Ibrahim's blog

Observations (Week 11)

This week was full of results and observations. The SEM (Scanning Electron Microscope) did its magic again. We got the chance to see our untreated plastics (PVC 3, LDPE 4, SPI 5, SPI 6) and the images didn’t disappoint (figure 1a, 1b, 1c, and 1d). We couldn’t locate bacteria on the untreated plastics, which in theory we should’ve because our plastics contain Pseudomonas bacteria. The research team has suspicions as to why we couldn’t locate bacteria. We will troubleshoot in the coming weeks and have an answer. Remember while observing the images, at the bottom, you will see a number with an 'x' next to it, this tells you how zoomed in you are.

Figure 1b: untreated plastic 4

Figure 1a untreated plastic 3

Figure 1c: untreated plastic 5

Figure 1d: untreated plastic 6

Figure 2: Membrane filtration method under the hood.

The team also had a chance to filter (Membrane filtration method) the Pseudomonas bacteria and plastics so that we can get pure Pseudomonas and plastic contacts only, removing excess water and chemicals (figure 2). As usual, the Pseudomonas species, Pseudomonas putida, Pseudomonas stutzeri, and Pseudomonas aeruginosa were placed under suitable temperature (37°c), and Pseudomonas fluorescence was also placed on its suitable temperature (25°C). After one day of growth, the strangest thing happened. The Pseudomonas putida and Pseudomonas stutzeri produced a dark pink pigment (figure 3a and 3b). Usually, MRSA (Methicillin-resistant Staphylococcus aureus) has a pink pigment, but in our case two Pseudomonas species produced a pink pigment, which for me was exciting.

Figure 3b: Pseudomonas stutzeri

Figure 3a: Pseudomonas putida