S-STEM Scholar Rolanda Bell's Blog

From previous conversations with Johnathan, I knew he was a numbers guy, so I decided to to ask if he could help me with my dilemma. You know what?...Johnny on the spot came right through like I knew he would. This idea is so amazing that I couldn't believe it. He suggested using a type of cohort analysis to calculate the missing part of the growth curve. My calculations indicated that I would miss the transition occurring around 16 hours. Johnathan suggested to get another culture started around 5:00 pm, and come the next day at 9:00 am (16 hours later) and record what I missed. Awesome...right? Turns out I didn't miss a thing after all.

I don't know how many of you have met our fellow STEM student Johnathan, but he is the tall guy with glasses. He's kinda funny, very nice, and super smart. I was chatting with him one day and realized that he was a mathematical genius. Which was convenient because I had a mathematical predicament. I was trying to calculate a growth curve for three species of Lactobacilli. However, after collecting some preliminary data and calculating a few estimations, I realized that I would miss an important change in my bacteria. Unlike E. coli, Lactobacilli take much longer than 10 hours to complete their growth cycle. After asking to stay after hours, I was informed that the lab had not been Rolanda proofed, so I couldn't stay pass 5:00 pm. Facing this conundrum, I decided to consult with Phoenix college's brain trust- Matt and Josh. They came up with the idea of monitoring carbon dioxide levels during the period when I wasn't there. Then I could use the data to

Every time I start a project, I always think that I'm going to kick that football right away. And then life happens, and I'm flat on my back. This semester I have decided to examine the inhibitory effects of lactic acid producing bacteria on two common food pathogens: E. coli and Salmonella. In my mind I had this laid out perfectly. In my gut, I knew this wouldn't be easy, but I think my enthusiasm kept me from seeing how difficult it would really be. Nevertheless, I will persevere. And by the end of the semester, I will have kicked that football.

I have always known that Science was a subject I wanted to study. I received my first microscope when I was 8 years old, and have participated in every Science fair since the 5 th grade. In high school, I developed a real interest in bacteria, and centered by next 3 Science fair projects around Microbiology. I would schedule my study halls around my Science teacher’s break, and she would let me culture random things to see what would happen. She was the one who encouraged me to pursue a career in Science.   

                                                                                            Staphylococcus Aureus on Mannitol Plate S. Aureus was identified in two of the participants in my study. Although this organism is typically described as an opportunistic pathogen, it is a part of the normal skin flora of approximately 1/4 of the US population. S. Aureus is also associated with dry skin and atopic dermatitis (Williams et al, 2017). Consistent with current research, the person in our dry skin condition had the most colonies of S. Aureus when compared to the participants with normal and combination skin.  Biochemical characteristics of S. Aureus include, mannitol  +, coagulase +, glucose +, lactose (+) or (-) , and anaerobic.

                                                                                                                      Corynebacterium on blood agar Hello STEM Family, I’d like you to meet my friend Cory. Cory is long, dark, and radiates positivity. I know what you’re thinking, but currently Cory is cohabitating with S. Epidermis on Mt. St. Nares. They’ve been together for the last thirty days. However, if you want to   meet a special friend like Cory, here’s what to look for. They have to be comfortable swimming in shallow and deep water as there is little oxygen down there; have an insatiable sweet tooth, lactose tolerant, and a bubbly personality. Corynebacterium and S. Epidermis were isolated from the nose of our participant with combination skin. Both are gram positive bacteria; however, Corynebacterium are rods and S. Epidermis are coccoid. Biochemical properties include: catalase positive, facultative anaerobic,   beta hemolysis positive, and glucose positive. Cor