increasing pH to shape the chain elongation reactor microbiota

Here, we present the microbial community investigation in two continuous anaerobic bioreactors from 16S rRNA gene dynamics in enrichment cultures. By progressively increasing pH from 5.5 to 6.5 with different changing modes in both bioreactors operated for 238 days, we observed some rare species emerged which indicated high functional redundancy in such long-term closed reactor systems. After the disturbance, the reactor performance returned to the previous state while the communities developed to a different state (decreases in diversity and evenness, increase in richness.