A study of several blue-green algae in the electron microscope

Summary All of the three blue-green algae, Anabaena cylindrica, Mastigocladus laminosus and Nostoc muscorum are characterized by the presence of multi-layered envelopes (sheath, wall and plasma membrane), photosynthetic lamellae and a variety of intracellular granules. Sections of heterocysts of Anabaena cylindrica showed the presence of an internal membrane system as well as lamellae. An unusual feature of the structure of Nostoc muscorum was the presence of densely stained intracellular membranes or lamellae. The results emphasize the variability in appearance of the internal structure of the blue-green algae and point to the need for detailed investigations of the influence of change in physiological environment on the anatomy of these organisms.     

Measurement of the Cyanophycin Granule Polypeptide Contained in the Blue-Green Alga Anabaena cylindrica

An assay was developed to determine the amount of cyanophycin granules in blue-green algae. The amount of this polypeptide in cells of Anabaena cylindrica was measured as a function of culture age and was compared with changes in other proteinaceous cellular components. The data presented support the notion that the cyanophycin granule is a cellular nitrogen reserve.     

Quantitative relationship between two reaction centersin the photosynthetic system of blue-green algae

The quantitative relationship between reaction centers I andII was studied with blue-green algae Anabaena cylindrica, Anabaenavariabilis and Anacystis nidulans grown under different lightconditions. The number of reaction centers I was estimated fromthe P700 content and that of reaction centers II, from the O₂yield of repetitive short flashes. Supplementary determinationswere done with three other blue-green algae and one red alga.The maximum number of reaction centers II counted from the O₂yield of repetitive short flashes was markedly smaller thanthe total number of P700 in all algae tested when the algaewere grown under weak light; in the extreme case (Anabaena cylindrica),the ratio was only 0.258?0.015. This ratio became larger andclose to unity when the algae were grown under stronger light.Variation in the number of reaction centers in a single cellsuggested that reaction center I was a variable component. Ourresults indicate that the proportion of the two reaction centersmay markedly vary in blue-green algae depending on the growthconditions (Received November 13, 1978; )     

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, and Anacystis nidulans strain TX20) were closely similar in molecular size, since enzyme activity was eluted at the same volume after sucrose gradient centrifugation. Further analysis by gel filtration indicated that the four blue-green algal carboxylases were nearly identical in molecular weight, ranging from 449 to 453,000. The amino acid composition of the Anabaena carboxylase was determined and was found to resemble closely the composition of the large subunit from eukaryotic photosynthetic organisms.     

几种固氮蓝藻的固氮酶活性及其某些特性

对三种固氮蓝藻:固氮鱼腥藻(水生686)、柱孢鱼腥藻和鱼腥藻7120的整细胞及无细胞抽提液的固氮酶活性,进行了比较研究。水生686的整细胞酶活虽然不低(51.9毫米乙烯峰高/光密度/30分),仅次于柱孢鱼腥藻,但其无细胞抽提液的酶活却最低。这可能与它含有大量藻胶有关。研究了Mn++、Fe++对蓝藻固氮酶的作用,以及测定其在不同酶浓度下的反应动力学表明:柱孢鱼腥藻中不存在象深红螺菌中所看到的那种激活因子。用甲苯-乙醇溶液处理藻细胞,对固氮酶作原位测定,探索了它的氧损伤及氧保护机理。       

