Cyanobacterial Consortium Research Articles

Photocatalytic degradation of antibiotics by N-doped carbon nanoflakes-nickel ferrite composite derived from algal biomass

This work reports the synthesis of nickel ferrite (NiFe) nanoparticles, N-doped mesoporous carbon nanoflakes (NCF) and novel nickel ferrite-carbon nanoflakes (NiFe@NCF) nanocomposite using solvothermal method. NCF was derived from a cyanobacterial consortium consisting of Anabaena, Lyngbya and Weistiellopsis, rich in carbon and nitrogen. The synthesized nanoparticles were used as heterogeneous photocatalyst for degradation of two harmful water pollutants, ciprofloxacin (CIP) and levofloxacin (LEV). 99.91% LEV and 98.86% CIP were degraded within 50 and 70 min of visible light irradiation using NiFe@NCF following pseudo first order kinetics. This improved efficiency of the nanocomposite may be attributed to its higher surface area, reduction of band gap (from 2.42 to 2.19 eV), more active sites as well as charge carrier mobility with decreasing agglomeration tendency of the magnetic nickel nanoparticles upon being embedded on NCF. N-doping improves light harvesting property, retards charge recombination and extends as well as delocalises ᴨ-conjugated system resulting in enhanced photocatalytic activity. The scavenging experiments and EPR analysis reveal that O2−• and •OH are the main active species taking part in the degradation process. The material performs well within a wide range of pH and can be effectively used up to 5 repetitive cycles. A feasible photocatalytic degradation mechanism of the antibiotics against NiFe@NCF nanocomposite is also put forwarded along with their possible degradation pathways from LCMS studies.

Development of a Solar Energy-Based Prototype, CyanoClean, for Arsenic Removal from Groundwater Using Cyanobacterial Consortium

Development of a Solar Energy-Based Prototype, CyanoClean, for Arsenic Removal from Groundwater Using Cyanobacterial Consortium

Application of multigene genetic programming and water evaporation optimization technique for modeling and optimization of removal of heavy metals from ash pond water using cyanobacterial consortium

Abstract Heavy metals such as Lead(II), Nickel(II), Manganese(II), Cadmium(II), Chromium(VI), etc., are leached from the coal ash of thermal power plants. These metals contaminate ash pond water and subsequently contaminate groundwater. Phycoremediation using microalgae/cyanobacteria is an emerging technology for removal of heavy metals. The present study aims at phycoremediation of the said heavy metals from ash pond water using cyanobacterial consortium of Limnococcus limneticus and Leptolyngbya subtilis followed by the development of an accurate data-driven Multigene Genetic Programing (MGGP) approach for modeling and optimization of the process. The developed model was used to obtain a correlation between the average removal of metals and biomass production with all input factors such as the initial metal concentrations, pH, and days of incubation. To maximize metal removal and biomass production, the Water Evaporation Optimization (WEO) technique was applied to determine optimal values of input parameters. The application of WEO for the optimization of the phycoremediation process is the first of its kind and here lies the novelty of the study.

Viral diversity and dynamics and CRISPR-Cas-mediated immunity in a robust alkaliphilic cyanobacterial consortium.

In many industries, from food to biofuels, contamination of production systems with predators is a costly problem and requires the maintenance of sterile operating conditions. In this study, we look at the robustness of one such alkaliphilic consortium, comprised largely of a cyanobacterium Candidatus Phormidium alkaliphilum, to viral predation. This consortium has existed without a community crash for several years in laboratory and pilot-scale environments. We look at clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems and viral dynamics in this consortium at four conditions using metagenomic analyses. Results show that while there are active viral members in this community, viral predation of the cyanobacteria is low and does not affect the community dynamics. The multiple CRISPR arrays within the Phormidium were found to be static following the initial lab establishment of consortium. Multiple cryptic CRISPR-Cas systems were detected with uncertain viral protection capacity. Our results suggest that the dynamics of potential viruses and CRISPR-Cas-mediated immunity likely play an important role in the initial establishment of consortia and may continue to support the functional robustness of engineered microbial communities throughout biotechnology applications. IMPORTANCE Biotechnology applications utilizing the function of microbial communities have become increasingly important solutions as we strive for sustainable applications. Although viral infections are known to have a significant impact on microbial turnover and nutrient cycling, viral dynamics have remained largely overlooked in these engineered communities. Predatory perturbations to the functional stability of these microbial biotechnology applications must be investigated in order to design more robust applications. In this study, we closely examine virus-microbe dynamics in a model microbial community used in a biotechnology application. Our findings suggest that viral dynamics change significantly with environmental conditions and that microbial immunity may play an important role in maintaining functional stability. We present this study as a comprehensive template for other researchers interested in exploring predatory dynamics in engineered microbial communities.

