Fatty acid activation and utilization by Alistipes finegoldii, a representative Bacteroidetes resident of the human gut microbiome

Abstract

Members of the Bacteroidetes phylum, represented by Alistipes finegoldii, are prominent anerobic, Gram‐negative inhabitants of the gut microbiome. The lipid biosynthetic pathways were analyzed using bioinformatic analyses, lipidomics, metabolic labeling and biochemistry to characterize exogenous fatty acid metabolism. A. finegoldii only produced the saturated fatty acids. The most abundant lipids were phosphatidylethanolamine (PE) and sulfonolipid (SL). Neither phosphatidylglycerol nor cardiolipin are present. PE synthesis is initiated by the PlsX/PlsY/PlsC pathway, whereas the SL pathway is related to sphingolipid biosynthesis. A. finegoldii incorporated medium‐chain fatty acids (≤14 carbons) into PE and SL after their elongation, whereas long‐chain fatty acids (≥16 carbons) were not elongated. Fatty acids >16 carbons were primarily incorporated into the 2‐position of phosphatidylethanolamine at the PlsC step, the only biosynthetic enzyme that utilizes long‐chain acyl‐ACP. The ability to assimilate a broad‐spectrum of fatty acid chain lengths present in the gut environment is due to the expression of two acyl‐acyl carrier protein (ACP) synthetases. Acyl‐ACP synthetase 1 had a substrate preference for medium‐chain fatty acids and synthetase 2 had a substrate preference for long‐chain fatty acids. This unique combination of synthetases allows A. finegoldii to utilize both the medium‐ and long‐chain fatty acid nutrients available in the gut environment to assemble its membrane lipids.

Ethnicity Associations With Food Sensitization Are Mediated by Gut Microbiota Development in the First Year of Life

“…The Bacteroidetes possess pyroxidine-dependent enzymes to produce and metabolize sphingolipids, and, for this purpose, can utilize exogenous odd-chain fatty acids available from breast milk fatty acids or the breakdown of milk lipids. [29][30][31] Furthermore, Bacteroides are able to synthesize odd-chain fatty acids from the elongation of propionate, a short-chain fatty acid they commonly produce. 32,33 Valerate and ethanol are consumed in the elongation process of propionate.…”

Fermented Maillard Reaction Products by Lactobacillus gasseri 4M13 Alters the Intestinal Microbiota and Improves Dysfunction in Type 2 Diabetic Mice with Colitis

“…In addition, the Alistipes genus is known to be a colitis-attenuating genus and a producer of propionate and butyrate in IBD [ 56 , 57 ]. Alistipes finegoldii can efficiently construct membrane lipids using medium-chain fatty acids in the gut epithelium [ 58 ]. Hungateiclostridium straminisolvens , previously classified as CSK1, which is a cellulolytic bacterium, has not been studied sufficiently; however, it produces acetate and isopropanol [ 59 ].…”

Screening of Microbes Associated With Swine Growth and Fat Deposition Traits Across the Intestinal Tract

“…In chickens, increased Prevotellaceae UCG-001 in the cecum was correlated with improved laying performance and egg quality in hens (Sun et al, 2020). Alistipes finegoldii has been relatively comprehensively studied and is involved in lipid metabolism via its bacterial type II fatty acid biosynthesis system for producing saturated fatty acids ≤ 16 carbons (Radka et al, 2019).…”