Fernandez 1
Tad Fernandez Isolating Microbes
Bio 260 Taleen Der-Ghazarian
May 13, 2024
Control of Microbial Disk 5/12/24: Purpose:
The purpose of this lab is to use the disk-diffusion method to test disinfectants. We’re to split our agar plates into four sections and isolate the microbes we had from our sour dough project. I had enough agar plates to use two different colonies I noted. In a few days we’re able to determine which disinfectants successfully stopped bacterial growth. This sample uses Pine-
sol, Lysol, H
2
O, and bleach. Data:
On 5/12/24, I was able to test a controlled experiment by using 4 solutions. This sample uses Pin-sol, Lysol, H
2
O, and bleach. I was able to use tweezers, sterile disks, a tea candle, and 70% isopropyl alcohol for sterilizing my samples. For discussion purposes, I have attached a picture of my two agar plates side by side. I used two plates to see the differences between incubation periods. Today is technically day 1, by 5/16/24, I should have plenty data regarding zone inhibition and which solution appeared most effective on my agar plate. My guess would be
bleach and Lysol, since I use Lysol to clean my counter tops, and bleach with water to remove stains/ dirt from my clothes. The active ingredient in Pine-sol consists of Citric acid 1.75%, other
ingredients 98.25%, total 100% solution. For Lysol, Alkyl (50% C
14
, 40% C
12, 10% C
16
) dimethyl benzyl ammonium saccharinate 0.10%, ethanol 58%, other ingredients 41.90%, total 100% solution. Lastly, ingredient in bleach consists of Sodium Hypochlorite 6%, Other ingredients: 94.0%, total 100%, Yields 5.7 available chlorine. What I learned:
What I will learn in a few days are which disinfectants may inhibit bacterial growth on my agar plates. I have two samples which I can refer to regarding the samples I used for this lab. Three solutions are considered disinfectants and I’ll be able to see which disinfectants are the most effective after their incubation period. I’ll have more data for this lab and an update of my agar plates 5/16/24. I’ll be measuring diameter of zone inhibition with each solution I used during this lab.