Acidithiobacillus ferrivorans SS3 presents little RNA transcript response related to cold stress during growth at 8 °C suggesting it is a eurypsychrophile

Abstract

Acidithiobacillus ferrivorans is an acidophilic bacterium that represents a substantial proportion of the microbial community in a low temperature mining waste stream. Due to its ability to grow at temperatures below 15 °C, it has previously been classified as ‘psychrotolerant’. Low temperature-adapted microorganisms have strategies to grow at cold temperatures such as the production of cold acclimation proteins, DEAD/DEAH box helicases, and compatible solutes plus increasing their cellular membrane fluidity. However, little is known about At. ferrivorans adaptation strategies employed during culture at its temperature extremes. In this study, we report the transcriptomic response of At. ferrivorans SS3 to culture at 8 °C compared to 20 °C. Analysis revealed 373 differentially expressed genes of which, the majority were of unknown function. Only few changes in transcript counts of genes previously described to be cold adaptation genes were detected. Instead, cells cultured at cold (8 °C) altered the expression of a wide range of genes ascribed to functions in transcription, translation, and energy production. It is, therefore, suggested that a temperature of 8 °C imposed little cold stress on At. ferrivorans, underlining its adaptation to growth in the cold as well as suggesting it should be classified as a ‘eurypsychrophile’.Electronic supplementary materialThe online version of this article (doi:10.1007/s00792-016-0882-2) contains supplementary material, which is available to authorized users.

Comparative Genome Analysis Provides Insights into Both the Lifestyle of Acidithiobacillus ferrivorans Strain CF27 and the Chimeric Nature of the Iron-Oxidizing Acidithiobacilli Genomes

“…Most of the genes proposed to be involved in cold adaptation in At. ferrivorans strain SS3 were also detected in strain CF27 ( Liljeqvist et al, 2015 ; Christel et al, 2016 ) (Supplementary Table S5 ). These include the genes for (i) compatible solute synthesis and assimilation, such as sucrose and trehalose ( Supplementary Figure S1 ); (ii) cold shock proteins (CSP) to maintain cell integrity and metabolism, in particular nucleic acid binding chaperones; (iii) stabilization of transcripts; (iv) folding of newly synthesized proteins; (v) membrane fluidity maintenance.…”

Bioinformatic Analyses of Unique (Orphan) Core Genes of the Genus Acidithiobacillus: Functional Inferences and Use As Molecular Probes for Genomic and Metagenomic/Transcriptomic Interrogation

“…Locus tags for the five families are provided .a Gene expression for families I–V was extracted from Christel et al (2016a,b) and Osorio et al (2013) .b Information regarding protein abundance levels when A. caldus was subjected to growth at pH 1, 2, or 4 was taken from Mangold et al (2013). Abundance of proteins is expressed as “up in low pH” or “up in high pH” relative to protein levels found at pH 2 (Mangold et al, 2013).…”

“…a Gene expression for families I–V was extracted from Christel et al (2016a,b) and Osorio et al (2013) .…”

“…RNA transcript analysis indicates that all five family genes are expressed in A. ferrivorans SS3 in two different conditions: continuous culture at 20°C (Christel et al, 2016a) and at 8°C (Christel et al, 2016b), adjusted to pH 2.5 with sulfuric acid plus trace elements. A proteomic study of A. ferrooxidans ATCC 23270 on elemental sulfur as electron donor under aerobic and anaerobic conditions (Osorio et al, 2013) showed that family III was expressed in this strain.…”

Using Flexible Gold-Titanium Reaction Cells to Simulate Pressure-Dependent Microbial Activity in the Context of Subsurface Biomining

“…The activity of ore-leaching acidophilic microorganisms has been studied in many laboratories for a diverse array of parameters 2,3,4,5,6 . However, pressure effects on the microbial activity resulting from the difference between ambient surface lab conditions (near 1 bar) and the subsurface at a depth of 1,000 m with hydrostatic conditions (~100 bar), are not well-documented.…”