The impact of polystyrene nanoplastics (PSNPs) on physiological and biochemical parameters of the microalgae Spirulina platensis

Abstract

Nanoplastics, as emerging pollutants, have harmful effects on living organisms and the environment, the mechanisms and extent of which remain unclear. Microalgae, as one of the most important biological groups in the food chain and sensitive environmental indicators to various pollutants, are considered a suitable option for investigating the effects of nanoplastics. In this study, the effects of polystyrene nanoplastics on the growth rate, dry weight, chlorophyll a and carotenoid levels, proline, and lipid peroxidation in the Spirulina platensis were examined. Three concentrations of 0.1, 1, and 10mgL-1 of PSNPs were used alongside a control sample with zero concentration, with four repetitions in one-liter containers for 20 days under optimal temperature and light conditions. Various analyses, including growth rate, dry weight, proline, chlorophyll a and carotenoid levels, and lipid peroxidation, were performed. The results indicated that exposure to PSNP stress led to a significant decrease in growth rate, dry weight, and chlorophyll a and carotenoid levels compared to the control sample. Furthermore, this stress increased the levels of proline and lipid peroxidation in Spirulina platensis. Morphological analysis via microscopy supported these findings, indicating considerable environmental risks associated with PSNPs. Environmental ImplicationThe research looked into how polystyrene nanoplastics (PSNPs) affect the physiological and biochemical aspects of the Spirulina platensis. Nanoplastics, as pollutants that are becoming more common, can have negative impacts on living organisms and the environment. Since microalgae are crucial parts of the food chain and can act as indicators of pollution in the environment, they were chosen as the focus of this study. Different concentrations of PSNPs 0.1, 1, and 10mgL-1 were used, along with a control group. The results indicated a significant drop in growth rate, dry weight, and chlorophyll levels in the microalgae exposed to PSNPs, while levels of proline and lipid peroxidation increased. These findings suggest a serious potential for environmental damage from PSNPs.