- Could the isolates grow on the influent as a sole carbon source
- Determine the rate of growth on the influent at mesophilic temperatures (30oC)
- Did the cultures form floc and no produce the viscous solids seen in the existing biomass.
The microbe tested was a interesting Rhodococcus strain that was originally isolated for chlorinated hydrocarbon and herbicide degradation. What is interesting is that within 24 hours of growing on the influent, the Rhodococcus cultures entered log phase growth. What is interesting is that in response to the waste, the Rhodococcus formed a hydrophobic mass that floated and was very stable. With continued feeding of the influent, we added other Pseudomonas cultures that had previously not done well on the waste. Interestingly, with the addition of the Pseudomonas strains the floc started to form without the hydrophobic or viscous biopolymers seen earlier. This is an very noticeable case of how finding the right cultures can create the needed biomass. It is rare to see a true hydrophobic growth phase, and every less common to see how the hydrophobic phase ends with the addition of a secondary culture. I'm including a photo of the test flask. I am continuing the test to see what increasing F/M ratio does to floc formation.