Many microalgae look very similar but are actually highly biodiverse. In our waterways, this has important ecological implications. For industry, understanding microalgal biodiversity can underpin our use of algae to make products like biofuels.
Understanding the diversity of our microalgae
Our challenge is to understand microalgal biodiversity and its importance in the Australian landscape. Microalgae are highly diverse and differences within and between both species and populations lead to significant differences in biogeography and the environment.
The Australian National Algae Culture Collection (ANACC) holds cultures of unique Australian microalgal biodiversity collected from marine, estuarine, freshwater and hypersaline environments from tropical to temperate Australia and Antarctica. The collection includes representatives of most classes of microalgae, making it an important resource for research into their biodiversity, role, distribution, richness, taxonomic relationships and potential uses. This is particularly important for algae of economic value or environmental concern.
The collection supports information sharing for research, community benefit, policy development and conservation. ANACC is part of the Australian Microbial Resources Information Network and contributes to Australia's digital natural history collection, the Atlas of Living Australia. We take a lead role in initiatives such as the Network of Asia Oceania Algae Culture Collections to support microalgal research and development in our region.
Supoprting industry scale uses of algae
Botryococcus braunii is a microalgae found all over the world. It forms blooms in fresh and weakly saline inland waters. While identical when viewed morphologically, chemical characterisation of a group of hydrocarbon lipids known as botryococcenes shows this algae has distinct chemical races: A, B, L and S.
The B race is of great interest to the algae biofuel industry as its botryococcenes can form more than 50 per cent of its dry weight. This algae can be used as a drop-in feedstock for hydrocracking to produce sustainable biofuels such as octane, kerosene and diesel.
At CSIRO we are describing the biodiversity of Botryococcus from tropical Northern Australia through to the cool, temperate waters of Tasmania. We have found that the chemical races of Botryococcus match their genomic barcodes, suggesting they are discrete genetic clades.
The major limitation to industry-scale exploitation of Botryococcus is its slow growth rate. Our goal is to use our knowledge of natural bloom dynamics to find strains with the potential for both fast growth rates and high lipid production.