Cell physiology and rupture

Recovering lipids and proteins from microalgal biomass requires the microscopic cells to be ruptured (Yap et al. 2014). The APG has shown that by processing pre-concentrated biomass, this can be done in an energy efficient manner at large scale using high pressure homogenisation (Yap et al. 2015). We have also shown that efficient processing of microalgal biomass is highly dependent on the species of microalgae (Spiden et al. 2013). Importantly, growth conditions that effect lipid accumulation in algae, also alter the biophysical attributes of the microalgal cells relevant to cell rupture, such as cell size and cell wall thickness and strength (Yap et al. 2016). Relatedly, the changes in the physiology of algae due to altered growth conditions effect their harvesting and dewatering properties (Baroni et al. 2019).

More recently, the group has shown that the rheology of algae slurries changes dramatically as a result of cell rupture (Mettu et al. 2019) and that the viscoelastic nature of concentrated algae slurries greatly attenuates ultrasound reducing its effectiveness for large-scale cell rupture (Yao et al. 2018).


Mettu, S., Yao, S., Law, S.Q.K., Sun, Z., Scales, P.J., Ashokkumar, M., Martin, G.J.O. (2019). Rheological properties of concentrated slurries of harvested, incubated and ruptured Nannochloropsis sp. cells. BMC Chemical Engineering, 1:8.

Yao, S., Mettu, S., Law, S.K.Q., Ashokkumar, M., Martin, G.J.O. (2018). The effect of high-intensity ultrasound on cell disruption and lipid extraction from high-solids viscous slurries of Nannochloropsis sp. biomass. Algal Research 35, 341-348.

Baroni, É.G., Yap, K.Y., Webley, P.A., Scales, P.J., Martin, G.J.O. (2019). The effect of nitrogen depletion on the cell size, shape, density and gravitational settling of Nannochloropsis salina, Chlorella sp. (marine) and Haematococcus pluvialis. Algal Research, 39, 101454.

B.H.J. Yap, S.A. Crawford, R.R. Dagastine, P.J. Scales, G.J.O. Martin, Nitrogen deprivation of microalgae: effect on cell size, cell wall thickness, cell strength, and resistance to mechanical rupture, Journal of Industrial Microbiology and Biotechnology, 43 (2016) 1671–1680.

B.H.J. Yap, G.J. Dumsday, P.J. Scales, G.J.O. Martin, Energy evaluation of algal cell disruption by high pressure homogenization, Bioresource Technology, 184 (2015) 280–285.

B.H.J. Yap, S.A. Crawford, G.J. Dumsday, P.J. Scales, G.J.O. Martin, A mechanistic study of algal cell disruption and its effect on lipid recovery by solvent extraction, Algal Research, 5 (2014) 112-120.

E.M. Spiden, B.H.J. Yap, D.R.A. Hill, S.E. Kentish, P.J. Scales, G.J.O. Martin, Quantitative evaluation of the ease of rupture of industrially promising microalgae by high pressure homogenization, Bioresource Technology, 140 (2013) 165–171.