【摘要】 酸性矿山废水(acid mine drainage, AMD)是一种寡营养、低pH以及富含重金属离子的极端酸性生境。该生境中含有大量的嗜酸、耐酸微生物，是系统中碳、氮和硫等物质循环的主要驱动者。Acidiphilium属菌株为兼性异养微生物，在AMD生境中丰度小于1%,但其与优势物种Acidibacillus经常表现出伴生关系，这说明Acidiphilium属在该系统中可能具有特殊的生态功能。为了探讨Acidiphilium属的生态功能和角色，从极端酸性环境中筛选到Acidiphilium属的菌1株，经16S rDNA和ANI比对，命名为Acidiphilium cryptum Acc2。Acidiphilium cryptum Acc2基因组含有1 066个蛋白编码基因，序列总长为4 917 178 bp,均高于该属其他菌的基因大小。Acidiphilium属泛基因组是开放的，共含有47 242个蛋白编码基因，699个蛋白编码基因(1.48%)被鉴定为核心基因，可变基因共有33 457个蛋白编码基因，占70.82%,2 705个蛋白编码基因是特有基因，占5.73%。其重金属抗性基因的Ka/Ks值95.5%以上均低于1,具有较强的纯化选择。Acidiphilium属基因组中基因之间的流动和交换频率相对其他物种更高，对菌株的进化和环境适应能力具有较大的正向影响。阐明了Acidiphilium属基因组进化和基因水平转移的规律，揭示了其环境适应性进化机制。更多还原

【Abstract】 Acid mine drainage(AMD) represents a uniquely acidic ecosystem, marked by oligotrophic conditions, a low pH environment, and elevated concentrations of heavy metals. Within this milieu, a diverse array of acidophilic and acid-tolerant microorganisms thrives, playing pivotal roles in the biogeochemical cycling of carbon, nitrogen, sulfur, and various other elements. The complex interplay between heterotrophic and autotrophic microorganisms underscores a significant ecological niche, with the Acidiphilium genus, a group of facultative heterotrophic microorganisms constituting a minor proportion(<1%) of the AMD microbial community. Notably, these organisms often engage in symbiotic interactions with prevalent species like Acidibacillus, suggesting that Acidiphilium species fulfill unique and crucial ecological functions within the AMD ecosystem. In order to investigate the ecological function of Acidiphilium, a strain of Acidiphilium was isolated from an extremely acidic environment. It was identified as Acidiphilium cryptum Acc2 after being compared with ANI by 16S rDNA. The Acidiphilium cryptum Acc2 genome contained 1 066 protein-coding genes with a total sequence length of 4 917 178 bp, all of which were larger than the gene size of other strains in the genus. It was an open genome, containing 47 242 protein-coding genes, 699 protein-coding genes(1.48%) were identified as core genes, 33 457 protein-coding genes were variable genes(70.82%), and 2 705 protein-coding genes were unique genes(5.73%). The Ka/Ks values of heavy metal resistance genes of 95.5% were all lower than 1, which showed strong purification selection. The flow and exchange frequency between genes in the genome of the genus Acidiphilium was higher than that of other species, and it had a greater positive impact on the evolution and environmental adaptability of strains. This research shed light on their evolutionary trajectories and gene transfer mechanisms, offering insights into their environmental adaptation mechanism and ecological significance in AMD environments.更多还原