a new antibiotic cyanobacterin lu-2. the antibiotic is synthesized by the cyanobnacterium under intensive cultivation conditions in a liquid mineral medium. cyanobacterin lu-2 is an exometabolite; its maximum accumulation in the medium is achieved at 34 degrees. cyanobacterin lu-2 is active against many cyanobacteria tested, including those of microcystis and aphanizomenon which are principals to give rise to blooms in ... | 1991 | 1819038 |
| sequence-specific endonucleases from the cyanobacterium nostoc sp. atcc 29132. | the nitrogen-fixing cyanobacterium nostoc sp. atcc 29132 was shown to contain two sequence-specific endonucleases. nsp(29132) i was an isoschizomer of asuii, and nsp(29132) ii was an isoschizomer of bamhi. nsp(29132) ii was shown to generate ends that could be ligated to those generated by bamhi. | 1991 | 1840140 |
| gene cluster rpobc1c2 in cyanobacteria does not constitute an operon. | the core enzyme of the cyanobacterial dna-dependent rna polymerase contains a unique component, gamma, which is absent from the corresponding enzymes of other eubacteria. in the heterocystous cyanobacterium nostoc commune the gene encoding gamma, rpoc1, is immediately adjacent to, and downstream of, rpob. the rpoc1 gene, and a 3' adjacent gene, rpoc2, correspond to the single rpoc gene found in escherichia coli with respect to those domains conserved within their translational products. northern ... | 1991 | 1899176 |
| cadmium toxicity to photosynthesis and associated electron transport system of nostoc linckia. | | 1991 | 1900451 |
| orientation and linear dichroism of mastigocladus laminosus phycocyanin trimer and nostoc sp. phycocyanin dodecamer in stretched poly(vinyl alcohol) films. | the linear dichroism (ld) spectra of the c-phycocyanin (c-pc) trimer disks oriented in poly(vinyl alcohol) films (pva) at room temperature and at 95 k were determined. utilizing the known atomic coordinates of the chromophores (schirmer, t., bode, w. and huber, r. (1987) j. mol. biol. 196, 677-695) and theoretical estimates of the orientations of the transition dipole moments relative to the molecular framework, the ld spectra were simulated using the pairwise exciton interaction model of sauer ... | 1991 | 1905956 |
| response of enzymes involved in the processes of antioxidation towards benthiocarb and methylparathion in cyanobacteria nostoc muscorum. | | 1991 | 1912703 |
| the amino-acid sequence of three proteins of photosystem i of the cyanobacterium fremyella diplosiphon (calothrix sp pcc 7601). | three proteins containing 138 amino acids (psad protein), 80 amino acids (psac protein) and 66 amino acids (psae protein) of the photosystem i (ps i) complex of the cyanobacterium fremyella diplosiphon (calothrix sp pcc 7601) were isolated and sequenced. comparison with previously known sequences showed a close relationship to homologous proteins of nostoc, another filamentous cyanobacterium. | 1991 | 1930733 |
| growth, chlorophyll a content, nitrogen-fixing ability, and certain metabolic activities of nostoc muscorum: effect of methylparathion and benthiocarb. | | 1991 | 1932863 |
| physiological sources of reductant for nitrogen fixation activity in nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | pure cultures of the symbiotic cyanobacterium-bryophyte association with anthoceros punctatus were reconstituted by using nostoc sp. strain ucd 7801 or its 3-(3,4-dichlorophenol)-1,1-dimethylurea (dcmu)-resistant mutant strain, ucd 218. the cultures were grown under high light intensity with co2 as the sole carbon source and then incubated in the dark to deplete endogenous reductant pools before measurements of nitrogenase activities (acetylene reduction). high rates of light-dependent acetylene ... | 1991 | 1938924 |
| binding of cadmium by cyanobacterial growth media: free ion concentration as a toxicity index to the cyanobacterium nostoc uam 208. | a quantitative study of cadmium binding to three different growth media for nitrogen-fixing cyanobacteria was done with the aid of a solid state ion-specific electrode. kratz and myers modified medium and arnon medium bound large amounts of cd2+, bg11o medium had less binding capacity. of the media components, phosphate ion showed the greatest ability to bind cd2+. different phs, the size of cell inoculum and two buffers (tricine and hepes, 25 mm) also changed the availability of free cadmium io ... | 1991 | 1953030 |
