Extreme Acidophiles

Molecular evidence for the polyphyletic origin of low pH adaptation in the genus Klebsormidium (Klebsormidiophyceae, Streptophyta)

“…High concentrations of heavy metals such as Fe, Cu, Pb, Al and Zn are often recorded in soils and waters with low pH (Gross 2000, Aguilera et al 2007b, Novis & Harding 2007, Spijkerman & Weithoff 2012, whereas at sites with geothermal activities acidity is accompanied by high temperatures (up to 83°C; Huss et al 2002, Pollio et al 2005, Spijkerman & Weithoff 2012. Additionally, most extremely acidic environments contain relatively low concentrations of dissolved organic carbon, and may therefore be considered oligotrophic (Johnson 1998), with further limitation for the growth of autotrophic organisms.…”

“…Organisms living in these environments can be separated into acidophiles (acidloving organisms, adapted to pH values as low as 0.05 and unable to grow at neutral pH) and acidotolerant (acid-tolerating organisms, with growth optima at higher pH but able to tolerate low values) (Johnson 1998, Gross 2000. Some algal taxa are particularly able to adapt to low pH and are a recurrent presence in acidic habitats; these are mainly unicellular organisms such as species of the green algal genus Chlamydomonas, the euglenophyte Euglena, the chrysophyte Ochromonas, the diatom Pinnularia and red algae of the class Cyanidiophyceae (Johnson 1998, Huss et al 2002, Ciniglia et al 2004, Pollio et al 2005, Novis & Harding 2007, Spijkerman & Weithoff 2012. However, some multicellular algae with filamentous habit may also occur in these habitats; of these, species of Klebsormidium P.C.Silva, Mattox & Blackwell are the most frequently recorded.…”

“…Some well-known cases are represented by certain sites affected by volcanic activities (Baffico et al 2004, Pollio et al 2005, streams with naturally low pH produced by leaching of fumic and fluvic acids from podocarp rainforests (Novis & Harding 2007) and rivers originating from areas with massive bodies of iron and copper sulfites (Aguilera et al 2007a(Aguilera et al , 2007b. More often, however, the low pH is the result of human influence, mostly in the form of acid mine drainage released by mining activities (Lukešová 2001, Sabater et al 2003, Novis & Harding 2007. The extent of these effects is usually localized, and consequently the distribution of highly acidic habitats is patchy and fragmented (Gross 2000, Weisse et al 2011.…”

Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics

“…In AMD, identification of acidophilic algal communities has been undertaken in various regions of the world (e.g. Levings et al, 2005, Novis andHarding, 2007) including in the Iberian Pyrite Belt (IPB) (e.g. Aguilera et al, 2006;Amils et al, 2011;Sabater et al, 2003,;Valente et al, 2016).…”

Heavy metal bioaccumulation in sediment, common reed, algae, and blood worm from the Shoor river, Iran

“…Some studies have shown that Spirogyra can accumulate Al and Fe (Bailey and Stokes, 1985; Sheoran and Bhandari, 2005), and other metals (Das and Ramanujam, 2011). According to Haritonidis and Malea (1999), Novis and Harding (2007), and Das et al (2008), the absorption of metals by Spirogyra highly depends on the algal taxon, age of Spirogyra , seasonal variation, the metal, the age of the material, and other environmental factors. Benson et al (1981) reported that Spirogyra is a proper organism for heavy metal monitoring.…”