Raman spectroscopic detection of Nickel impact on single <i>Streptomyces</i> cells – possible bioindicators for heavy metal contamination

Abstract

Heavy metal contamination of soil has an immense impact on the surrounding environment, such as the ground water, and hence, has become an important issue within bioremediation. Therefore, heavy metal contamination has to be determined preferably cost‐efficiently, rapidly, and reliably. Here, soil bacteria of the genus Streptomyces are used as bioindicators for heavy metal contamination investigated via micro‐Raman spectroscopy. A single cell approach is studied to avoid time‐consuming culturing and plate counting. Bacteria of Streptomyces galilaeus were incubated in Ni 2+ enriched media and single cell spectra were recorded. Supervised statistics linear discriminant analysis was used to evaluate the influence of the culture age and the anion on bacterial cells, which has been determined to be minor compared with the spectral impact of Ni 2+ . The identification of the Raman spectra according to different Ni 2+ concentration ranges is accomplished with a prediction accuracy of about 88%. Therefore, we conclude that Streptomyces can be used as a bioindicator to predict Ni 2+ concentrations in the micromolar range. Copyright © 2011 John Wiley &amp; Sons, Ltd.