The facilitating role of phycospheric heterotrophic bacteria in cyanobacterial phosphonate availability and Microcystis bloom maintenance

BackgroundPhosphonates are the main components in the global phosphorus redox cycle. Little is known about phosphonate metabolism in freshwater ecosystems, although rapid consumption of phosphonates has been observed frequently. Cyanobacteria are often the dominant primary producers in freshwaters; yet, only a few strains of cyanobacteria encode phosphonate-degrading (C-P lyase) gene clusters. The phycosphere is defined as the microenvironment in which extensive phytoplankton and heterotrophic bacteria interactions occur. It has been demonstrated that phytoplankton may recruit phycospheric bacteria based on their own needs. Therefore, the establishment of a phycospheric community rich in phosphonate-degrading-bacteria likely facilitates cyanobacterial proliferation, especially in waters with scarce phosphorus. We characterized the distribution of heterotrophic phosphonate-degrading bacteria in field Microcystis bloom samples and in laboratory cyanobacteria “phycospheres” by qPCR and metagenomic analyses. The role of phosphonate-degrading phycospheric bacteria in cyanobacterial proliferation was determined through coculturing of heterotrophic bacteria with an axenic Microcystis aeruginosa strain and by metatranscriptomic analysis using field Microcystis aggregate samples.ResultsAbundant bacteria that carry C-P lyase clusters were identified in plankton samples from freshwater Lakes Dianchi and Taihu during Microcystis bloom periods. Metagenomic analysis of 162 non-axenic laboratory strains of cyanobacteria (consortia cultures containing heterotrophic bacteria) showed that 20% (128/647) of high-quality bins from eighty of these consortia encode intact C-P lyase clusters, with an abundance ranging up to nearly 13%. Phycospheric bacterial phosphonate catabolism genes were expressed continually across bloom seasons, as demonstrated through metatranscriptomic analysis using sixteen field Microcystis aggregate samples. Coculturing experiments revealed that although Microcystis cultures did not catabolize methylphosphonate when axenic, they demonstrated sustained growth when cocultured with phosphonate-utilizing phycospheric bacteria in medium containing methylphosphonate as the sole source of phosphorus.ConclusionsThe recruitment of heterotrophic phosphonate-degrading phycospheric bacteria by cyanobacteria is a hedge against phosphorus scarcity by facilitating phosphonate availability. Cyanobacterial consortia are likely primary contributors to aquatic phosphonate mineralization, thereby facilitating sustained cyanobacterial growth, and even bloom maintenance, in phosphate-deficient waters.CDjGUzfe77vQSL5wxbu5DEVideo

Dark fermentation of expired fruit juices for biohydrogen production followed by treatment and biotechnological exploitation of effluents towards bioplastics and microbial lipids

The treatment and biotechnological exploitation of expired fruit juices (EFJ) towards biohydrogen, polyhydroxyalkanoates (PHAs) and lipids production was investigated. The EFJ were initially fermented via an acidogenic consortium, during which the effect of the organic loading rate (OLR, 20–40 g sugars/L.d) on the sugars uptake and the yields of metabolites i.e. hydrogen, volatile fatty acids (VFAs) and lactate, was studied. The increase of the OLR resulted to lower bioconversion of sugars and metabolic shift to lactate production, whereas the highest hydrogen yield, 10.83 ± 0.41 L H2/m3 EFJ, was obtained for the OLR 30 g sugars/L.d. The acidogenic effluents were then utilized for the production of PHAs and microbial lipids, via bacterial heterotrophic and cyanobacterial consortia, respectively. The PHAs produced were in all cases copolymers, and the highest yield, 20.69 ± 1.01 kg PHAs/m3 EFJ was achieved from the effluent with the highest VFAs content. Microbial lipids were also successfully produced from all effluents. The results revealed that low VFAs and high sugars concentration, allowed cyanobacterial growth of up to 373.5 mg /L.d and maximum lipid content of up to 11.7 % d.w. (5.47 ± 0.49 kg biolipids/m3 EFJ), as well as significant substrate degradation (dissolved oxygen demand - d-COD, total nitrogen-ΤΝ, orthophosphates-PO43-, total sugars up to about 93 %, 95 %, 67 % and 96 %, respectively).

