Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8087801 | Algal Research | 2015 | 8 Pages |
Abstract
Considerable investment through public/private consortia has been towards increasing the productivity from mass algal cultivation for making the industries involved more economically viable. Although high-tech solutions have been popular in recent years, I questioned whether low-tech answers through the method that algae are cultivated could shed light on increasing productivity in mass cultivation systems. Shade-limited growth was studied for Thalassiosira pseudonana (marine diatom) cultures exposed to 85 Ein mâ 2 dâ 1 under continuous light, and mixed through a 20 cm water column (a standard depth for open pond cultivation), to compare ash-free dry weight (AFDW) and chlorophyll-a (Chl-a) concentrations, net primary productivity (P) and specific growth rates (μ) obtained by batch culture, continuous culture, and semi-continuous culture. Under shade-limiting conditions, both AFDW and Chl-a concentrations varied inversely with μ for the three cultivation methods. During the linear growth phase of batch culture, P did not vary in relation to μ or biomass (B), therefore μ = P / B, and growth rate varied as a power for biomass. For continuous culture methods, B is a function of μ (as dilution rate), therefore B = P μm, and m = â 1 if linear growth is modeled. Net primary production did vary in relation to μ for both continuous and semi-continuous cultures, and m > â 1. Therefore continuous and semi-continuous culture methods did not reproduce a linear growth phase as found for shade-limited growth. For growth rate > 0.5 doubling dâ 1, semi-continuous culture had highest, and continuous culture had lowest P for the three methods compared. These results provide evidence that the method of cultivation introduces large variability to net primary productivity under shade-limiting conditions, and needs consideration in the design of cultivation systems and microbiological experiments.
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Christopher D. Hewes,