Impact of Arthrospira platensis Morphology on Growth Performance and Zinc Bioaccumulation

The cyanobacterium Arthrospira platensis has garnered significant attention for its biotechnological applications; however, morphological and physiological variations among different species can considerably influence their industrial viability. This research provides a detailed comparative analysis of two variants of A. platensis (designated as L and S), which exhibit differing trichome morphologies—linear and spiral, respectively. The study investigates their molecular identity, growth characteristics, and resilience to zinc-induced stress. Notably, strain S, characterized by spiral trichomes, exhibited enhanced biomass production (OD۵۹۰ = ۲.۶ ± ۰.۰۴). In contrast, strain L, with linear trichomes, demonstrated reduced growth (OD۵۹۰ = ۱.۸ ± ۰.۰۳) and impaired metabolic efficiency at high zinc concentrations, suggesting reduced stress adaptability (p < ۰.۰۵). Molecular identification through ۱۶S rRNA sequencing confirmed both strains as A. platensis, showing ۹۹% similarity to type strains in the NCBI database. Both morphologies exhibited concentration-dependent zinc enrichment, with enrichment factor (EF) values reaching ۱۷.۰۳ for strain S and ۱۶.۷۳ for strain L at a zinc concentration of ۱۱ mg L⁻¹. The superior zinc accumulation capacity of the spiral morphotype is likely attributable to a combination of structural and physiological factors. These results underscore the significant influence of trichome morphology on stress tolerance, positioning morphology S as a promising candidate for bioaccumulation and large-scale cultivation. This study offers valuable insights into strain selection for industrial applications.

کلیدواژه ها:

Arthrospira platensis ، Trichome morphology ، Zinc stress ، Bioaccumulation ، Growth characteristics