262-268Carbon (neutral) based renewable liquid
biofuels are alternative to petroleum derived transport fuels that contribute
to global warming and are of a limited availability. Microalgae based biofuels
are considered as promising source of energy. <i style="mso-bidi-font-style:
normal">Lyngbya sp. and Synechococcus
sp. were studied for the possibility of biodiesel production in different media
such as ASNIII, sea water enrichment medium and BG11. The sea water enrichment
medium was found superior in enhancing the growth rate of these microalgae.
Nitrogen depletion has less effect in total chlorophyll <i style="mso-bidi-font-style:
normal">a content, at the same time the lipid content was increased in both
Lyngbya sp. and <i style="mso-bidi-font-style:
normal">Synechococcus sp. by 1.4 and 1.2 % respectively. Increase in
salinity from 0.5-1.0 M also showed an increase in the lipid content to 2.0 and
0.8 % in these strains; but a salinity of 1.5 M has a total inhibitory effect
in the growth. The total biomass yield was comparatively higher in tubular LED
photobioreactor than the fluorescent flat plated photobioreactor. Lipid
extraction was obtained maximum at 60 ºC in 1:10 sample: solvent ratio.
GC-MS analysis of biodiesel showed high content of polyunsaturated fatty acids
(PUFA; 4.86 %) than saturated fatty acid (SFA; 4.10 %). Biodiesel production
was found maximum in Synechococcus
sp. than Lyngbya sp. The viscosity of
the biodiesel was closely related to conventional diesel. The results strongly
suggest that marine microalgae could be used as a renewable energy source for
biodiesel production