Nutrient acquisition and limitation for the photoautotrophic growth of Synechocystis sp. PCC6803 as a renewable biomass source |
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Authors: | Hyun Woo Kim Raveender Vannela Chao Zhou Bruce E Rittmann |
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Institution: | 1. Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, 1001 South McAllister Avenue, P.O. Box 875701, Tempe, Arizona 85287‐5701;2. telephone: 1‐480‐294‐4534;3. fax: 1‐480‐727‐0889 |
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Abstract: | Photoautotrophic microorganisms (cyanobacteria and algae) offer high promise as a source of biomass for renewable energy due to their rapid growth rates and high biomass yields. To provide a framework for evaluating the feasibility of growing phototrophic microorganisms with high biomass production rates, we operated a bench‐scale photobioreactor using Synechocystis sp. PCC6803 and with light conditions imitating actual day–night light irradiance (LI). During the time of peak LI, PCC6803's specific growth rate (1.7 day−1) and the nitrate uptake rate (0.46 g N/g DW day) were high compared to past reports. Analysis employing the stoichiometry of photosynthesis of PCC6803 and ionic speciation showed that bicarbonate and phosphate were driven to very low concentrations for the high‐LI conditions. In particular, the systematic evaluation of rate‐limiting factors identified when the CO2–Ci supply rate needed to be increased to mitigate HCO depletion and a large pH increase. It also showed that the traditional BG‐11 medium needs to be augmented with phosphate to avoid severe P depletion. This work exploits quantitative understanding the stoichiometry and kinetics of cyanobacteria for the high‐rate production of a renewable biomass. Biotechnol. Bioeng. 2011;108: 277–285. © 2010 Wiley Periodicals, Inc. |
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Keywords: | photoautotrophic biomass renewable biomass stoichiometry rate‐limiting factors inorganic carbon inorganic nutrients |
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