Abstract:
Spirulina (Arthrospira platensis) is a nutrient-rich blue-green cyanobacterium extensively
cultivated for sustainable food production, pharmaceuticals, and industrial applications.
However, the high cost of conventional growth media poses a challenge to largescale production.
Traditionally, Spirulina is cultured in Zarrouk’s medium (ZM), which provides optimal nutrients
but is expensive for large-scale cultivation. The study aimed to identify a cost-effective alternative
to ZM by incorporating betel fertilizer (BF), a readily available and inexpensive nutrient source.
Five culture media formulations were tested: 100% ZM, 75% ZM +25% BF, 50% ZM + 50% BF,
25% ZM + 75% BF and 100% BF, each with three replicates. Growth performance, biomass yield,
pigment content, cell productivity, maximum specific growth rate, cell doubling time and
economic viability were assessed over a 16-day cultivation period. Cultures were maintained
under a continuous illumination (35W fluorescent tubes, 300–500lux) and continuous aeration.
Results revealed that up to 50% of ZM can be replaced with BF without significantly affecting
growth rate, biomass yield, cell concentration, maximum specific growth rate or cell productivity.
Statistical analysis using one-way ANOVA (p > 0.05) showed that the 50% mixture performed
similarly to the 100% ZM treatment in these parameters, while reducing production cost.
Furthermore, Duncan’s multiple range test confirmed that the mean values across these
treatments were not significantly different. Pigment content analysis also showed no statistically
significant decline (p > 0.05) up to the 50% mixture compared to 100% ZM, indicating that BF
substitution did not compromise biochemical composition. These findings demonstrate that
replacing 50% of ZM with BF preserves Spirulina growth efficiency while significantly lowering
production costs, presenting a promising alternative for commercial cultivation.
