Genetic control of heterocyst formation in the blue-Green algae Nostoc muscorum and nostoc linckia

1977 ◽  
Vol 114 (2) ◽  
pp. 155-159 ◽  
Author(s):  
H. N. singh ◽  
J. K. Ladha ◽  
H. D. Kumar
Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 245 ◽  
Author(s):  
MH Mian

Denitrification of nitrogen from applied NH4+ and NO3-, and nitrogen released from Azolla caroliniana, Anabaena variabilis and Nostoc muscorum, was studied in a flooded soil. Denitrification did not occur in Azolla-, Anabaena-, Nostoc- or ammonium sulfate-treated soil, incubated at 18� to 25�C, until after 30 days since time was required to develop a surface-oxidized layer where nitrification could first take place. About 32, 45 and 49% of the total nitrogen in Azolla, Anabaena and Nostoc was released as mineral-N in 60 days, with 96, 93 and 93% respectively of this being lost as N2. Thus potentially serious losses of nitrogen from Azolla and blue-green algae may be avoided if their incorporated residues in flooded soils are left no longer than 3 weeks before planting a rice crop. Denitrification started within 3 days of incubation in the sodium nitrate-treated soil. About 10 and 75% of the ISN applied as ammonium sulfate and sodium nitrate, respectively, was lost as N, in 60 days. In addition, a substantial amount of 15N+4- N was formed from the applied 15NO-3-N (about 9% of the total amount added) in 60 days, indicating that a dissimilatory pathway also existed in this soil.


1977 ◽  
Vol 32 (1-2) ◽  
pp. 118-124 ◽  
Author(s):  
Georg H. Schmid ◽  
Helga List ◽  
Alfons Radunz

An antiserum to lutein agglutinates thylakoids of Nostoc muscorum and Oscillatoria chalybea. From this it follows that lutein is located in the outer surface of the thylakoid membrane of these blue-green algae. The same result is obtained for an antiserum to neoxanthin. As neoxanthin is supposed not to occur in blue-green algae it follows that in this case the antibody action should be directed towards a carotenoid with allenic structure. The antisera to lutein and neoxanthin inhibit in both investigated algal species photosynthetic electron transport on the oxygen-evolving side of photosystem II. Moreover, the inhibition sites of both antisera are identical in Nostoc muscorum and are located between the sites of electron donation of the artificial electron donors tetramethyl benzidene and diphenylcarbazide. In the case of the blue-green alga Oscillatoria chalybea the inhibition sites of both antisera differ. Whereas the inhibition site of the antiserum to neoxanthin lies again between the sites of electron donation of tetramethyl benzidine and di­phenylcarbazide, the inhibition site of the antiserum to lutein appears to be situated at least partially beyond the site of electron donation of tetramethyl benzidine. The degree of inhibition of electron transport reactions with Nostoc muscorum is for both antisera 50 - 60 per cent and is pH-dependent. The pH-optimum lies at pH 7.2 for the antiserum to neoxanthin and at 7.8 for the antiserum to lutein. In comparison to this data the same antisera inhibit electron transport in chloroplasts from higher plants only by 20%. This low degree of inhibition in higher plants is apparently due to the fact that the surfaces of the thylakoids are not accessible to antibodies within the grana. In contrast to this the thylakoid surfaces of blue-green algae are fully accessible because the thylakoids are unstacked. The thylakoids of Oscillatoria chalybea have the tendency towards aggregation. Therefore, the results concerning the accessibility of the carotenoids to antibodies are not so clear cut as with Nostoc muscorum.


1974 ◽  
Vol 20 (10) ◽  
pp. 1311-1321 ◽  
Author(s):  
Willy Lange

Many planktonic blue-green algae produce natural chelators which enable them to grow at high pH's in the absence of artificial chelators. The growth of 10 cyanophytes without an added chelator was found to differ widely with the algal species. Bacteria-containing cultures of Anabaena cylindrica, Anacystis nidulans, Lyngbya sp., Microcystis aeruginosa, Nostoc muscorum, and Phormidium foveolarum produced their own chelators and grew just as well as the controls with artificial chelating agents. Bacteria-containing cultures of Anabaena circinalis, Gloeotrichia echinulata, Oscillatoria rubescens, and Aphanizomenon flos-aquae did not produce chelators and, in the absence of artificial agents, grew poorly or perished early. The alga-produced, extracellular chelators were water-soluble and capable of chelating and controlling metal compounds that would exist in colloidal form at pH's above 7. Accordingly, in the absence of artificial chelators, the non-chelator-forming species grew in the filtrates of the chelator-forming algae the same as in the presence of artificial agents. Bacteria were not involved in the formation of natural chelators, since axenic cultures of Anabaena circinalis, Anacystis nidulans, Microcystis aeruginosa, Nostoc muscorum, and Phormidium foveolarum in the absence of artificial chelators performed about the same as the bacteria-associated species. Also, the filtrates of axenic, chelator-forming Anacystis cultures had the same growth-stimulating effect on non-chelator-forming species as filtrates from bacteria-associated cultures. The natural chelators showed partial thermolability.While the growth of chelator-forming species in the absence of artificial chelators was normal during the logarithmic phase, a peculiar, continuing production of total organic matter was observed with strongly declining cell numbers of Lyngbya, Microcystis, and Phormidium. The terminal cultures of these species were gelatinous, owing to the presence of extracellular matter, probably consisting of polysaccharides.


