Your Guide to Glucose Oxidase

Glucose Oxidase is a truly crucial enzyme with hundreds of applications in dozens of industries. In this article we'll be taking a look at what Glucose Oxidase is, what it does and exactly why this little enzyme is so important to so many people.

• What Is It?
  Also known as "GOx", Glucose Oxidase is a naturally occurring oxido-reductase enzyme which causes the oxidation of glucose, turning it into hydrogen peroxide. Structurally, this is a dimeric protein and, as is the case with the majority of proteins which work on cells externally, it is coated with carbohydrate chains.


• What Does It Do?
  In cells, the chief function of GOx is to break down sugars into their metabolites. The enzyme occurs naturally in honey where it performs a function as a natural preservative. This is because GOx creates an "antimicrobial barrier" on the honey's surface. This antimicrobial barrier is created when GOx on the surface of the honey reduces atmospheric Oxygen to Hydrogen Peroxide (H2O2). The antibacterial properties of honey are well documented, as can be seen in the use of the substance as a key ingredient in natural skincare. Its effectiveness is all down to Glucose Oxidase! But this is not all that it does. Most importantly GOx produces a colour reaction to H2O2 when it is used with a peroxidase reaction. This allows the medical and scientific establishment to identify and measure the quantities of free glucose (sera) in blood plasma. Similar tests allow food manufacturers to monitor and control the levels of glucose present in raw vegetable material, food products, fermentation processes and much more.


• How Is Glucose Oxidase Made?
  GOx only occurs naturally in small quantities. Although due to its usefulness in such a diverse range of industries, it is now manufactured on a large scale. The process for production is relatively simple: When a fungus known as Aspergillus Niger is fermented it produces Glucose Oxidase. Initially the liquid from the fermented fungus is not suitable for use as such an enzyme but, after purification it is ready for use. The liquid is purified using several processes: multiple precipitation; fractionation; chromatography; and filtration. For every 200 litres of liquid produced by the fermentation process, a few kilograms of freeze-dried Glucose Oxidase is produced.


• Uses in the Food Industry
  We've already mentioned the glucose-monitoring function of GOx in the food industry, but it has a number of other functions too. In bakery Glucose Oxidase can be used to replace oxidants like bromate - this makes bread dough stronger. It is also helpful in the packaging and preservation of food items. It prevents egg-whites from browning and assists with the removal of air from packaging.