Lipids of Haliphthoros philippinensis: An oomycetous marine microbe

Abstract

Lipids of the marine oomycetous microbe Haliphthoros philippinensis were characterized by chromatographic and spectroscopic techniques. Total lipid content of this organism was relatively low and not very responsive to manipulation of the culture conditions. Neutral lipid comprised 21% of the total lipid and the polar lipids were mainly phosphatidylcholine (44%), phosphatidylethanolamine (15%), and a ceramide-phosphorylethanolamine (19%). Palmitic (16:0) was the primary saturated fatty acid at 25% of the total fatty acids, and arachidonic acid (20:4n-6, ARA) and eicosapentaenoic acid (20:5n-3, EPA) were the major unsaturated fatty acids at 19 and 21%, respectively. Fucosterol was the principal sterol at 59% of the total sterols. The effects of several cultivation variables on growth and EPA production by this species were investigated. Among those tested, glucose and sodium glutamate were the most efficient carbon and nitrogen sources for growth, respectively. When the mycelium was cultivated for 6 d to produce biomass under optimal growth conditions, and then transferred to low temperature for an additional 13 d without glucose, the EPA content reached 31% of the total fatty acids and the yield was 203 mg/L. When the same experiment was performed with glucose supplementation during the low-temperature phase, EPA composed 27% of total fatty acids and yield reached 316 mg/L, or a 285% increase over that from mycelium cultured for 6 d at 24°C, and 56% over that cultured at 16°C for 13 d. ARA production did not respond accordingly.

Identification of food sources of invertebrates from the seagrass Zostera marina community using carbon and sulfur stable isotope ratio and fatty acid analyses

“…Lipids of L. squalida contain large amounts of 20:4(n-6), which is probably derived by the assimilation of some component of the eelgrass blade community besides diatoms and P. lejolisii. This component may be a species of fungi rich in 20:4(n-6); many such fungi are encountered on seagrasses (Novak 1984) and may contain high concentrations of 20:4(n-6) (Kim et al 1998).…”

Identification of Lipid Markers of Plasmopara viticola Infection in Grapevine Using a Non-targeted Metabolomic Approach

“…Although we could not identify them formally due to the lack of standards, other major C16:1 ceramides of P. viticola are very likely to include Cer(d16:1/18:0), Cer(d16:1/20:0), and Cer(d16:1/22:0) (Figure 3 ). Several shingophospholipids containing a C16:1 sphingosine have been detected in different plant Oomycete pathogens (Lhomme et al, 1990 ; Kim et al, 1998 ; Moreau et al, 1998 ). However, Cer(d16:1/16:0), Cer(d16:1/18:0), Cer(d16:1/20:0), and Cer(d16:1/22:0) had never been reported in Oomycetes before this work.…”