Anabaena Cylindrica Research Articles

Epilithic Microalgae Isolated from Biofilm on Borobudur Temple Stone

Borobudur Temple is a historical heritage building located in an open area and made of porous building materials (stone materials). This condition makes the Borobudur Temple susceptible to various problems related to degradation and weathering. Biodeterioration of Borobudur Temple may be caused by activities of living organisms present in the biofilm of stone. Continuous monitoring and evaluation need to be carried out by observing and isolating the growth of micro-organisms, including epilithic microalgae. Therefore, this study aims to isolate and identify epilithic microalgae from the biofilm on Borobudur Temple stones. Epilithic microalgae were isolated to obtain a uni-algae and maintained under culture conditions. The morphological of microalgae were observed using light microscopy, while the 18S rRNA gene sequence determined the molecular identification of microalgae for eukaryotic and 16S rRNA sequence for prokaryotic. A total of nine epilithic microalgae were successfully isolated from the biofilm of Borobudur Temple stones. The isolated were identified as Ankistrodesmus falcatus, Tetraselmis cordiformis, Pseudendoclonium arthropyreniae, Anabaena cylindrica, Nostoc gelatinosum, Oscillatoria limnetica, Messastrum gracile, Stigeoclonium aestivale, and Scenedesmus acuminatus. This is the first study for the identification of microalgae from Borobudur temple stones. The isolates will be collected and will be used as a source for further study.

Selection of water source for water transfer based on algal growth potential to prevent algal blooms

Water transfer is becoming a popular method for solving the problems of water quality deterioration and water level drawdown in lakes. However, the principle of choosing water sources for water transfer projects has mainly been based on the effects on water quality, which neglects the influence in the variation of phytoplankton community and the risk of algal blooms. In this study, algal growth potential (AGP) test was applied to predict changes in the phytoplankton community caused by water transfer projects. The feasibility of proposed water transfer sources (Baqing River and Jinsha River) was assessed through the changes in both water quality and phytoplankton community in Chenghai Lake, Southwest China. The results showed that the concentration of total nitrogen (TN) and total phosphorus (TP) in Chenghai Lake could be decreased to 0.52 mg/L and 0.02 mg/L respectively with the simulated water transfer source of Jinsha River. The algal cell density could be reduced by 60%, and the phytoplankton community would become relatively stable with the Jinsha River water transfer project, and the dominant species of Anabaena cylindrica evolved into Anabaenopsis arnoldii due to the species competition. However, the risk of algal blooms would be increased after the Baqing River water transfer project even with the improved water quality. Algae gained faster proliferation with the same dominant species in water transfer source. Therefore, water transfer projects should be assessed from not only the variation of water quality but also the risk of algal blooms.

Sequential recovery of C-phycocyanin and chlorophylls from Anabaena cylindrica

Cyanobacteria are attracting the attention worldwide as a reliable and sustainable feedstock for the production of biofuels, food colorants and biochemically active compounds. Anabaena cylindrica (A. cylindrica) is a cyanobacterium with a significant widespread occurrence in Portuguese freshwaters, with C-phycocyanin and chlorophylls, compounds with a high market value, being abundantly produced by the species. This work presents the development of a sequential downstream process to obtain C-phycocyanin and chlorophyll from A. cylindrica. The C-phycocyanin extraction is carried using Na-phosphate (20 mM, pH 7) buffer, while aqueous solutions of surface-active compounds (250 mM), as well as ethanol, were screened for the extraction of the chlorophylls. After selecting the best solvents to recover both pigments from A. cylindrica, the operational conditions (solid-liquid ratio, time of extraction and temperature) were optimized, allowing the recovery of around 90% and 55% of the total content of C-phycocyanin and chlorophylls, respectively. Finally, dextran/copolymer-based ABS were applied to promote the purification of C-phycocyanin from the residual chlorophylls and other contaminant proteins, leading to an increase in the C-phycocyanin purity of 4-fold, without compromising its photostability.

First description of betalains biosynthesis in an aquatic organism: characterization of 4,5-DOPA-extradiol-dioxygenase activity in the cyanobacteria Anabaena cylindrica.

