Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
27 May 2024 | Story Leonie Bolleurs | Photo Supplied
Inaugural
At the inaugural lecture of Prof Dirk Opperman were, from the left: Prof Opperman, Prof Vasu Reddy, Prof Koos Albertyn, Head of the Department of Microbiology and Biochemistry, and Prof Paul Oberholster, Dean of the Faculty of Natural and Agricultural Sciences.

Prof Dirk Opperman, a distinguished biochemist in the Department of Microbiology and Biochemistry, recently (21 May 2024) delivered his inaugural lecture on the Bloemfontein Campus of the University of the Free State (UFS).

The title of his lecture was: Exploring, Exploiting, and Evolving Life at the Atomic Level.

Prof Vasu Reddy, Deputy Vice-Chancellor: Research and Internationalisation at the UFS, welcomed guests, stating, "An inaugural lecture is a major milestone, celebrating a life’s work that culminates in the title of professor. It marks an important chapter in an academic career, with much more to be achieved in the journey of producing important knowledge.”

He believes that an event such as this highlights the university’s pride in the achievements of its academic staff and aligns with Vision 130. “The UFS is proud to host such lectures, as they are significant moments to reveal and showcase the value of excellence in our knowledge pool in research, teaching, and innovation. As a university, we strive to make a difference through groundbreaking work, particularly in addressing society's challenges,” said Prof Reddy, emphasising that this topic truly speaks to the university’s commitment to impactful work in the hard sciences.

Deciphering the unknown

The topic of the lecture captures the essence of Prof Opperman’s research. He explains that ‘exploring’ refers to the determination of the three-dimensional structures of proteins and enzymes. ‘Exploiting’ involves the use of these enzymes to convert substrates into products of value, and ‘evolving’ pertains to mutating the DNA to change the protein, giving it different functions, activities, selectivity, or specificities.

In his lecture, he remarked that if we know the structures of these proteins and enzymes, we can explore what to do with them and how to change them. According to him, there are the unknown knowns, the unknown unknowns, and the known unknowns. “We may know of specific activities and reactions by microorganisms, but we don’t know which enzyme is responsible; similarly, we can know the reactivity of an enzyme, but not necessarily their true physiological functions. I am trying to figure out all these unknowns,” he said.

In his lecture, he also raised the question of whether AI could replace experimental determination of protein structures. "No, not yet; it is only predictions," he believes, commenting that navigating the unknown unknowns is a dangerous place in science.

Establishing the field of structural biology

Prof Opperman, born and raised in the Free State, completed his undergraduate studies at the UFS. Later, in 2008, he obtained his PhD in Biochemistry from the same university. Following his doctoral studies, he conducted postdoctoral research on directed evolution under the guidance of Prof Manfred T Reetz at the Max Planck Institute for Coal Research in Germany, one of the world’s top institutions.

In 2010, he was appointed to the Department of Microbiology and Biochemistry at the UFS, where he has since established the field of structural biology, setting up the infrastructure essential for the advancement thereof. This includes equipment, techniques, and methods for determining the three-dimensional structure of proteins. “It is done using protein crystallisation and then X-ray diffraction,” he explains. Most of these X-ray diffraction experiments are then performed at particle accelerators called synchrotrons, such as Diamond Light Source (UK), which can produce intense X-rays.

His current research explores the interface of evolutionary and structure-function relationships of biocatalysts, with a particular focus on their application in green chemistry. Prof Opperman says that understanding both the structure and the function of an enzyme allows one to manipulate it to perform other functions.

Contributing to the broader goals of sustainable development

One of the projects he is working on highlights the potential for sustainable practices in waste management. Prof Opperman is currently part of a European Research Area Network Cofund partnership on Food Systems and Climate (FOSC), which focuses on developing biocatalysts for upcycling waste. An aspect of this work involves studying enzymes that degrade feathers, thereby converting feather waste into useful products such as fertiliser.

Regarding the contribution of his research to the broader goals of sustainable development and environmental protection, he says that enzymes are the base for biotechnology and the bioeconomy. “They can be sustainably produced, the reactions are environmentally friendly, and the resulting products can be classified as natural. There’s no need to use sources that are not sustainable to extract some of these molecules from,” he explains.

His significant contributions to the field are reflected in more than 50 authored and co-authored papers, some of which are published in prestigious journals such as Science, Nature Communications, and Angewandte Chemie. As an NRF B-rated researcher, his work has received funding from various local and international organisations, including industries such as Sasol and the Global Challenges Research Fund.

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