BIOPROSPECTING MICROALGAE FOR β-CAROTENE AND SYNTHESIS OF NANOPARTICLES FOR ENVIRONMENTAL APPLICATIONS - A ZERO WASTE APPROACH

Abstract

The exponential rise in global population, technological development, and rise in lifestyle standards have brought a heavy load on natural resources to fulfill the demand, and it is increasing day by day. The conventional sources of food and energy are limited and are getting exhausted at a very fast rate. Environmental pollution is another concern due to increased anthropogenic activities. This has led to identification of novel sources for fulfilling the anthropogenic demands in terms of energy and food. Algae have been recently explored extensively as an alternative source for conventional ones. In this study, we have evaluated native microalgae for nutraceuticals and synthesis of nanoparticles for environmental pollution remediation. Microalgae isolate was identified as Graesiella emersonii based on morphological and molecular identification. Beta carotene was extracted from this isolate. Various parameters were optimized for optimum extraction of beta-carotene. The beta-carotene was used for its antioxidant activity. The leftover algal extract was used for synthesis of silver nanoparticles. The formation of silver nanoparticles was confirmed using spectrophotometer. The synthesized silver nanoparticles were tested for their antibacterial against Escherichia coli, and were found to be effective. Further, silver nanoparticles were used for photocatalytic degradation of methylene blue with an efficiency of more than 88% in ten hours. In addition to this, the silver nanoparticles were tested as an adsorbent for removal of heavy metals from synthetic wastewater. They were found to remediate 64 % of chromium in 48 hours.