topbar image

Micobiological analysis

Microbiological control in the beverage industry and water treatment is of vital importance to validate the quality of production. The detection of micro-organisms (yeast cells and bacteria) as early as possible can prevent the occurrence of production losses or health problems.

captured yeast cells
Current technology
Currently the ‘plate count’ method is being used in e.g. breweries. A well defined volume of beer with potential contaminants is being filtered through a paper filter plate that captures the contaminants. The filter is subsequently placed on a cultivating plate, which is selected for specific yeast and/or bacteria and is stored in an incubation stove. After 48-96 hours of incubation, the number of yeast/bacteria colonies are being count on the filter plate with the eye, which number is a measure for the amount of living micro-organisms present in the original beer sample.

A new, rapid detection method
For situations in which rapid results (within half an hour) are required, Aquamarijn, in collaboration with a few breweries, has therefore developed a new, fast test method using a microsieve test disc. In this test method, the liquid sample is quickly filtered through the microsieve disc. Most of content of your sample is retained at the membrane surface, and then being scanned by microscope directly. The inertness of the membrane allows for immediate staining, directly at the membrane surface for use with fluorescence microscopy. As membrane material has no autofluorescence, this yields clear images. Because the total surface area of the MAS is small compared to the collected sample, it is easy to count individual micro-organisms.

cell colouring
Furthermore, with the microsieve test method it is possible to differentiate with selective staining agents between dead and living cells, something that is difficult with ‘plate count’ (living cells only), ATP (living cells only) and PCR (dead plus living cells) methods.

Quality control
The microsieve test disc may be used in applications other than beer screening. The test disc may also be applied for the quality control of drinking water on the presence of Cryptosporidium, Legionella and E-Coli. Furthermore in the biomedical field it may be applied to observe e.g. cell growth. For recognition of cell aberrations it is worthwhile to place the cells well arranged on a regular sieve grid.

Properties