Toxic metal resistance in biofilms: diversity of microbial responses and their evolution

Chemical and surface analysis during evolution of arsenopyrite oxidation by Acidithiobacillus thiooxidans in the presence and absence of supplementary arsenic

“…A general increase of total protein with significant differences (p b 0.05 for data, n = 3) is clearly observed after 48 and 240 h of assay in the absence of supplementary arsenic (Table 3). However, an opposite behavior is observed in the presence of supplementary arsenic, lowering down the protein production after 48 h (Table 3), thus confirming the detrimental effect (damage) of toxic arsenic during biofilm evolution, in agreement with our previous analyses and reports in the literature (Dave et al, 2008;Leng et al, 2009;Koechler et al, 2015). According to the electrophoretic analysis (Fig.…”

“…This behavior agrees with hazardous effects observed for toxic metal species (i.e. Cr, Hg, Ni) during cell attachment of leaching (Dave et al, 2008;Leng et al, 2009;Nguyen et al, 2015) and non-leaching bacteria (Lièvremont et al, 2009;Koechler et al, 2015). Note that arsenopyrite biooxidation by A. ferrooxidans under acidified M2 culture medium (pH 1.8) results in the formation of realgar (As 2 S 2 )-like and ferric oxide compounds, thus limiting bacterial attachment to SM surface and enhancing the requirement of available Fe 2+ species in the system (Liu et al, 2011).…”

“…modifying biofilm evolution), as occurs in bioleaching operations. Indeed, if leaching acidophilic microorganisms are successfully adapted to toxic species (Bowen et al, 2013;Koechler et al, 2015), then biofilms structures induce protein production as survival strategy to metal-resistance and therefore, enabling the progress of SM bioleaching under different conditions (Dopson et al, 2003;Chen et al, 2004). Fig.…”

“…The presence of toxic metals or metalloids (i.e. As, Cr, Hg) (Koechler et al, 2015) can modify the structure (i.e. proteins, lipids, exopolysaccharides) and performance of these biofilms (Ram et al, 2005;Dave et al, 2008;Ngoma et al, 2015).…”

CytR Homolog of Pectobacterium carotovorum subsp. carotovorum Controls Air-Liquid Biofilm Formation by Regulating Multiple Genes Involved in Cellulose Production, c-di-GMP Signaling, Motility, and Type III Secretion System in Response to Nutritional and Environmental Signals

“…This bacterial biomass comprises of exopolysaccharides [EPSs (mainly cellulose)], proteins, and extracellular DNA (Sutherland, 2001; White et al, 2003; Yap et al, 2005; Liang et al, 2010). The contents ultimately determine the architecture and the stability of a biofilm biomass (Koechler et al, 2015) although their quantities vary depending on the bacterial strains and environmental conditions (Zogaj et al, 2001; Solano et al, 2002; Haque et al, 2012). The sessile bacterial biomass are known to have a hetero-dimensional structure (Oliver et al, 2014) with micro-channels and extended limbs to trap nutrients.…”