During fermentation, the type and quantity of the genetic products that are emitted by the bacteria vary. Henkel experts have identified the genes that – in simplified terms – switch the bacteria on and off, and how this affects the results of the fermentation. They have also developed a method that makes it possible to measure gene activity during the fermentation process. Behind the pioneering results are many years of research achievement by a complete competence network of industrial and academic partners.

The DNA Chip supplies snapshots of the fermentation process
In cooperation with the University of Göttingen, Germany, Henkel developed a DNA chip. The DNA chip enables a large number of genes or gene products to be analyzed simultaneously in a high-throughput procedure. The DNA chip is not much larger than a coin and consists of glass or plastic. It is divided into many small fields, each of which contains its own specific gene. The exact position of each gene on the chip is known. The chip can therefore be referred to as a DNA array. All of the approximately 4,000 genes of a production strain can be positioned on it. To study the biological processes in the bacteria during fermentation, the researchers take samples at certain intervals and analyze them with the help of the DNA chip. Specific interactions of components of the sample with the material in the array are made visible by means of a color reaction. In this way, the researchers obtain a snapshot of the status of the bacteria. The data then have to be statistically analyzed – using bioinformatic methods – to obtain a reliable statement about the result of the experiment. However, this analysis takes up to five days and is therefore unsuitable for fast analysis of the fermentation process.

Rapid analysis with the electrical BioChip
Since the DNA chip with all the genes of the bacterium (about 4,000) is unsuitable for rapid analysis, Henkel researchers worked together with the University of Greifswald to develop an electrical BioChip. In contrast to the DNA chip, the electrical BioChip contains just a few marker genes. The activity of the marker genes serves as a measure for the productivity of the bacteria. The sampling and sample preparation for the BioChip test are carried out automatically, and the analyzer measures the electrical signals generated on the chip. The scientists obtain the results in less than an hour, whereas previously, when the DNA chip was used, they had to wait for several days after the fermentation was complete. For the first time, the knowledge acquired can be used immediately to intervene in the ongoing process and monitor the results of these interventions. Productivity fluctuations in industrial fermenters can be avoided, and new production strains can be developed faster.