Niyom Kamlangdee and K.W. Fan

pp. 643 - 650

Abstract

Five Schizochytrium strains (N-1, N-2, N-5, N-6, and N-9) were isolated from fallen, senescent leaves
of mangrove tree (Kandelia candel) in Hong Kong. The fungi were cultivated in glucose yeast extract medium
containing 60 g of glucose, 10 g of yeast extract and 1 L of 15‰ artificial seawater, initial pH 6.0, with shaking
for 52 hr at 25ºC. Biomass yields of 5 isolates ranged from 10.8 to 13.2 g/l. Isolate N-2 yielding the highest
dried cell mass at 13.2 g/l and isolate N-9 grew poorly with 10.8 g/l of biomass. EPA (Eicosapentaenoic acid,
20:5n-3) yield was low in most strains, while DHA (Docosahexaenoic acid, 22:6n-3) was high on the same
medium. The contents of DHA in biomass varied: 174.9, 203.6, 186.1, 171.3 and 157.9 mg/g of dried-biomass
for Schizochytrium isolate N-1, N-2, N-5, N-6, and N-9, respectively. Isolate N-2 had the highest proportion of
DHA in fatty acid profile with 15:0, 28.7%; 16:0, 21.3%; 18:0, 0.9%; 18:3, 0.2%; 20:4, 0.3%; 20:5, 0.9%;
22:4, 6.7%; 22:6, 36.1%; and others, 9.3%. The salinity range for growth of Schizochytrium isolates was from
0-30‰ with optimum salinity for growth between 20-30‰.

Keywords

• Schizochytrium
• docosahexaenoic acid (DHA)
• polyunsaturated fatty acid
• Thraustochytrids