Aphanizomenon Flos-aquae Research Articles

Collapses of Aphanizomenon flos-aquae blooms resulting in massive fish kills in eutrophic lakes: effect of weather

(1978). Collapses of Aphanizomenon flos-aquae blooms resulting in massive fish kills in eutrophic lakes: effect of weather. SIL Proceedings, 1922-2010: Vol. 20, No. 1, pp. 208-213.

Struttura e biomassa dei popolamenti fitoplanctonici del Lago Omodeo (Sardegna centrale)

Abstract Composition and biomass of phytoplanktonic communities of Lago Omodeo (Central Sardinia).—A qualitative and quantitative study has been made on the phytoplankton of Lago Omodeo. The algal associations are typical of eutrophic waters. The dominant blue-green algae in summer and autumn were: Chroococcus dispersus, Microcystis flos-aquae, Aphanizomenon flos-aquae, Anabaena flos-aquae, Anabaena planctonica; dominant in winter and spring the diatom Melosira distans. The mean standing crop of algae for the trophogenic zone was 9.2 mm3/l; a maximum crop of 53 mm3/l was recorded in August during a Microcystis bloom.

The influence of daylength, light intensity and temperature on the growth rates of planktonic blue-green algae

The in vitro growth rates under continuous light of the four dominant blue-green algae in Lough Neagh, Anabaena flos-aquae Bréb., Aphanizomenon flos-aquae Ralfs fa. gracile Lemm., Oscillatoria agardhii Gom. and Oscillatoria redekei van Goor were slower than in situ rates from Lough Neagh that had been corrected for hours of light received by the algae. However, by culturing on a 6: 18 light-dark cycle in vitro growth rates were obtained that were similar to the in situ rates. Under continuous light small species showed the fastest growth with Oscillatoria redekei the dominant species. However, this pattern was almost completely reversed under the light-dark cycle with Oscillatoria redekei only exhibiting the fastest growth rate under low light conditions. This observation showed agreement with Lough Neagh field data which showed that Oscillatoria redekei reached its maximum crop in April while the other three species were dominant during the summer months. Compared to the generally assumed high thermal tendency of blue-green algae the temperature maxima of the four species were low. No growth was observed at 35°C for any species while Anabaena flos-aquae was severely inhibited at 25°C.

Chelating agents and blue-green algae

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.

Purification of Aphanizomenon flos-aquae toxin and its chemical and physiological properties

A toxin in chromatographically pure form has been isolated from natural blooms of the blue-green alga Aphanizomenon flos-aquae. The toxin is a strongly basic substance, which gives a positive ninhydrin reaction and appears to be a guanidine derivative. A dose of 2·7 μg injected intraperitoneally into 20 g mice caused death in 4·9 min. The purified toxin reversibly blocks action potentials and tension development in amphibian nerve-muscle preparations without alteration of the resting potential. The toxin differs from saxitoxin in some of its chemical and physical properties, and some of its effects on neuromuscular systems.

Phytoplankton succession in a Eutrophic lake with special reference to blue-green algal blooms

An investigation of phytoplankton in Astotin Lake was made between mid-May of 1966 and September of 1967 with particular attention to the ice-free seasons. Astotin Lake is a typical, small eutrophic, kettle lake with shallow, landlocked, hard water in the Canadian prairies. High concentrations of nutrients supported heavy blooms of blue-green algae throughout the summer. The spring communities were dominated by Asterionella formosa in 1966 and by Cyclotella meneghiniana in 1967. Oxygen depletion under ice-cover probably explains the failure of an Asterionella formosa population to appear in 1967. Deficiency of silica and a rise in water temperature apparently caused the decline of the spring pulses of diatoms. Relatively high summer water temperature favoured the blue-green algal blooms and resulted in a high concentration of organic matter. The decomposition of dead Anabaena cells played an important part in the development of subsequent waterblooms, i.e., Microcystis aeruginosa and Aphanizomenon flos-aquae. The sequence of waterblooms of those species was closely related to the change in water temperature. A flos-aquae became incompatible with M. aeruginosa when the temperature fluctuated in a wide range. Most of the non-blue green algae apparently were inhibited by these cyanophyte blooms. Great species diversity appeared intermittently between blooms and a few species of the Scenedesmaceae and the Oocystaceae were relatively compatible to these blooms.

