An ethanolamine-phosphate modified glycolipid in Clostridium acetobutylicum that responds to membrane stress

Abstract

Two phosphorus-containing glycolipids have previously been observed in Clostridium acetobutylicum. We had shown that the concentration of one of them increases in response to increased unsaturation of the membrane lipid hydrocarbon chains, suggesting a potential role in the regulation of lipid polymorphism in this organism. Mass spectrometry shows that these glycolipids are ethanolamine phosphate (Etn-P)-containing derivatives of a mono- and diglycosyldiradylglycerol. The content of both diglycosyldiradylglycerol and the Etn-P-monoglycosyldiradylglycerol, which increase upon increased unsaturation of the membrane, also increase upon addition of octanol to the medium. Thus, it appears that the Etn-P-monoglycosyldiradylglycerol along with the diglycosyldiradylglycerol may serve to stabilize the membrane bilayer during membrane stress caused by the presence of the solvents produced during fermentation.

The cellular lipids of Romboutsia

“…Recent studies of clostridia have demonstrated that these are major components of the lipidome in C. difficile [3], Clostridiumtetani [8], Clostridium sporogenes , some strains of C. botulinum Group I that are related to C. sporogenes [6], Clostridium psychrophilum [4], and Clostridium acetobutylicum [5,29,30]. We note that three of the glycolipids common to Romboutsia , MHDAG, DHDAG and TriHDAG, were also found in C. difficile .…”

Lipidomic Analysis of Clostridium cadaveris and Clostridium fallax

“…The same lipid was subsequently found in C. sporogenes and in related Group I strains of C. botulinum (Guan et al, ). Etn‐P‐modified monoglycosyl and diglycosyl‐DRG have also been found in Clostridium acetobutylicum (Tian et al, ). Both Etn‐PGlcNac diradylglycerol and Etn‐P‐hexosylDRG have been found in Clostridium psychrophilum , an obligately anaerobic psychrophilic species from Antarctica (Guan et al, ).…”

“…Both Etn-PGlcNac diradylglycerol and Etn-P-hexosylDRG have been found in Clostridium psychrophilum, an obligately anaerobic psychrophilic species from Antarctica . In C. acetobutylicum, Etn-P-hexosylDRG was found to increase in amount when the total membrane lipids were enriched in a monounsaturated fatty acid (oleic acid) or when octanol was added to the growth medium (Johnston and Goldfine, 1992;Tian et al, 2013). Clostridium acetobutylicum also contains monoglycosyl and diglycosyl-DRG.…”

“…In C. acetobutylicum , Etn‐P‐hexosylDRG was found to increase in amount when the total membrane lipids were enriched in a monounsaturated fatty acid (oleic acid) or when octanol was added to the growth medium (Johnston and Goldfine, ; Tian et al, ). Clostridium acetobutylicum also contains monoglycosyl and diglycosyl‐DRG.…”

Engineering membrane and cell-wall programs for tolerance to toxic chemicals: Beyond solo genes

“…For example, C. acetobutylicum under octanol stress modifies the polar headgroups of lipids to stabilize the bilayer by increasing the presence of the charged ethanolamine-phosphate group to certain diglycerides[59]. In a computer simulation, lipid bilayers with phosphatidylcholine (PC, common in eukaryotes, rare in prokaryotes) headgroups were more susceptible to ethanol permeation compared to those with phosphatidylserine (PS) or phosphatidylethanolamine (PE)[60].…”