The biosynthesis of betalamic acid, the structural unit of pigments betalains, is performed by enzymes with 4,5-DOPA-extradiol-dioxygenase activity. These enzymes were believed to be limited to plants of the order Caryophyllales and to some fungi. However, the discovery of Gluconacetobacter diazotrophicus as the first betalain-forming bacterium opened a new field in the search for novel biological systems able to produce betalains. This paper describes molecular and functional characterization of a novel dioxygenase enzyme from the aquatic cyanobacterium Anabaena cylindrica. The enzyme was found to be a homodimer of a polypeptide of 17.8kDa that, opposite to previous related enzymes, showed a strong inhibition by excess of the precursor L-DOPA. However, its heterologous expression has allowed detecting the formation of the main compounds in the biosynthetic pathway of betalains. In addition, phylogenetic analysis has shown that this enzyme is not close related to enzymes from plants, fungi or proteobacteria such as G. diazotrophicus. The presence of enzymes that produce these health-promoting compounds is more diverse than expected. The discovery of this novel dioxygenase in the phylum cyanobacteria expands the presence of betalamic acid-forming enzymes in organisms of different nature with no apparent relationship among them.

Co-inoculation of rhizobia, azospirilla and cyanobacteria for increasing common bean production

The combined inoculation of Rhizobium (R. tropici+R. freirei), Azospirillum brasilense, and Anabaena cylindrica, a diazotrophic cyanobacterium, is a technology that has not yet been tested and established in the production of the common bean (Phaseolus vulgaris). The inoculation may be a promising strategy for increasing crop productivity by combining the benefits of biological nitrogen fixation with the production of plant growth phytohormones. Therefore, the objective of this study was to evaluate the co-inoculation of Rhizobium, Azospirillum brasilense, and Anabaena cylindrica as an alternative method for optimizing the symbiotic performance and development of the common bean at greenhouse conditions. The treatments were as follows: (T1) control without N and inoculation, (T2) N addition (100 kg N ha-1), (T3) Riz (addition of R. tropici+R. freirei), (T4) Azo (Azospirillum brasilense addition), (T5) Ana (Anabaena cylindrical addition), (T6) Riz+Azo, (T7) Riz+Ana, (T8) Azo+Ana, (T9) Riz+Azo+Ana. We used a completely randomized experimental design with four replications. The co-inoculation of Riz+Azo+Ana promoted plant height, root length and volume, shoot dry matter, accumulated shoot N, number and dry matter of nodules at flowering, number of grains per pod, hundred seed weight, and grain production of the common bean, contributing to increased yield per plant. We observed an increase in common bean grain yield ranging from 62 to 84% after double and triple co-inoculation of rhizobia with azospirilla and/or cyanobacteria, with the highest yield observed in the plants inoculated with Riz+Azo+Ana (84%), similar to those observed in plants after N addition. However, field experiments are necessary to elucidate the performances of the inoculated beneficial microorganisms.

Co-inoculation of Anabaena cylindrica with Azospirillum brasilense increases grain yield of maize hybrids

Cyanobacteria, a group of N2 fixing bacteria, and some species of them are free-living or associated with other bacteria, such as Azospirillum. Their association promotes the growth and productive performance of maize (Zea mays), showing variable responses according to the maize hybrid used. Thus, the aim of this study was to evaluate the effects of inoculation and co-inoculation of the Anabaena cylindrica (cyanobacteria) with Azospirillum brasilense on the development and productive performance of four maize hybrids. The field experiments were carried out in two locations (Londrina and Faxinal, Paraná State, Brazil), using a randomized block experimental design, in a 4 × 4 factorial arrangement, with four replications. Four inoculation treatments were evaluated (A. cylindrica + A. brasilense, A. cylindrica, A. brasilense, and an uninoculated control) in four maize hybrids (512 PW, 2A620 PW, 2B810 PW, Status Viptera 3). The following characteristics were evaluated: plant height, ear insertion height, stem diameter, leaf area index, chlorophyll index, nitrogen, phosphorus and potassium leaf content, number of grain rows per ear, number of grains per row, number of grains per ear, number of ear per plant, mass of 1000 grains, nitrogen content in the grains and yield. The co-inoculation of A. cylindrica with A. brasilense favored the development and yield performance of maize hybrids, with an increase of 966.63 kg ha−1 (9.37%) in Londrina and 1743.79 kg ha−1 (23.1%) in Faxinal, in comparison to the uninoculated control. The maize hybrids showed the similar behavior, regardless of the inoculation or co-inoculation with A. brasilense and A. cylindrica. Therefore, these microorganisms can be recommended as inoculants.