Phosphorus availability and nitrogenase activity in aquatic blue-green algae

Metabolically active phosphorus-starved cultures of blue-green algae assimilate ³²P rapidly in the light and in the dark. The uptake of phosphorus results in a rapid (within 15 min) stimulation in acetylene reduction by Anabaena cylindrica, A. flosaquae, Anabacnopsis circuiaris and Chlorogloea fritschii, with a response being obtained to less than 5 μg/1 of phosphorus. Uptake of phosphorus also causes a rapid increase in respiration in the dark but not in photo respiration, and the size of the cellular ATP pool and the ¹⁴CO₂ fixation rate both increase more slowly. The metabolism of phosphorus-sufficient cells, which assimilate phosphorus more slowly, shows little response when phosphorus is provided. Excess phosphorus is stored in the vegetative cells of blue-green algae as polyphosphate bodies which may form within 60 min of adding phosphorus to phosphorusstarved cells and which serve as a source of phosphorus for the algae when exogenous phosphorus is limiting. Preliminary results from Scottish waters suggest that urban effluents are important sources of available-phosphorus for algal growth and that the levels entering fresh waters from agricultural land are, per unit volume, lower. In both types of water the levels of available-phosphorus are rather similar to the levels of orthophosphate-phosphorus present. Most detergents tested serve as a source of phosphorus for nitrogen-fixing blue-green algae and cause a rapid stimulation in reduction when added to phosphorus-starved cultures. Of the detergents assayed, the biological types were richest in available phosphorus. The addition of detergents may result in a rapid increase in number of polyphosphate bodies present in the algae. Detergents in general also contain an inhibitor of algal metabolism. Whether a stimu-lation or an inhibition occurs depends on the quantities of detergent added and on whether or not the alga is phosphorus-deficient.     

Observations of Toxic Blue-Green Algae (Cyanobacteria) in Some Scandinavian Lakes

Blooms of blue-green algae from 51 eutrophic Scandinavian lakes were investigated during the period 1978–1984, to ascertain the occurrence of toxinogenic species. Toxicity assays were performed by intraperitoneal injection of suspensions of freeze-dried algal material in mice. Toxin-producing blue-green algae were found in 30 lakes. They belonged to 11 different species of the six genera Anabaena, Aphanizomenon, Gomphosphaeria, Microcystis, Nodularia and Oscillatoria. The presence of toxinogenic strains of blue-green algae seemed quite constant in several of the localities studied. In some lakes, more than one toxic species were found to develop simultaneously. The level of toxicity showed large variation (MLD100, 6 to > 2500 mg/kg), but clinical and pathological changes were quite uniform. The results indicate that water-blooms of toxin-producing blue-green algae, in the geographical area in question, are regionally widespread. In some localities, blooms of blue-green algae are apparently always toxic. Several aspects of the toxic blue-green algae problem are discussed.     

Effects of low concentrations of bisulfite-sulfite and nitrite on microorganisms.

A wide range of microorganisms was tested to determine their sensitivity to low concentrations of bisulfite-sulfite and nitrite, solubility products of SO2 and NO2, respectively. Photosynthesis by blue-green algae (cyanobacteria) was more strongly inhibited by 0.1 mM bisulfite-sulfite and 1 mM nitrite at pH 6.0 than photosynthesis by eucaryotic algae and respiration of bacteria, fungi, and protozoa. At pH 7.7, blue-green algae were still more sensitive to bisulfite-sulfite and nitrite than eucaryotic algae, but the toxicity of bisulfite-sulfite and nitrite decreased as the pH increased. Photosynthesis by Anabaena flos-aquae at pH 6.0 was inhibited 25% by a bisulfite-sulfite concentration of 10 micrometer and 15% by a nitrite concentration of 50 micrometer. Photosynthesis by the blue-green alga, Lyngbya sp., was not exceptionally sensitive to chlorate and thiosulfate. Acetylene-reducing activity of Beijerinckia indica was completely inhibited by 0.1 mM bisulfite-sulfite at pH 4.0, the suppression being decreased with increasing pH.     

Algal nitrogen fixation in the tropics

Summary a)Nitrogen fixation in rice fields. Nitrogen-fixing blue-green algae grow abundantly in tropical regions and are particularly common in paddy fields. Their possible role in the nitrogen accumulation of soil has been studied. The most vigorous nitrogen-fixing blue-green algae have been assessed for use as green manure in rice fields and favorable effects have been reported in India and other countries. b)Nitrogen fixation by algae in water. The planktonic blue-green algae occur abundantly at certain time of the year in sea water and lake water, and some of them are known to be nitrogen fixers. Certain Japanese species of blue-green algae can withstand high temperatures including ten nitrogen-fixing species from hot-spring waters. c)Nitrogen fixation by symbiotic blue-green algae. Certain species of blue-green algae form associations with other organisms such as fungi, liverworts, ferns and seed plants. The relationship between these two organisms is on one occasion commensal and on others symbiotic. Certain symbiotic blue-green algae are provided with the ability to fix the atmospheric nitrogen.     

