Naturally weathered polypropylene microplastic from environment and its toxic behaviour in Artemia salina.

The increasing use of polypropylene (PP) in consumer products leads to the microplastic (PP MPs) contamination of the aquatic ecosystems. Comprehensive toxicological studies of weathered/aged and new PP MPs with Artemia salina are a need of the hour. Our study explores the toxicological differences between naturally weathered (aged) and prepared new PP MPs on Artemia salina. Both the weathered and new PP MPs were prepared using controlled grinding and sieving at ≤ 125 µm. Artemia salina was treated with different concentrations (0.25, 0.5, and 1 mg/mL) of PP MP particles for up to 48 h. The uptake of weathered PP MP particles by Artemia salina was higher than the new PP MPs. The accumulation of PP MP particles was found in the intestine. There was increased oxidative stress recorded in the animal treated with the weathered PP MPs than the new PP MPs. Artemia salina treated with weathered PP MPs showed higher ROS generation and increased, activity of oxidative enzymes like LPO, SOD, and CAT. Collectively, our findings underscore the detrimental effects of weathered and prepared new PP MPs on Artemia salina, which is an ecologically significant species of zooplankton. There is an urgent need and effective measures required to address plastic disposal strategies in an environmentally safe manner.

Biophotonic perception on Desmodesmus sp. VIT growth, lipid and carbohydrate content.

Constant and fluctuating light intensity significantly affects the growth and biochemical composition of microalgae and it is essential to identify suitable illumination conditions for commercial microalgae biofuel production. In the present study, effects of light intensities, light:dark cycles, incremental light intensity strategies and fluctuating light intensities simulating different sky conditions in indoor photobioreactor on Desmodesmus sp. VIT growth, lipid and carbohydrate content were analyzed in batch culture. The results revealed that Desmodesmus sp. VIT obtained maximum lipid content (22.5%) and biomass production (1.033 g/L) under incremental light intensity strategy. The highest carbohydrate content of 25.4% was observed under constant light intensity of 16,000 lx and 16:08 h light:dark cycle. The maximum biomass productivity of Desmodesmus sp. VIT (53.38 mg/L/d) was occurred under fluctuating light intensity simulating intermediate overcast sky condition.