Greetings everyone!
My 2nd week was not as long as the 1st week but it’s still packed with a lot of information. Let me start with the applications on these polyvalent phages to water treatment if in case you are wondering.
Applications
a) These viruses (polyvalent phages) can target bacteria that have shown resistance to antibiotics. This type of biological control could be used in remediating problems in the water such as bacteria-induced corrosion of pipes.
b) Conjugated or immobilized polyvalent phages could be used to effectively infect problematic bacteria in a biofilm. The immobilization could be engineered (e.g. using magnetic nanoparticles) to enhance the delivery system and target these problematic bacteria.
The phages studied in the lab have been tested on the following bacterial hosts; Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium. These bacteria are known to be prevalent in wastewater. I am thinking of using the E. coli for the lesson that I have thought last week. The results of the different investigations about polyvalent phages can lead to a system where we don’t need to use antibiotics or chemicals anymore in treating wastewater. So it is really a promising endeavor!
In the lab, we continued the experimentation last week using the different dilutions of phages and bacteria to find a good result of viral plaques for isolation. The 50 uL (undiluted) and 100 uL of phage showed the best result so far. Dr. Yu suggested to also try 100 uL and 200 uL of bacteria to create a better bacterial lawn and compare the results.
I also happened to have a short chat with another visiting scholar from Brazil since her project is also on polyvalent phages. She mentioned the method called “Drop Spot Test” where it works like the antibiotic test on bacteria where you can see a circular zone of inhibition. In this test, you can drop a 10 uL of phage solution and see the plaque formation after 24 hours. I think it was such a very cool idea for a lesson. Although this is just a qualitative test but students can really see effects of viral lytic infection. Productive conversations to different people can really bring a lot of valuable information most of the time! I just need to try this myself using resources that are available in the classroom (e.g nutrient agar and phage and bacteria purchased from vendors like Carolina Biological and others) and see if it works.
As for the enzyme laccase, since we finished the immobilization last week, we wanted to find out if the sample has been completely immobilized by measuring its activity using the plate reader. Once this done, we can proceed with the testing of the effectivity of the enzyme when it comes to its ability to oxidize the methyl green dye, a representative of the dyes that are commonly found in wastewater from the textile industry. And oh, since the nanoparticles used to immobilized the enzyme is magnetic (Silica-coated magnetic nanoparticles), we don’t need to centrifuge the sample to obtain the supernatant fluid, we just used a Neodymium single disc magnet to bring the enzyme down to the bottom of the eppendorf tube, pretty cool huh! 🙂
I will never forget this part of the experiment because I did something wrong to Yolanda’s magnet (huhuhu!) Don’t ever underestimate the power of the neodymium magnets. I accidentally placed it at around 6 to 8 inches away from another magnet that is thicker and oh boy, the disc magnet was drawn to the bigger one and it cut into half. I felt so guilty that I felt like I have to replaced it so I went online, searched for it on amazon and ordered one 🙂 Charge to experience. You learn as you go! No regrets though 🙂 Stay tune for week 3!
