Lipids of the zygomycete Absidia corymbifera F-965.

The cell lipids of the zygomycete Absidia corymbifera F-965 extracted with isopropanol and CHCl3-MeOH mixtures at the exponential growth phase comprise 20+/-2% of mycelium dry wt. The lipids consist of: triacylglycerols (51% of the total lipids extracted), diacylglycerols (9%), monoacylglycerols (3%), ergosterol (5%), ergosterol peroxide (5alpha,8alpha-epidioxyergosta-6,22-diene-3beta-ol) (3%), fatty-acid esters of ergosterol (less than 0.5%), free fatty acids (4%), glucocerebroside (3%), and glycerophospholipids (22%). The main phospholipids are phosphatidylethanolamine (39% of the total phospholipids), phosphatidyl-myo-inositol (17%), diphosphatidylglycerol (12%), phosphatidic acid (7%), phosphatidylcholine (6%), phosphatidylglycerol (3%), and two unusual phospholipids reported earlier, N-acetylphosphatidylethanolamine (7%) and N-ethoxycarbonyl phosphatidylethanolamine (9%). In addition, two unknown acidic phospholipids are present in traces. Saturated fatty acids of the lipids are dominated by n-hexadecanoic acid and unsaturated ones by octadecenoic acid; octadecadienoic and octadecatrienoic acids are present in lesser amounts. Ergosterol peroxide as well as the above glucocerebroside which contains 9-methylsphinga-4(E),9(E)-dienine have first been revealed in zygomycetes.

A novel lipopeptide, an inhibitor of bacterial adhesion, from the thermophilic and halotolerant subsurface Bacillus licheniformis strain 603.

A new Bacillus licheniformis strain, 603, isolated from a mixture of drilling fluid and subsurface thermal water, has been found to produce a cyclic lipopeptide which is released into cultural medium as well as present in cells as the major lipid constituent (57% of the total cell lipids extractable with 2:1 chloroform-methanol). The quantitative ratio of the extracellular and intracellular lipopeptide has been estimated as 23:10. The metabolite represents a heptapeptide, L-Asp-->L-Leu-->L-Leu-->L-Val-->L-Val-->L-Glu-->L-Leu, N-acylated to the N-terminal amino acid, L-Asp, by a 3-hydroxy fatty acid (from 13:0 to 17:0 with n-, iso-, and anteiso-chains), the 3-OH group of which is esterified by the C-terminal amino acid, L-Leu. The chemical structure of the lipopeptide has been established by means of infrared (IR), 1H- and 13C-nuclear magnetic resonance (NMR) spectroscopy, electrospray ionisation (ESI) mass spectrometry (MS), including secondary ion mass spectrometry, along with chemical and enzymatic degradation. Although a diversity of similar metabolites synthesised by various B. licheniformis strains are presently known, such a structure has not been reported thus far. Added to the growth medium of strain 603 at the concentration of 1.6 microg/ml, the lipopeptide prevents adhesion of cells to a glass surface. Also, it exhibits a considerable growth-inhibiting activity against Corynebacterium variabilis and a much lower activity against Acinetobacter sp.

Beta-D-glucopyranosyl caldarchaetidylglycerol is the main lipid of the acidophilic, mesophilic, ferrous iron-oxidising archaeon Ferroplasma acidiphilum.

Chloroform-methanol-extractable lipids account for about 5% by weight of dry cells of the acidophilic, autotrophic, mesophilic, ferrous compound-oxidising, cell wall-less archaeon Ferroplasma acidiphilum strain Y(T), about 90% of these being contributed by phospholipids and glycophospholipids. The most abundant constituent (about 55% of total lipids) was purified by DEAE cellulose and silica gel column chromatography. By means of matrix-assisted laser desorption ionisation mass spectrometry, infrared spectroscopy, (1)H-nuclear magnetic resonance spectroscopy, and chemical degradation experiments it was established to be beta-D-glucopyranosyl caldarchaetidylglycerol, the isopranyl chains of which have a cyclopentane ring each.