Bio-precipitates produced by two autochthonous boron tolerant Streptomyces strains

MORAGA, NORMA BEATRIZ; IRAZUSTA, VERÓNICA; AMOROSO, MARÍA JULIA; RAJAL, VERÓNICA BEATRIZ

Journal of Environmental Chemical Engineering

ELSEVIER SCIENCE BV

Año: 2017 vol. 5 p. 3373 - 3383

2213-3437

Boron is widespread in the environment. Although contaminated soils are hard to recover different strategieshave been investigated in the recent years. Bioremediation is one of the most studied because it is eco-friendlyand less costly than other techniques. The aim of this research was to evaluate whether two Streptomyces strainsisolated from boron contaminated soils in Salta, Argentina, may help remove boron from such soils. For this,they were grown in different liquid media with two boric acid concentrations and their specific growth rate andspecific boric acid consumption rate were determined. Both strains showed great capacity to remove boron fromthe media. Increasing boric acid concentrations affected negatively the specific growth rate, however the specificboric acid consumption rate was superior. Boron bio-precipitates were observed when the strains grew in thepresence of boric acid, probably due to an adaptive response developed by the cells to the exposure, for whichmany proteins were differentially synthetized. This strategy to tolerate high concentrations of boron by immobilizingit in bio-precipitates has not been previously described, to the best of our knowledge, and may have agreat potential application in remediating soils contaminated with boron compounds.