Developing a high-throughput screen for the isolation of the model green alga Chlamydomonas reinhardtii from soil samples

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Biological Sciences

Abstract

BBSRC : Rory Craig : BB/M010996/1

Algae are an amazingly diverse group of organisms that are integral to the function of ecosystems, performing approximately half of global carbon fixation. Furthermore, algae have a key role to play in the fight against climate change, as they can be used to produce environmentally clean biofuels and other valuable bioproducts. Despite their importance, we know very little about how these species actually live in natural environments. This includes almost a complete lack of knowledge concerning whether different species are adapted to specific ecological conditions, and little understanding of the population genetics of species (e.g. if there are distinct genetic populations within species, what rates of migration exist between populations, etc.).

The green alga Chlamydomonas reinhardtii is the foremost research species in algal biology. Several decades of cell biology, biochemistry and genetics research have been performed using this species, making it the ideal model to investigate a number of pertinent questions. These range from exploring the ecology and population genetics of algae, to understanding the biochemical pathways underlying biofuel production. Despite its wide use across several fields and extensive attempts to sample the species, it has only been successfully isolated 36 times, and almost all research has been performed on a single line of related laboratory strains. While this severely limits our understanding of population genetics, it also means that the genetic and phenotypic diversity present in the species is ignored in biotechnology research (e.g. no selective breeding has been performed to increase biofuel yields).

In this proposal to the UK-Canada Globalink Doctoral Exchange Scheme, we aim to develop a high-throughput screen to detect the presence of C. reinhardtii in environmental samples, and to subsequently isolate the species from samples where it is present. This would be achieved by developing a unique genetic marker for C. reinhardtii, that could be amplified and detected from environmental samples using standard molecular biology techniques. Once developed, this technique would be extended to a wide variety of sites differing in their environment, allowing us to gain some of the first insights into the ecological preferences of the species. Furthermore, we would begin to build a collection of isolates that could be used for both population genetics and biotechnology applications.

This work would be performed with Prof. Rob Ness and his research group at the University of Toronto, as part of a 3-month research exchange from the University of Edinburgh. Samples would be collected from around Ontario and Quebec, starting in locations where the species has been isolated previously. If successful, the approach could also be extended to other algal species in the future, which is especially important given that several industrial model species are known from only a single cultured isolate (e.g. Chromochloris zofingiensis).

In summary, we aim to develop a laboratory technique that will facilitate the high-throughput sampling of a biologically important species, enabling several new questions to be explored across the diverse field of algal biology.

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