(668d) Extracellular Glycerol Production By Dunaliella Tertiolecta in a Membrane Photobioreactor

Photosynthetic microalgae can be used as bio-factories to produce value-added chemicals from carbon dioxide. One such chemical is glycerol, which is used as a precursor in many industrial manufacturing, including in the production of food and pharmaceuticals. Many marine microalgae, especially those belonging to Dunaliella sp., are able to produce intracellular glycerol under saline environment to regulate cellular osmotic pressure. Some microalgae, such as Dunaliella Tertiolecta, are also able to produce extracellular glycerol. While the use of microalgae in glycerol production has the advantages of carbon capture and utilization, it may also generate microalgae biomass, which can act as precursors in the production of various other useful compounds, including biofuels.

The extracellular glycerol production from microalgae is a great opportunity as it avoids the usual issues related to harvesting or downstream separation of microalgae. However, the production of extracellular glycerol by microalgae is typically low and it may not be very economical to produce. On approach to improve the yield of intracellular glycerol by microalgae can be the use of membrane photobioreactor (MPBR), such that a very high biomass density can be maintained in the MBR, which may translate in high yield of glycerol.

In this research, an MPBR based on microfiltration was designed and operated for high-throughput extracellular glycerol production using Dunaliella Tertiolecta. The effects of various operating parameters, such as biomass concentration, CO₂ supply, hydraulic retention time, light intensity and medium salinity on biomass accumulation and glycerol production were investigated. The results indicated that the MPBR has high potential in economical and sustainable production for glycerol.