| effect of four heavy metals on the biology of nostoc muscorum. | this study presents the effects of cr, pb, ni and ag on growth, pigments, protein, dna, rna, heterocyst frequency, uptake of nh4+ and no3-, loss of electrolytes (na+ and k+), nitrate reductase and glutamine synthetase activities of nostoc muscorum. the statistical tests revealed a direct positive correlation between the metal concentration and inhibition of different processes. ni was found to be more toxic against growth, pigments and heterocyst differentiation compared to the other metals. inh ... | 1990 | 1975195 |
| genetic transformation of glutamine auxotrophy to prototrophy in the cyanobacterium nostoc muscorum. | glutamine auxotrophic (gln-) and l-methionine d,l-sulfoximine (msx) resistant (msxr) mutants of n. muscorum were isolated and characterized for nitrogen nutrition, nitrogenase activity, glutamine synthetase (gs) activity and glutamine amide, alpha-keto-glutarate amido transferase (gogat) activity. the glutamine auxotroph was found to the gogat-containing gs-defective, incapable of growth with n2 or nh4+ but capable of growth with glutamine as nitrogen source, thus, suggesting gs to be the primar ... | 1990 | 1978772 |
| structural and chemical properties of a flavodoxin from anabaena pcc 7119. | structural and chemical properties of a flavodoxin from anabaena pcc 7119 are described. the first 36 residues of the amino-terminal amino acid sequence have been determined and show extensive homology with flavodoxins isolated from other sources. anabaena flavodoxin exhibits a net negative change (-3) in the helix-1 segment as found with other cyanobacterial flavodoxins synechococcus 6301 (anacystis nidulans) and nostoc mac, but in contrast to the net positive charge found in this region in the ... | 1990 | 2119231 |
| immunologically cross-reactive and redox-competent cytochrome b6/f-complexes in the chlorophyll-free plasma membrane of cyanobacteria. | plasma and thylakoid membranes were separated and purified from cell-free extracts of the cyanobacteria anacystis nidulans, synechocystis 6714, anabaena variabilis and nostoc sp. strain mac. immunoblots of the membrane proteins using antisera raised against subunits i-iv of the chloroplast b6/f-complex gave evidence for the presence of a homologous complex in both plasma and thylakoid membranes from the four species of cyanobacteria investigated. both plasma and thylakoid membranes catalyzed the ... | 1990 | 2121543 |
| reconstitution of electron transport in photosystem i with psac and psad proteins expressed in escherichia coli. | a fusion protein, denoted psac1, which contains an amino-terminal extension of five amino acids (mehsm...) and is derived from an in vitro modified form of the psac gene of synechococcus sp. pcc 7002, has been over-expressed in escherichia coli. the product of the psad gene of nostoc sp. pcc 8009 has similarly been over-expressed. the psac1 and psad proteins can be combined with the photosystem i core protein of synechococcus sp. pcc 6301 to reconstitute electron transport from p700 to the termi ... | 1990 | 2125006 |
| isolation and characterization of hepatotoxic microcystin homologs from the filamentous freshwater cyanobacterium nostoc sp. strain 152. | a strain of the filamentous cyanobacterium nostoc sp. isolated from a lake in finland was found to produce at least nine hepatotoxic peptides with chemical and toxicological properties similar to those of the hepatotoxic hepta- and pentapeptides produced by other cyanobacteria. toxins were isolated and purified by high-performance liquid chromatography. amounts available for five of the purified toxins (p6, p14, p15, p16, and p18) were adequate for high-performance liquid chromatography amino ac ... | 1990 | 2125813 |
| identification of a periplasmic c-type cytochrome as electron donor to the plasma membrane-bound cytochrome oxidase of the cyanobacterium nostoc mac. | photoautotrophically grown cyanobacterium nostoc sp. strain mac (pcc 8009) released up to about 10 nmol of a c-type cytochrome per ml packed cells after treatment with edta under conditions that left the plasma membrane absolutely intact as judged from the absence of cytosolic proteins in the supernatant. spectra of the ascorbate reduced cytochrome revealed peaks at 553, 522 and 416 nm. the protein was purified to an a-553/a-275 ratio of 0.8. midpoint potential (at ph 7), isoelectric point and a ... | 1990 | 2162667 |
