生物冶金过程中的关键微生物及其碳循环代谢途径研究

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

摘要:

[目的]深入研究极端酸性环境中微生物的碳循环过程。[方法]应用16S rRNA高通量测序和功能基因芯片技术对德兴铜矿中浸矿堆（LH）和积液池（LS）两个子系统中的微生物群落结构组成和功能基因组成进行分析；并运用PICRUSt功能基因预测的方法对群落功能进行预测。[结果]功能基因芯片和功能预测分析都表明碳循环基因在子系统间存在显著差异（P < 0.05），且碳固定相关的卡尔文循环、还原性三羧酸循环等基因以及碳降解相关的己聚糖和纤维素等基因在LS系统中都要明显高于LH系统。碳循环功能基因在子系统之间的差异与环境条件相关，其中TON、Ca、ES、Fe³⁺和P作用显著。[结论]在极端酸性环境中，环境条件的差异会对微生物群落碳循环功能基因产生筛选作用，参与碳循环的微生物的种类和相对丰度都发生变化，最终改变了群落碳循环模式。

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.