Journal of Microbial & Biochemical Technology

Advances in molecular tools for routine monitoring of toxic algae and pathogens in aquatic ecosystems

Joint Event on 4^th World Congress and Expo on Applied Microbiology & 2^nd International Conference on Food Microbiology

November 29-December 01, 2017 Madrid, Spain

Linda K Medlin, Delphine Guillebault, Elisa Villa, Julia Baudart and Jahir Orozco

Marine Biological Association of the UK, UK
Microbia Environnement, Observatoire Océanologique de Banyuls sur Mer, France
Laboratoire de Biodiversite et Biotechnologies Microbiennes - University Pierre and Marie Curie, CNRS, France

Scientific Tracks Abstracts: J Microb Biochem Technol

Abstract:

Microarrays are oligonucleotides applied to the surface of a glass slide in an ordered array. When rRNA sequences are used, these are called phylochips, which can identify organisms and is a relatively new, innovative microarray application. Phylochips can facilitate monitoring for any microorganism in any environment and visualize its changes in abundance over time for longterm records. We developed in three EU projects: a phylochip for the detection of toxic algae in marine waters and for freshwater pathogens in freshwater and tested them with environmental samples in five countries for the toxic algae and six countries for the freshwater pathogens. Water samples were filtered until they clogged or concentrated into one litre using a kidney dialysis filter, of which free filters are being distributed upon request. Total RNA was extracted using TriReagent, fluorescently labelled and hybridised to the phylochip. The pattern captured via fluorescent excitation in the microarray scanner is exported as an excel file and analyzed based on presence/absence of probe signals in a hierarchical fashion. For a species to be present, probes for higher taxa, viz., genus to kingdom must also be present. Where calibration curves have been made, then the microarray signal can be converted into cell numbers. In a fourth EU project microarray probes were transferred to a SHA coupled to an electrochemical and a colorimeter detection. The electrochemical detection was 16 fold higher than that obtained in earlier applications and the colorimetric detection was automated for a real time in-situ assay in a buoy.

Biography :

Linda K Medlin obtained her PhD from Texas A&M University in 1983 and is currently a Research Fellow at the Marine Biological Association of the UK where she co-ordinated the FP7 EU project MIDTAL. During her employement at University of Paris and at Microbia Environnement, she directed two additional FP7 projects Aqua and SMS. All three of these projects involved the making of species specific probes for early warning systems for toxic algae and/or freshwater pathogens and applying them in a microarray or biosensor format and for making phylochips for the analysis of marine biodiversities using microarrays. She has published over 250 research papers including 35 chapters in books. She has participated in over 18 EU grants and many other national funding proposals from the UK and Germany.