Growth in sulfidic mineral environments: metal resistance mechanisms in acidophilic micro-organisms

Abstract

Acidophilic micro-organisms inhabit some of the most metal-rich environments known, including both natural and man-made ecosystems, and as such are ideal model systems for study of microbial metal resistance. Although metal resistance systems have been studied in neutrophilic micro-organisms, it is only in recent years that attention has been placed on metal resistance in acidophiles. The five metal resistance mechanisms identified in neutrophiles are also present in acidophiles, in some cases utilizing homologous proteins, but in many cases the degree of resistance is greater in acidophiles. This review summarizes the knowledge of acidophile metal resistance and presents preliminary in silico studies on a few known metal resistance systems in the sequenced acidophile genomes.

Diversity of bacterial communities in acid mine drainage from the Shen-bu copper mine, Gansu province, China

“…Sequences of clones recovered from JYC-1 belonging to the γ-Proteobacteria were the most abundant (almost 85.1%). These bacteria are typically found in low pH environments (Bond et al 2000a;Bond et al 2000b;Burton and Norris, 2000;Dopson et al 2003;Gonzalez-Toril et al 2003;Okabayashi et al 2005). In contrast, the most abundant clones (60.2 and 52.4%) in samples JYC-2 and JYC-3 belonged to α-Proteobacteria.…”

“…Johnson reported that a wide range of heterotrophic and chemolithotrophic bacteria can be detected in the acid-leaching environments (Dopson et al 2003). Traditionally, through the culture-dependent methods, Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans are recognized as the major chemolithotrophic bacteria responsible for acid production in metal-leaching environments (Johnson, 1998;Hallberg and Johnson, 2001).…”

Illumina MiSeq sequencing investigation on the contrasting soil bacterial community structures in different iron mining areas

“…Arthrobacter, which is atypical Cr 6+ reducing bacteria (Asatiani et al 2004), turned out to be closely related to Cr content in mining area (R 2 =0.726, P<0.05) and became the dominant genera in group H. Thiobacillus was known as an important genus closely related to catalyzing ferrous ions and oxidizing the reducing inorganic sulfur (Dopson et al 2003). In our samples, Thiobacillus had relative high abundance in the genera which only found in polluted area and its reads abundance in group H Fig.…”

Molecular insight into extreme copper resistance in the extremophilic archaeon ‘Ferroplasma acidarmanus’ Fer1

“…However, investigation of the biochemical and genetic metal homeostasis and resistance mechanisms of acidophilic microorganisms, particularly of the archaea, is virtually in its infancy. These archaea represent challenging yet environmentally relevant systems for an increased understanding of metal resistance and homeostasis (Dopson et al, 2003).…”