Improving xanthan gum production

Lead Research Organisation: University of Nottingham
Department Name: Sch of Biosciences

Abstract

Xanthan gum is one of the world's most widely used hydrocolloids. A BBSRC CASE project has discovered that with certain polyelectrolytes, xanthan solutions exhibit dramatic phase separation, resulting in a liquid crystalline xanthan-rich domain and a substantial viscosity drop. This project aims to show that this discovery can improve the xanthan production process by:- (a) Increasing the limiting xanthan concentration in the fermentation process. (b) Providing an environmentally acceptable alternative to solvent to solvent recovery of product. (c) Combining this approach with the use of an oscillatory baffled bioreactor. We wish to demonstrate proof of principle, backed by a patent application before continuing discussions with a major xanthan producers. The CASE sponsor has filed a patent on other aspects of the original work, but we have been advised that we can protect inventions relating to the fermentation process. The work will combine existing expertise at the Universities of Nottingham and Strathclyde.

Publications

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Description The project has led to a much better understanding of the exploitation potential of the underlying discovery (phase separation of xanthan gum in presence of a polyelectrolyte) both in terms of (i) higher yields of xanthan gum and (ii) the lower environmental impact of the improved product recovery process. In both aspects, specific process and material recommendations can be made and applied to the current xanthan fermentation process. However, in order to be economic, it was found that the marketing of xanthan blends (mixtures of the fermented product and the added polyelectrolyte) should be explored. It is anticipated that use of these blends would not have a negative impact on major current applications of xanthan gum and there may even be advantages in terms of product performance. In addition to commercially available polyelectrolytes, a novel approach involving the use of low molecular weight xanthan gum as the added polyelectrolyte ,was also investigated. Preliminary results are encouraging and it is envisaged to explore this idea as part of an industry funded project (1 year PostDoc) with a major xanthan gum supplier.

The Oscillatory Baffled Reactor (OBR) has been demonstrated to be at least as efficient as the current xanthan fermentation process based on stirred tank reactors in terms of xanthan gum production rate, with significantly lower energy inputs. This means that an overall xanthan fermentation process based on the OBR will have a decreased power consumption which is significant since power consumption of the current process is a major limiting factor in continuing the fermentation to higher yields.
Exploitation Route Partly as a result of the Follow- on project relationships have been built:

(a) Between the Nottingham and Strathclyde groups.

(b) With Danisco who are a major manufacturer of xanthan gum.



The latter has recently sponsored work on aspects of xanthan gum science at Nottingham (value ~£135k). On the more direct commercial side, there is now an agreement in place with Danisco where the company will look at patented technology on xanthan gum developed and partly owned by the University of Nottingham (WO/2006/064173) with an option to licence this technology from the University. The length of this option agreement is three months. Over 20 staff from the UoN visited the Danisco pilot plant in Brabrand in Denmark producing this new form of xanthan gum on an industrial scale. Preliminary reports indicate that this was technically very successful. We consider the most likely path to exploitation of the ideas developed from the Follow-on project is through further development of the relationship with Danisco.
Sectors Agriculture, Food and Drink,Healthcare,Manufacturing/ including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology