Ecological Assessment and Molecular Characterization of Spirulina in Freshwater Reservoirs of Kohat, Pakistan

Abstract

This pioneering study uniquely identifies and characterizes the presence of algal species, mainly Spirulina, from water reservoirs in the Kohat district of Pakistan, a previously unstudied region for microalgae dynamics. Conducted over one year, from July 2022 to June 2023, the study examined 156 samples from 26 freshwater bodies in Kohat. Only one sample from Usterzai (pH 8.6 ± 0.08, TDSs 313 ± 0.81 mg/L, DO 4.50 ± 0.05 mg/L, EC 540 ± 0.81 µS/cm) contained Spirulina sp., highlighting its rarity and specific environmental preferences. The other 155 samples, with varying parameters, contained different microalgae. Microscopic analysis further confirmed the presence of Spirulina in only one sample. The morphological and molecular analyses of the isolated Spirulina culture showed variability within the population, with phylogenetic analysis illuminating closer relationship with Arthrospira platensis. While multivariate analyses identified key environmental parameters influencing algal species distribution, the selective presence of Spirulina was found less relevant, which requires further investigation in terms of nutrient availability, microbial interactions, or subtle variations in water chemistry for ecological preferences and adaptations.