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 microscope evidence was obtained for localization of phycobiliproteins in phycobilisomes of Nostoc muscorum. Phycobilisomes were observed in all species examined in situ, strenghening the hypothesis that phycobilisomes are common to all phycobiliprotein-containing photosynthetic blue-green algae.     

固氮蓝藻“红圈病”的研究——Ⅰ.“红圈病”在大面积培养蓝藻中的危害以及防范措施

对蓝藻“红圈病”的病症、发病条件、传播程度方式、危害进行了研究。结果表明,发病条件与蓝藻最佳生长条件基本一致;病原通过水体和带病藻体传播,对藻的产量和质量均造成严重危害。同时探讨了综合防治措施。     

Utilisation of blue-green algae as biofertilisers

Biologically active compounds may be liberated from blue-green algae growing on the surface of moist soils. Such compounds may also be released as exudates from algae grown in liquid culture.This report describes inoculation of soils in pots, containing radish or tomato plants, with algal suspensions or exudates, which resulted in increased growth rates of both plants and increased their overall yield. Autoclaved exudates were generally as effective as fresh exudates. Interaction of effects between the various active substances depends on the algal species and method by which the soils are amended.     

The occurrence of the hydrogenase in some blue-green algae

Several blue-green algae were surveyed for the occurrence of the hydrogenase which was assayed by the oxyhydrogen or Knallgas reaction in the intact organisms. In aerobically grown cultures, the reaction was detectable in Anabaena cylindrica, Nostoc muscorum and in two Anabaena variabilis species, whereas virtually no activity was observed in Anacystis nidulans and Cyanophora paradoxa. In these latter two algae, the reaction was, however, found after growth under molecular hydrogen for several days, which drastically increased the activity levels with all the algae tested. In the nitrogen fixing species, the activity of the Knallgas reaction was enhanced when all combined nitrogen was omitted from the media. H₂ and hydrogenase could not significantly support the CO₂-fixation in photoreduction experiments with all blue-green algae investigated here. Hydrogenase was assayed by the dithionite and methyl viologen dependent evolution of hydrogen and was found to be present with essentially the same specific activity levels in preparations of both heterocysts and vegetative cells from Anabaena cylindrica. Na₂S₂O₄ as well as H₂ supported the C₂H₂-reduction of the isolated heterocysts. The H₂-dependent C₂H₂-reduction did not require the presence of oxygen but was strictly light-dependent where H₂ served as an electron donor to photosystem I of these cells. It is concluded that hydrogen can be utilized by two different pathways in blue-green algae.Abbreviations Chl chlrophyll - CP creatine phosphate - CP kinase creatine phosphokinase - DCMU N-(3,4-dichlorophenyl)N,N-dimethylurea     

In vivo fluorometric method for early detection of cyanobacterial waterblooms

A specific method was developed for monitoring the concentration of cyanobacteria (blue-green algae) before waterblooms, based on their characteristics ofin vivo fluorescence. The excitation and emission spectra of cyanobacteria are very different from those of eukaryotic algae, due to the importance of phycocyanin, rather than chlorophylla, in determining the fluorescence characteristics. Our results, based on four cyanobacteria:Microcystis aeruginosa, Anabaena cylindrica, Phormidium tenue andSpirulina platensis, indicate that excitation at 620 nm and its emission at 645 nm is a sensitive and specific method for their detection. Furthermore, the addition of 10 M photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) induced only 3% increase in phycocyanin fluorescence, suggesting that this measurement is almost independent of the ongoing rate of photosynthesis.Author for correspondence     

Effect of blue-green alga (Cyanobacteria) and their exometabolites on formation of resting forms and variability of Yersinia pseudotuberculosis