Nutrient management and medium reuse for cultivation of a cyanobacterial consortium at high pH and alkalinity.

Alkaliphilic cyanobacteria have gained significant interest due to their robustness, high productivity, and ability to convert CO2 into bioenergy and other high value products. Effective nutrient management, such as re-use of spent medium, will be essential to realize sustainable applications with minimal environmental impacts. In this study, we determined the solubility and uptake of nutrients by an alkaliphilic cyanobacterial consortium grown at high pH and alkalinity. Except for Mg, Ca, Co, and Fe, all nutrients are in fully soluble form. The cyanobacterial consortium grew well without any inhibition and an overall productivity of 0.15 g L−1 d−1 (AFDW) was achieved. Quantification of nutrient uptake during growth resulted in the empirical formula CH1.81N0.17O0.20P0.013S0.009 for the consortium biomass. We showed that spent medium can be reused for at least five growth/harvest cycles. After an adaptation period, the cyanobacterial consortium fully acclimatized to the spent medium, resulting in complete restoration of biomass productivity.

Pilot-scale outdoor trial of a cyanobacterial consortium at pH 11 in a photobioreactor at high latitude

The biomass of microalgae and cyanobacteria yields a variety of products. Outdoor pilot plant trials typically grow a single species at circumneutral pH and provide CO2 by gas sparging. Here a cyanobacterial consortium was grown at high pH (beyond 11) and high dissolved carbonate concentrations (0.5 M) in an outdoor 1,150 L tubular photobioreactor for 130 days in Calgary, Canada. The aim was to assess the productivity and robustness of the consortium. Importantly, the system was designed to enable future integration of air capture of CO2. Productivity was between 3.1 and 5.8 g ash-free dry weight per square metre per day, depending on biomass density and month. 16S rRNA amplicon sequencing showed that cyanobacterium Candidatus “Phormidium alkaliphilum” made up 80% of the consortium. The consortium displayed robust growth and adapted to environmental conditions. Bicarbonate uptake pushed medium pH past 11, demonstrating the ability to achieve CO2 delivery by air capture.

Ecological Interactions of Cyanobacteria and Heterotrophs Enhances the Robustness of Cyanobacterial Consortium for Carbon Sequestration.

Lack of robustness is a major barrier to foster a sustainable cyanobacterial biotechnology. Use of cyanobacterial consortium increases biodiversity, which provides functional redundancy and prevents invading species from disrupting the production ecosystem. Here we characterized a cyanobacterial consortium enriched from microbial mats of alkaline soda lakes in BC, Canada, at high pH and alkalinity. This consortium has been grown in open laboratory culture for 4 years without crashes. Using shotgun metagenomic sequencing, 29 heterotrophic metagenome-assembled-genomes (MAGs) were retrieved and were assigned to Bacteroidota, Alphaproteobacteria, Gammaproteobacteria, Verrucomicrobiota, Patescibacteria, Planctomycetota, and Archaea. In combination with metaproteomics, the overall stability of the consortium was determined under different cultivation conditions. Genome information from each heterotrophic population was investigated for six ecological niches created by cyanobacterial metabolism and one niche for phototrophy. Genome-resolved metaproteomics with stable isotope probing using 13C-bicarbonate (protein/SIP) showed tight coupling of carbon transfer from cyanobacteria to the heterotrophic populations, specially Wenzhouxiangella. The community structure was compared to a previously described consortium of a closely related cyanobacteria, which indicated that the results may be generalized. Productivity losses associated with heterotrophic metabolism were relatively small compared to other losses during photosynthesis.

Analyses of genetic variability and genotype x cyanobacteria interactions in biofortified maize (Zea mays L.) for their responses to plant growth and physiological attributes

