CH3 - New tools for MIC-diagnosis: developing monitoring systems for microbial biofilm populations

• Research unit: COST
• Project number: C98.0016

Key words (English)

Molecular tools; MIC-diagnosis; microbial biofilm; corrosive biofilm library; biofilm development; corrosiveness of microbes.

Research programs (English)

COST-Action 520 - Biofouling et matériaux

Short description (English)

See abstract

Further information (English)

Full name of research-institution/enterprise: Universität Zürich Institut für Pflanzenbiologie / Mikrobiologie

Partners and International Organizations (English)

B, DK, FIN, F, D, GR, H, I, NL, P, RO, SI, E, S, CH, GB

Abstract (English)

Abstract 2002 Using as inocula biofilms originating from oligotrophic natural aquatic environments and from actual corrosion cases, we were successful in growing biofilms on a variety of metallic surfaces. A mini reactor was used to monitor non-invasively, the colonization, early stages in development and aging of biofilms. Several strains of microorganisms were isolated from metal corroding biofilms and have been cultivated in vitro. They are currently being characterized phenotypically and genotypically using classical methods and modern molecular biology techniques. DNA extraction methods were improved in order to obtain good templates for PCR (Polymerase Chain Reaction). This allows us to obtain information about the member populations of the biofilm communities without having to isolate every organism. Employing DNA fingerprinting, cloning and sequencing combined with CLSM (Confocal Laser Scanning Microscopy) and ESEM (Environmental Scanning Electron Microscopy) techniques made it possible to construct detailed 3-d images of the spatial distribution of organisms within the biofilm and to identify functional properties of some of the community members. Presently, we are constructing biofilm clone libraries using 16S-rDNA PCR products obtained from total DNA extracted from biofilms. Selected isolates are employed to develop organismically defined low diversity biofilms to be used in assigning corrosion abilities to particular organisms. The results will allow us to establish a 'corrosive biofilm library'. The degree of biofilm-caused surface alteration is visualize by SEM and the corrosiveness of the biofilm is measured polarographically. Abstract 2003 Methods for the investigation of metal corroding biofilms applying molecular tools have been established. This approach will be generally applicable to any biofilm forming community on metals and other surfaces. Application of the procedures are presented for biofilms grown reproducibly on stainless steel coupons in a mini-reactor. We provide step-by step protocols to perform the analysis and illustrations of results. By studying the phylogenetic relatedness of microorganisms involved in biofilm formation, we have attempted to find corrosion-related clusters of bacteria. Applying these methods to the analysis of microbioal communities which constitute corrosive biofilms is the first step in an attempt to correlate microbal species and their metabolic potential to corrosion under definable environmental conditions and particular materials.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C98.0016