Coupling metabolic reprogramming with sacrificial cell lysis: multi-omics insights into an ascorbic acid-associated Se(IV) reduction and extrusion hypothesis in Lactiplantibacillus plantarum

Mechanisms supporting microbial survival under lethal selenite [Se(IV)] concentrations during bioremediation remain elusive. This study employed integrated multi-omics to analyze Lactiplantibacillus plantarum BSe (LPB) under extreme Se(IV) stress. LPB achieved 76.32% removal at 100 mM Se(IV), but this high efficiency came at a significant cost to cell viability and intracellular biomass. Multi-omics integration suggested a sophisticated survival strategy coupling metabolic reprogramming with a sacrificial cell lysis. Specifically, carbon flux was redirected from glycolysis to the pentose phosphate pathway to fuel NADPH generation. Furthermore, a > 35-fold surge in intracellular dehydroascorbic acid strongly suggests the putative activation of de novo ascorbic acid synthesis as a potential alternative reductant pathway. Finally, multi-omics data lead us to propose a mechanism whereby LPB adopts a putative sacrificial cell lysis to extrude SeNPs, evidenced by the downregulation of peptidoglycan-binding proteins and concurrent upregulation of autolysins like lysozyme and RecX. Collectively, these findings suggest LPB survives lethal Se(IV) stress through a trade-off mechanism: rewiring metabolism to power an ascorbic acid-associated Se(IV) reduction pathway while sacrificing structural integrity to export SeNPs.