Abstract

Microorganisms actively participate in biogeochemical cycles of various elements in the environment, including gold. To explore the core microbiota associated with gold ore, this study examined the bacterial composition of mined rock from the Rozália gold mine (two subsurface samples from the gold mine and one from the heap of mined ore) using a cultivation approach. Cultivation analyses showed the occurrence of bacteria with colony forming units (CFU) ranging from 2.18 × 10⁵ to 3.16 × 10⁵ per 1 gram of dry ore material, and the data analysis indicates that the type of cultivation medium used significantly influences the observed biodiversity of cultivable bacteria. Cultivated members of the microbial community were identified using a combination of MALDI-TOF MS and 16S rRNA gene sequencing. The cultivable microbiota of gold-bearing ore samples was predominantly composed of the phylum Proteobacteria. Identification of 473 isolates revealed the presence of 4 dominant genera: Rhizobium, Microbacterium, Pseudomonas, and Acinetobacter, which together accounted for 89% of the gold ore-associated cultivated bacteria. These results are consistent with previous studies on the microbiota of gold mines and suggest that these genera constitute the core microbiota of gold ore.

摘要

微生物积极参与环境中各种元素（包括金）的生物地球化学循环。为了探索与金矿石有关的核心微生物区系，本研究使用栽培方法检查了来自Rozália金矿的开采岩石的细菌组成（金矿的两个地下样品和矿堆中的一个地下样品）。栽培分析显示，菌落形成单位（CFU）的范围为2.18×10 ⁵至3.16×10 ⁵每1克干矿石材料中的数据，数据分析表明所使用的培养基类型显着影响观察到的可培养细菌的生物多样性。使用MALDI-TOF MS和16S rRNA基因测序相结合，确定了微生物群落的培养成员。含金矿石样品的可培养微生物群主要由Proteobacteria门所组成。473个分离株的鉴定揭示了4个主要属的存在：根瘤菌，微细菌，假单胞菌和不动杆菌，占金矿石相关培养细菌的89％。这些结果与先前关于金矿微生物群的研究一致，并表明这些属构成了金矿石的核心微生物群。