High biomass, pigments and high antioxidant capacity
under immobilized cell cultures indicate that a growth culture
simulating the in situ growth conditions of N. lobatus
would be an effective approach for scaling-up its biomass
production and antioxidant capacity. N. lobatus is a filamentous
branched diazotroph which grows luxuriantly
attached to the rock surfaces of streams in the form of solid
mucilaginous balls containing unialgal population. Probably
due to this innate capacity, the biomass, pigments
and antioxidant capacity of this alga appeared high under
immobilized cell culture. High concentrations of carotenoids
and phycobiliproteins (phycocyanin and phycoerythrin),
as recorded in N. lobatus have high commercial
value. Both of these pigments have been shown to have
antioxidant properties and are used as natural food colourants
and food additives. Concentration of phycoerythrin
was substantially high in N. lobatus (about 11% of dry wt
in normal growth medium), which increased substantially
by added P and Fe (14.4%). This has added advantage
because phycoerythrin is now increasingly being used in a
variety of fluorescence immunoassays, diagnostics and biomedical
researches.