Study on the key microbes and mtabolic pathways of carbon cycling in bioleaching system

Abstract:

[Objective] To understande the role of microbes for carbon cycling in acid mine drainage (AMD) system. [Methods] The 16S rRNA high-throughput sequencing, PICRUSt functional prediction method and functional gene chip technology were used to analyze the microbial community composition and functional gene composition in the two systems of leaching heap (LH) and leaching solution (LS) in Dexing Copper Mine. [Results] Both functional gene array and functional prediction analysis show that there were significant differences in the carbon cycle genes between LH and LS (P < 0.05). Besides, the carbon fixation genes related to Calvin cycle and reductive tricarboxylic acid cycle, and carbon degradation genes related to hemicellulose and cellulose degradation were both higher in LS than LH. The differences were caused by environmental condition, especially for contents of TON, Ca, ES, Fe³⁺ and P. [Conclusion] In the extremely acid environment, differences in environmental condition can screen for different carbon cycling genes. Then, the categories of microbies participating in the main carbon cycling process would decrease in leaching solution, while the relative abundance would increase, and eventually change the carbon cycling pattern.

Key words:bioleaching;extreme environment;carbon cycling;GeoChip;functional prediction