Development of DNA Microarray Technology for Environmental Applications

Microarray technology is a powerful tool for parallel detection of genes and their expression in biological systems. Its potential in addressing environmental biotechnology issues is still unexplored. This study presents two key issues related to the use of microarray technology in mixed microbial systems: signal strength and specificity. A glass-based small DNA microarray was robotically printed using 17 full-length and 50 partial gene probes (80-120 bp long) of the pdt locus involved in encoding pyridine 2,6-bis-thiocarboxylate (PDTC), a molecule implicated in the transformation of carbon tetrachloride by Pseudomonas stutzeri strain KC. This array was tested for signal strength and specificity using Cy5 and Cy3 labeled DNA from pure cultures of strain KC and mixed communities. The results suggest that for the selected set of genes, partial and full-length probes may be equally specific under environmental conditions. However, the former may require alternative strategies to increase sensitivity because of lower signal strength.