Bacterial catabolism of membrane phospholipids links marine biogeochemical cycles

Abstract

In marine systems, the availability of inorganic phosphate can limit primary production leading to bacterial and phytoplankton utilization of the plethora of organic forms available. Among these are phospholipids that form the lipid bilayer of all cells as well as released extracellular vesicles. However, information on phospholipid degradation is almost nonexistent despite their relevance for biogeochemical cycling. Here, we identify complete catabolic pathways for the degradation of the common phospholipid headgroups phosphocholine (PC) and phosphorylethanolamine (PE) in marine bacteria. Using Phaeobacter sp. MED193 as a model, we provide genetic and biochemical evidence that extracellular hydrolysis of phospholipids liberates the nitrogen-containing substrates ethanolamine and choline. Transporters for ethanolamine (EtoX) and choline (BetT) are ubiquitous and highly expressed in the global ocean throughout the water column, highlighting the importance of phospholipid and especially PE catabolism in situ. Thus, catabolic activation of the ethanolamine and choline degradation pathways, subsequent to phospholipid metabolism, specifically links, and hence unites, the phosphorus, nitrogen, and carbon cycles.

Changes in environmental and engineered conditions alter the plasma membrane lipidome of fractured shale bacteria

“…This suggests subsequent PC degradation to choline residues. We believe that like several bacteria ( 43 – 45 ), H. congolense WG10 expresses functional phospholipases that hydrolyze redundant PCs to choline (see Supplementary Appendix Fig. S1 and text).…”

Swinging between the beneficial and harmful microbial community in biofloc technology: A paradox

“…Heterotrophic bacteria in a biofloc system usually influence these specific metabolic pathways and conditions that produce varying end products during amphibolic degradation. During catabolic processes, heterotrophic bacteria break down organic compounds to produce ATP through oxidative phosphorylation (a source of cell energy and precursor) for the biosynthesis of synthesize amino acids, nucleotides, and other cellular building blocks [ 171 , 172 ]. The organic acids produced by Bacillus sp during the breakdown of organic matter in BFT generally serves as an energy source for other microorganisms in the system and biosynthesis of the various products in the pathway [ 14 , 173 ].…”

LPS-Dephosphorylating Cobetia amphilecti Alkaline Phosphatase of PhoA Family Divergent from the Multiple Homologues of Cobetia spp.

“…In bacteria, ALPs play a major role in utilizing organic phosphates as an alternative source of the vital macronutrient, phosphorus (P), in P i -deficient environments [ 12 , 13 , 14 ]. The bacterial ALPs catalyze the hydrolysis of sugar phosphates, DNA and RNA (5′-, 3′-ends), nucleotide mono-, di-, and triphosphates (dNMP, dNDP, dNTP), lipid phosphatidates, polyphosphates (polyP), and pyrophosphates, which are prevalent in environments rich in organics [ 3 , 15 , 16 , 17 ]. However, some ALPs were found to catalyze the cleavage of sulfate and phosphate di- and triesthers, including neurotoxins with P-O-C bonds, due to their evolutionarily catalytic proficiency, and are thus ecologically relevant [ 13 , 18 , 19 ].…”