A novel thraustochytrid in vitro isolate from the abalone Haliotis roei in Western Australia

Thraustochytrids are heterotrophic protozoa that can be saprophytic, parasitic, or symbiotic. They have become increasingly important as a potential source of polyunsaturated fatty acids. This study describes the isolation and characterisation of a novel thraustochytrid isolate from the abalone Haliotis roei in Western Australia. Isolate W7B6 was propagated in vitro and characterised using optical and electron microscopy as well as phylogenetic analysis. This thraustochytrid exhibits characteristic cell types of the Thraustochytriaceae family, including small sporogenous cells, cysts, encysted amoebosporangia and amoebosporangia. The sequencing and phylogenetic analysis of the 18S rDNA sequence of the W7B6 isolate indicate its classification within the Monorhizochytrium clade, nested within the broader Aurantiochytrium super-clade. This study adds a new thraustochytrid strain that potentially has significance in the bio-production of long-chain fatty acids.