beta-Maltose → Trehalose

Participants

Reaction Conditions

Reaction Steps

A seed culture of Thermus aquaticus (ATCC 33923) was inoculated in a nutrient culture medium, and cultured similarly as the method in Experiment 15, followed by centrifuging the resultant culture to obtain 50 g wet cells having about 1,500 units of a maltose-trehalose converting enzyme activity. The cells were suspended in 100 ml of 2.5% sodium alginate having a viscosity of 300-400 cp, a reagent commercialized by Wako Pure Chemical Industries, Ltd., Tokyo, Japan. The resultant slurry was continuously dropped into 0.1M CaCl2 solution, which was stirring by a magnetic stirrer, from the height of about 20 cm above the surface of the solution to form spherical gels having a diameter of about 2 mm. The gels were allowed to stand in the solution at ambient temperature for about 2 hours, then filtered with a Buchner funnel to obtain cells immobilized with alginate. The immobilized cells were packed in a jacketed-glass column, a diameter of 30 mm and a length of 200 mm, and heated to 60° C. The column was fed with a downstream of 40% maltose solution (pH 6.5) at SV 0.2 to obtain an about 66% trehalose solution which was then in usual manner purified, concentrated and spray dried to obtain a powder trehalose in a yield of about 90%, d.s.b. The powder has a relatively-low reducing power and a mild sweetness, and, similarly as the product in Example A-12, this renders it arbitrarily useful in a variety of compositions such as food products, cosmetics and pharmaceuticals.

Provenance & Evidence