Executive Summary : | Microalgal biomass is regarded as the most substantial new resource that can complement agricultural biomass as renewable resource of clean energy. Owing to several attributes that include, efficient biomass production per unit land area than agricultural crops, high growth rate and a greater carbon dioxide sequestration capacity compared crop plants. They can be efficiently cultivated in seawater and wastewater, thus they are not reliant on the freshwater which is a limited resource worldwide. Microalgae cultivation has numerous environmental and economic advantages, as they are valuable sources of essential substances like, pigments, polymers, proteins, various biopharmaceutical, nutraceutical, and biofuels (Kumar et al., 2022b; Saini et al., 2020). Obtaining any products from microalgae biomass requires dewatering of microalgal biomass and is one of the main bottleneck being faced by the industries. Also it is the significant cost driver in the production of microalgae-based products as biomass harvesting itself costs around 20-30% of total biomass production. Inorganic flocculants and synthetic organic flocculants are commonly used for biomass harvesting, which is pH sensitive, required in very high dosages, non-biodegradable, toxic to the environment and contaminate the harvested biomass. Consequently, the biomass cannot be used as feedstock for food/feed and other high-value products intended for human applications as biomass might contain toxic metals and toxic monomer released in the harvesting process. Natural organic polymers like Gums, starches, dextran have also been used in biomass harvesting. These natural polymers are linked with severe limitations like feeble harvesting efficiency and low shelf life despite the bio-degradability and eco-friendly attributes. Several microbes, including microalgae, synthesize polymeric material known as extracellular polymeric substances (EPS), either secreted into the immediate environment or loosely bound to the cell wall. These biopolymers are attributed to the spontaneous aggregation of microalgal cell in the culture solution. These biopolymeric materials can be extracted and explored for biomass harvesting; also, they could be functionalized through the green synthesis method to augment the harvesting potential. It could be a practical and eco-friendly approach towards biomass harvesting. Hence, the primary focus of this project work is intended towards the isolation and identification of native oleaginous microalgal strains and developing a bioharvesting approach through natural biopolymers EPS to provide an eco-friendly, effective solution towards microalgal biomass harvesting for feasible production of microalgal based products. Furthermore, microalgal biomass will be screened for anticancer and antioxidant activities to identify and isolate bioactive compounds that could be beneficial to mankind to treat illness and provide a better health perspective. |