The interaction of acidophiles driving community functional responses to the re-inoculated chalcopyrite bioleaching process

摘要

Re-inoculation was an effective way to improve bioleaching efficiency by enhancing the synergetic effects of bio-genic Fe~(3+) coupling with S° oxidation. However, the complex microbial interactions after re-inoculation have received far less attention, which was crucial to the bioleaching performances. Herein, the enriched ferrous oxidizers (Fe-0) or sulfur oxidizers (S-O) were inoculated to chalcopyrite microcosm, then they were crossly re-inoculated again to characterize the interspecific interaction patterns. The results showed that the dominant species in Fe groups were Acidithiobacillus ferrooxidans, while A thiooxidans predominated in S groups. Introducing Fe-O resulted in a great disturbance by shifting the community diversity and evenness significantly (p < 0.05). In comparison, the communities intensified by S-O maintained the original composition and structures. Microbial networks were constructed positively and modularly. The networks intensified by Fe-O were less connected and complex with less nodes and edges, but showed faster responses to the re-inoculation disturbance reflected by shorter average path length. Interestingly, the genus Leptospirillum were identified as keystones in S groups, playing critical roles in iron-oxidizing with lots of sulfur oxidizers. The introduced sulfur oxidizers enhanced microbial cooperation, formed robust community with strong bio-dissolution capability, and harbored the highest bioleaching efficiency. These findings improved our understanding about the acidophiles interactions, which drive community functional responses to the re-inoculated bioleaching process.