title: Robust, high-productivity phototrophic carbon capture at high pH and alkalinity using natural microbial communities.
abstract: BACKGROUND
  Bioenergy with carbon capture and storage (BECCS) has come to be seen as one of the most viable technologies to provide the negative carbon dioxide emissions needed to constrain global temperatures. In practice, algal biotechnology is the only form of BECCS that could be realized at scale without compromising food production. Current axenic algae cultivation systems lack robustness, are expensive and generally have marginal energy returns.
  
  
  RESULTS
  Here it is shown that microbial communities sampled from alkaline soda lakes, grown as biofilms at high pH (up to 10) and high alkalinity (up to 0.5 kmol m-3NaHCO3and NaCO3) display excellent (>1.0 kg m-3day-1) and robust (>80 days) biomass productivity, at low projected overall costs. The most productive biofilms contained >100 different species and were dominated by a cyanobacterium closely related toPhormidium kuetzingianum(>60%).
  
  
  CONCLUSIONS
  Frequent harvesting and red light were the key factors that governed the assembly of a stable and productive microbial community.
authors.affiliation: Department of Geosciences, University of Calgary, 2500 University Drive NW, EEEL 509, Calgary, AB T2N 1N4 Canada.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Sharp
authors.affiliation: Department of Geosciences, University of Calgary, 2500 University Drive NW, EEEL 509, Calgary, AB T2N 1N4 Canada.
authors.forename: Sydney
authors.initials: S
authors.lastname: Urschel
authors.affiliation: Department of Geosciences, University of Calgary, 2500 University Drive NW, EEEL 509, Calgary, AB T2N 1N4 Canada.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Dong
authors.affiliation: School of Geography and Earth Science, McMaster University, Hamilton, ON Canada.
authors.forename: Allyson L
authors.initials: AL
authors.lastname: Brady
authors.affiliation: School of Geography and Earth Science, McMaster University, Hamilton, ON Canada.
authors.forename: Greg F
authors.initials: GF
authors.lastname: Slater
authors.affiliation: Department of Geosciences, University of Calgary, 2500 University Drive NW, EEEL 509, Calgary, AB T2N 1N4 Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Strous
keywords: Algae biofuel; Biofilm; Microbial ecology; Mixed-community; Phormidium kuetzingianum