MSE Research Project Database

Towards sustainable production of biofuels and bio-products from microalgae: the induction of autolysis in microalgal cells to enhance biomass processing


Project Leader: Greg Martin
Staff: Dr Ronald Halim
Primary Contact: Greg Martin (gjmartin@unimelb.edu.au)
Keywords: algae; biofuel; biotechnology; cell mechanics; energy efficiency
Disciplines: Chemical & Biomolecular Engineering
Domains:

Global warming and the rapid depletion of fossil fuels have sparked an unprecedented need for carbon-neutral biofuels. Throughout the past decade, microalgae have been proven to be one of the most promising feedstock for biofuels and commodity products (such as pigments, ω-3 fatty acids and protein) due to their high areal productivity and minimal requirement for agriculturally valuable freshwater and arable land.

Microalgal products are generally intracellular in nature and can only be recovered after they have been liberated from the cells. Microalgal cell walls are composed of tough interlinking biopolymers (polysaccharides and protein) that confer the cells with a formidable defense against externally applied mechanical, chemical and enzymatic treatments. The high energy requirement associated with cell disruption has remained a major barrier to sustainable biomass processing and thus the commercialisation of microalgal bio-industry. At the University of Melbourne, we have investigated a low-cost anaerobic treatment to induce autolysis in lipid-rich Nannochloropsis cells. We have shown that the treatment triggers a series of endogenous processes that cause the cells to ingest their own cell wall and become more susceptible to rupture. Overall, the treatment reduces the energy required for cell rupture and can double the yield of biofuel-convertible lipid.

The project aims to:

  • Apply the anaerobic treatment to other industrially relevant microalgae strains outside the Nannochloropsis genus and evaluate the universality of the cell-weakening phenomenon amongst microalgal cells.
  • Understand the physiological and biochemical changes that take place in the varied cell walls of these microalgae during autolysis, and how this relates to cellular strength and rigidity.
  • Convert the anaerobic treatment from a batch to a continuous system.

The Algal Processing Group specialises in the development of new science and technology for the processing of microalgal biomass. We seek a PhD candidate with a strong background in chemical / bioprocess engineering and an interest in microalgal biotechnology. The student will have opportunities to develop and direct his/her own research program.

Further information: https://chemical.eng.unimelb.edu.au/algal-processing-group/