Bioindication of heavy metals in aquatic environment using photosynthetic pigments in cyanobacteria

Freshwater resources is seriously threatened by heavy metals pollution. Thus developing an effective screening method for the presence of heavy metals is required. In this paper, the potential of using cyanobacteria for heavy metals detection in water bodies is determined. The cyanobacteria Anabaena cylindrica had been cultured, immobilized, and exposed to Cu, Pb, and Cd with the concentrations of 0.01 – 10.00 mg/L. The responses of the cells to the heavy metals were measured for 60 min. The effect of the cell culture age and cell density were determined as well. The cells with 7 days of culture age, and the amount of cell with density of OD= 0.5 A (measured at 700 nm wavelength) were found to produce highest photosynthetic fluorescence for the detection for heavy metals. The cells were capable to provide detectable fluorescence emission within 10 min of exposure. Thus the cyanobacteria was identified as a good candidate to serve as bioindicator for the heavy metals in water.

Organic Fertilizer Comparison on Growth and Nutrient Content of Three Kale Cultivars

Selecting supplemental nitrogen (N) fertilizer for use on certified organic farms can be difficult and confusing. There are many options commercially available to farmers with similar N concentrations but widely different ingredients. Experiments were conducted in a certified organic field and high tunnels near Fort Collins, CO in 2013 and 2014 to evaluate the impact of organic fertilizers on yield and nutrient concentrations of three kale (Brassica oleracea and Brassica napus) cultivars. This study includes an organic fertilizer (cyano-fertilizer), which is produced on-farm by growing N-fixing cyanobacteria (Anabaena cylindrica) in raceway ponds. The three fertilizer treatments were hydrolyzed fish emulsion, alfalfa (Medicago sativa) meal, and cyano-fertilizer. These were applied at rates calculated by subtracting soil nitrate concentration from a target 50 mg·kg−1 to the depth of 6 inches of soil. Cyano-fertilizer and hydrolyzed fish emulsion were applied in liquid form, while the alfalfa meal was incorporated dry into the soil before planting. Biweekly measurements of plant height were taken on three cultivars of kale: Dinosaur, Red Russian, and Winterbor. Leaf weight, leaf area, and N, iron (Fe), and zinc (Zn) concentrations were measured during three to four monthly harvests each year. Organized in a split-plot experimental design, there were three treatment replications with subplots of different kale cultivars. Fertilizer treatment did not significantly affect plant height, leaf weight, leaf area, or plant N, Fe, and Zn concentrations. However, there were cultivar differences in plant height, leaf area, and yield. Kale cultivar choice had a larger impact on yield and plant nutrient concentrations than fertilizer choice, because fertilizers were applied at similar N rates.

Effect of Nitrogen-Fixing Cyanobacteria on the Growth of Wheat Crop

Isolation and purification of cyanobacteria from kafr El-Sheikh soil samples revealed that, two isolates (Anabaena cylindrica and Nostoc clacicola) were acquired as bacterial free cyanobacteria and nitrogen fixed. These cynobacteria isolates were produced auxin (Indole-3-acetic acid), gibberellins (Gibberellic acid) and cytokinin (Zeatin). Therefore, when inoculation with Anabaena cylindrica, Nostoc clacicola and their mixture were significantly increased the plant height, number of spikes/m2, 1000-grain weight, grain yield, straw yield protein content% on wheat crop and total counts of cyanobacteria in soil.

Pilot-scale production of phylloquinone (vitamin K1) using a bubble column photo-bioreactor

Phylloquinone (vitamin K1) is an essential nutrient for both humans and animals; it plays a key role in blood coagulation amongst other processes. In this work we describe the scale-up of a biosynthetic process for phylloquinone production using the cyanobacterium Anabaena cylindrica. A 50 L bubble column photo-bioreactor was used to cultivate A. cylindrica and the effects of a wide range of operating conditions including superficial velocities (0.67–6.7 cm s−1), day lengths (12–24 h), sparger designs and medium compositions were examined. The column design and superficial velocity had minimal impact on phylloquinone production, while changes to the medium composition and day length had large impacts. By varying these factors we were able to achieve final phylloquinone titres of the order 280 μg L−1 and productivities of 40 μg L−1 day−1, which are approximately double the values previously obtained. The biomass produced has clear applications in human and animal nutrition as its phylloquinone concentration was approximately 330 μg g−1 (dry basis); this being ten times higher than rich dietary sources. Conclusions regarding the effect of photo-bioreactor design and operating conditions can be applied to the production of phylloquinone, as well as the scale-up of cyanobacterial cultures more broadly.