General and applied hydro-biology, particularly as a vehicle of schistosoma. Hypereutrophy, modern deterioration of water

Observações hidrobiológicas do Lago de Brasília, em 1965, mostraram algas planctônicas Desmidiaceae predominantes, com espécies dos gêneros Staurastrum, Micrasterias, Euastrum, Cosmarium Xanthidium, Bambusina, Closterium, Spondilosium, Penium, principalmente, de águas puras e naturais; conforme o texto, são sêres comuns nas águas indígenas do Brasil Central. Mas a nova capital brasileira cresceu ràpidamente, alcançando oerto de meio milhão de habitantes: a influência do homem se apresentou e, em 1968, já causava outro regime hidrobiológico dentro das faixas de saprobidade, com planctos cosmopolitas indicadores de poluição. Encontramos águas já mesossapróbias com cianofíceas indesejáveis em quantidades maciças, como as Aphanizomenon flos-aquae, a Anacystis cyanea (= Microcystis aeruginosa), Anabaenopsis, Gomphosphaeria e outras. O lago que era "Lago de Desmidiáceas" passou a ser um "Lago de Cianofíceas". Os índices de eutrofização dependem de eutrofizantes no numerador, divididos por desmidiáceas no denominador. Quanto maior o número de algas eutrofizantes, tanto maior a eutrofização; exatamente o que acontece no lago de Brasília. os autores chamam a atenção para os estudos de saprobidade das águas do lago, baseado na teoria que os moluscos Planorbidae se instalem dependentes do regime de poluição mesossapróbio; supõe-se por isso a razão por que êsses moluscos acompanham o homem nas suas migrações. Poder-se-à determinar a faixa de saprobidade em que se instalam os moluscos, suspeitando-se entre os regimes A- e B- mesossapróbio. Propõem medidas preventivas de caráter hidrobiológico para evitar a instalação de planorbídeos. Embora os esgotos sejam todos muito bem tratados sanitàriamente e não há nenhum perigo ou queixa quanto a essa parte; mas é o resultado do tratamento de esgotos e restos de águas usadas pelo homem que fornecem nutritivos às àguas: N, P, Ca, Cl, K, etc. ... e que eutrofizam. A eutrofização normal é ótima; o lago fica produtivo de bom plancto e ótimos peixes. Para eutrofia em excesso, os autores criaram o nôvo têrmo HIPEREUTROFIA, descrevem êsses fenômenos, de ordem geral, com explosivo crescimento da população planctônica e fitoplanto mesossapróbio causador de calamitosos problemas. Pode a "hipereutrofia" ser considerada uma nova e grave "praga das águas" que surgiu depois da 2ª guerra mundial, devido á rápida industralização e explosão populacional do homem. Medidas preventivas contra a hipereutrofia poderão ser conseguidas com planejamentos integrados das bacias dos rios, lagos e baías evitando despejos de excessos de nutrientes, em zonas que fiquem como reservas, preservando a biota aquática natural e normal. É possível tal planejamento no Brasil, porque é um dos poucos países, com bacias de rios e lagos artificiais ainda não poluídos.

Toxicity and environmental requirements of a strain of Aphanizomenon flos-aquae (L.) Ralfs.

