A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae
| dc.contributor.author | van Hille, R | |
| dc.contributor.author | Fagan, M | |
| dc.contributor.author | Bromfield, L | |
| dc.contributor.author | Pott, R | |
| dc.date.accessioned | 2016-08-25T10:35:24Z | |
| dc.date.available | 2016-08-25T10:35:24Z | |
| dc.date.issued | 2014 | |
| dc.date.updated | 2016-08-23T10:04:55Z | |
| dc.description.abstract | Threat of global warming due to carbon dioxide (CO2) emissions has stimulated research into carbon sequestration and emissions reduction technologies. Alkaline scrubbing allows CO2 to be captured as bicarbonate, which can be photochemically fixed by microalgae. The carbon concentrating mechanism (CCM), of which external carbonic anhydrase is a key component, allows organisms to utilise this bicarbonate. In order to select a suitable strain for this application, a screening tool is required. The current method for determining carbonic anhydrase activity, the Wilbur and Anderson assay, was found to be unsuitable as a screening tool as the associated error was unacceptably large and tests on whole cells were inconclusive. This paper presents the development of a new, whole cell assay to measure inorganic carbon uptake and external carbonic anhydrase activity, based on classical pH drift experiments. Spirulina platensis was successfully used to develop a correlation between the specific carbon uptake (C) and the specific pH change (dpH). The relationship is described by the following: C[mmol C (g dry algae)−1 h−1] = 0.064 × (dpH). Inhibitor and salt dissociation tests validated the activity and presence of external carbonic anhydrase and allowed correlation between the Wilbur and Anderson assay and the new whole cell assay. Screening tests were conducted on S. platensis, Scenedesmus sp., Chlorella vulgaris and Dunaliella salina that were found to have carbon uptake rates of 5.76, 5.86, 3.86 and 2.15 mmol C (g dry algae)−1 h−1, respectively. These results corresponded to the species' known bicarbonate utilisation abilities and validated the use of the assay as a screening tool. | en_ZA |
| dc.identifier | http://dx.doi.org/10.1007/s10811-013-0076-6 | |
| dc.identifier.apacitation | van Hille, R., Fagan, M., Bromfield, L., & Pott, R. (2014). A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae. <i>Journal of Applied Phycology</i>, http://hdl.handle.net/11427/21541 | en_ZA |
| dc.identifier.chicagocitation | van Hille, R, M Fagan, L Bromfield, and R Pott "A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae." <i>Journal of Applied Phycology</i> (2014) http://hdl.handle.net/11427/21541 | en_ZA |
| dc.identifier.citation | van Hille, R., Fagan, M., Bromfield, L., & Pott, R. (2014). A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae. Journal of applied phycology, 26(1), 377-385. | en_ZA |
| dc.identifier.issn | 0921-8971 | en_ZA |
| dc.identifier.ris | TY - Journal Article AU - van Hille, R AU - Fagan, M AU - Bromfield, L AU - Pott, R AB - Threat of global warming due to carbon dioxide (CO2) emissions has stimulated research into carbon sequestration and emissions reduction technologies. Alkaline scrubbing allows CO2 to be captured as bicarbonate, which can be photochemically fixed by microalgae. The carbon concentrating mechanism (CCM), of which external carbonic anhydrase is a key component, allows organisms to utilise this bicarbonate. In order to select a suitable strain for this application, a screening tool is required. The current method for determining carbonic anhydrase activity, the Wilbur and Anderson assay, was found to be unsuitable as a screening tool as the associated error was unacceptably large and tests on whole cells were inconclusive. This paper presents the development of a new, whole cell assay to measure inorganic carbon uptake and external carbonic anhydrase activity, based on classical pH drift experiments. Spirulina platensis was successfully used to develop a correlation between the specific carbon uptake (C) and the specific pH change (dpH). The relationship is described by the following: C[mmol C (g dry algae)−1 h−1] = 0.064 × (dpH). Inhibitor and salt dissociation tests validated the activity and presence of external carbonic anhydrase and allowed correlation between the Wilbur and Anderson assay and the new whole cell assay. Screening tests were conducted on S. platensis, Scenedesmus sp., Chlorella vulgaris and Dunaliella salina that were found to have carbon uptake rates of 5.76, 5.86, 3.86 and 2.15 mmol C (g dry algae)−1 h−1, respectively. These results corresponded to the species' known bicarbonate utilisation abilities and validated the use of the assay as a screening tool. DA - 2014 DB - OpenUCT DP - University of Cape Town J1 - Journal of Applied Phycology LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 SM - 0921-8971 T1 - A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae TI - A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae UR - http://hdl.handle.net/11427/21541 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/21541 | |
| dc.identifier.vancouvercitation | van Hille R, Fagan M, Bromfield L, Pott R. A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae. Journal of Applied Phycology. 2014; http://hdl.handle.net/11427/21541. | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher | Springer | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.source | Journal of Applied Phycology | en_ZA |
| dc.source.uri | http://link.springer.com/journal/10811 | |
| dc.subject.other | Aqueous chemistry | |
| dc.subject.other | Carbon concentrating mechanism | |
| dc.subject.other | Screening test | |
| dc.title | A modified pH drift assay for inorganic carbon accumulation and external carbonic anhydrase activity in microalgae | en_ZA |
| dc.type | Journal Article | en_ZA |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Article | en_ZA |