Activity of microorganisms in acid mine water. I. Influence of acid water on aerobic heterotrophs of a normal stream.
Comparison of microbial content of acid-contaminated and nonacid-contaminated streams from the same geographical area indicated that nonacid streams contained relatively low numbers of acid-tolerant heterotrophic microorganisms. The acid-tolerant aerobes survived when acid entered the stream and actually increased in number to about 2 x 10(3) per ml until the pH approached 3.0. The organisms then represented the heterotrophic aerobic microflora of the streams comprised of a mixture of mine drainage and nonacid water. A stream which was entirely acid drainage did not have a similar microflora. Most gram-positive aerobic and anaerobic bacteria died out very rapidly in acidic water, and they comprised a very small percentage of the microbial population of the streams examined. Iron- and sulfur-oxidizing autotrophic bacteria were present wherever mine water entered a stream system. The sulfur-oxidizing bacteria predominated over iron oxidizers. Ecological data from the field were verified by laboratory experiments designed to simulate stream conditions.
D000143:Acids / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D004463:Ecology; D006863:Hydrogen-Ion Concentration; D008906:Mining; D014867:Water; D014871:Water Microbiology
D000143:Acids; D014867:Water