Touchy Feely GM Algae
Professor Mike Allen, Plymouth Marine Laboratory
“We can now feel and observe the nanoscale structural impacts of genetic modification at the cell surface with unprecedented resolution.”
Prof Mike Allen, Plymouth Marine Laboratory
The genetic manipulation of marine microalgae has transformed the production of a variety of membrane associated products, such as triacyl glycerides, omega 3 oils and triterpenoids. However, previous focus has been on product yield and hence little is known about how microalgal membrane function is affected by the production of these metabolites. As the use of microalgal platforms becomes more established, this becomes more relevant since alterations of membrane function in microalgae may have consequences, both positive and negative, for potential biotechnology applications.
The challenge is to improve understanding of microalgal membrane function in order to understand the effects of genetic manipulation(s) and gain insight into ways to optimise metabolite production.
Professor Mike Allen is a Microbial Biochemist at the Plymouth Marine Laboratory (PML). The research in his laboratory encompasses wide-ranging aspects of Industrial Biotechnology, including biocatalysis, bioremediation, biotransformation, bioprocessing and technology development. One aspect of this is the development and application of genetically modified microalgae for high value products. Algenuity is a UK company that develops, produces and licenses technology, tools and knowhow to increase microalgae productivity, improve strain traits, reduce time to market and drive industry success for global impact.
Professor Allen and his colleagues, Dr Tracey Beacham and Dr Andrew Landels, applied for a CBMNet Proof-of-Concept award with Algenuity. Their joint project aimed to investigate membrane topography of microalgae used as Industrial Biotechnology platforms. In particular, the research aimed to assess the effect that genetic engineering may have on microalgal cell membranes.
High-speed Atomic Force Microscopy (AFM) was used to characterise the lipid topography of the cell surface of Phaeodactylum tricornutum. Observing nanoscale structures in living cells is technically challenging and, in this case, required the development of novel techniques. Progress was made towards engineering a suitable substrate for cell adhesion and imaging and in developing methodologies, such as a ‘Liquid Cell Microcosm’.
Although this work is ongoing, it was sufficiently advanced to allow the visualisation of wild-type microalgae in different phases of cell growth. It was observed that there were very clear differences in the membranes of cells in early exponential growth phase (i.e. actively growing) compared to cells entering stationary phase. This may correlate with the polyunsaturated fatty acid profile of cells in different stages of growth.
As well as wild-type cells, the researchers also imaged membrane topography in a strain that produced increased amounts of the ‘omega 3 and 6 oils’. Interestingly, differences in ‘roughness’ of the cell surface were observed, suggestive of membrane changes.
The researchers plan to use the methodologies developed in this project to make similar observations on other industrially relevant strains of P. tricornutum, including strains expressing triterpenoids. A publication detailing their newly developed methodologies is currently in preparation.
The high-speed AFM technology is being applied to other projects within PML and Professor Allen has obtained internal funding to support the use of the novel ‘Liquid Cell Microcosm’ technology.
The collaboration between Professor Allen and Algenuity will continue in the near future with two studentships, one based at PML and one at Algenuity. Further funding applications to Innovate UK are being progressed and Professor Allen has already been successful in securing funding from the National Biofilms Innovation Centre (NBIC).
“Understanding how to visualise microalgae cell surfaces at high resolution is a key step to potentially using this part of the cell in a commercial context.”
Dr Andrew Spicer, Algenuity