The micro alga, Spirulina is a rich source of protein, which is
used as a protein supplement for humans, chicks and also in aquaculture.
Among the cultures, CS-1 registered maximum biomass production and S-20
showed highest biomass production among the local isolates. Optimum temperature
of 35°C was the best for maximum biomass production of S. platensis
cultures. Among the cultures CS-1 culture, put forth maximum biomass production
at 35°C. The biomass production of all S. platensis cultures
was maximum at pH 10.0. Among the cultures, CS-1 recorded maximum biomass
at pH 10.0. S. platensis culture S-20 showed highest biomass production
among the local isolates. S. platensis cultures were grown under
different light wave lengths ranging from 340-700 nm and observed that
it grows best in red light but later on there was no significant difference
between the biomass produced under red and normal white lights. S.
platensis culture CS-1 has shown the highest chlorophyll, carotenoids
and phycocyanin and protein contents. When the extracted protein was resolved
on a 15% SDS-PAGE gel, the cultures have polypeptide subunits ranging
from the molecular weights 20 to 95 kDa. The liquid nitrogen method was
found to be the best by extraction higher quantity of phycocyanin from
all S. platensis cultures. Among the cultures, S. platensis
culture CS-1 recorded the highest phycocyanin content and among the local
isolates SM-2 showed the highest pigment content. SDS-PAGE analysis of
phycocyanin pigment revealed two characteristic bands with a molecular
weights of 14.3 and 20.1 kDa approximately for α and β subunits.