Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
02 June 2022 | Story Leonie Bolleurs | Photo Supplied
Walter van Niekerk_
If you are so focused on achieving only certain goals in your life, you might miss the best opportunities, believes Dr Walter van Niekerk, who recently received his PhD in Agricultural Economics.

Being relevant in a constantly changing agricultural environment. This is one of Dr Walter van Niekerk’s biggest motivations in his working life. The place where he believes he will be able to do just that, is the University of the Free State (UFS). “The university was the best plan for my life,” he says. 

Whether it is in research or in learning and teaching, Dr Van Niekerk, Lecturer in the UFS Department of Agricultural Economics, believes that with a positive attitude and the ability to be adaptable to change, one will be able to make the most of any opportunity crossing your path. If you give 110% every day, you will be ready for any possibility. He is lecturing Agricultural Finance and Agri-business Management, focusing on agricultural business plans, to first- and third-year students, respectively. 

Contribute to findings on predation management

At the recent April graduation ceremonies, he was awarded his PhD. The title of his thesis was: An estimation of the downstream economic implications of predation in the South African red meat industry.

In his thesis, he outlined the economic impact of predation in the livestock sector and red meat industry. He believes the significant damage caused by predators cannot be controlled by man-made borders. “There is a reason for these animals' existence; they just need to be managed properly at national level by government,” he says.

The aim of his study was to contribute to and combine any findings on the predation problem, and to put these findings on a macroeconomic platform to inform government of the extent of this problem in order for them to develop strategies, policies, and mitigation methods to reduce predation and lessen the impact thereof.

Thus far, excerpts from his thesis have also been published as two articles in peer-reviewed scientific journals – a peer-reviewed journal of the National Museum, Indago, as well as the journal, Frontiers in Sustainable Supply Chain Management.

With predation being a constant point of discussion at agricultural associations’ monthly meetings, he believes that the research topic he has selected for his PhD is relevant and that the outcomes of his study will be able to make a difference in the agriculture sector. His work is more than just theory. He identified a problem – the damage that predation does to the red meat industry – and found a practical solution to it.  

Students staying relevant in a fast-changing environment 

Besides the possible impact he will have on the red meat industry, the PhD was also a means to an end – to develop himself as an agricultural economist in order to become an industry expert in his field.

He also takes his role as lecturer very seriously. It is important to him that his students, once they have completed their studies, must have an actual understanding of the field and that they must be able to stay relevant in a fast-changing environment by practically applying what they have learnt. 

In his free time, Dr Van Niekerk enjoys applying his knowledge. Besides his consultancy work with farmers, he also serves on Free State Agriculture’s Young Farmer Committee, and he is a technical adviser to the National Lucerne Trust (NLT), assisting them with their grading processes to ensure that their quality system is free of any irregularities, and that they stay relevant in the industry. 

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.

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept