Biological Activity Reaction (BART) Test for HETEROTROPHIC AREOBIC BACTERIA – HAB
HAB-BART testers are designed to detect the activities of general (HAB) bacteria. HAB stands for heterotrophic aerobic bacteria but is has been simplified to general HAB bacteria to make it easier to understand. These bacteria are able to degrade different organics very efficiently both oxidatively (generates biomass and carbon dioxide) and reductively (by fermentation to create mild organic acids as well as carbon dioxide). This test functions using methylene blue to determine what type of activity are occurring in the tester.
Often you need to test water for the presence of bacteria without trying to determine the particular groups of bacteria that may be present. When total aerobic bacteria are present and active, the blue dye in the BART bleaches either from the bottom up or the top down.
The test measure the ability of the total aerobic bacteria to respire while degrading the various nutrients in the dehydrated culture medium. Methylene blue, the dye, acts as an alternative to oxygen for microbial respiration. When the microbes respire, the methylene blue changes to a colorless form. The faster the dye is bleached, the greater the level of respiration and the larger or more aggressive the total aerobic bacteria population.
Aerobic bacteria can cause several problems in water, including slime formations, turbidity, taste and odor, corrosion, health risks, and hygiene risks. When a problem is detected, you may want to conduct more testing to determine precisely the nature of the microbial problem. You can use other BARTs to detect several types of bacteria.