| chemical composition, in vitro protein digestibility and in vitro available iron of blue green alga, nostoc commune. | blue-green alga, nostoc commune, contained moderate amounts of protein and iron. its in vitro protein digestibility was 43.50%. the soluble and ionic iron from the alga was extractable to some extent at ph 1.5 but was not detectable at ph 8.0. the digestion by protease did not affect the iron detection. heat processing at 100 and 120 degrees c failed to increase the digestibility and the content of available iron. the dietary fiber in the alga may be responsible for low protein digestion and low ... | 1990 | 2170966 |
| cytotoxic, antiviral indolocarbazoles from a blue-green alga belonging to the nostocaceae. | 6-cyano-5-methoxy-12-methylindolo[2,3-alpha]carbazole and 6-cyano-5-methoxyindolo[2,3-alpha]carbazole are responsible for most of the cytotoxicity and antiviral activity associated with the blue-green alga nostoc sphaericum ex-5-1. the compounds are active against hsv ii and show weak cytotoxicity against kb and lovo human carcinoma cell lines. | 1990 | 2175302 |
| polysome turnover in immobilized cells of nostoc commune (cyanobacteria) exposed to water stress. | water stress induced changes in the polysome content of immobilized cells of the desiccation-tolerant cyanobacterium nostoc commune utex 584. cells maintained an intact protein synthesis complex during 2 h of drying at -99.5 mpa. polysomes were not recovered from cells subjected to extended periods of desiccation. | 1986 | 2430937 |
| cyanobacterial rna polymerase genes rpoc1 and rpoc2 correspond to rpoc of escherichia coli. | the dna-dependent rna polymerase (ribonucleoside triphosphate:rna nucleotidyltransferase, ec 2.7.7.6) of cyanobacteria contains a unique core component, gamma, which is absent from the rna polymerases of other eubacteria (g. j. schneider, n. e. tumer, c. richaud, g. borbely, and r. haselkorn, j. biol. chem. 262:14633-14639, 1987). we present the complete nucleotide sequence of rpoc1, the gene encoding the gamma subunit, from the heterocystous cyanobacterium nostoc commune utex 584. the derived a ... | 1989 | 2495268 |
| effect of bimetallic combinations of ni, cr, and pb on growth, uptake of nitrate and ammonia, 14co2 fixation, and nitrogenase activity of nostoc muscorum. | the toxicity of cr, ni, and pb individually as well as in combination (cr + ni, cr + pb, ni + pb) on growth, final yield, uptake of no3- and nh4+, photosynthesis, and nitrogenase activity of nostoc muscorum has been studied. all test metals, when used individually, depicted toxicity against the above-mentioned processes of test cyanobacterium. however, their interactive effect was found to be mostly of antagonistic type. antagonism was more prevalent in those combinations containing nickel. in a ... | 1989 | 2496971 |
| toxicity of three herbicides to some nitrogen-fixing cyanobacteria. | the effects of some common rice field herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-d), machete, and saturn, on the paddy field nitrogen-fixing cyanobacteria nostoc linckia, nostoc calcicola, nostoc sp., and anabaena doliolum were studied. these cyanobacteria were found to be more tolerant to 2,4-d (lethal doses 1500-2000 micrograms/ml) than to machete and saturn (lethal doses 6-8 micrograms/ml). the effects of these three herbicides on some physiological processes of n. linckia were s ... | 1989 | 2500323 |
| novel water stress protein from a desiccation-tolerant cyanobacterium. purification and partial characterization. | a desiccation-tolerant cyanobacterium nostoc commune accumulates a novel group of acidic proteins when colonies are subjected to repeated cycles of drying and rehydration. the proteins occur in high concentrations; they have isoelectric points between 4.3 and 4.8 and apparent molecular masses between 30 and 39 kda. the purification of three of these proteins with molecular masses of 33, 37, and 39 kda is described. the amino-terminal sequence of the 39-kda protein is ala-leu-tyr-gly-tyr-thr-ile- ... | 1989 | 2501307 |