Microbe-mediated enrichment of crops has emerged as an environment-friendly intervention to tackle the problems of eroding soil fertility and malnutrition globally. The responses of a set of ten biofortified maize genotypes to three cyanobacterial inoculants (cyanobacterial consortium BF1-4, Anabaena sp.–Trichoderma sp. biofilm-An-Tr and Anabaena sp.+ Providencia sp. -CR1 + PR3) were evaluated over a period of two years. Significant genetic variation existed among the maize inbreds for all soil microbial parameters, soil macronutrients (N and P) and micronutrients (Mn and Zn), besides physiological and nutritional quality traits. Genotype x Inoculants interaction was more significant for soil glomalin (32 %), organic carbon (26 %), soil polysaccharides (20 %) and soil available N (18 %). Genotype x inoculants x environment (years) interactions significantly influenced available Zn (36 %), organic carbon (31 %), glomalin (30 %), available N (20 %) and polysaccharides (20 %). Promising genotype-inoculant combinations of PMI-Q2+ BF1-4 or An-Tr, PMI-PV2+BF1-4 or CR1 + PR3, HP-467-13 + BF 1-4 or An-Tr were identified, which can be evaluated across agro-ecologies. It was concluded that cyanobacterial inoculation can lead to N savings, improved soil fertility and enhanced crop vigor in maize.

Influence of monoterpenoids on the growth of freshwater cyanobacteria

Cyanobacteria are characterized by a very high tolerance to environmental factors. They are found in salt water, fresh water, thermal springs, and Antarctic waters. The wide spectrum of habitats suitable for those microorganisms is related to their particularly effective metabolism; resistance to extreme environmental conditions; and the need for only limited environmental resources such as water, carbon dioxide, simple inorganic salts, and light. These metabolic characteristics have led to cyanobacterial blooms and the production of cyanotoxins, justifying research into effective ways to counteract the excessive proliferation of these microorganisms. A new and interesting idea for the immediate reduction of cyanobacterial abundance is to use natural substances with broad-spectrum biological activity to restore phytoplankton diversity. This study describes the effects of selected monoterpenoid derivatives on the development of cyanobacterial cultures. In the course of the study, some compounds ((±)-citronellal, (+)-α-pinene) showed the ability to inhibit the colonization of the tested photosynthetic bacteria, while others (eugenol, eucalyptol) stimulated the growth of these microorganisms. By analyzing the results of these experiments, information was obtained on the mutual relations of cyanobacteria and the tested monoterpenes, which are present in the aquatic environment.Key points• Monoterpenoids significantly inhibit the growth of single cyanobacterial strains.• Monoterpenoids can inhibit the growth of cyanobacterial consortia.• Natural substances can control the growth of freshwater cyanobacteria.

Application of Artificial Neural Network and Particle Swarm Optimization for modelling and optimization of biosorption of Lead(II) and Nickel(II) from wastewater using dead cyanobacterial biomass

Removal of heavy metals through biosorption using biomass offers several advantages over other conventional techniques such as low cost, high efficiency, environmentally friendly, etc. In the present article, biosorption of Nickel(II) and Lead(II)was investigated using dried biomass of cyanobacterial consortium. OFAT (one-factor-at-a-time) analysis was used to assess the effect of input parameters on the removal of potentially toxic elements by varying initial metal ion concentration (2–10 mgL−1), adsorbent dose (0.1–1.0 gL-1), pH (for Pb(II): 2–6, for Ni(II): 2–8) and temperature (25°C–45°C) individually, at constant shaking speed of 150 ​rpm. Results showed that removal using biomass attained highest values in as short time as 15 ​min. The investigations also showed the removal is highly effective at lower initial concentrations of heavy metals. Maximum removal of Lead(II) (87.27 ​± ​1.75%) and Nickel(II) (92.57 ​± ​0.77%) was obtained at pH 6 and 45°C and at pH 7 and 25°C, respectively, within 15 ​min with 0.1 gL-1 biomass. Both the Langmuir model and Freundlich model were seen to fit the equilibrium data. Further, Artificial Neural Network was used to model the biosorption process. Subsequently, Particle Swarm Optimization was applied to optimize the operating conditions for the removal of both the metals.

Parametric study on CO2 sequestration using cyanobacterial consortium and production of macromolecules: experimentation, modelling and optimization

AbstractSequestration of CO2 using microalgae is one of the imperative, cost effective and environment‐friendly processes for carbon sequestration and for production of biomass. In the present study, a cyanobacterial consortium was used for the sequestration of CO2 at diverse initial CO2 concentrations (5–30%), pH of the medium (7–11) and inoculum sizes (5–12.5%). The cyanobacterial consortium showed sustainability in growth upto 30% CO2. The overall CO2 fixation capacity was found as 0.0692 and 0.071 mol CO2/g algae at 15% CO2, pH 9 and at 10% and 12.5% inoculum, respectively, after 14 days. Characterization of dry biomass before and after CO2 sequestration was done using Fourier Transform Infrared spectroscopy. Various algorithm of artificial neural network (ANN) model and a number of activation functions were tried to arrive at best ANN model for such process. Finally, Particle swarm optimization was used for optimization of input variables for maximum sequestration of CO2.

