Two-tier vessel for photoautotrophic high-density cultures
- 448 Downloads
Two-tier vessels, developed for culturing of microalgae and cyanobacteria at high cell density on a shaken platform, were assembled from a flat lower chamber to be filled with a CO2 buffer and an upper flat sterile chamber for the culture that was separated from the lower chamber by a porous polypropylene membrane. Diffusive gas exchange with the atmosphere was controlled by the O2 outlet channel. Referred to surface area, rates of CO2 transfer to a shaken weakly alkaline buffer solution across the membrane were higher than those reached on the conventional pathway through the free upper liquid surface. Membrane-mediated CO2 supply enabled rapid growth of Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002 up to ultrahigh cell density. The biomass (dry weight) concentration of Synechococcus cultures reached more than 30 g L−1 on a buffered medium with adequate concentrations of mineral nutrients. An increase of 15 to 20 g L−1 was observed during repeated two-day cycles. Separate pathways for CO2 supply and oxygen outlet prevented significant loss of CO2. Convective gas flow through the oxygen outlet channel enabled the estimation of the O2 generation rate. The permeability of the channel for diffusive O2/N2 exchange limited the O2 concentration to a moderate value. It is concluded that shaken flat cultures using CO2 supply through a porous hydrophobic membrane and diffusive release of O2 through a separate pathway are promising for research on microalgae and cyanobacteria.
KeywordsBicarbonate Cyanobacteria Microalgae Oxygen stress Synechocystis sp. PCC 6803 Synechococcus sp. PCC 7002
Authors are grateful to Prof. Dr. T. Buckhout and Dr. R. Steuer, Institute of Biology, Humboldt-University, for improving the language and critical comments.
- Bähr L (2013) Wachstum von Cyanobakterien bei extrem hoher Zelldichte in Starklicht-Photobioreaktoren mit membranvermitteltem Eintrag von anorganischem Kohlenstoff in Kulturmedien mit hohen Konzentrationen von HCO3 − und mineralischen Nährstoffen. Diploma thesis, Humboldt-University Berlin, Germany 55 ppGoogle Scholar
- Dankwerts PV (1965) The absorption of gases in liquids. Pure Appl Chem 10:625–864Google Scholar
- Edsall JT (1969) Carbon dioxide, carbonic acid and bicarbonate ion: physical properties and kinetics of interconversion. In: Forster E, Edsall J T, Otis AB, Roughton F J W (eds.) CO2: chemical, biochemical and physiological aspects. NASA SP-188, pp. 15–34Google Scholar
- Ehwald R, Bähr L, Wüstenberg A, Soh J H (2014) Method, photobioreactor and photosynthesis layer for the culture of photoautotrophic microorganisms. USA patent application US 20140315280 A1Google Scholar
- Ehwald R, Bähr L, Wüstenberg A (2015) Research Photobioreactor. USA patent application US 20150087049 A1Google Scholar
- Kang LJ, Chen XJ, Pan XJ, Chang FY, Liu YD (2009) Effect of elevated bicarbonate concentration on growth, chlorophyll A fluorescence and ultrastructure of Microcystis aeruginosa (cyanobacterium). Fresenius Environ Bull 18:687–693Google Scholar
- Rippka R, Derulles J, Waterbury JB, Herdman M, Stanier RY (1979) Generic assignments, strain histories and properties of pure cultures of cyanobacteria. J Gen Microbiol 111:1–61Google Scholar
- Tsoglin LN, Gabel BV, Falkovich TN, Semenenko VE (1996) Closed photobioreactors for microalgal cultivation. Russ J Plant Physiol 43:131–136Google Scholar
- Warburg O, Krippahl G (1960) Weiterentwicklung der manometrischen Methoden (Carbonatgemische). Z Naturforsch C 15b:364–367Google Scholar
- Warburg O, Geissler W, Lorenz S (1961) CO2 - Drucke über Bicarbonat-Carbonatgemischen. Z Naturforsch C 16b:283Google Scholar