A toxic strain of Aphanizomenon flos-aquae was isolated and cultured in a defined medium (ASM-1). This strain fixes nitrogen, has a pH optimum of 7.5, and has maximum growth rates at 5000 lux and 26 °C. Phosphorus levels of 1.0 μM readily supported populations of 1 × 105 cells/ml with stimulation of growth evident at a concentration of 0.1 μM P. Tris is inhibitory to growth of this alga at concentrations above 2.5 mM.Toxin production is related to age of culture, temperature, and light intensity but not nitrogen source.Intraperitoneal injection of toxic extracts into Fundulus heteroclitus, Cyprinodon variegatus, and white mice gave a LD100 of 0.5 mg/kg, 0.5 mg/kg, and 8 mg/kg, respectively. Assays with Notemigonus crysoleucas and Bosmina longirostris indicate that the toxin from naturally occurring bloom populations (1 × 106 cells/ml), if released all at once, would be capable of killing certain species of fish and microcrustaceans. Daphnia catawba, however, was much more resistant to toxin (LD100 = 1.0 mg/ml) while cyclopoid copepods, ostracods, and chydorid cladocerans were completely unaffected by toxin concentrations of 2.0 mg/ml. The possible ecological significance of this toxic alga in relation to fish kills is also discussed.

Toxins of a blue-green alga: similarity to saxitoxin.

Toxins were isolated from the freshwater blue-green alga Aphanizomenon flos-aquae. The toxic fractions were characterized by paper and thin-layer chromatography, isolation characteristics, infrared spectra, physiological activity, and reactivity with specific color reagents. The toxic fractions appear to be similar, if not identical, to saxitoxin (paralytic shellfish toxin), which is produced by the marine dinoflagellate Gonyaulax catenella.

Demonstration of a toxin from Aphanizomenon flos-aquae (L.) Ralfs.

A potent toxin was extracted from a natural population of the blue-green alga, Aphanizomenon flos-aquae. The toxin is thermo- and acid-stable; alkaline labile; soluble in water and ethanol; insoluble in acetone, ether, and chloroform; and readily dialyzable. Preliminary studies show that the alga contains a toxin which, when released from lysed cells, operates at the membrane level, destroying excitability without alteration of the transmembrane resting potential.

Acetylene reduction by nitrogen-fixing blue-green algae.

Known nitrogen-fixing species of blue-green algae are capable of reducing acetylene to ethylene, but acetylene is not reduced by Anacystis nidulans, which does not fix nitrogen. Cycad root nodules which contain blue-green algae as endophytes reduce acetylene. Acetylene reduction is inhibited by carbon monoxide. Nitrate or ammonium-nitrogen has no immediate effect on algae reducing acetylene, but algae grown on nitrate-nitrogen gradually lose their capacity to reduce acetylene. Nitrate-nitrogen also inhibits heterocyst formation in these algae and there is a fairly direct correlation between the abundance of heterocysts in a particular sample and its capacity to reduce acetylene. Aphanizomenon flosaquae reduces acetylene and fixes nitrogen in unialgal culture and there is strong presumptive evidence that these reductions are carried out by the alga rather than by associated bacteria. The molar ratios of ethylene: ammonia produced vary within the range 1.4–1.8.

The carotenoids of blue-green algae—II. : The carotenoids of Aphanizomenon flos-aquae

The carotenoid composition of Aphanizomenon flos-aquae has been re-examined in a quantitative manner. The epiphasic fraction comprised β-carotene (I), flavacin, aphanin and aphanicin. The last two were shown to be identical with echinenone (IV) and canthaxanthin (VI) respectively. The hypophasic fraction contained in addition to aphanizophyll small amounts of myxoxanthophyll. Aphanizophyll and myxoxanthophyll are different pigments.

