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06 March 2020 | Story Thabo Kessah | Photo Tsepo Moeketsi
Dr Ocaya
Dr Richard Ocaya’s research addresses the skills development and transfer millennium goal of many governments globally.

With the Fourth Industrial Revolution becoming a reality, Dr Richard Ocaya’s research is receptive to the fact that Africa and the world need to re-imagine their research. His research focuses on electronic instrumentation design for scientific measurements, computational physics on atomic nano-atomic structures, and semiconducting organic compounds materials built on silicon to realise Schottky devices.

Software developer 
“I develop most of the instrumentation that I apply in my research – both software and hardware,” said Dr Ocaya, a Physics Lecturer and Programme Director: Physics and Chemistry on the UFS Qwaqwa Campus.

“I am active in scientific computing through the computing cluster and software development, mathematical physics for material science modelling, and embedded instrumentation design using microprocessors. I also have deep interest in radio and data telemetry, in which I hold a South African patent issued in 2013. My present international collaborations are with like-minded researchers in similar fields in Saudi Arabia, Turkey, Japan, Egypt, South Korea, and the United States,” he added.

How does his research talk to the real world?
“The driving principle of all areas of my research has always been to deploy cutting-edge research to actual, real-world applications for the immediate betterment of Africans. The areas of my research align closely with the millennium goals of many governments globally, including the Republic of South Africa. These goals pertain to skills development and transfer that position us to better address the challenges of energy, water, and other priorities.”

Dr Ocaya is currently co-promoting a PhD student, having previously supervised one PhD, two MSc, and more than twenty honours students. He is a self-taught electronics and computer programmer, whose curiosity led him to question ‘the voices and music coming from a box; a radio’. “In my quest to satisfy my curiosity, I collected many discarded devices, took them apart, and tried so many circuits, only to have them fail because the theory was lacking. After thousands of failed projects and with me barely thirteen and in lower secondary school, my first ever project actually worked,” he said.

NRF-rating
He is the author of the book Introduction to Control Systems Analysis using Point Symmetries: An application of Lie Symmetries, which is available in all major bookstores such as Amazon, in both print and e-book format. He is a C3 NRF-rated researcher whose work makes a pioneering contribution to the new and growing field of phononics, an independent field of the now established photonics.

“This field will someday lead to improved energy-storage devices and faster processors due to more efficient heat removal from nanodevices,” he concludes.


News Archive

Research eradicates bacteria from avocado facility
2017-01-17

 Description: Listeria monocytogenes Tags: Listeria monocytogenes

Listeria monocytogenes as seen under an electron
microscope. The photo was taken with a transmission
electron microscope at the microscopy unit of the UFS.
Bacteriophages (lollipop-like structures) can be seen
next to the bacterial cells.
Photo: Supplied

“The aim of my project was to identify and characterise the contamination problem in an avocado-processing facility and then to find a solution,” said Dr Amy Strydom, postdoctoral fellow in the Department of Microbial Biochemical and Food Biotechnology at the University of the Free State (UFS).

Her PhD, “Control of Listeria monocytogenes in an Avocado-processing Facility”, aimed to identify and characterise the contamination problem in a facility where avocados were processed into guacamole. Dr Strydom completed her MSc in food science in 2009 at Stellenbosch University and this was the catalyst for her starting her PhD in microbiology in 2012 at the UFS. The research was conducted over a period of four years and she graduated in 2016. The research project was funded by the National Research Foundation.

The opportunity to work closely with the food industry further motivated Dr Strydom to conduct her research. The research has made a significant contribution to a food producer (avocado facility) that will sell products that are not contaminated with any pathogens. The public will then buy food that is safe for human consumption.


What is Listeria monocytogenes?

Listeria monocytogenes is a food-borne pathogenic bacterium. When a food product is contaminated with L. monocytogenes, it will not be altered in ways that are obvious to the consumer, such as taste and smell. When ingested, however, it can cause a wide range of illnesses in people with impaired immune systems. “Risk groups include newborn babies, the elderly, and people suffering from diseases that weaken their immune systems,” Dr Strydom said. The processing adjustments based on her findings resulted in decreased numbers of Listeria in the facility.

The bacteria can also survive and grow at refrigeration temperatures, making them dangerous food pathogens, organisms which can cause illnesses [in humans]. Dr Strydom worked closely with the facility and developed an in-house monitoring system by means of which the facility could test their products and the processing environment. She also evaluated bacteriophages as a biological control agent in the processing facility. Bacteriophages are viruses that can only infect specific strains of bacteria. Despite bacteriophage products specifically intended for the use of controlling L. monocytogenes being commercially available in the food industry, Dr Strydom found that only 26% of the L. monocytogenes population in the facility was destroyed by the ListexP100TM product. “I concluded that the genetic diversity of the bacteria in the facility was too high and that the bacteriophages could not be used as a control measure. However, there is much we do not understand about bacteriophages, and with a few adjustments, we might be able to use them in the food industry.”

Microbiological and molecular characterisation of L. monocytogenes

The bacteria were isolated and purified using basic microbiological culturing. Characterisation was done based on specific genes present in the bacterial genome. “I amplified these genes with polymerase chain reaction (PCR), using various primers targeting these specific genes,” Dr Strydom said. Some amplification results were analysed with a subsequent restriction digestion where the genes were cut in specific areas with enzymes to create fragments. The lengths of these fragments can be used to differentiate between strains. “I also compared the whole genomes of some of the bacterial strains.” The bacteriophages were then isolated from waste water samples at the facility using the isolated bacterial strains. “However, I was not able to isolate a bacteriophage that could infect the bacteria in the facility.

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