PRJNA13696
Biofilm microbial community from 5-way (CG) acid mine drainage site at Iron Mountain, California.
The Richmond mine at Iron Mountain, California, is an acid mine drainage (AMD) superfund site. AMD is a worldwide environmental problem that arises largely from microbial activity. Acid solutions form when rocks rich in sulfide minerals are oxidized upon exposure to air and water (acid rock drainage), but the rates of sulfide oxidation are typically slow and the sulfuric acid is rapidly neutralized by interaction with surrounding silicate minerals (hydrolysis reactions). Perhaps one of the most intriguing aspects of the AMD problem is that the majority of the AMD formed is due directly to microbial activity.  This project is a genome-based approach that enables culture-independent understanding of microbial activity relevant to geochemical processes that occur in AMD systems. The biofilm sequencing project was designed to explore the distribution and diversity of metabolic pathways in these communities (e.g., nitrogen fixation, sulfur oxidation, iron oxidation), in order to understand the mechanisms by which the microbes tolerate the environmental extremes, and to evaluate how these tolerance mechanisms impact the geochemistry of the environment.  This community sample was collected from a low-complexity microbial biofilm growing hundreds of feet underground within a pyrite (FeS<sub>2</sub>) ore body.  This represents a self-contained biogeochemical system characterized by tight coupling between microbial iron oxidation and acidification due to pyrite dissolution. Samples of pink biofilm and associated acid mine drainage were collected from the Richmond Mine, Iron Mountain CA from the 5-way (CG) site in March 2002.  Iron Mountain is located at 40 deg 40' 38.42'' N and 122 deg 31' 19.90'' W (Elevation ~ 3,100 ft). The 5-way biofilm was growing at pH 0.83 on the surface of 42 deg C AMD solution.   Random shotgun sequencing of this biofilm resulted in the first reconstruction of multiple genomes directly from an environmental sample.    The WGS project and sequences deposited into the Trace Archive can be found using the Project data link.