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11 July 2022 | Story Andre Damons | Photo Supplied
Prof Martie Smith and Prof Drik Opperman
Prof Martie Smit and Prof Dirk Opperman in the Department of Microbiology and Biochemistry filed a patent entitled “Process for the chemical modification of alkanes, fatty acids and fatty alcohols”.

Flavours and fragrances have a wide application in the food, feed, cosmetic, chemical and pharmaceutical sectors. Many flavour compounds are still produced via chemical synthesis or via extraction from plant or animal sources. However, there is increasing interest in their bio-production or the use of flavour compounds of (micro) biological origin. 

One reason for this shift is that chemical synthesis often uses environmentally unfriendly processes. Chemical synthesis usually also produces racemic mixtures with the second enantiomer, mirror image of the looked-for compound, often having undesirable organoleptic properties. Furthermore, the consumer has developed a “chemophobia”-attitude towards synthetic chemical compounds, especially when related to food and home-care products.  This applies even to nature-identical compounds – products that occur in nature but are produced via a non-natural chemical process. Products produced with the use of enzymes or microbes from “natural” substrates can be labelled “natural”. The flavour and fragrance industry thus pay higher prices for such products labelled as “natural”.  

The invention

A University of the Free State (UFS) team, led by Prof Martie Smit and Prof Dirk Opperman in the Department of Microbiology and Biochemistry are conducting exciting research in this area. They filed a patent entitled “Process for the chemical modification of alkanes, fatty acids and fatty alcohols”.  

The invention relates to a process for the enzymatic in-chain hydroxylation of C12 to C16 fatty acids, alcohols, and alkanes. Hydroxylation of C12 fatty acid and alcohol provides routes for the synthesis of “natural” δ-dodecalactone. The advantage of these routes is that they do not rely on massoia lactones. Massoia lactones are derived from the bark of Massoia trees which grow in Indonesia. Harvesting of the bark kills the trees.  

The cytochrome P450 enzymes (P450s) claimed in this patent are to the inventors’ knowledge the most regioselective enzymes described thus far that can be used for the synthesis of δ-dodecalactone from lauric acid or 1-dodecanol. The approach that the technology takes is to claim cytochrome P450 enzymes that share 70 % amino acid identity to a set of selected P450s for the regioselective hydroxylation of lauric acid and 1-dodecanol to synthesise δ-dodecalactone.

Still in early stage

The current state of development is early stage with the technology only demonstrated in the laboratory on a small scale (100-200 ml). Before the technology can be commercialised the team would need to further improve the regioselectivity and stability of the P450s and proof that the reactions can be scaled up in bioreactors. The technology will probably be delivered as an enzyme (amino acid sequence) with the desired properties. 

There are other research groups working on a synthetic biology approach for the de novo synthesis of δ-dodecalactone from glucose by genetically engineered microbes. It is still unclear how such a process will compare in terms of product yields, economics and environmental impact with the processes proposed by the UFS patent.

If the team had to partner with a commercial company, their first choice would be to work with an established flavour and fragrance company. Another possibility would be the small French flavour and fragrance company that Dr Alizé Pennec, the post-doc and co-inventor who initially discovered the unique P450 activity, is working for.

Please view the videos for more information on patents.

The Vice-Rector: Research and Internationalisation has released two new calls for applications for funding. Academic staff and researchers are encouraged to submit applications for these funds. At this stage we are not accepting projects from Research Fellows. 

The two funds are: 

1.  The Industrial Engagement Fund 
2.  The Intellectual Property Commercialisation Fund

Each fund has its own guidelines and application process. The guidelines are attached. The applications must be filled in on RIMS.

The RIMS application forms can be found through this link

For more information please click the documents below:



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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