Microalgae as a source of vitamin K1

Vitamin K1 has recently been identified as a potentially important nutrient for prevention of chronic diseases, especially those associated with aging, like osteoporosis and cardiovascular disease. Currently the majority of Vitamin K1 is produced via chemical synthesis; the aim of this work is to examine the potential to produce Vitamin K1 using microalgae. Biological synthesis produces only the active E-isomer, whereas chemical synthesis produces 10–20% of the inactive Z-isomer. Biosynthesis also utilises mild operating conditions, sustainable production methods, and has the potential to simultaneously produce other beneficial compounds. Seven different species of microalgae were screened; the cyanobacterium Anabaena cylindrica was identified as the richest source of vitamin K1. Concentrations were of the order 200 μg g−1 on a dry-weight basis, which is around six times higher than rich dietary sources such as spinach and parsley; one gram of the algae provides approximately three times the daily adult intake for Vitamin K1. By optimizing the growth conditions (lighting and medium), the productivity was increased fourfold to 22 μg L−1 d−1. Analysis of the nutritional properties of the biomass revealed that it contained high levels of protein (69% (w/w)) and Vitamin B12 (1.5 μg g−1), in addition to the high concentration of phylloquinone. An animal study was performed to evaluate the potential toxicity of the biomass; however, no evidence of acute toxicity was observed even at relatively high addition rates (15% (w/w)). These results support the use of microalgae, specifically A. cylindrica, as a source of phylloquinone.

Morphological and isotopic changes of heterocystous cyanobacteria in response to N2 partial pressure.

Earth's atmospheric composition has changed significantly over geologic time. Many redox active atmospheric constituents have left evidence of their presence, while inert constituents such as dinitrogen gas (N2 ) are more elusive. In this study, we examine two potential biological indicators of atmospheric N2 : the morphological and isotopic signatures of heterocystous cyanobacteria. Biological nitrogen fixation constitutes the primary source of fixed nitrogen to the global biosphere and is catalyzed by the oxygen-sensitive enzyme nitrogenase. To protect this enzyme, some filamentous cyanobacteria restrict nitrogen fixation to microoxic cells (heterocysts) while carrying out oxygenic photosynthesis in vegetative cells. Heterocysts terminally differentiate in a pattern that is maintained as the filaments grow, and nitrogen fixation imparts a measurable isotope effect, creating two biosignatures that have previously been interrogated under modern N2 partial pressure (pN2 ) conditions. Here, we examine the effect of variable pN2 on these biosignatures for two species of the filamentous cyanobacterium Anabaena. We provide the first in vivo estimate of the intrinsic isotope fractionation factor of Mo-nitrogenase (εfix =-2.71±0.09‰) and show that, with decreasing pN2 , the net nitrogen isotope fractionation decreases for both species, while the heterocyst spacing decreases for Anabaena cylindrica and remains unchanged for Anabaena variabilis. These results are consistent with the nitrogen fixation mechanisms available in the two species. Application of these quantifiable effects to the geologic record may lead to new paleobarometric measurements for pN2 , ultimately contributing to a better understanding of Earth's atmospheric evolution.

Identification of surface polysaccharides in akinetes, heterocysts and vegetative cells of Anabaena cylindrica using fluorescein-labeled lectins.

In response to environmental changes, Anabaena cylindrica differentiate three cell types: vegetative cells for photosynthesis, heterocysts for nitrogen fixation, and akinetes for stress survival. Cell-surface polysaccharides play important roles in cyanobacterial ecophysiology. In this study, specific cell-surface sugars were discovered in heterocysts, akinetes and vegetative cells of A. cylindrica using 20 fluorescein-labeled lectins. Both N-acetylglucosamine-binding lectins WGA and succinylated WGA bound specifically to the vegetative cells. Akinetes bound to three mannose-binding lectins (LCA, PSA, and ConA), and one of the galactose-binding lectins (GSL-I). Heterocyst also bound to ConA. However, the heterocysts in all4388 mutant of Anabaena sp. PCC 7120, in which the putative polysaccharide export protein gene all4388 was disrupted, exhibited diminished binding to ConA. Identification of distinct cell-surface sugar helped us to understand the role of polysaccharide for each cell type. Fluorescence-activated cell sorting may be applicable in isolating each cell type for comparative "omics" studies among the three cell types.

4-Oxo-β-apo-13-carotenone from the Cyanobacterium Anabaena cylindrica PCC 7122.

