Isolation and characterization of a Scenedesmus acutus strain to be used for bioremediation of urban wastewater

Abstract

Green microalgae, due to their short growth cycle and to their ability to photosynthetically fix carbon dioxide producing an oil-rich biomass, have been proposed as an attractive alternative feedstock for the production of "second generation" biofuels. However, it has been anticipated that owing to their ability to colonize very different environments characterized by high levels of nitrogen, they can also be good candidates for bioremediation, thus integrating environmental protection with sustainable biomass production. We have isolated a strain belonging to Scenedesmus genus from urban wastewater. This isolate, Scenedesmus acutus PVUW12, was tested for its ability to grow and actively deplete eutrophicating inorganic molecules present in wastewater. In order to test its biomass productivity, the PVUW12 strain was grown in a verticalcolumn photobioreactor using standard growth medium obtaining a maximal productivity of 0.3 g dry weight L −1 d. When the same strain was grown in the photobioreactor filled with wastewater collected from the final step of the local urban purifier plant containing 18.8 mg L −1 nitrate, we observed complete nitrogen removal coupled with a biomass production of about 0.74 g dry weight L −1 within 3 days. After 10 days, the recovered biomass was analyzed for triglyceride content which was found to be 9.3% of the dry biomass. However, when algal cells were left for additional 10 days in static conditions the triglyceride content increased to 28.8%. These data show that this Scenedesmus strain can be used for wastewater bioremediation producing a biomass suitable for energy production.

Selection of microalgae for biodiesel production in a scalable outdoor photobioreactor in north China

“…This lipid content was much higher than most of the records in the outdoor cultures, indicating a lipid content of 15.6% for Botryococcus braunii (Bazaes et al, 2012), 19-32% for Chlorella sp (Moheimani, 2012(Moheimani, , 2013, 34.7% for N. oculata and N. salina (Quinn et al, 2012), less than 30% for S. acutus (Doria et al, 2011), and 24-30% for Tetraselmis suecica (Moheimani, 2013). In addition, the lipid productivity averaged at 28.1 mg…”

Can algal biotechnology bring effective solution for closing the phosphorus cycle? Use of algae for nutrient removal: Review of past trends and future perspectives in the context of nutrient recovery

“…Proulx et al 1993;Chevalier et al 2000;Doria et al 2012). For this purposes, the microalgae can be cultivated in suspension or attached to a firm surface.…”

“…were tested to develop technology suitable for the cool climate in Canada (Talbot and de la Noüe 1993; Chevalier et al 2000). Doria et al (2012) isolated the microalga Scenedesmus acutus from municipal wastewater and recorded its biomass production coupled with reduction in nutrients during growth in a tubular bioreactor (50 l). She reports a biomass production of 0.24 g DW l −1 d −1 and complete removal of N from wastewater.…”

Growth of microalgae Scenedesmus sp in ethanol vinasse

“…The pH in all the photobioreactors increased to about 7.0-8.0, which was a positive factor considering that vinasse pH was 4.0. Doria et al (2012) and Oliveira (2013) demonstrated the growth of microalgae using wastewater. The results of Oliveira (2013) were similar to those obtained in this study, which obtained a production of 0.48 g/L in cultures with 28% of vinasse.…”

“…They can also be used to treat the industrial effluents and sewage. Doria et al (2012) used Scenedesmus acutus inoculated in wastewater from anaerobic digestion process that resulted in a production of 0.74 g/L of biomass in eight days. Oliveira (2013) observed that Scenedesmus sp could be used to treat up to 30% of domestic effluents (vinasse has similar characteristics) and obtained a biomass production of 0.48 g/L in ten days.…”