High-throughput isolation, using flow cytometric cell sorting
based on red and green fluorescence, and forward-light
scatter was used to isolate a diverse range of microalgae taxa
from Singapore’s coastal marine waters. Of 96 strains isolated,
a total of 21 strains were characterized for intrinsic growth
rate, biomass production and intracellular lipid content. The
three best strains with respect to lipid accumulation and
biomass generation were all Nannochloropsis sp. (strains 31, 47
and 51), with a rapid and robust growth (growth rate -
> 0.55 d1), lipid contents ranging from 42.5 to 45% as biomass
DW, and a corresponding FAME yield ranging between 16 and
22% of DW. Furthermore, these strains have a predominance
of SFA and MUFA e corresponding to a favourably high cetane
number for biodiesel feedstock. The screening procedure
provided useful ways to select microalgae, and is recommended
as an essential process for biodiesel feedstock
production. In the screening process, NR fluorescence was
used as a high-throughput screening method for determination
of microalgae cellular lipid content. Besides lipid content,
biomass production is also a critical factor to select a favourable
microalgae strain. Nannochloropsis strains are undergoing
on-going investigation to further enhance biomass productivity
and lipid yield to improve their viability as a biodiesel