Iranian Research Organization for Science and Technology (IROST) Microbiology, Metabolites and Biotechnology 2980-8855 9 1 2026 07 01 Impact of Arthrospira platensis Morphology on Growth Performance and Zinc Bioaccumulation 1 7 1618 10.22104/mmb.2025.7797.1180 EN Avisha Samimiazad Department of Food Science and Technology, NT.C., Islamic Azad University, Tehran, Iran 0009-0006-5674-4545 Saeed Mirdamadi Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran 0000-0002-8356-771X Abbas Akhavan Sepahi Department of Microbiology, NT.C., Islamic Azad University, North Tehran Branch, Tehran, Iran Marjaneh Sedaghati Department of Food Science and Technology, NT.C., Islamic Azad University, Tehran, Iran Maliheh Safavi Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran Journal Article 2025 08 04 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 (OD590 = 2.6 ± 0.04). In contrast, strain L, with linear trichomes, demonstrated reduced growth (OD590 = 1.8 ± 0.03) and impaired metabolic efficiency at high zinc concentrations, suggesting reduced stress adaptability (p < 0.05). Molecular identification through 16S rRNA sequencing confirmed both strains as A. platensis, showing 99% similarity to type strains in the NCBI database. Both morphologies exhibited concentration-dependent zinc enrichment, with enrichment factor (EF) values reaching 17.03 for strain S and 16.73 for strain L at a zinc concentration of 11 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. https://mmb.irost.ir/article_1618_f60bb6bb4c96d4df93c51bd69dcc15a0.pdf