The 125-day performance of the three inoculated TBR systems was evaluated in terms of output gas composition, CRCO, PRCH₄, and PRCO₂ at different LRCO, as shown in Figure . Among the three reactors, R1 inoculated with AS, showed the fastest startup, achieving complete CO conversion within just 10 days at LRCO of 5.16 Nm³m⁻³d⁻¹. The system stabilized rapidly, maintaining steady PRCH₄, and PRCO₂ at 1 and 3 Nm³m⁻³d⁻¹ on average, respectively. This exceptional performance reflects the efficient microbial adaptation to CO within the AS inoculum, which is known to have a diverse community rich in CO-utilizing archaea and bacteria . However, this performance depends upon the nature of the inoculum and the experimental conditions it is exposed to. For example, reported contrasting results for CO conversion in batch reactors. reported that the anaerobic sludge from a methanogenic reactor fed with cattle manure exhibited the highest CO consumption rates. This was attributed to a greater relative abundance of CO-consuming bacteria compared to other inocula taken from similar reactors fed with sewage sludge or gaseous H₂/CO₂.