Evaluation of a native oleaginous marine microalga Nannochloropsis oceanicafor dual use in biodiesel production and aquaculture feed

Screening of native microalgal species for different biotechnological applications is a key step to achieve a strong algal database with successful commercial applications. In the present study, a new strain namely Nannochloropsis oceanica NIOF15/001 was isolated and identified phylogenetically using rbcL and the newly designed Cyt-c as an alternative molecular marker. The late exponential phase of the isolate was recorded at the 10th day of growth in f/2 medium, with a maximum cellular dry weight (CDW) of 0.722 g L-1 and relatively high lipid content of 37.7% of CDW. The isolate showed biomass and lipid productivities of 75.6 and 28.6 mg L-1 day(-1), respectively. The recorded biomass productivity in the current study was 1.4, 3.0, 3.6 and 2.0 times higher than that recorded in the previous studies for N. oceanica IMET, N. oceanica CASACC201, N. oceanica DUTO1 and N. oceanica CCNM 1081, respectively. In general, values of cetane number (52.3), iodine value (94.7 g I-2/100 g oil), cold filter plugging point (4.7 degrees C) and kinematic viscosity (3.97 mm(2) s(-1)) of the produced fatty acid methyl esters complied with those recommended by international standards. Furthermore, application of 0.1 g L-1 of lipid-free dry biomass enhanced Artemia survival by 500% and growth by 40%. The present study suggested the new isolate N. oceanica NIOF15/001 as a promising marine microalga for dual use in aquaculture and biodiesel production.