Isolation and Characterization of Actinomycetes from Acidic Cultures of Ores and Concentrates

Abstract

Mining industry is a source of wealth but also of environmental pollution in Peru. In this study 12 colonies of actinomycetes were isolated in acidic cultures from mineral ores and concentrates from mines of the Peruvian highlands. The isolates were characterized phenotypically by microscopy and growth at different conditions as pH tolerance, temperature, and sodium chloride, heavy metals resistance; ferrous iron and thiosulfate oxidation. All isolates were identified as actinomycetes based on their cultural and spore characteristics. Most of the isolates were able to grow at 8 - 45°C and pH 4 - 11. 60% of isolates grew at 10% NaCl but none of them growth at 13%. Iron oxidation was shown by 60% of isolates at pH 4, but only 25% were able to oxidize iron at pH 2. Thiosulfate oxidation was not detected in any isolate. Most of the isolates showed capacity to grow in medium with 200 ppm of Pb, Fe, Zn and 100 ppm of Cu. All of the physiological characteristics found in this work indicate the potential of these isolates as source for bioremediation and bioleaching.

The Effect <i> </i>of <i> Streptomyces sp. </i>Isolated from Acidic Cultures of Minerals on Plant Development in Environments Polluted with Mercury

“…Phenothypic identification. The bacteria used in this study were isolated from minerals and ores as previously described [2]. Colony size, texture, and color of the aerial and substrate mycelium were observed on Glycerol-Yeast Extract (GYE) Agar at pH 7 and 28ºC.…”

“…Concentrations of 10, 50, 100, 200 and 400 ppm of this metal were added to standard GYE 1/10 medium. Moreover, the isolates were evaluated to determine their growth at 1.5%, 5%, 7% and 10% of sodium chloride; at pH 2.8, 4 y 7 and 8ºC, 30ºC and 45 ºC of temperatures [2]. The ability to tolerate different concentrations of mercury, growth at different conditions as pH tolerance, temperature, and sodium chloride were evaluated by abundant, regular, little or no growth.…”

“…Microorganisms can be used to concentrate, remove and recover metals from polluted zones; also some microorganisms have abilities as biofertilizers including actinomycetes [1]. In this study four strains of actinomycetes which has been isolated from minerals and concentrates from mines of the Peruvian highlands [2], were characterized molecular and phenotypically and tested for their effects on the growth of Lactuca sativa, Medicago sativa and Phaseolus vulgaris seeds exposed to mercury. We have demonstrated the ability of the four strains to rehabilitate the mercury polluted environment.…”

Actinobacteria Isolated From Mineral Ores in Peru

“…A total of13 isolates of arsenopyrite, 9 of pyrite, 1 of polymetallic sulphide and 1 of magnetite were used. In a previous study, physiological characteristics of 6 of the 24 strains were reported (Matsubara and Hurtado, 2013).To perform the tests, Casein-Starch medium (AAC)and Glycerol-Yeast Extract medium (XGAL) (Matsubara and Hurtado, 2013) and sometimes 10% dilutions of these media were used: AAC 1/10 and XGAL 1/10. ISP4 medium Agar-starch-mineral salts was also used (Shirling and Gottlieb, 1966).…”

“…Also, the composition of acidic waters (Bacelar-Nicolau and Johnson, 1999) and sediments from water from mining activity (Blötheet al, 2008;Sanchez-Andrea et al, 2011) have been evaluated and the presence of sequences of Actinobacteria and sequences belonging to the order Acidimicrobiales and Actinomycetales were reported (Bacelar-Nicolauand Johnson, 1999; Blötheet al, 2008). It's been possible to isolate actinobacteria from orders different to acidimicrobiales from tailings or mining concentrates (Matsubara and Hurtado, 2013;Schippers et al, 2002), founding genres such as Catellatospora (Lee et al, 2000a), Saccharothrix (Lee et al, 2000b), Pseudonocardia (Lee et al, 2001), and Nocardiopsis metallicus (Schipperset al, 2002). Bacterial leaching or Bioleaching is a process that implies the solubilization of metals using microorganisms and it's determined by the mineralogy and other factors.…”