Physiological Responses of Methanosarcina barkeri under Ammonia Stress at the Molecular Level: The Unignorable Lipid Reprogramming

• DOI: 10.1021/acs.est.2c09631
• Publication Date: 2023-02-23T16:09:04Z
• Authors: Chao Liu; Xuemeng Zhang; Chuang Chen; Yue Yin; Guohua Zhao; Yinguang Chen
• Keywords: Methanogen; Sphingolipid; Lipidome; Methanosarcina barkeri

Acetotrophic methanogens' dysfunction in anaerobic digestion under ammonia pressure has been widely concerned. Lipids, the main cytomembrane structural biomolecules, normally play indispensable roles guaranteeing cell functionality. However, no studies explored effects of high on acetotrophic lipids. Here, a high-throughput lipidomic interrogation deciphered lipid reprogramming representative acetoclastic methanogen (Methanosarcina barkeri) upon exposure. The results showed that conspicuously reduced polyunsaturated lipids and longer-chain lipids, while accumulating with shorter chains and/or more saturation. Also, correlation network analysis visualized some sphingolipids as most active participant lipid–lipid communications, implying ammonia-induced enrichment these triggered other changes. In addition, we discovered decreased integrity, elevated permeability, depolarization, diminished fluidity lipid-supported membranes restraint, verifying noxious ramifications abnormalities. Additional revealed destabilized structure extracellular polymeric substances (EPSs) capable protecting e.g., declining α-helix/(β-sheet + random coil) 3-turn helix ratios. Furthermore, abiotic impairment critical EPS bonds, including C–OH, C═O–NH–, S–S, biotic downregulation functional proteins involved transcription, translation, building blocks' supply were unraveled stress implied crucial mechanisms for reshaping.