Publications

[influence of light on the biological fixation of nitrogen by nostoc commune].		1952	12978729
necessity of boron for nostoc muscorum.		1952	13002436
studies on the photosynthetic reaction. i. the assimilation of acetate by nostoc muscorum.		1953	13084591
[energetic antibiotic properties of a soil alga; nostoc muscorum ag..].		1954	13172944
[the fine structure of the nostoc slime].		1954	13206292
studies on the photosynthetic reaction. ii. sodium formate and urea feeding experiments with nostoc muscorum.		1954	16654631
the effect of light on this developmental cycle of nostoc muscorum, a filamentous blue-green alga.		1961	13759768
the participation of filament anastomosis in the developmental cycle of nostoc muscorum, a blue-green alga.		1962	14463093
studies with cyanidium caldarium. i. the fine structure and systematic position of the organism.	the fine structure of cyanidium caldarium, as seen in thin sections of kmno(4)-fixed cells examined with the electron microscope, is described. this organism, whose taxonomic position among algae is undetermined, contains a single well defined chloroplast, a nucleus, and mitochondria. studies, with the electron microscope, of chlorella pyrenoidosa and nostoc are also reported. structural differences within cells of cyanidium, chlorella, and nostoc are discussed. it is concluded that if nostoc ca ...	1962	14472748
physiological and biochemical studies on nitrogen fixing blue-green algae. i. on the nature of cellular and extracellular nitrogenous substances formed by nostoc commune.		1962	13918955
action spectrum for developmental photo-induction of the blue-green alga nostoc muscorum.	the dark-grown cyanophyte requires a brief exposure to light from the 650 mmicro region of the spectrum before it can complete its developmental cycle. induction is reversed by exposure to green light. a blue protein, presumably allophycocyanin (absorption maximum, 650 mmicro) has been demonstrated in aqueous extracts of the cyanophycean cells.	1962	17836542
algae: nitrogen fixation by antarctic species.	algae from terrestrial and fresh-water habitats in antarctica were examined for ability to fix atmospheric nitrogen. nostoc commune was the only species capable of growing in nitrogen-free medium; nitrogen fixation by this species was verified by assimilation of n(15). the importance of nitrogen-fixing algae to terrestrial life in the antarctic is discussed.	1963	17812987
physiological and biochemical studies on nitrogen fixation by blue-green algae. iii. the growth and nitrogen fixation of nostoc commune as influenced by culture conditions.		1963	13980209
the relationship of cellular differentiation to colonial morphogenesis of the blut-gree alga, nostoc muscorum a.		1964	14188771
amino acid composition and c-terminal residues of algal biliproteins.	1. r-phycoerythrin from ceramium rubrum and c-phycocyanin from nostoc muscorum have been obtained in purified form by fractional crystallization, followed by chromatography and gel-filtration. 2. the amino acid composition of both chromoproteins was determined; 85% of the total weight of both was recovered as amino acids. 3. alanine was identified as the only c-terminal amino acid of r-phycoerythrin, each molecule of which contained about 12 terminal groups. 4. serine was identified as the only ...	1965	14342224
[fixation of molecular nitrogen by some representatives of the genera aanbaena and nostoc].		1966	5995733
possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction.		1969	5779919
induction by ultraviolet irradiation of mutation in the blue-green alga nostoc linckia (roth) born. et flah.		1969	5782614
biosynthesis of alkanes in nostoc muscorum.		1969	5798100
cytophaga that kills or lyses algae.	a myxobacterium (cytophaga n-5) isolated from sewage kills or lyses an array of living green and blue-green algae. when assayed with nostoc muscorum or plectonema boryanum, plaques form like those caused by the blue-green algal virus lpp-1. this isolate lyses or inhibits mutually gram-positive and gram-negative eubacteria.	1969	4891858
possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction.		1969	4181442
gas vacuole development in a blue-green alga.	de novo productioni of gas vacutoles can be induced in the blue-green alga nostoc muscorum by transferring the cells from a defined medium to distilled water. the unusual ultrastructure of the gas vacuole membranes permits their easy recognition when specimens are prepared for electron microscopy by freeze-etching. the youngest gas vacuoles are biconical organelles; 48 hours after induction the gas vacuoles reach their miaximum observed length when they are cylinders (1.5 by 0.1 micro) with corn ...	1969	17807814
fixation of elementary nitrogen by nostoc punctiforme (kütz.) hariot and scytonema bohneri schmidle in pure and unialgal cultures.		1970	5412270
peptide chain initiation in a species of nostoc and in chloroplasts of euglena gracilis.		1970	11945364
isolation and characterization of a virus infecting the blue-green alga nostoc muscorum.		1971	4108613
