Microbial Communities and Interactions in Low pH Environments
D. Barrie Johnson
from: Acidophiles: Life in Extremely Acidic Environments (Edited by: Raquel Quatrini and D. Barrie Johnson). Caister Academic Press, U.K. (2016) Pages: 121-138.
Most of the types of interactions that occur between microorganisms in environments considered to be non-extreme have also been observed in those which are extremely acidic. These include interactions that are both positive (mutualism, commensalism, synergy and syntrophy) and negative (competition, amensalism, predation and pathogenicity) from the perspective of one or more of the co-habiting microorganisms. Carbon flow between autotrophic (chemolithotrophs and phototrophs) and heterotrophic acidophiles is now known to operate in both directions and can help sustain stable consortia of these prokaryotes. By catalysing redox transformations of iron and sulfur, bacteria and archaea can generate electron donors and acceptors used by other species of acidophiles and thereby induce rapid biogeochemical cycling of these elements, a key characteristic of many low pH environments. Examples of relatively simple and more complex communities that have been studied in acidic streams, pit lakes and anthropogenic (biomining) environments are used to illustrate the importance of microbial interactions at low pH read more ...