Role of Actinobacteria in bioremediation

POLTI, MARTA ALEJANDRA; APARICIO, JUAN DANIEL; AMOROSO, MARÍA JULIA DEL ROSARIO

Microbial Biodegradation and Bioremediation

Elsevier

Año: 2014; p. 269 - 286

The class Actinobacteria represents an important componen to the microbial population in soils. Their metabolic diversity and specific grow the characteristics make them well suited as agents for bioremediation. Actinobacteria are a ubiquitous group of microorganisms widely distributed in various natural ecosystems. They are Gram-positive bacteria, historically known as high guanine plus cytosine (G+C) content base in DNA (55 -75 mol%); however, new species are known that do not respond to this rule. This group is very heterogeneous, since it includes a broad spectrum of microorganisms that are chemically, morphologically, and physiologically very different. This morphological diversity is manifested by a continuous transition from coca and bacilliform cells to hyphae that fragment and branch, forming aerial mycelium with long chains of spores. Actino spores are formed as are sult of nutrient depletion and can survive prolonged desiccation. This ability to sporulate is very important for their survival in the environment. In general, optimal conditions for growth are temperatures of 25-30 °C and neutral pH, but many species have been isolated from extreme environments. These bacteria are, in most cases, aerobic, although some may be microaerophilic or anaerobic. They are heterotrophic, meaning that both simple and complex carbon sources can be used. Physiological diversity is manifested by the production of a large number of biotechnologically important metabolites (antibiotics, enzymes, enzyme inhibitors, immunomodulators, etc.). Also, within their particular characteristics, they have a characteristic odor of wet earth, due to the production of a metabolite called geosmin.