purification and properties of glycogen isolated from a blue-green alga, nostoc muscorum.	alpha granules were isolated from a blue-green alga, nostoc muscorum, in large quantities and high purity by sucrose density gradient centrifugation. sodium deoxycholate was used to eliminate membrane contamination. isolated alpha granules from this species have average dimension of 31 nm in width and 65 nm in length. each alpha granule consists of two equal parts. attempts to dissociate the intact granule under mild conditions into relatively large subunits did not succeed. analytical centrifug ...	1971	4993320
nitrogen metabolism of nostoc muscorum & phormidiu phormidium fragile.		1971	5004444
[nitrogen excretion by nitrogen fixing blue-green algae. i. growth of anabaena cylindriea and nostoc muscorum in various media, at different temperatures, and under light of different wavelengths (author's transl)].		1973	4272180
occurrence of cell lytic enzymes in blue-green bacteria.	detergent extracts of three blue-green bacteria (agmenellum quadruplicatum strain bg1, anacystis nidulans strain tx20, and nostoc sp. strain mac) contained enzymes capable of lysing suspensions of micrococcus lysodeikticus. the enzyme preparation from a. quadruplicatum released soluble reducing fragments from purified peptidoglycan. the lytic activity exhibited a ph optimum between 6 and 7, was relatively heat stable, and was susceptible to attack by proteolytic enzymes. these results extend the ...	1973	4745432
light-induced oxidation-reduction reactions in a cell-free preparation from the blue-green alga nostoc muscorum: the role of cytochrome f, cytochrome b558, c550, and p700 in noncyclic electron transport.		1973	4148619
role of reduced exogenous organic compounds in the physiology of the blue-green bacteria (algae): photoheterotrophic growth of a "heterotrophic" blue-green bacterium.	nostoc sp. (strain mac) was shown to be capable of using glucose, fructose, or sucrose as a sole source of carbon and energy in the dark. in the light in the absence of exogenously supplied co(2), this strain exhibited a more versatile metabolism. in addition to the three sugars above, glycerol and acetate served as sole sources of carbon. this photoheterotrophic growth in the absence of exogenously supplied co(2) appears to involve o(2)-evolving photosynthesis. the action spectrum for photohete ...	1973	4196252
ultrastructural development of nostoc muscorum a.		1973	4198641
differentiation in nostoc muscorum: nitrogenase is synthesized in heterocysts.	cellular differentiation can be observed in certain filamentous blue-green algae after transfer of the cells from medium containing nh(4) (+) or no(3) (-) to nitrogen-free medium. the appearance of differentiated cells (heterocysts) is accompanied by an increase in the activity of nitrogenase, an enzyme complex that reduces n(2) to nh(3). we have separated vegetative cells from heterocysts in differentiated filaments of nostoc muscorum, and analyzed their proteins by polyacrylamide-gel electroph ...	1973	4200722
phycobilisomes from a blue-green alga nostoc species.	phycobilisomes were isolated from a nostoc sp. strain mac in phosphate buffer (ph 7.0) by treatment with 1% brij 56 and centrifugation on discontinuous sucrose gradients (2.0, 1.0, 0.5, and 0.25 m in the proportions 6:4:4:10 ml, respectively). absorption spectra of isolated phycobilisomes showed the presence of phycoerythrin, phycocyanin, and allophycocyanin. the phycobilisome pigments were partially resolved by electrophoresis on acrylamide gels. stained gels demonstrated that each main protein ...	1973	4200843
phycobilisomes in blue-green algae.	fifteen species of freshwater blue-green algae, including unicellular, filamentous, and colonial forms, were subjected to a variety of fixatives, fixation conditions, and stains for comparison of the preservation of phycobilisomes. absorption spectra of the corresponding in vivo and released photosynthetic pigments, in 10 of the species that were maintained in culture, demonstrated the presence of phycocyanin in all 10 species and phycoerythrin in only 2 of them. spectroscope and electron micros ...	1974	4204443
heterotrophic growth of the nitrogen fixing blue-green alga nostoc muscorum.		1974	4212052
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
two plant-type ferredoxins in light-grown and dark-grown cells of the blue-green bacterium nostoc strain mac.		1975	236956
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
[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
partial purification and properties of ornithine transcarbamoylase from nostoc muscorum kützing.	ornithine transcarbamoylase (carbamoyl phosphate:l-ornithine carbamoyltransferase, ec 2.1.3.3) has been partially purified from the blue-green alga nostoc muscorum kützing, an organism in which the enzyme seems to be involved in a bicarbonate-fixing pathway leading to citrulline. pertinent to possible regulation of this pathway, the enzyme shows hyperbolic substrate kinetics, has a molecular weight estimated at 75,000 daltons, and its catalytic capability is little influenced by a selection of m ...	1975	16659361
