present address of Orn-u-ma Tanadul is Department of Agronomy, Faculty of Agriculture, Kasetsart University, Kamphangsaen Campus, Nakhon Pathom 73140, Thailand.
The impact of elevated CO2 concentration on the quality of algal starch as a potential biofuel feedstock
Article first published online: 20 FEB 2014
© 2014 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 111, Issue 7, pages 1323–1331, July 2014
How to Cite
Tanadul, O.-u.-m., VanderGheynst, J. S., Beckles, D. M., Powell, A. L.T. and Labavitch, J. M. (2014), The impact of elevated CO2 concentration on the quality of algal starch as a potential biofuel feedstock. Biotechnol. Bioeng., 111: 1323–1331. doi: 10.1002/bit.25203
- Issue published online: 29 MAY 2014
- Article first published online: 20 FEB 2014
- Accepted manuscript online: 29 JAN 2014 02:43AM EST
- Manuscript Accepted: 22 JAN 2014
- Manuscript Revised: 14 JAN 2014
- Manuscript Received: 18 SEP 2013
- Royal Thai Government and a Jastro-Shields Research Award to OT
- Chevron Technology Ventures and the NSF. Grant Number: MCB-1139644
- Chlorella sorokiniana;
- CO2 concentration;
- starch characteristics
Cultured microalgae are viewed as important producers of lipids and polysaccharides, both of which are precursor molecules for the production of biofuels. This study addressed the impact of elevated carbon dioxide (CO2) on Chlorella sorokiniana production of starch and on several properties of the starch produced. The production of C. sorokiniana biomass, lipid and starch were enhanced when cultures were supplied with 2% CO2. Starch granules from algae grown in ambient air and 2% CO2 were analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The granules from algae grown in 2% CO2 were disk-shaped and contained mainly stromal starch; granules from cultures grown in ambient air were cup-shaped with primarily pyrenoid starch. The granules from cells grown in 2% CO2 had a higher proportion of the accumulated starch as the highly branched, amylopectin glucan than did granules from cells grown in air. The rate of hydrolysis of starch from 2% CO2-grown cells was 1.25 times greater than that from air-grown cells and 2–11 times higher than the rates of hydrolysis of starches from cereal grains. These data indicate that culturing C. sorokiniana in elevated CO2 not only increases biomass yield but also improves the structure and composition of starch granules for use in biofuel generation. These modifications in culture conditions increase the hydrolysis efficiency of the starch hydrolysis, thus providing potentially important gains for biofuel production. Biotechnol. Bioeng. 2014;111: 1323–1331. © 2014 Wiley Periodicals, Inc.