This week we started the first round of CARMEn biological testing. The team has spent a long time researching "Pseudomonas take-over"- the effect of P. aeruginosa dominating mixed-species colonies between P. aeruginosa and S. aureus. From the team's research and some helpful advice from Dietrich Lab members, we decided on using TSB (a nutrient rich medium which should help S. aureus grow comfortably) and a 1:1000 starting ratio of P. aeruginosa. We hope this combination of medium and starting concentration ends up a recipe for success!
On Thursday, Swati mixed a 1% Agar 3% TSB medium, and on Friday, she spotted over 50 plates of various sizes with different combinations of P. aeruginosa, S. aureus, dual-species biofilms, and colonies grown next to each other. Several of the plates were placed at 25°C (approximately ambient temperature) and 4°C (cold-stow temperature) where they will be pulled out and harvested in 1-week intervals to determine the length of time the colonies are viable in each of the two temperature conditions. The other plates will be observed periodically for the span of 14 days (while kept at 25°C) to determine what the growth pattern of the bacteria looks like in various sized Petri dishes.