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(A) Predicted structure of 6S RNA in A. ferrooxidans, A. caldus and A. thiooxidans. (B) Known structure of 6S RNA in E. coli K12.
Source publication
Small regulatory RNAs (srRNAs) control gene expression in Bacteria, usually at the post-transcriptional level, by acting as antisense RNAs that bind targeted mRNAs or by interacting with regulatory proteins. srRNAs are involved in the regulation of a large variety of processes such as plasmid replication, transposition and global genetic circuits t...
Context in source publication
Context 1
... RNA genes have recently been identified in many bacterial genomes [16,17]. An RNA of the about the right length (187 nucleotides) and with a predicted secondary structure that contained key interacting single stranded bulges was identified in the genomes of the acidithiobacilli (Figure 2). The roles of the five candidate srRNAs predicted in the acidithiobacilli are unknown and represent an important challenge for the experimental biologist. ...
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Extreme acidophiles play central roles in the geochemical cycling of diverse elements in low pH environments. This has been harnessed in biotechnologies such as biomining, where microorganisms facilitate the recovery of economically important metals such as gold. By generating both extreme acidity and a chemical oxidant (ferric iron) many species o...
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Citations
... Genome data of bioleaching microorganisms is beginning to be mined to identify and predict the role of small regulatory RNAs (srRNAs) in gene regulation (Shmaryahu and Holmes 2007). Also, preliminary investigations are beginning to reveal mechanisms involved in the regulation of Fe(II) and S oxidation in A. ferrooxidans (Amouric et al. 2009) including the possible use of a srRNA (Shmaryahu et al. 2009). ...
This mini-review describes the current status of recent genome sequencing projects of extremely acidophilic microorganisms and highlights the most current scientific advances emerging from their analysis. There are now at least 56 draft or completely sequenced genomes of acidophiles including 30 bacteria and 26 archaea. There are also complete sequences for 38 plasmids, 29 viruses, and additional DNA sequence information of acidic environments is available from eight metagenomic projects. A special focus is provided on the genomics of acidophiles from industrial bioleaching operations. It is shown how this initial information provides a rich intellectual resource for microbiologists that has potential to open innovative and efficient research avenues. Examples presented illustrate the use of genomic information to construct preliminary models of metabolism of individual microorganisms. Most importantly, access to multiple genomes allows the prediction of metabolic and genetic interactions between members of the bioleaching microbial community (ecophysiology) and the investigation of major evolutionary trends that shape genome architecture and evolution. Despite these promising beginnings, a major conclusion is that the genome projects help focus attention on the tremendous effort still required to understand the biological principles that support life in extremely acidic environments, including those that might allow engineers to take appropriate action designed to improve the efficiency and rate of bioleaching and to protect the environment.
Important protagonists in geomicrobiology are the “biomining” microorganisms which are used to recover valuable metals from
mineral ores and concentrates. These microorganisms either convert insoluble metal sulfides to soluble metal sulfates, a process
referred to as bioleaching, or weaken the ore by removing iron and/or sulfur making the valuable metal accessible to subsequent
chemical treatment, a process known as biooxidation (Rawlings 2005; Rawlings and Johnson 2007). The drawback of this industrial
biotechnology is the formation of acid mine drainage (AMD) from uncontrolled abandoned mines, mine dumps or tailing dams,
and acid rock drainage when sulfide-rich ores are exposed to air and weathering.
