Chapter 12 - Extremophilic microbes and their application in bioremediation of environmental contaminants

Abstract

Extremophilic microorganisms are capable of thriving in one or more hostile habitats such as extreme temperatures (cold or hot), pH (acidic or alkaline), and high pressure levels where normal microorganisms cannot survive. These unique adaptive capabilities of extremophiles make them suitable catalysts for bioremediation of heavy metal, petroleum and hydrocarbon contaminated soil and water through various strategies such as biohydrometallurgy [bioleaching and biomining (Sulfolobus metallicus, Metallosphaera sedula, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, etc.), oil recovery/remediation (Pseudomonas sp., Bacillus sp., Geobacillus sp., Petrobacter sp., Clostridium sp. etc.), water-treatment (Proteobacteria, Bifidobacterium, Clostridium sp., Peptostreptococcus, Bacteroidetes, Acidobacteria, Chloroflexi, Tetrasphaera sp., Trichococcus sp., Candidatus sp., Microthrix, Rhodobacter sp., Hyphomicrobium sp., Geobacter sp., etc.)] and biopolymers such as biosurfactants (Pseudomonas sp., Torulopsis sp., Arthrobacter sp., Acinetobacter sp., Rhodococcus erythropolis, Bacillus subtilis), exopolysaccharides (Halobacterium distributum, Haloferax volcanii, etc.), and bioplastics (Haloferax mediterranei). Genetic engineering of microflora well-adapted to aforementioned environmental conditions may offer more effective bioremediation of contaminated sites.