Actinobacteria Isolation from Metal Contaminated Soils for Assessment of their Metal Resistance and Plant Growth Promoting (PGP) Characteristics

Abstract

A review. Heavy metals and metalloids removal can be considered as one of the most important world challenges because of their toxicity and direct impact on human health. Many processes have been introduced but biol. processes of remediation seem to offer the most suitable soln. in terms of efficiency and low cost. Actinobacteria constitute one of the major microbial populations in soil, and this can be attributed to their adaptive morphol. structure as well as their exceptional metabolic power. Among microbes, actinobacteria are morphol. intermediate between fungi and bacteria. Studies on microbial diversities in metal contaminated lands have shown that actinobacteria may constitute a dominantiy active microbiota in addn. to α-proteobacteria. Furthermore, isolation studies have shown metal removal mechanisms which are reminiscent of notable multi-resistant strains, such as Cupriavidus metallidurans. Apart from members of genus Streptomyces, which produce more than 90% of commercialized antibiotics, and the nitrogen fixing Frankia, little attention has been given to other members of this phylum. This is because of difficult culture condition requirements and maintenance. In this review, the focus was on specific isolation of actinobacteria and their potential applications in metal bioremediation and plant growth promotion. [on SciFinder(R)]