ISOLATION AND CHARACTERIZATION OF A DESMODESMUS SPECIES FROM VIETNAM WITH POTENTIAL FOR THE PRODUCTION OF ANIMAL FEEDSTOCKS AND NUTRACEUTICALS

In this work, a microalgal strain (NL3) was isolated using waste water sampled from shrimp cultivation ponds in the central province of Ninh Thuan, Vietnam. The 18S rDNA-ITS region (3492 bp) was sequenced and used for the phylogenetic identification. As a result, the isolate was identified as Desmodesmus sp. NL3, genus Desmodesmus, family Scenedesmaceae. Desmodesmus sp. NL3 is considered as potential production of biomass with the highest biomass obtained at stationary phase of 1.54 ± 0.06 g L-1. Salinity tolerance experiments (10, 20, 30 and 35‰) were conducted. Desmodesmus sp. NL3 was proved to be highly tolerant to the all the salinities tested. The biomass and protein contents were high and did not vary much among those treatments. FAME analyses of the control and salinity treatments showed that fatty acid chain lengths were of C16 – C18 in which C18:2 and C18:3 were dominant. Therefore, this resulted in the high accumulation of PUFA ranging from 65.80% TFA to 71.53% TFA. Of the four salinity treatments, the highest FAME content of 15.59 %DW was recorded in salinity of 35‰. In terms of pigment, HPLC – DAD was employed for the study and the results reported a high accumulation of lutein which was 4.01, 7.00, 5.67 and 2.24 mg/g DW in 10, 20, 30 and 35‰, respectively.