Isolation and characterization of Thraustochytrids from Malaysian mangrove ecosystem for fatty acids and terpenoid production

Thraustochytrids are well-known for their ability to produce a variety of fatty acids, including polyunsaturated fatty acids (PUFAs), saturated fatty acids (SFA), odd-chain fatty acids (OCFA), as well as terpenoids such as squalene and carotenoids. However, despite Malaysia's extensive mangrove ecosystems, there have been limited studies on the diversity and potential of these microorganisms to produce fatty acids and terpenoids. In this study, we have isolated and screened oleaginous thraustochytrids capable of producing PUFAs and terpenoids from the mangrove ecosystem at Kelanang, Selangor, Malaysia. Nine dominant thraustochytrid strains with distinct macroscopic and microscopic characteristics were further cultivated in three different types of medium: YEP, GY, and BURJA and the impact of these media on the production of fatty acids, squalene, and carotenoids were evaluated. All isolates exhibited significant production of docosahexaenoic acid (DHA) and palmitic acid (C16:0). The highest DHA and C16:0 yields were observed in isolate S1 grown in YEP medium (50.89%) and in isolate S10 grown in GY medium (69.03%), respectively. Additionally, isolate S13 demonstrated a remarkable capacity for pentadecanoic acid (C15:0) production, reaching nearly 15% of total fatty acids (w/w) when cultivated in GY medium. Squalene production reached up to 652.38 mg L-1 in isolate S5, while isolate S10 emerged as the highest carotenoid producer, yielding 1.77 mg L-1 in GY medium. Isolates S5 (Thraustochytrium striatum strain S5), S1 (Aurantiochytrium limacinum strain S1), and S10 (Thraustochytrium kinnei strain S10) show promising potential for further optimisation and industrial applications in the sustainable production of high value bioproducts such as lipids, DHA, squalene, and carotenoids.