The challenge
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.
Our response
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.
Oil droplets exuded from a Botryococcus colony under slight pressure. This image is a dual channel overlay of differential interference contrast (DIC) + chlorophyll 'a' in-vivo fluorescence. The image has been manipulated to reveal cells with (red) and without the fluorescence channel (green).
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.