Hello All!
I was assigned into Dr. Alvarez’s lab under the mentorship of Dr. Pingfeng Yu to work on Poyvalent Phages with the assistance of Dr. Chu, a visiting scholar from China whose expertise is also on polyvalent phages. I could go to either of them depending on who is available in the lab. I was also introduced to different researchers and visiting scholars and had a chance to speak to them about their projects. In addition to polyvalent phages, I got interested with the work of Yolanda Moldes, a visiting scholar from Spain because she is working on remediating emerging pollutants in wastewater using the enzyme laccase. This really sparked my interest because I want to know how enzymes work in removing pollutants in the water such as dyes, BPAs and other compounds that are known to be endocrine disruptors. I asked her if she could show me the process of the investigation and graciously said ‘yes’ to my request but my primary investigation is on polyvalent phages.
Viruses that infect bacteria are called phages or bacteriophages. Usually, a phage is specific to its host, however there are times when one phage could infect multiple strains of bacteria (hosts) hence they are called polyvalent phages. The phages used in the lab were isolated from a wastewater treatment facility in Houston. The isolation of the phage(s) is not part of my investigation, instead my task is to characterize these phages as they infect a certain host by understanding the compounds released by each species of bacteria as they lysed due to viral infection. What these compounds are and how we can detect them are the challenges that I need to face throughout the course of the investigation with the assistance of my mentors.
This week, I learned the following;
a) inoculating bacteria
b) culturing phages (I learned that you need two layers of agar, a fixed agar and a soft agar on top where bacteria grow and create a bacterial lawn. The agar used was LB. The phage or phages will infect these bacteria and form viral plaques – zone of infected cells which can be visibly seen as clear circular structures in the bacterial lawn). This part of the lab is an initial idea of a lesson that I could write to show lytic infection of viruses since I haven’t come across a lab on lytic infection so far.
c) diluting the concentration of bacteria and phages using the 10-fold serial dilution method. A good review for me since I don’t really do this much in my own lab.
d) perfecting my pipetting skills (Pipettors of different volumes are just one of my best buddies in the lab. I did a lot of pipetting throughout the week that I think I’m becoming like a pro on this! lol!)
The goal of the first week is to determine the best phage to bacteria ratio which could produce good size of viral plaques where we can isolate a phage for purification. This wasn’t attained the first day so we kept modifying our volumes and dilutions throughout the week.
e) immobilizing the enzyme laccase using magnetic nanoparticles (with Yolanda’s assistance, I was able to observe the process of immobilizing enzyme using the nanoparticles. It was a complicated process which I think can’t be done in my school lab, but I will continue to explore and maybe bring this investigation in my classroom. Several researches showed that enzyme immobilization is more stable and more effective in catalyzing reactions than those free ones. Now, I am thinking if there is a simpler way to immobilize this enzyme but still using nanoparticles that can be done in the classroom lab, my hopes are high!)
It feels like my week was really packed. I had plenty of take aways and I love every moment of it.This is why lab immersion stands out as an avenue for professional growth because you experience the process itself including failures. I am excited of the remaining weeks to come!!!
