Robust Bioprocess Design and Engineering for Novel Biosurfactant Production

Biosurfactants are naturally occurring amphiphiles with a range of unique properties including biodegradability and tolerance of a wide range of temperature and pH. These properties have led to increasing commercialisation by a number of companies in recent years, in a range of cleaning and personal care products, along with an increasing demand for new biosurfactant structures. A wide variety of biosurfactant producing microorganisms can be found throughout nature, providing a wealth of diversity to be explored for novel biosurfactant molecules.

In order to exploit the available biosurfactant diversity there is a need for a combined genetic and bioprocess engineering approach, especially if novel molecules are to be exploited industrially. In particular efficient, scalable and high productivity fermentation processes must be developed1. Using a metagenomics approach the olsB gene involved in the synthesis of a novel lyso-ornithine lipid biosurfactant was identified from a metagenomic library prepared from sediment collected at the Buffelspruit Dam, Bela Bela, Limpopo Province, South Africa. The novel olsB gene has been expressed in E. coli and the lyso-ornithine lipid biosurfactant characterised, with their potential suitability for use in industrial applications having been explored2.

To realise the potential of this novel lyso-ornithine lipid biosurfactant the next step is to scale up production in order to assess the full spectrum of performance parameters and identify the most relevant products/processes and industries for further development of the biosurfactant as a high-value bioactive. This requires a biochemical engineering approach to develop a scalable and robust fermentation process for lyso-ornithine lipid production and the investigation of the use of inexpensive substrates, such as crude or waste materials, to reduce production cost.

During this PhD project a robust and scalable bioreactor process for biosurfactant production will be engineered, to give a high productivity, high titre novel lyso-ornithine lipid producing bioprocess. The project builds on previous work carried out by the Institute for Microbial Biotechnology and Metagenomics (IMBM), University of the Western Cape, South Africa.