Application of Cyanobacterial Consortium to Remove Ammoniacal-N, Phenol, and Nitrate from Synthetic Coke-Oven Wastewater as Tertiary Treatment

AbstractThis investigation focused on phycoremediation of pollutants from synthetic coke-oven wastewater using a cyanobacterial consortium of Leptolyngbya sp. and Planktothrix sp., and biomass prod...

Priming maize seeds with cyanobacteria enhances seed vigour and plant growth in elite maize inbreds.

Biofilm formation of a nitrogen-fixing cyanobacterium Anabaena torulosa with a beneficial fungus Trichoderma viride (An-Tr) was examined under laboratory conditions. A gradual enhancement in growth over A. torulosa alone was recorded in the biofilm, with 15-20% higher values in nitrogen fixation, IAA and exopolysaccharide production illustrating the synergism among the partners in the biofilm. To investigate the role of such biofilms in priming seed attributes, mesocosm studies using primed seeds of two maize inbred lines (V6, V7) were undertaken. Beneficial effects of biofilm (An-Tr) were recorded, as compared to uninoculated treatment and cyanobacterial consortium (Anabaena-Nostoc; BF 1-4) at both stages (7 and 21 DAS, days after sowing) with a significant increase of more than 20% in seedling attributes, along with 5-15% increment in seed enzyme activities. More than three- to fivefold higher values in nitrogen fixation and C-N mobilizing enzyme activities, and significant increases in leaf chlorophyll, proteins and PEP carboxylase activity were observed with V7-An-Tr biofilm. Cyanobacterial inoculation brought about distinct changes in the soil phospholipid fatty acid profiles (PLFA); particularly, significant changes in those representing eukaryotes and anaerobic bacteria. Principal component analyses illustrated the significant role of dehydrogenase activity and microbial biomass carbon and distinct elicited effects on soil microbial communities, as evidenced by the PLFA. This investigation highlighted the promise of cyanobacteria as valuable priming options to improve mobilization of nutrients at seed stage, modulating the abundance and activities of various soil microbial communities, thereby, enhanced plant growth and vigour of maize plants.

Control of productivity of agrocenosis

In this work, the authors used statistical processing of results of the long-term field several pieces of research by the method of multivariate analyze, factor analysis, and visualization of data with the use of the computer program Statistica 10. They created the multivariate Electronic Database for in-depth analysis and description of the effect of microbial preparations based on heterotrophic and phototrophic microorganisms on the efficiency of plant-microbial symbiotic systems in agrocenoses of legumes. Based on the field experiments on southern Chernozem in the steppe zone of the Crimea, the biological activity of the soil and the physiological and biochemical potential of soybean, pea, chickpea, peavine, and lentil were determined. The direction of microbiological and enzymatic processes in the rhizosphere was established, as well as interactive connections in the system “microorganisms – plants – soil”. The use of microbial preparations had a greater impact (2 times, p < 0.05) on the physiological and biochemical status of plants, crop structure, seed productivity, and grain quality. To a lesser extent, it influenced the biological activity of the soil in the agrocenosis of legumes. The advantage of using polyfunctional Cyanobacterial consortium in growing legumes for realizing the potential of plant-microbe interactions compared to monobacterization with Rhizobofit, fungi arbuscular mycorrhizae and biological products Rhizobofit, Phosfoenterin, and Biopolicyd was shown.

Direct capture and conversion of CO2 from air by growing a cyanobacterial consortium at pH up to 11.2.

Bioenergy with carbon capture and storage (BECCS) is recognized as a potential negative emission technology, needed to keep global warming within safe limits. With current technologies, large‐scale implementation of BECCS would compromise food production. Bioenergy derived from phototrophic microorganisms, with direct capture of CO2 from air, could overcome this challenge and become a sustainable way to realize BECCS.Here we present an alkaline capture and conversion system that combines high atmospheric CO2 transfer rates with high and robust phototrophic biomass productivity (15.2 ± 1.0 g/m 2/d). The system is based on a cyanobacterial consortium, that grows at high alkalinity (0.5 mol/L) and a pH swing between 10.4 and 11.2 during growth and harvest cycles.