| effects of three pesticides on msx-induced ammonia photoproduction by the cyanobacterium nostoc linckia. | three pesticides (2,4-d, basalin, aldrin) inhibited l-methionine-dl-sulfoximine (msx)-induced photoproduction of ammonia by the nitrogen-fixing cyanobacterium nostoc linckia. combinations of pesticides and msx were inhibitory except at low concentrations (100 and 500 micrograms/ml) of 2,4-d which stimulated nh+4 production. similar results were obtained when pesticides were added 6 hr after the addition of msx, but the inhibition was weaker. when msx was added to the culture 6 hr after the addit ... | 1989 | 2509191 |
| photosynthetic co2 fixation and ribulose bisphosphate carboxylase/oxygenase activity of nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | the cyanobacterium nostoc sp. strain ucd 7801, immediately after separation from pure cultures of a reconstituted symbiotic association with the bryophyte anthoceros punctatus, exhibited a rate of light-dependent co2 fixation that was eightfold lower than that measured in the free-living growth state. ribulose bisphosphate carboxylase/oxygenase (rubpc/o) specific activity was also eightfold lower in cell extracts of symbiotic strain 7801 relative to that in free-living cultures. the in vitro act ... | 1989 | 2509431 |
| nostoc commune utex 584 gene expressing indole phosphate hydrolase activity in escherichia coli. | a gene encoding an enzyme capable of hydrolyzing indole phosphate was isolated from a recombinant gene library of nostoc commune utex 584 dna in lambda gt10. the gene (designated iph) is located on a 2.9-kilobase ecori restriction fragment and is present in a single copy in the genome of n. commune utex 584. the iph gene was expressed when the purified 2.9-kilobase dna fragment, free of any vector sequences, was added to a cell-free coupled transcription-translation system. a polypeptide with an ... | 1989 | 2536677 |
| nitrogen fixation (nif) genes of the cyanobacterium anabaena species strain pcc 7120. the nifb-fdxn-nifs-nifu operon. | a second nitrogen fixation (nif) operon in the cyanobacterium (blue-green alga) anabaena (nostoc) sp. strain pcc 7120 has been identified and sequenced. it is located just upstream of the nifhdk operon and consists of four genes in the order nifb, fdxn, nifs, and nifu. the three nif genes were identified on the basis of their similarity with the corresponding genes from other diazotrophs. the fourth gene, fdxn, codes for a bacterial type ferredoxin (mulligan, m. e., buikema, w. j., and haselkorn ... | 1989 | 2553733 |
| comparison of dna restriction fragment length polymorphisms of nostoc strains in and from cycads. | dna was prepared from cyanobacteria freshly isolated from coralloid roots of natural populations of five cycad species: ceratozamia mexicana mexicana (mexico), c. mexicana robusta (mexico), dioon spinulosum (mexico), zamia furfuraceae (mexico) and z. skinneri (costa rica). using the southern blot technique and cloned anabaena pcc 7120 nifk and glna genes as probes, restriction fragment length polymorphisms of these cyanobacterial symbionts were compared. the five cyanobacterial preparations show ... | 1989 | 2569858 |
| an analysis of restriction endonuclease sites in cyanophages infecting the heterocystous cyanobacteria anabaena and nostoc. | an analysis of restriction endonuclease cleavage of dna isolated from cyanophages that infect anabaena and nostoc species of cyanobacteria has provided evidence for counter-selection of restriction endonuclease sites. these include sites containing subsequences which are methylated by host (anabaena pcc 7120) methylase(s) akin to the dam and dcm enzymes of escherichia coli. other sites which are counter-selected have no common sequence structure. the latter include those of the endogenous restri ... | 1988 | 2832536 |
| phycotoxicity of linear alkylbenzene sulfonate. | dose- and time-dependent effects of linear alkylbenzene sulfonate, a major component of synthetic detergent, to the blue-green alga nostoc muscorum, were studied under laboratory conditions. toxicity was evident, at doses above 0.001%, from the decrease in biomass, heterocyst number, and protein content and pathomorphological alterations. | 1988 | 2837383 |