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
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
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
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
purification and characterization of glucose dehydrogenase from a heterotrophically grown blue-green alga.	nadp- and nad-dependent glucose dehydrogenase was partially purified from a dark-grown blue-green alga (endophytic nostoc strain mac). polyacrylamide gel electrophoresis established that a single protein possessed dual activity for either nadp or nad. no other electron acceptor substituted for pyridine nucleotides and no evidence for a flavin prosthetic group was found. although the km for nadp was 8.8 mum and for nad 328 mum, the enzyme was equally active with nad or nadp at saturating levels o ...	1976	16659685
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
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
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
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
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
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
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
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
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
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
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
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
phycobilisomes from blue-green and red algae: isolation criteria and dissociation characteristics.	a general procedure for the isolation of functionally intact phycobilisomes was devised, based on modifications of previously used procedures. it has been successful with numerous species of red and blue-green algae (anabaena variabilis, anacystis nidulans, agmenellum quadruplicatum, fremyella diplosiphon, glaucosphaera vacuolata, griffithsia pacifica, nemalion multifidum, nostoc sp., phormidium persicinum, porphyridium cruentum, p. sordidum, p. aerugineum, rhodosorus marinus). isolation was car ...	1979	16660778
light-induced changes in allophycocyanin.	several lines of evidence indicate that allophycocyanin is the previously unidentified "phycochrome" observed in extracts of blue-green algae.fractions containing phycoerythrin, phycocyanin, and allophycocyanin and exhibiting light-induced absorbance changes were prepared from extracts of nostoc muscorum and fremyella diplosiphon by isoelectric focusing. illumination of such fractions with red light (650 nanometers) causes a reduction in absorbance at 620 nm ( approximately 1 to 2%) and an incre ...	1980	16661143
photophosphorylation capacity of stable spheroplast preparations of anabaena.	spheroplasts from anabaena 7119 (formerly designated nostoc muscorum) were prepared in the presence of serum albumin in 0.5 molar sucrose. electron transport and photophosphorylation were preserved (> 70% of the maximum rate for 1 week). the ph profile of electron transport and photophosphorylation in the reactions h(2)o --> nadp, h(2)o --> methyl viologen, and h(2)o --> ferricyanide shows that uncoupling by ammonia is small throughout and increases slightly with higher ph. adp + pi increased na ...	1980	16661453
response of n(2)-fixing cyanobacteria to salt.	the effect of salt on photosynthetic activity, acetylene reduction, and related activities was examined in two species of cyanobacteria, nostoc muscorum and calothrix scopulorum. photosynthesis was more resistant to high salt concentration than was n(2) fixation. the salt resistance of both activities increased after a period of exposure of the cells to salinity. the transfer of electrons via ferredoxin and ferredoxin-nicotinamide adenine dinucleotide phosphate reductase was found to be extremel ...	1980	16345644
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
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
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
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
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
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
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
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
chlorophyll-protein complexes of the cyanophyte, nostoc sp.	four chlorophyll-protein complexes have been resolved from the cyanophyte, nostoc sp., by sodium dodecyl sulfate (sds) polyacrylamide gel electrophoresis at 4 c. complexes solubilized by sds from spinacia oleracea were run for comparison. as has been well documented, the p700-chlorophyll a-protein complex from the higher plant and blue-green algal samples are similar, and the light-harvesting pigment protein complex is present only in the former. most noteworthy are two closely migrating chlorop ...	1980	16661198
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
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