January 1, 2010.
Increased carbon dioxide levels in the atmosphere and its influence on climate change is a growing concern in the scientific, political, and social communities. Methods of mitigation are being tested to explore carbon capture and storage through the biosynthesis of stable carbon-containing compounds using different strains of calcifying cyanobacteria. By utilizing marine genera, the cyanobacteria could potentially be grown in brine waste waters, conserving valuable fresh water resources. In this experiment, two strains of Synechococcus were cultured in flasks with varying levels of CO2: air, 5% CO2, and 15% CO2. Growth of each culture was monitored by measuring optical density and pH level, as calcification requires an alkaline environment. Morphological characteristics of each culture were analyzed through light microscopy and scanning electron microscopy to compare differences in cell surface and association. Preliminary results have shown inconsistent morphology and growth. Cultures started from previous experiments lacked duplication of observed filamentous morphology, but exhibited better growth in high CO2 levels. The incubation of cultures in media with varying levels of calcium chloride will be used to analyze and compare the sequestration of carbon through calcium carbonate production. Analysis of the chemical composition of precipitates in the media and the S-layer of cells will verify the presence of calcium carbonate. Methods include the use of SEM-EDX (energy-dispersive X-ray spectroscopy) and polarized light microscopy. If experimental outcomes verify efficient production of calcium carbonate from sources of high CO2, these cyanobacteria may be viable systems for capturing carbon.
Lawrence Berkeley National Laboratory (LBNL)