Abstract
Zhuqueibacterota is a novel bacterial phylum proposed based on hot spring metagenomes and public metagenome-assembled genomes, classified within the Fibrobacterota-Chlorobiota-Bacteroidota superphylum. This globally distributed phylum consists of one class and five orders, with the majority of its members being facultative anaerobes. Notably, the order Zhuqueibacterales utilizes hydrogen as an electron donor for carbon fixation through the Calvin Benson Bassham cycle. Phylogenetic and metabolic analyses reveal the phylum's key role in the carbon cycle, with frequent horizontal gene transfer events influencing its evolutionary trajectory.