Research, carried out with the use of bacteriological methods and polymerase chain reaction, revealed that the transformation of Y. pseudotuberculosis, associated with blue-green algae Anabaena variabilis, into resting (noncultivable) forms took shorter time than in soil extract containing no algae. The exometabolites of "old" cultures of these algae sharply accelerated the formation of resting Y. pseudotuberculosis forms. The influence of the algae and the products of their metabolism was manifested far more intensively at 22 degrees C than at 4 degrees C. After passage through infusoria resting Y. pseudotuberculosis forms, preserved in the mucous covering of cyanobacteria, partially reverted into vegetative forms, capable of growing on solid culture media. The revertants essentially differed from the initial vegetative forms by having lower enzymatic activity, agglutinability and cytopathogenicity, as well as by the loss of plasmid p45. The probable role of blue-green algae, widely spread in soils and water reservoirs, in the processes of reversible transformation of Y. pseudotuberculosis vegetative and resting forms, closely connected with seasonal changes of temperature conditions.     

Physiological studies on nitrogen-fixing blue-green algae

Summary The various types of blue-green algae known to fix nitrogen are considered. Particular attention has been paid to the effects of oxygen and other physiological parameters on nitrogenase activity and on the ecological distribution of the group. Data on nitrogen fixation by cell-free extracts of blue-green algae are presented.     

Studies with deoxyribonucleic acid from blue-green algae

Summary The total DNA in species of blue-green algae is similar to that of bacteria on an individual cell, but not on a dry weight, basis. The % G+C content of DNA from four species of blue-green algae has been determined by melting temperature measurement. An attempt tomeasure genetic homology between blue-green algae and certain bacterial species is described.     

Nitrogenase Activity in Relation to Intracellular Organisms in Sphagnum Mosses

Electron microscopic studies of Sphagnum lindbergii (Schimp.) and S. riparium (Ångstr.) have revealed the presence of intracellular organisms such as blue-green algae, green algae, bacteria and fungi. Nitrogenase activities of these Sphagnum mosses were found to be related mainly to the presence of intracellular Nostoc filaments. The appearance of nitrogen-fixing blue-green algae within bryophytes is thus not restricted to liverworts. The association is likely to be of ecological importance as it seems to occur in very acid habitats generally lacking blue-green algae. Possible interrelations between the moss, the blue-green algae and different types of bacteria are discussed.     

Glycollate oxidation by thylakoids of the cyanobacteria Anabaena cylindrica,Nostoc muscorum and Chlorogloea fritschii

The intracellular distribution of glycollate dehydrogenase EC 1.2.1.17 has been investigated in extracts of the cyanobacteria (blue-green algae) Anabaena cylindrica, Nostoc muscorum and Chlorogloea fritschii. Most of the enzyme activity was associated with a chlorophyll-containing cell-free pellet, which also exhibited Photosystem I and II activities. Sucrose density gradient centrifugation of this washed pellet resulted in the formation of a green band within which maximal chlorophyll concentration and enzymic glycollate oxidation coincided. Antiserum raised to this fraction obtained from A. cylindrica inhibited glycollate dehydrogenase and Photosystem II activity. The data indicate that most of the cyanobacterial glycollate dehydrogenase is associated with the thylakoids and thus provide evidence for the dual role of these membranes in photosynthetic and respiratory processes.Abbreviations DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - DCPIP 2,6-dichlorophenolindophenol - DPC diphenylcarbazide     

太湖蓝藻滤液的遗传毒性研究

蓝藻爆发是环境污染引发的重要事件之一,随之产生的蓝藻毒素又直接危及区域水安全.该论文采用蚕豆和大蒜根尖微核试验研究了太湖蓝藻暴发期间蓝藻滤液的遗传毒性.结果表明,同阴性对照相比,所有试验处理对蚕豆根尖细胞微核发生率的影响显著增加;对大蒜根尖细胞微核发生率而言除蓝藻滤液8倍稀释液的影响不显著外,其它水平效应显著高于阴性对照,而且表现出一定的剂量效应.暴发期蓝藻滤液原液对蚕豆根尖细胞微核发生率影响显著高于阳性对照(0.8mg·mL^-1环磷酰胺)的效应,从而说明蓝藻暴发时期蓝藻滤液具有较强的遗传毒性.通过微核试验效果分析,蚕豆作为植物监测系统的敏感性和稳定性都优于大蒜材料.