Aislamiento y caracterización molecular de cepas fitoplanctónicas obtenidas en Engabao, Guayas-Ecuador.

El interés industrial en microorganismos fitoplanctónicos como microalgas y cianobacterias se debe al elevadopotencial biotecnológico que poseen en sintetizar compuestos bioactivos, a la facilidad de adaptarse adiferentes fuentes de nutrientes, condiciones extremas de supervivencia y a la capacidad bioabsorbente demetales pesados, principalmente en aguas residuales. El objetivo del presente estudio consistió en aislar ycaracterizar fenotípica y genotípicamente microorganismos fitoplanctónicos de piscinas de estabilización deEngabao, Guayas-Ecuador, mediante el uso de diferentes medios de cultivos y de los marcadores molecularesITS, ITS2, LSU y 16S RNAr. Los resultados del cultivo celular durante siete días mostraron que la microalgaChls1 con medio BG11 pH 7.8 alcanzó 25.4 x 106cel mL-1, la cianobacteria Syn1 fue de 340.6 x 106cel mL-1,mientras que para Nod1 se empleó análisis de clorofila a alcanzando al séptimo día 6.33 μg mL-1. Los estudiosmoleculares se realizaron empleando un protocolo modificado de extracción y purificación de ADNg obteniendouna óptima concentración y calidad del ADN para las tres cepas: Chls1 146 ng µL-1, Syn1 326 ng µL-1 y Nod1158.8 ng µL-1. El uso de análisis polifásicos en base a caracteres morfológicos y ADNg de las cepas, se amplificópor PCR y se secuenció; las cepas identificadas fenotípica y genotípicamente mediante los primers ITS2, ITS yLSU corresponde a la microalga Chlorella sorokiniana con 99,48%, 99,07% y 99,77% de similitud de identidad,mientras que los aislados cianobacterianos Synechococcus sp. y Nodosilinea sp. con el análisis de la región 16SRNAr presenta porcentajes de identidad de 97,47% y 99,83%; a pesar de no emplear cebadores específicos paraestos microorganismos, el uso de varias regiones, aumenta la confiablidad en la identificación taxonómica yfilogenética; estas especies poseen alto potencial biotecnológico y de gran impacto económico.

Photosynthetic Conversion of CO2 Into Pinene Using Engineered Synechococcus sp. PCC 7002

Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO2 to various longer carbon chain fuels. Pinene has become increasingly attractive since pinene dimers contain high volumetric energy and have been proposed to act as potential aircraft fuels. However, cyanobacteria cannot directly convert geranyl pyrophosphate into pinene due to the lack of endogenous pinene synthase. Herein, we integrated the gene encoding Abies grandis pinene synthase into the model cyanobacterium Synechococcus sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L−1 in the lab-scale tube photobioreactor with CO2 aeration. Specifically, the results showed a mixture of α- and β-pinene (∼33:67 ratio). The ratio of β-pinene in the product was significantly increased compared with that previously reported in the engineered Escherichia coli. Furthermore, we investigated the photoautotrophic growth performances of Synechococcus overlaid with different concentrations of dodecane. The work demonstrates that the engineered Synechococcus is a suitable potential platform for β-pinene production.

Optimization of the Growth and Performance of Several Cynobacteria Species in a Pilot Scale Raceway Pond for CO2 Bio-Sequestration

Due to the limited availability of fresh water and the high cost of land for plant culture, microalgae cultivation has attracted significant attention in recent years and has been shown to be the best option for CO2 bio-sequestration. Bio-sequestration of CO2 through algae bioreactors has been hailed as one of the most promising and ecologically benign methods available. This research study was taken up to alleviate certain limitations associated with the technology such as low CO2 sequestration efficiency and low biomass yields. In this study three distinct cyanobacterial strains, Chlorella sp., Synechococcus sp., and Spirulina sp., were tested in 10 litre raceway ponds for their capacity for CO2 bioconversion and high biomass production under various CO2 concentrations at different EC. The highest growth rate of all tested cyanobacterial strains was observed during the first 4 days of cultivation under CO2 5% to 10%. Additionally, all these cyanobacterial strains were explored for their bioremediation capabilities. The results showed that the Chlorella sp., Synechococcus sp., and Spirulina sp. were able to remove COD of the wastewater by 56%, 48% and 77% respectively and the BOD removal efficiency was 48%, 30% and 52% respectively. The primary results indicated that the Spirulina sp. was to be the best cynobacteria studied in terms of biomass production, CO2 bioconversion, and bioremediation capacities. Therefore, the Spirulina sp. was further scaled up in 1500 litre raceway pond for CO2 bio-sequestration and biomass production. The biomass collected was utilised to extract biomolecules such as protein, carbohydrate and lipids.

