81-15 Transforming Jackfruit Waste into a Sustainable Medium to Enhance Biomass Production and Astaxanthin Accumulation in the Green Microalga Desmodesmus sp.

Abstract:

ABSTRACT

Commercial microalgae cultivation depends on synthetic growth media that increase production costs and limit opportunities for recycling nutrient-rich organic wastes. This study investigated the potential of unsupplemented Digested Jackfruit Waste Medium (DJWM) as a sustainable alternative to synthetic Bold's Basal Medium (BBM) for cultivating Desmodesmus sp. within a circular bioeconomy framework. Batch cultures were grown for 16 days using a range of DJWM dilutions to identify the optimal balance between nutrient availability and osmotic stress. A 50% DJWM dilution produced dry biomass yields (0.64 g L^-1) and specific growth rates (0.30 d^-1) that were statistically indistinguishable (p > 0.05) from those obtained with BBM, while significantly increasing astaxanthin accumulation (7.05 mg g^-1) (p < 0.05). The optimized medium also promoted rapid assimilation of nitrogen and phosphorus recovered from jackfruit waste, demonstrating efficient nutrient recycling. Replacing synthetic medium with DJWM reduced media formulation costs by approximately six-fold while diverting organic residues from landfills and recovering valuable nutrients that would otherwise be lost from the agricultural system. These findings demonstrate that jackfruit waste can serve as an effective, low-cost cultivation medium for microalgae while supporting nutrient recovery, waste valorization, and sustainable biomass production. The study highlights the potential of waste-derived growth media as nature-based solutions that integrate agricultural waste management with environmental biotechnology and circular resource use.

Keywords: Desmodesmus sp.; jackfruit waste; nutrient recovery; astaxanthin; Circular bioeconomy; environmental biotechnology.

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