The effect of species diversity on lipid production by micro-algal communities

Abstract

International audienceCurrent research investigating the importance of diversity for biofuel lipid production remains limited. In contrast, the relationship between diversity and productivity within terrestrial and algal primary producers has been well documented in ecology. Hence, we set out to investigate, experimentally, whether diversity may also affect lipid production in micro-algae. We investigated the growth and lipid production of micro-algae using species from all major algal groups. Algae were grown in a large number of treatments differing in their diversity level. Additionally, we compared the growth and lipid production of laboratory communities to natural lake and pond phytoplankton communities of different diversity. Our results show that lipid production increased with increasing diversity in both natural and laboratory micro-algal communities. The underlying reason for the observed 'diversity-productivity' relationship seems to be resource use complementarity. We observed higher lipid production of highly diverse algal communities under the same growth and resource supply conditions compared to monocultures. Hence, the incorporation of the ecological advantages of diversity-related resource-use dynamics into algal biomass production may provide a powerful and cost effective way to improve biofuel production

Low algal diversity systems are a promising method for biodiesel production in wastewater fed open reactors

“…Algal biodiesel production will therefore be limited by the standing crop of the microalgae and also by the lipid content. Both the quality and quantity of lipids produced will vary with the identity of the algal species as well as the site specific growth conditions (Brennan and Owende 2010, Sydney et al 2011, Yang et al 2011, Stockenreiter et al 2012). This variability probably reflects alteration in relative rates of production and utilization of storage lipids and modifications in the properties of cellular membranes (Rodolfi et al 2009).…”

“…Algae offer a tangible promise to fulfill the need for an alternative source of energy. While growing algae outdoors is generally expensive, the cost of this method of cultivation can be greatly reduced by using wastewater as a medium for their growth (Ahrens and Sander 2010, Clarens et al 2010, Park et al 2011, Stockenreiter et al 2012. Algae can also produce a variety of high value compounds such as biodiesel and biofertilizer, without contributing to atmospheric carbon dioxide (Borowitzka 1995, Olaizola 2003, Banerjee and John 2005, Banerjee and Kushwaha 2005.…”

“…It has been suggested that diverse algal assemblages may contribute to more productive and / or more stable open reactors because of a generally positive relationship among plant diversity, stability, and productivity (McCann 2000, Rooney and McCann 2012, Stockenreiter et al 2012) but tests of this are lacking in algal production systems. In a small scale test (reaction wells), Stockenreiter et al (2012) found that more diverse algal assemblages had higher lipid production.…”

“…It has been suggested that diverse algal assemblages may contribute to more productive and / or more stable open reactors because of a generally positive relationship among plant diversity, stability, and productivity (McCann 2000, Rooney and McCann 2012, Stockenreiter et al 2012) but tests of this are lacking in algal production systems. In a small scale test (reaction wells), Stockenreiter et al (2012) found that more diverse algal assemblages had higher lipid production. Because an abundance of planktivorous fish is often associated with suppression of herbivorous zooplankton (that naturally colonize outdoor tanks) and high standing crops of algae (Carpenter et al 1985(Carpenter et al , 1995, it has been suggested that including planktivorous fish increases algal production .…”

Journal of Oceanography and Marine Research

“…In aquatic systems positive biodiversity effects were observed in manipulation experiments, i.e., experiments in which biodiversity was artificially manipulated to simulate species loss or artificial communities, with higher plants [20,32,33], macroalgae [34][35][36][37][38], and microalgae [22,[39][40][41][42]. Manipulation experiments with species from oceanic systems show a positive biodiversity-ecosystem functioning effect for primary producers, i.e., plants and algae [33].…”