Hydrogen-oxidizing bacteria: A promising contributor to environmental sustainability and resource recycling

Single-cell proteins (SCPs) derived from hydrogen-oxidizing bacteria (HOB) are a promising strategy to address global food challenges. As versatile microorganisms with rich carbon metabolism, they also have the potential to address environmental emission issues. HOB efficiently utilize carbon through the Calvin-Benson-Bassham (CBB) cycle under autotrophic conditions, introducing an innovative approach to industrial exhaust treatment. In heterotrophic environments, HOB rapidly degrade organic pollutants, including organic carbon, to meet emission standards. Their nitrogen-fixing capacity further supports the production of sustainable nitrogen fertilizers and enables greener agricultural practices. This study systematically reviews the key metabolic pathways of HOB and summarizes their applications in waste gas treatment, organic pollutant purification, and ammonia production. The potential of HOB as drivers of sustainable carbon and nitrogen cycling has been confirmed, offering broader solutions to various environmental and food issues.