Identification of novel, electricity-producing bacteria has garnered remarkable interest because of the various applications of electricigens in microbial fuel cell and bioelectrochemical systems.Shewanella marisflaviBBL25, an electricity-generating microorganism, uses various carbon sources and shows broader sugar utilization than the better-knownS. oneidensisMR-1. To determine the sugar-utilizing genes and electricity production and transfer system inS. marisflaviBBL25, we performed an in-depth analysis using whole-genome sequencing. We identified various genes associated with carbon source utilization and the electron transfer system, similar to those ofS. oneidensisMR-1. In addition, we identified genes related to hydrogen production systems inS. marisflaviBBL25, which were different from those inS. oneidensisMR-1. When we culturedS. marisflaviBBL25 under anaerobic conditions, the strain produced 427.58 ± 5.85 μl of biohydrogen from pyruvate and 877.43 ± 28.53 μl from xylose. AsS. oneidensisMR-1 could not utilize glucose well, we introduced theglkgene fromS. marisflaviBBL25 intoS. oneidensisMR-1, resulting in a 117.35% increase in growth and a 17.64% increase in glucose consumption. The results ofS. marisflaviBBL25 genome sequencing aided in the understanding of sugar utilization, electron transfer systems, and hydrogen production systems in otherShewanellaspecies.