New insights into the biochemical composition of estuarine diatom Halamphora sp. isolated from Munambam-Azheekode Estuary, Kerala, India

Abstract

Halamphora sp., an amphoroid diatom, collected and isolated from the Munambam-Azheekode Estuary within the Vembanad-Kol, Ramsar site of India’s Kerala state. The biochemical composition of Halamphora sp. is depicted with special reference to salinity changes (10, 20, 30, and 40 psu) at two culture stages. The highest growth rate and maximum cell density occurred at 30 psu. Lower salinities promoted higher protein and carbohydrate content during the stationary phase, while lipid production was higher in the log phase at lower salinities. Notable amounts of short, medium, and long-chain fatty acids, with C20:5 and C22:6 being particularly prominent, along with increased levels of C18:3n3 Polyunsaturated Fatty Acids (PUFAs). The findings recommend that 30 psu provides optimal growth and nutritional composition for Halamphora sp. in various industrial applications, especially in the production of biodiesel and aquaculture feeds.