Apocarotenoids are widely distributed among living organisms (bacteria, fungi, algae, plants and even animals) and have been associated with several signaling functions. These compounds are generated by the activity of carotenoid cleavage dioxygenases (CCDs), whose diversity greatly contributes to the large number of apocarotenoids that have been described so far. It is nevertheless expected that a considerable diversity of these molecules is yet to be discovered. In this work, we describe the isolation and structural elucidation of the apocarotenoid 4-oxo-β-apo-13-carotenone from the cultured freshwater cyanobacterium Anabaena cylindrica PCC 7122, corresponding to the first report of this compound from natural sources.

The growth of filamentous microalgae is increased on biochar solid supports

Growth of filamentous microalgae and filamentous cyanobacteria can be enhanced when porous substrates are introduced into photobioreactors as solid supports. In this study, a biochar was tested as a solid support for cultures of Klebsormidium flaccidum and Anabaena cylindrica using BG11 culture medium, and their growth was compared with cultures without solid support. After 20 days of incubation with a 16:8 (light: dark) photoperiod, dry biomass and total carbon and nitrogen contents were determined in cultures of these microalgae with and without carbonaceous solid supports. Growth of A. cylindrica was enhanced by 80% in the presence of biochar as compared to the cultures without biochar. Also, the total nitrogen content of the material harvested from the solid support cultures with A. cylindrica was enhanced by about 10%. Scanning Electron Microscopy (SEM) images showed biofilm formation on the surface of the biochar with extension of the filaments attached to the external surfaces.

Bioselective synthesis of gold nanoparticles from diluted mixed Au, Ir, and Rh ion solution by Anabaena cylindrica

Over the last years, an environmentally friendly and economically efficient way of nanoparticle production has been found in the biosynthesis of metal nanoparticles by bacteria and cyanobacteria. In this study, Anabaena cylindrica, a non-toxic cyanobacterium, is deployed in a diluted ionic aqueous mixture of equal concentrations of gold, iridium, and rhodium, of 0.1 mM each, for the selective biosynthesis of metal nanoparticles (NPs). To analyze the cyanobacterial metal uptake, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) were applied. Only gold can be found in crystalline and nanoparticle form inside the cells of A. cylindrica, and it is the only metal for which ICP-MS analyses show a rapid decrease of the concentration in the culture medium. A slight decrease of rhodium and none of iridium was observed in the evaluated timeline of 51 h. The average diameter size of the emerging gold nanoparticles increased over the first few days, but is found to be below 10 nm even after more than 2 days. A new evaluation method was used to determine the spatially resolved distribution of the nanoparticles inside the cyanobacterial cells. This new method was also used to analyze TEM images from earlier studies of A. cylindrica and Anabaena sp., both incubated with an overall concentration of 0.8 mM Au3+ to compare the metal uptake. A. cylindrica was found to be highly selective towards the formation of gold nanoparticles in the presence of rhodium and iridium.

Characterization of Seven Species of Cyanobacteria for High-Quality Biomass Production

Bioconversion of photosynthetic cyanobacteria biomass feedstock into biofuels, and commodity chemical compounds is limited. Seven strains of cyanobacteria, namely: Synechocystis PCC 6803, Synechococcus PCC 7942, Nostoc muscorum, Oscillatoria sp., Anabaena cylindrica, Lyngbya sp. and Phormidium sp. were characterized for their growth, biomass, carbohydrates and lipids production. The maximum specific growth rate, the number of generations, biomass, and lipid yield as well as lipid content (13.1%) were observed in Synechocystis PCC 6803 among the evaluated strains. Overall 11.0, 7.5, 8.9, 4.8, 10.3, and 8.4% lipid, and 14.8, 32.1, 18.6, 26.2, 17.3, 27.8% carbohydrate content were obtained in Synechococcus PCC 7942, N. muscorum, Oscillatoria sp., A. cylindrica, Lyngbya sp. and Phormidium sp., respectively. In contrast, carbohydrate content in Synechocystis PCC 6803 cells was 9.89%. N. muscorum and Phormidium sp. were elucidated as a good candidate species for the carbohydrate enriched biomass. Therefore, Synechocystis PCC 6803 was screened as a robust species for lipid-based biofuels, while Phormidium sp. and N. muscorum can be exploited for the carbohydrate enriched biomass production.

Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis

Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show that chitosan may rapidly compromise membrane integrity and kill certain cyanobacteria leading to release of cell contents in the water. A strain of Cylindrospermopsis raciborskii and one strain of Planktothrix agardhii were most sensitive. A 1.3 h exposure to a low dose of 0.5 mg l−1 chitosan already almost completely killed these cultures resulting in release of cell contents. After 24 h, reductions in PSII efficiencies of all cyanobacteria tested were observed. EC50 values varied from around 0.5 mg l−1 chitosan for the two sensitive strains, via about 5 mg l−1 chitosan for an Aphanizomenon flos-aquae strain, a toxic P. agardhii strain and two Anabaena cylindrica cultures, to more than 8 mg l−1 chitosan for a Microcystis aeruginosa strain and another A. flos-aquae strain. Differences in sensitivity to chitosan might be related to polymeric substances that surround cyanobacteria. Rapid lysis of toxic strains is likely and when chitosan flocking and sinking of cyanobacteria is considered in lake restoration, flocculation efficacy studies should be complemented with investigation on the effects of chitosan on the cyanobacteria assemblage being targeted.

Effect of Algae Based Diets on Growth Performance, Body Composition and Fatty Acid Profile of Indian Major Carp, Rohu Labeo Rohita, Hamilton)

Six iso-energetic (352 kcal gross energy/100 g feed) and iso-nitrogenous (32% crude protein) experimental diets containing one of the four algae (Anabaena cylindrica, AN; Nostoc salbasa, NS; Spirulina platensis, SP; Westleopsis prolifica, WS) as the major dietary ingredient (40% of the total composition) or algal meal mixture with supplemental protein (AMM+PS) or only algal meal mixture (AMM) were tested against a control diet to find out the suitability of algal meal to develop practical diet for rohu fingerling. The experimental fish of average weight 2.0 ± 0.1 g were fed at a rate equaling 4% of body wt/day for 8 weeks at an experimental temperature of 28 ± 2°C. Significant (p<0.05) enhancement in growth rate was observed in the groups fed with WS (571%) followed by the groups fed with NS (517.6%) and SP (502.8%) as compared to that of the groundnut oil, rice bran and soybean meal based control diet (406.4%). Fingerlings fed with algal meal mixture (AMM) gained least (255.2%). Diet with WS performed well in terms of FCR, PER, HSI, MR and CF when AMM showed least efficiency. Fish fed with SP showed better protein utilization (ANPU%) as compared to the other dietary groups. Carcass protein was not affected by any diet. The MUFA and PUFA of liver and PUFA of muscle increased over the initial value fed with control and experimental diets. But the MUFA of muscle with these diets are less than the initial. The SFA content in all diets of both the tissues is either same or less than initial value except with AMM diet. The total n-3PUFA in liver increased with all diets over the initial value. But this increase in muscle was observed only with AN, NS, WS and AMM+PS diets. The n-6PUFA of liver and muscle remained either same or increased with all diets over initial value. This study showed that individual algal diets gave better result in growth performance and PUFA content. Among all the algal diets WS found to be the best.

Characterization of Co-Cultivation of Cyanobacteria on Growth, Productions of Polysaccharides and Extracellular Proteins, Nitrogenase Activity, and Photosynthetic Activity.

Cyanobacteria as biofertilizers are benefit to reduce the use of chemical fertilizers and reestablish the ecological system in soil. In general, several strains of cyanobacteria were involved in the biofertilizers. The co-cultivation of cyanobacteria were characterized on growth profile, production of polysaccharides and extracellular proteins, nitrogenase activity, and photosynthetic activity for three selected N2-fixing cyanobacteria, Anabaena cylindrica (B1611 and F243) and Nostoc sp. (F280). After eight-day culture, the highest dry weights were obtained in F280 pure culture and co-cultivation of B1611 and F280. Higher production of extracellular proteins and cell-bonding polysaccharides (CPS) were observed in co-cultivations compared with pure culture. The highest released polysaccharides (RPS) contents were obtained in pure culture of F280 and co-cultivation of F280 and F243. Galactose and glucose were major components of CPS and RPS in all samples. Trehalose was a specific component of RPS in F280 pure culture. Based on the monosaccharide contents of CPS and RPS, F280 was the dominant species in the related treatments of co-cultivation. The nitrogenase activities in all treatments exhibited a sharp rise at the late stage while a significant decrease existed when three cyanobacteria strains were mixed. Photosynthetic activities for all treatments were determined with rapid light curve, and the related parameters were estimated.