Student continues research on antimicrobial properties of natural oils

Student filling centrifuge
Rosemary Nwabuogu

Most college students have pictures of themselves, their friends or their pets on their cell phones. Rosemary Nwabuogu has photos of microbes.

            The biology major thumbed quickly through rows and rows of pictures of petri dishes with various levels of growth before finding what she was looking for - a series of photos in which the number of microbes in the petri dish decreased as the amount of cinnamon oil in the dish increased.

            “That's really pretty, but it's deadly,” she said, pointing to the bacteria growing in a sample of chicken.

            The photos are from her research this summer with Dr. Om Singh, associate professor of biology at Pitt-Bradford. Nwabuogu is the third student he has worked with on this project to test natural antibiotics and their potential use in the food industry.

            Earlier students from the project are now at the University of Pittsburgh and University of Pennsylvania pursuing graduate work. Nwabuogu, a senior from Jefferson Hills, hopes that her exposure to research at the undergraduate level will help her pursue a career within the medical field.

            Nwabuogu said more medical schools are requiring undergraduate research, and she can see why.

            “I feel like if you're learning on your own, you learn better,” she said. Nwabuogu is testing natural oils this summer to determine their antibiotic properties. She has tested cinnamon, cloves, garlic and rhododendron in a multistep process. Previous students tested ginger, red chilis and black pepper, Singh said.

            Beginning in May, Singh put Nwabuogu through a three-week boot camp of lab techniques to ensure that her work would be consistent with the other students' and usable for his research.

            “It was strenuous,” Nwabuogu said. “Research can mentally and physically tire you out.” While working five to 10 hours a day in the lab, she was reading assigned scientific literature at night.

            After a few weeks, Singh turned her loose, and now stops by the lab only in the afternoon to see if she's run into any problems or has any questions. It's a lot of pressure, she said, for her professor to trust her with the outcome of his research.

            At first she was frustrated by the slow process of research before accepting that getting to the point of making new progress can be excruciatingly slow. Working alone in the lab all day can be relaxing, frustrating or lonely, but enjoyable, she said, depending on the day. At night, she works on a paper Singh has assigned.

            So what takes all this time in the lab? Part of it is spent making the oils to be tested; the other part is spent testing the oils' ability to inhibit the growth of bacteria on ground chicken and beef.

            Everything for the experiments came straight from the local supermarket.

            To make the oil, Nwabuogu grinds cinnamon sticks, for example, into a fine powder, then sets them in a filter over a pot of boiling water in a closed system. The steam from the water travels through the grounds, into a collecting tube where it is cooled and turned back into liquid that is collected in a beaker.

            When a couple pints of liquid have been collected, Nwabuogu examines the cloudy liquid to find less than a teaspoon of essential oil at the bottom. She uses a chemical process to separate the oil from the water, and the oil is then stored in one of a dozen tiny dropper-topped bottles. Months of work are stored on a single shelf in the lab.

            Once the oil has been extracted, Nwabuogu tests its antibiotic properties methodically. Each kind of oil is tested at different strengths and at different temperatures and the number of microbes grown meticulously noted.

            Where all of this research could lead someday, said Singh, editor of the forthcoming book “ Food Borne Pathogens and Antibiotic Resistance,” is to reduce the amount of or destroy bacteria that food has when it comes home from the grocery store. In theory, it could be possible to create food items that would be shelf stable for a period of time instead of having to be frozen, saving grocers and consumers money and making more food transportable.

            It would take a long time to get to a result like that, but Singh and his students are working on it one drop at a time.