Biodegradation Analyses Services
Microbe Inotech Laboratories, Inc. has developed several tests for determining if and how well bioremediation can occur at your site.
1. Endpoint Assay
This analysis will indicate if any of the indigenous, or purchased strains of bacteria we have isolated are able to use your chosen contaminant or substrate as a carbon source. It also reveals how well the bacteria can use the carbon source compared to hundreds of other strains that have been tested. The Endpoint Assay uses the 96 well microtiter plate to give rapid testing with increased savings. In this test, the microplate is loaded with a suspension of your isolated bacteria, the contaminant you have chosen, and media and water for the positive and negative controls. Each unknown and control is done in replicates of at least four wells for added accuracy. After 24 hours incubation the plate is read in a microplate reader to determine the optical density of each of the wells. A dye in the wells turns purple if the bacteria are using the carbon source. The higher the optical density, the better your strains are at consuming the contaminant.
2. Kinetics Study
Once you have determined there are degraders present, and you would like to know how the addition of nutrients or oxygen will affect their growth rate, you may want to do a kinetics study. The Kinetics Study is similar to the Endpoint Assay in that it uses the 96 well microtiter plate, containing a tetrazolium dye that darkens proportionately to the metabolic activity of the strain. The kinetic plate is put into the microplate reader immediately after preparation. The optical density of the wells is then read every 10 minutes for 18 hours. Each reading is automatically plotted to create a growth curve. Comparisons of curves from wells with nutrients to the control wells gives your precise information about how the addition of any; substrates will affect the growth of your strains.
3. Comparative Population Assay
This is a MPN (most probable number) test that gives you the order of magnitude of your degrader populations. The 96 well plate is also used in this test. The Comparative Population Assay differs from the Endpoint or Kinetic Assays since a serial dilution of your soil or water sample is used directly in the plate, along with the contaminant, instead of the isolated strains. After 48 hours incubation, the plate is read in the microplate reader to determine the highest dilution at which growth is detected. This gives you the MPN of the degrader populations. Also in the plate are positive growth control wells. These wells provide you with the total heterotrophic plate count information.