AIST Stories No2

Impact in the following fields! Community lifeIndustry◦Food◦‌‌Safety and security◦‌‌Medical treatment, welfare, caregiving◦‌‌Environment, resources, energy◦‌‌Medical treatment, chemistry, biotechnology◦Food products◦‌‌Agriculture and fisheries29Another success at AIST!The route to isomerized sugar using glucose isomerase technologyResearch Institute); at the time they started developing an appropriate method, they had been engaged in enzyme research. The method that they adopted used the microbial enzyme glucose isomerase.Discovery of an enzyme to convert glucose into fructose!Glucose and fructose both possess the molecular formula C6H12O6. Although they are formed from the same atoms, their molecular structures are different and their properties also differ. Substances like this with the same molecular formula but with different molecular structures are known as isomers. Glucose is an isomer of fructose and vice-versa. Moreover, glucose isomerase is an enzyme that can isomerize glucose into fructose.A chemical reaction proceeds when glucose isomerase is added to a glucose solution held at 65–70°C and a pH of 6.8–7.2 and 50% of the glucose is converted to fructose. The resulting mixed solution of glucose and fructose is known as isomerized sugar. This sweet solution is used as a natural sweetener. In other words, glucose isomerase is all that is needed in order to directly convert glucose into fructose with high efficiency. Well then, how can large quantities of glucose isomerase be produced?Dr. Takasaki and his colleagues ascertained that bacteria known as actinomycetes held the key. Actinomycetes are a type of bacteria often used to make antibiotics. They are also known as ray bacteria on account of the manner in which they propagate, like thread stretching. It was found that one of the actinomycete groups that was discovered in soil could actively produce glucose isomerase from a substance contained in plants called xylan. Xylan is present in large quantities in the byproducts of cereal production, such as in corn cobs and husks, rice and wheat straw, chaff, and wheat bran. Using this method, raw materials that would normally be discarded and bacteria can be used to produce glucose isomerase cheaply. Furthermore, this glucose isomerase can be used to produce isomerized glucose syrup containing a large quantity of fructose. The glucose isomerase technology developed by AIST gives rise to a valuable sweetness from low-cost ingredients; this is very economical technology for manufacturing natural sweetener.Taking on the global sweetener market with patent acquisition as a springboardLow costSweetSweetGlucose100%Very sweetFructose 90%High fructose Glucose 80%GlucoseActinomycetes (ray bacteria)From the earthLow costLow costSweet potato(starch)XylanEnzymeGlucoseisomerase Soft drinks, foods, etc.ShippingDerivationProductionSeparationReturnVery sweetFructose 50%Fructose glucose (isomerized sugar) ◀Glucose isomerase crystalsThe enzyme laboratory at the time