Abstract:
The present study investigates the growth rate
and the effect of different pretreatment methods on lipid
yield and biodiesel quality produced from Desmodesmus
sp. isolated from Beira Lake, Colombo, Sri Lanka.
Desmodesmus sp. was cultivated using photobioreactors
providing the optimum cultivation conditions and growth
was determined by measuring the optical density and
direct cell count of the culture. Four different physical cell
disruption methods including manual grinding,
autoclaving, microwaving and water bath heating were
carried out using chlorophyll removed microalgae
biomass to investigate the effect of pretreatment on lipid
yield and biodiesel quality. The highest lipid yield was
obtained as 31.46 % for Desmodesmus sp. using water
bath heating method. However, there was no significant
impact on lipid yield after employing different cell
disruption methods. In addition, chlorophyll removal
reduced the lipid yield and increased the quality of the
biodiesel produced from Desmodesmus sp. Furthermore,
chlorophyll removal and cell disruption enhanced the
quality of biodiesel by increasing the saturated fatty acid
and monounsaturated fatty acid contents. Moreover,
cetane number, higher heating value and iodine value of
the biodiesel were within the acceptable range according
to biodiesel quality standards. Therefore, Desmodesmus
sp. can be identified as a potential source for microalgae
biodiesel production
