Removal efficiency of marine filamentous Cyanobacteria for Pyrethroids and their effects on the biochemical parameters and growth

Abstract Pesticides, widely used in agricultural fields, eventually washed into surface waters, affecting a wide range of non-target organisms, including marine biota. In order to evaluate the response of two filamentous cyanobacteria isolated from marine environment, Pseudanabaena sp. (MB.1007) and Leptolyngbya sp. (MB.1010) were exposed to different concentration of technical grades (5–100 μg.mL−1) and formulated commercial products (5–500 μg.mL−1) of cypermethrin and deltamethrin. Morphological parameters, growth rates, photosynthetic pigments, carbohydrates, lipids, ash, moisture, and protein contents were estimated. Cypermethrin at concentrations up to 20 μg.mL−1 stimulated growth rates, photosynthetic pigments, and biochemical parameters while deltamethrin showed inhibitory effects. Cypermethrin treated cells exhibited significant survivability as compared to those treated with deltamethrin. Analysis of recovered pesticides from the treated media showed the efficiency of both strains in pyrethroid removal. Pseudanabaena sp. (MB.1007) was found to be more efficient with up to 98.0% for cypermethrin and 99.0% for deltamethrin removal as compare to Leptolyngbya sp. (MB.1010) which showed removal efficiency of 82.0% for cypermethrin and 97.8% for deltamethrin. After removal study, a total of 35 chemical constituents have been identified from four different pooled culture media including 13 hydrocarbons (6, 10, 11, 12, 14, 15, 16, 18, 19, 31–33 and 35), 8 fatty alcohols and their derivatives (1, 2, 4, 7, 17, 20, 30, and 34), 8 aromatics including 2 phthalates (13 and 24), a fatty ketone (8), a furan (9), a fatty acid ester (23) and a fulvene (26). 3-phenoxy-benzaldehyde (3) and 1-(2-methyl-cyclopropyl)-ethanone (29), the degradation products of cypermethrin and deltamethrin, were also identified from the media exploiting GCMS.