Sequestration of CO2 using microorganisms and evaluation of their potential to synthesize biomolecules

ABSTRACTMicroalgae are the unicellular or multicellular photosynthetic microorganisms that can efficiently fix carbon dioxide (CO2) from various sources such as the environment, industrial flue gas, and some carbonate salts. In the present study, one green microalgal strain and a cyanobacterial consortium were used separately for the sequestration of CO2 at different pHs (7–11), at different initial concentrations of CO2 (5–20%), and at various inoculum sizes (5–12.5%). The maximum sequestration of CO2 was found to be 74.37 ± 0.49% and 71.12 ± 0.05% at 5% and 15% CO2 for green algae and cyanobacterial consortium. The biomass generated after sequestration of CO2 was utilized for the synthesis of biomolecules.

Application of RSM and ANN for optimization and modeling of biosorption of chromium(VI) using cyanobacterial biomass

Proper treatment of heavy metal ions present in wastewaters is a major concern. With extensive usage in various industries, Cr(VI) contamination has become threatening for the environment. Biosorption is a favorable technique for heavy metals removal. In the present study, dried cyanobacterial consortium of Dinophysis caudata and Dinophysis acuminata were used to assess its biosorption capability. The surface texture and morphology of the biosorbent were obtained through scanning electron microscopy. The presence of different chemical bonds, namely hydroxyl, C–H and C–N, was confirmed through FTIR study. Pseudo-second-order Mckay-Ho model was found to perform best to fit the kinetic data. Temkin adsorption isotherm model fit best to the equilibrium data. Response surface methodology (RSM) was employed to optimize Cr(VI) abatement. Effect of initial concentration (IC) of metal ion, temperature, pH variation and amount of adsorbent (AD) were studied during batch study. Maximum Cr(VI) abatement after 5 min contact time was 80.77% for an IC of Cr(VI) of 25 mg/L, at pH 11 and 45 °C with the AD of 2.5 g/L. The optimum removal conditions as shown by RSM study were IC of Cr(VI): 15 mg/L, AD: 1 g/L, pH: 11, and the removal was predicted as 81.72%. Artificial neural network-based model was further developed based on experimental points which indicated that the model can predict abatement of Cr(VI) for various operating conditions with reasonably high accuracy.

Development of a nitrogen-fixing cyanobacterial consortium for surface stabilization of agricultural soils

Cyanobacteria are recognized as important colonizers and protectors of soil surfaces, particularly in biological soil crusts (BSCs) of arid and semiarid regions. Comparatively, little attention has been paid to the growth of cyanobacteria, algae, and moss on agricultural soils in more humid regions like eastern North America. Growth of soil surface consortia (SSCs) in agricultural fields is typically rapid and ephemeral yet recurrent, thereby differing from classical BSCs of semiarid regions and algal mats of aquatic systems. Naturally occurring or intentionally applied cyanobacteria to agricultural soils could thus provide renewable sources of carbon and nitrogen (N) and a means to improve soil resilience. Here, we describe a soil microcosm-based protocol to assess cyanobacteria for their ability to form SSCs using three criteria: reliability of serial transfers in N-free culture media, robust growth in soil microcosms, and resistance to detachment from soil particles subjected to water flushing. Screening of 100 enrichment cultures from local SSCs yielded three that exhibited robust growth on N-free solid media and consistent microscopic appearance as filamentous, heterocystous cyanobacteria. One enrichment (DG1) grew reliably in liquid N-free media and was selected for comparison with pure cultures of commercial strains of other heterocystous cyanobacteria. Growth and biomass density of DG1 and commercial strains on moist, N-limited soils were tracked using chlorophyll a measurements and water flush tests. Anabaena spp. grew faster on soil surfaces, but their 80-day SSCs did not adhere to soil as well as DG1 or Nostoc spp. in water flush tests. The ability of DG1 and Nostoc spp. to produce flocculated growth in liquid culture appeared to be associated with greater soil adherence. While Nostoc spp. formed stable SSCs in soil microcosms, they exhibited lower growth rates and biomass densities than DG1. Attempts to purify the cyanobacterial strain(s) from other bacteria in the DG1 enrichment were unsuccessful. Based on initial metagenomics analysis, the DG1 enrichment was a consortium containing at least six other bacterial genotypes but dominated by one or more closely related strains of Cylindrospermum spp. (Nostocaceae). The presence of bacterial associates did not interfere with rapid growth and high biomass density in soil microcosms, as well as SSC stability in water flush tests. The artificial SSCs formed by DG1 showed good potential for use as a renewable N source for agroecosystems.