Abstract: A syntrophic enrichment for enhanced digestion (SEED) system is presented, in which a retrofit addition to existing anaerobic digestion infrastructure provides improved digestion process rate and biogas quality. The system provides optimal niche environments for accelerating fermentative, syntrophic and methanogenic metabolisms to increase digestion system loading rates and enhance main digester microbiome. Prescribed media formulations, reactor integrations, and operational methods using various fixed and loose media enhance global digestion system performance. The retrofitted system enables existing plants to transition from an outdated solids-management model to one of valorized biomethane production.