Phylogeny and Fatty Acid Profiles of New (Bacillariophyta) Species from Soils of Vietnam.

We studied the morphology, ultrastructure, and phylogeny of eight soil diatom strains assigned to the genus. Six of these strains, identified by us as new species, are described for the first time. We provide a comprehensive comparison with related species and include ecological data. Molecular phylogeny reconstruction using 18S rDNA and L affiliates the new strains with different subclades within , including 'borealis', 'grunowii' and 'stomatophora'. We also studied the fatty acid profiles in connection with the emerging biotechnological value of diatoms as a source of lipids. Stearic (36.0-64.4%), palmitic (20.1-30.4%), and palmitoleic (up to 20.8%) acids were the dominant fatty acids in the algae cultured on Waris-H + Si medium. High yields of saturated and monounsaturated fatty acids position the novel strains as a promising feedstock for biofuel production.