AP Research: Exploring the Potential for Horizontal Gene Transfer to Enhance Microalgal Efficiency in Wastewater Treatment
Advisor: Joselyne Campos
My research holds the promise of significant benefits in the field of environmental biotechnology. I aim to investigate a novel approach: the influence of increased permeability of microalgal cell walls on the efficiency of Horizontal Gene Transfer (HGT) from bacteria to microalgae. This unique study will shed new light on the potential of HGT in enhancing wastewater treatment. I will focus on how the augmentation of cell wall permeability in microalgae impacts HGT efficiency in conditions akin to wastewater treatment. Additionally, I will explore the environmental factors that strengthen HGT and how the transferred genes could enhance pollutant removal, nutrient uptake, or stress resilience in microalgae.
Project Blog
Week 0
Hello Readers!
For far, my senior project has been a busy whirlwind of research, emails, and tons of problem-solving.
For my project, I am researching how enzymatic treatments can increase microglial cell wall permeability to enhance horizontal gene transfer (HGT) from bacteria. HGT is crucial in evolution and biotechnology, but microalgea’s tough cell walls make gene transfer inefficient. In summary, my project explores whether certain enzymes can improve this process.
I was inspired by my interest in evolution biology and microbiology, particularly how genetic material moves between organisms outside of just reproduction. This is what led me to explore HGT and its potential applications!
So far, I have been trying to sort out the equipment I will need for my project. I have figured out what things I will need to find at a lab, what I will need to buy, and how much time I have to do everything. A major breakthrough came when I was in touch with a parent at BASIS who had a lab I could use. Now, I am focused on finalizing my methodology and securing a research mentor.
Weeks 1-4: Lab time!
Alright, we’re back! This week, I went all in—mixing my own LB broth, streaking plates on my dining table, sterilizing old jars in a pot like some weird science-soup hybrid, and trying to convince my bacteria to actually do something.
I measured out some Luria Broth (Miller’s) powder — not with a lab balance, but with a pocket scale that probably sees more use weighing coffee beans than microbiology supplies. I mixed the powder into distilled water and heated it in 30-second microwave bursts. The goal was to get it hot enough to sterilize without exploding all over the inside of the microwave. It was one of those moments where you realize how little control you actually have over microwaves, but somehow it worked. You can see the setup in one of the photos — a bowl, some plastic wrap, and a plate are involved. It was chaos. But it worked.
With the broth ready, I needed something sterile to store it in. I found a glass jar that used to hold bone broth, boiled it in a pot on the stove for about 15 minutes, and then cooled it in an ice bath before pouring in the hot LB. The whole thing felt very Frankenstein meets DIY cooking show. But honestly? That jar turned out to be one of the most reliable parts of this entire experiment.
I filled two 15 mL conical tubes with the cooled LB, added a few drops of liquid E. coli from a Carolina culture tube, loosely capped them, and put them in my 37°C incubator. I also streaked some of the culture onto an agar plate I had poured earlier with my freshly made LB agar. The plates came out surprisingly clean, considering I poured them on my kitchen table with the precision of someone pouring pancake batter while half-asleep. Still, they solidified nicely and looked good enough to use.
Thirteen hours later, I checked in. The tubes looked... the same. Maybe one of them was slightly hazy, but it was one of those “is this actually cloudy or am I just convincing myself it is?” kind of situations. But when I checked the streaked plate, there was definitely some faint growth. Barely visible, almost like condensation lines, but it was there. You can see it in one of the photos. It made me realize: the culture was alive, just starting slowly. Probably because I had used LB straight out of the fridge like a rookie.
Since the broth didn’t seem to be doing much, I decided to give it a boost. I took a sterile loop, grabbed a bit of the faint growth from the plate, and swirled it into the same broth tubes. That wasn’t part of the original plan, but at this point, the whole project was held together with good intentions and duct tape anyway. I figured the worst-case scenario was that nothing would change, and the best case was a culture that actually grew. Sometimes you just gotta improvise.
The rest of the night was me periodically checking the tubes, giving them gentle swirls, and hoping they'd eventually hit turbidity. I didn’t have a shaker, so I gave them a manual shake every couple of hours like some weird bacterial babysitter. It kind of worked — the next day, the difference between the inoculated tube and the control was clear. It wasn’t dramatic, but it was definitely cloudy. Not a perfect overnight culture, but it was alive, and that was good enough for me!
Now, I am working on transformation. Wish me luck!
Post 3: Final Post!
After several weeks of work, I finally wrapped up my E. coli transformation experiment. The goal was to test how environmental stress, including high salt concentration, nutrient limitation, and low pH, would affect transformation efficiency using the pGREEN plasmid. This plasmid contains both a gene for ampicillin resistance and one for GFP, which causes the cells to glow under blue light if successfully expressed.
I prepared six experimental groups: a negative control (E. coli without plasmid on ampicillin plates), a positive control (E. coli with pGREEN on standard LB + ampicillin), three stress conditions (salt, nutrient-limited, and low pH), and a group plated on LB without antibiotic to confirm that the cells and plasmid were viable.
After incubation, I saw exactly what I expected on the control plates: the negative control showed no growth, and the non-antibiotic plates had full lawns of E. coli. What surprised me was that, at the 16-hour mark, the only groups showing visible colony formation were the stress groups, not the positive control. Each had small, pinhead-sized colonies beginning to form. They didn’t glow right away, but over time, I was able to see faint fluorescence under blue light, confirming that the plasmid had been taken up and expressed.
The lack of growth on the positive control plates suggests that I may have made a mistake in that group, possibly forgetting to add the plasmid or making a pipetting error. Still, seeing the stress groups succeed showed that transformation can occur even under challenging conditions, and that the cells were more resilient than I expected. In the end, despite a few setbacks, the experiment worked, and I was able to see glowing colonies, which was the most rewarding part of the entire process.