Nofima Mat is focusing strongly on understanding the significance of the intestinal flora for health in both animals and humans, as well as understanding and manipulating the intestinal flora of production animals so as to reduce the extent of food pathogenic bacteria. We have collaboration projects with both medical and veterinarial connections in which we carry out analyses of microbial communities in connection with screening studies and intervention studies. Nofima Mat is also able to carry out in vitro fermentation trials on different substrata and study the effect on the intestinal flora. Nofima Mat is working on developing new bioinformatics and molecular methods for studying and understanding the complexity of microbial communities. Nofima Mat is also working on the commercialisation of these techniques.
The techniques in use are real time PCR, micro matrices and DNA sequencing. We are focusing on building up samples and DNA cleaning and we use automatic DNA cleaning in our projects. When working with PCR techniques it can be a big problem to separate DNA from living and dead cells. We use a nucleic acid binding colouring (ethidium monoazide) that selectively goes into the dead bacteria with damaged membranes. The colouring binds irreversibly to DNA and prevents PCR on DNA from the dead bacteria.
To analyse large sample quantities, which we believe is necessary to begin to understand the complexity of microbial communities, we have recently developed a method for direct DNA sequencing of microbial communities. The method makes it possible to quantify bacteria without the need for precultivation in a single sequence reaction.
Nofima Mat is also working on developing new methods for classifying bacteria. The method is based on the bacteria's genetic "fingerprint" and systemises bacteria by the genetic material. The driving force of this work is to create a common framework for the recognition of bacteria. The idea is that researchers from all over the world should be able to send samples in to the database to classify bacteria. The database is intended to serve the food industry, the clinical treatment system and the pharmaceutical industry.
Determining bacterial diversity
It can often be interesting to study which bacteria are found in foods and how the bacteria vary in the product during storage and after various treatments. This can be done using various methods and at Nofima Mat we use molecular biological "fingerprinting" techniques such as denaturing gradient gel electrophoresis (DGGE). This methodology is used to study bacteria in fresh fish and how the bacterial flora changes over time and with different preprocessing or storage. This provides useful information about hygiene, packaging and processing conditions for foods. The method can be used on all products to study the total microbial community or to look at individual bacteria or bacterial groups.
