A recombinant microorganism expressing at least a heterologous enzyme of an NADH-dependent pathway for conversion of a carbon source to n-butanol, metabolic intermediate and/or a derivative thereof and capable of producing n-butanol, a metabolic intermediate and/or a derivative thereof at a high yield and related methods. The recombinant microorganism engineered to inactivate a native enzyme of one or more pathways that compete with NADH-dependent heterologous pathway, and/or to balance the NADH-dependent heterologous pathway with respect to NADH production and consumption.