1984 ◽  
Vol 39 (6) ◽  
pp. 623-626 ◽  
Author(s):  
Irene Alpes ◽  
Erwin Stürzl ◽  
Siegfried Scherer ◽  
Peter Böger

An antibody prepared against purified cytochrome c-553 from Nostoc muscorum inhibits the redox function of cytochrome c-553 as checked by a diaphorase assay. 20 to 30% inhibition of NADPH-driven respiratory and light-induced oxygen uptake by Nostoc thylakoids is observed when cytochrome c-553 specific antibodies were applied. However, only 30 to 50% of the total cytochrome c-553 content is released from isolated membrane material, thus being accessible to antibodies. Supplementing the isolated membrane material with excess Nostoc cytochrome before adding the antibody abolishes inhibition. The data provide further evidence for soluble cytochrome c-553 being a link between photosynthetic and respiratory electron transport in blue- green algae.


1973 ◽  
Vol 28 (5-6) ◽  
pp. 285-291 ◽  
Author(s):  
P. Pohl ◽  
G. Drath

The nitrogen fixing blue-green algae, Anabaena cylindrica and Nostoc muscorum , were grown as 71 cultures in various media, at different temperatures (15 °C and 23 °C ), and under light of different wavelengths. In all cases, the amount of combined nitrogen excreted into the medium readied a value of 700 - 800 μMol N/1 of nutrient medium after 4 -6 weeks of growth. Thereafter, this value did not increase significantly. When several cultures of algae were successively grown in the same medium, or when culturing was carried out for a long time with frequent harvesting, the nitrogen content of the nutrient medium remained at approximately the same level as mentioned. The possible reasons for these observations are discussed.


1970 ◽  
Vol 175 (1040) ◽  
pp. 293-311 ◽  

The blue-green algae Anabaena flos-aquae and Nostoc muscorum may reduce acetylene to ethylene most actively at p O 2 levels below 0.2 atm. High p O 2 levels inhibit acetylene reduction, nitrogen fixation, respiration and 14 CO 2 fixation in A . flos-aquae . The effect is not solely via an inhibition of nitrogenase activity because inhibition of 14 CO 2 fixation by a species of Phormidium which does not fix nitrogen, and by A . flos-aquae grown on combined nitrogen also occurs. The inhibition of acetylene reduction in Anabaena is reversible in short-term experiments, the rate of recovery being rather similar irrespective of the p O 2 level to which the alga was subjected initially. 3(3,4-dichlorophenyl)-1-1-dimethyl urea (DCMU) at a concentration of 3 x 10 -5 M, which completely inhibits oxygen evolution and acetylene reduction but not respiration by aerobically grown Anabaena cultures also inhibits acetylene reduction in Na 2 S-grown cultures. Salicylaldoxime at a concentration of 10 -4 M which partially inhibits electron flow from photosystem II inhibits acetylene reduction to a greater extent under aerobic conditions than in the presence of Na 2 S. The presence of Na 2 S also results in the removal of free oxygen from the medium in the pH range at which Anabaena normally grows. The data suggest that under our conditions (1) the photolysis of water, or photosystem II is essential for the growth of A. flos-aquae in the presence of H 2 S ; (2) H 2 S may provide electrons when reducing power from the photolysis of water is reduced but not inhibited completely; (3) H 2 S prevents an accumulation of oxygen in the medium during photosynthesis. These physiological findings from the laboratory may help to explain why blue-green algae live not only in aerobic environments but also in habitats where reducing conditions may prevail.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Alice Jernigan ◽  
Christa Hestekin

Capillary electrophoresis single-strand conformational polymorphism (CE-SSCP) was explored as a fast and inexpensive method to differentiate both prokaryotic (blue-green) and eukaryotic (green and brown) algae. A selection of two blue-green algae (Nostoc muscorumandAnabaena inaequalis), five green algae (Chlorella vulgaris, Oedogonium foveolatum, Mougeotiasp.,Scenedesmus quadricauda, andUlothrix fimbriata), and one brown algae (Ectocarpussp.) were examined and CE-SSCP electropherogram “fingerprints” were compared to each other for two variable regions of either the 16S or 18S rDNA gene. The electropherogram patterns were remarkably stable and consistent for each particular species. The patterns were unique to each species, although some common features were observed between the different types of algae. CE-SSCP could be a useful method for monitoring changes in an algae species over time as potential shifts in species occurred.


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