Abstract
Recently, technologies have been developed that offer the possibility of using algal biomass as feedstocks to energy producing systems – in addition to oil-derived fuels (Bird et al., 2011, 2012). Growing native mixed microalgal consortia for biomass in association with geothermal resources has the potential to mitigate negative impacts of seasonally low temperatures on biomass production systems as well as mitigate some of the challenges associated with growing unialgal strains. We assessed community composition, growth rates, biomass, and neutral lipid production of microalgal consortia obtained from geothermal hot springs in the Great Basin/Nevada area that were cultured under different thermal and light conditions. Biomass production rates ranged from 39.0 to 344.1 mg C L−1 day−1. The neutral lipid production in these consortia with and without shifts to lower temperatures and additions of bicarbonate (both environmental parameters that have been shown to enhance neutral lipid production) ranged from 0 to 38.74 mg free fatty acids (FFA) and triacylglycerols (TAG) L−1 day−1; the upper value was approximately 6% of the biomass produced. The higher lipid values were most likely due to the presence of Achnanthidium sp. Palmitic and stearic acids were the dominant free fatty acids. The S/U ratio (the saturated to unsaturated FA ratio) decreased for cultures shifted from their original temperature to 15°C. Biomass production was within the upper limits of those reported for individual strains, and production of neutral lipids was increased with secondary treatment. All results demonstrate a potential of culturing and manipulating resultant microalgal consortia for biomass-based energy production and perhaps even for biofuels.
Highlights
Environmental and biological fluctuations make the maintenance of unialgal strains as a feedstock for fuels/biofuels challenging (Sheehan et al, 1998; Brennan and Owende, 2010)
During the aquatic species program (ASP) that conducted a myriad of activities aimed at producing algae for oil (Sheehan et al, 1998), biomass recycling was an example of a method employed for species maintenance
Microalgal consortia collected from naturally high-temperature environments present the possibility of robust communities, potentially having the advantage of resistance to invasion in production systems, and for elevated growth rates – biomass
Summary
Environmental and biological fluctuations (e.g., temperature, light levels, nutrient availability, pH, grazers, etc.) make the maintenance of unialgal strains as a feedstock for fuels/biofuels challenging (Sheehan et al, 1998; Brennan and Owende, 2010). During the aquatic species program (ASP) that conducted a myriad of activities aimed at producing algae for oil (Sheehan et al, 1998), biomass recycling was an example of a method employed for species maintenance. Even when such measures were employed, shifts in the dominant taxa often occurred (Weissman and Benemann, 1979; Sheehan et al, 1998). Such developments make algal biomass – beyond that which is oleaginous – possible feedstocks that could help in meeting energy demands
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call