Observations on the Growth and Colony Habits of Ten Strains of Aphanizomenon flos-aquae

Ten strains of the blue-green alga Aphanizomenon flos-aquae were obtained in unialgal culture by isolating single colonies from samples of waterbloom collected in south central Saskatchewan and eastern Ontario. Two strains from Saskatchewan produced large, ribbon-like colonies up to 30 mm long and 5 to 6 mm wide in a medium containing two different preparations of soil extract. Both strains produced typical small colonies in medium without soil extract or with other soil extract preparations. The large colonies produced by these strains were similar to those observed in plankton from south central Saskatchewan, Oregon, southern Germany, and Russia. Eight strains from Ontario produced only typical small colonies under identical or comparable conditions. After a prolonged period of growth in soil extract medium, all strains became partially or completely non-colonial. Soil extract was not essential for growth. Differences in the colony habit of the 10 strains in soil extract medium or of colonies observed in plankton samples could not be correlated with differences in cellular dimensions or appearance. Colony habit appears to depend on genetic and nutritional factors which may involve the associated bacterial flora as well as the alga.

THE ISOLATION, PURIFICATION, AND CULTURE OF BLUE–GREEN ALGAE

ALTHOUGH SPECIES of blue-green algae produce serious nuisance blooms and growths in lakes and streams, surprisingly little work has been done on their nutrition and physiology under controlled conditions in the laboratory. This is undoubtedly due to the difficulties that have been encountered in growing many species of Myxophyceae in pure culture, a point stressed in a recent publication by Rodhe (1948). He was unable, in spite of numerous attempts and modifications of the nutrient medium, to grow such common bloom-producers as Anabaena flos-aquae, Aphanizomenon flos-aquae, Coelosphaerium Naegelianum, or Microcystis aeruginosa in a nutrient solution which was suitable for continuous growth of forty species belonging to Chlorococcales, Volvocales, Conjugatae, Heterokontae, and diatoms. It is true that several species from the family Nostocaceae have been cultured in the laboratory in studies on nitrogen fixation (Allison and Morris, 1930; Allison et al., 1937; Fogg, 1947). However, usually the species grown have not been those that are troublesome in lakes and streams, and, as a result, this work has not contributed specific data on the growth requirements of the bloom producing algae. For this reason, a project was started in this laboratory in 1947, as one part of a general program of Lakes and Streams Investigations at the University of Wisconsin, with the purpose of obtaining basic data on the nutrition and physiology of blue-green algae. It was considered essential to isolate a number of species in bacteria-free cultures before nutrition experiments were started, for only in this way would the data obtained be specific for the algae. This paper is a report on the procedures used and progress made in isolating, purifying from bacteria, and culturing representative species of these organisms. The results of nutritional and physiological studies will be presented in later publications. NUTRIENT SOLUTION FOR BLUE-GREEN ALGAE.-A survey of the literature indicated that nutrient solutions had not been developed which were generally successful for the continuous culture of blue-green algae. Consequently, several solutions were tried which have been used extensively by 1Received for publication August 8, 1949. The authors wish to thank Dr. Francis Drouet of the Chicago Natural History Museum and Dr. R. I. Evans of the University of Wisconsin Botany Department for aid in identification of the blue-green algae isolated in this study. Appreciation is also expressed to Drs. A. Hasler and P. J. Allen for their interest and valuable suggestions, to Dr. J. F. Stauffer for aid, and use of ultraviolet irradiation apparatus, and to Dr. W. B. Sarles and Mr. A. C. Zagallo of the Agricultural Bacteriology Department for final tests of the purity of the irradiated cultures. This work was supported in part by the University Research Committee on funds from the Wisconsin Alumni Research Foundation, from Thomas E. Brittingham, Jr., and from the Lake Mendota Association. other investigators for green algae and diatoms. Of these, Chu No. 10, one of the seventeen nutrient solutions published by S. P. Chu (1942), gave most promising results. It soon was found that Chu No. 10 solution was improved as a culture medium for blue-green algae by substituting an organic source of iron, ferric citrate, for the ferric chloride specified by Chu. This improvement, due to increased iron availability, also has been reported by Rodhe (1948). Furthermore, he found by tests with o-phenanthroline that the addition of an equal amount of citric acid with the ferric citrate stabilized the concentration of reactive iron in the nutrient solution. This modification has been adopted. In the work to be reported here, therefore, the culture solution has the following composition: