hydrogenasecontaining

Hydrogenase-containing refers to organisms, cells, or proteins that possess hydrogenases, enzymes that catalyze the reversible oxidation of molecular hydrogen (H2). Hydrogenases are central to microbial energy metabolism, linking hydrogen turnover to electron transfer chains so cells can harvest energy under anaerobic conditions or dispose of excess electrons during fermentation. The two primary families are [NiFe]-hydrogenases and [FeFe]-hydrogenases, which differ in their active-site metal cofactors and catalytic properties. Some hydrogenases are tolerant to oxygen, while many are highly sensitive, influencing where and when they function in a given organism.

Hydrogenases perform either hydrogen uptake (oxidation) or hydrogen production (reduction) and can be membrane-bound or soluble. In bacteria, they often couple H2 oxidation to the reduction of ferredoxin or NAD(P)+, feeding electrons into central metabolism. In methanogenic archaea, hydrogenases donate electrons to CO2 reduction for methane formation. In some photosynthetic microorganisms, hydrogenases contribute to photobiological hydrogen production under conditions of transient anoxia, linking light energy to hydrogen metabolism.

Distribution and ecological significance are broad: hydrogenase-containing enzymes are found in diverse bacteria and archaea, and in a few eukaryotic lineages. They participate in global hydrogen turnover, influence anaerobic niche respiration, and shape microbial interactions in environments such as sediments, anaerobic digesters, and the intestinal microbiome. Their activity is often a limiting factor in surrounding redox balance and energy flow.

Biotechnological interest centers on hydrogenase-containing systems for sustainable hydrogen production, bioelectrochemical devices, and synthetic biology applications. Challenges include oxygen sensitivity, stability under operational conditions, and integration with non-native reaction partners. Ongoing research aims to enhance activity, durability, and compatibility with industrial processes.