"Bioprocess Scale-Up and Anticancer Phytochemicals of a Halotolerant Dunaliella Salina Isolate from Indian Coastal Waters"

Abstract

Dunaliella salina is a halotolerant, microalgae recognised for carotenoid accumulation under environmental stress. This study reports the first isolation, axenic establishment, large-scale cultivation, and comprehensive biochemical–pharmacological characterisation of a novel strain (APE0019B) collected from the coastal subtidal zone of Karnataka, India during a systematic survey of the Indian west coastline. Morphological identity was confirmed by pyriform, wall-less cells exhibiting intense orange-red carotenogenesis. The cryopreserved axenic culture retained approximately 94% viability over 24 months. Progressive scale-up biomass production from laboratory flasks through bubble-column photobioreactors to outdoor pilot-scale (250–300 L FRP tanks) yielded 3.9 kg freeze-dried biomass, confirming cultivation robustness under tropical conditions. Phytochemical screening of hot-water extracts revealed triterpenoids, saponins, flavonoids, and phenolics, with quantitative profiling showing 26.1 µg GAE g⁻¹ total phenolic, 8.2 µg TAE g⁻¹ total tannin, 11.2 µg BCE g⁻¹ total carotenoid, and 8.7 µg BSE g⁻¹ total sterol content. Both crude extract and an optimised multicomponent formulation exhibited considerable DPPH radical-scavenging activity and MTT-based cytotoxicity against MCF-7 human breast cancer cells. Collectively, these findings establish APE0019B as a scientifically validated, economically viable microalgal germplasm with promising potential for nutraceutical and pharmaceutical bioprospecting from Indian marine resources.