Phycoremediation of pollutants from secondary treated coke-oven wastewater using poultry litter as nutrient source: a cost-effective polishing technique

The present article focuses on the phycoremediation of pollutants from secondary treated coke-oven effluent through a green and economical route. A microalgal sample was collected and identified as a consortium of Chlorella sp. and Synechococcus sp. The culture cost was reduced by using poultry litter extract as supplementary material to BG-11 medium. Since major pollutants as present in real secondary treated coke-oven wastewater are phenol, ammoniacal-N (NH4+) and cyanide, several matrices were designed with these three major pollutants by varying their initial concentrations such as phenol (2–10 mgL−1), cyanide (0.3–1 mgL−1) and NH4+ (100–200 mgL−1), termed as simulated secondary treated coke-oven wastewater. Maximum removal was observed with individual solutions of phenol (4 mgL−1), cyanide (0.6 mgL−1), and NH4+ (175 mgL−1) while maximum removal in simulated secondary treated coke-oven wastewater was observed at higher concentrations of phenol (8 mgL−1) and cyanide (0.8 mgL−1) and the same concentration of NH4+ (175 mgL−1). Consortium was found effective to meet statutory limits of pollutants. Kinetic model was developed for predicting growth of consortium and observed that the poultry litter extract enriched BG-11 medium showed higher values of maximum specific growth rate (0.56 day−1) and carrying capacity (1,330 mgL−1) than that in BG-11 medium only.

Glucosidase Inhibitors Screening in Microalgae and Cyanobacteria Isolated from the Amazon and Proteomic Analysis of Inhibitor Producing Synechococcus sp. GFB01

Microalgae and cyanobacteria are good sources for prospecting metabolites of biotechnological interest, including glucosidase inhibitors. These inhibitors act on enzymes related to various biochemical processes; they are involved in metabolic diseases, such as diabetes and Gaucher disease, tumors and viral infections, thus, they are interesting hubs for the development of new drugs and therapies. In this work, the screening of 63 environmental samples collected in the Brazilian Amazon found activity against β-glucosidase, of at least 60 min, in 13.85% of the tested extracts, with Synechococcus sp. GFB01 showing inhibitory activity of 90.2% for α-glucosidase and 96.9% against β-glucosidase. It was found that the nutritional limitation due to a reduction in the concentration of sodium nitrate, despite not being sufficient to cause changes in cell growth and photosynthetic apparatus, resulted in reduced production of α and β-glucosidase inhibitors and differential protein expression. The proteomic analysis of cyanobacteria isolated from the Amazon is unprecedented, with this being the first work to evaluate the protein expression of Synechococcus sp. GFB01 subjected to nutritional stress. This evaluation helps to better understand the metabolic responses of this organism, especially related to the production of inhibitors, adding knowledge to the industrial potential of these cyanobacterial compounds.

Growth of Mutant Synechococcus SP. PCC 7002: Effects of Multi-Parameters and Prediction of Growth Rate

Understanding of the correlative effects of combined variables on the growth rate of the cyanobacteria is fundamental to the exploitation of cyanobacteria as a biological mechanism to produce biofuels. Cyanobacteria (blue-green algae) are phototrophic microorganisms that offers attractive benefits, among which is a direct conversion of CO2 to a range of valuable products such as carbon-based biofuels. One model of cyanobacteria species is the cyanobacterium Synechococcus sp. PCC 7002. This paper describes the model developed to investigate the combined impacts of the variables on the growth of the Synechococcus sp. PCC 7002. The variables understudy include the temperature of the media, light intensity, the concentration of NaNO3, and the concentration of the NPK. The data is obtained from a lab scale study in which the Synechococcus sp. PCC 7002 underwent mutagenesis procedures. It is hypotheses that certain combination of the variables plays a key role in determining the growth rate of Synechococcus sp. 7002. The growth rate is determined through the measurement of four response variables, carbohydrate concentration, percentage of CO2 uptake, cell dry weight (CDW), and optical density (OD). A multivariate PCA model was developed which unearths the underlying relationship between the variables. Promising results were yield from the proposed model. Distinctive correlations between the variables were clearly described by the PCA model.