Practical approach to trehalulose production using a reactor of immobilized cells

For efficient industrial production of trehalulose, we conducted an industrialization test using immobilized cells of the high-trehalulose producing bacteria, Pseudomonas mesoacidophila MX-45. Immobilized cells were prepared as follows ; cells were concentrated from culture, granulated with calcium alginate, and cross-linked with polyethylenimine and glutaraldehyde. First, we evaluated the useful life of the enzyme. Substrate sucrose solution was continuously fed into a column packed with immobilized cells at 25 deg C, and the enzyme activity remained stable for 300 days. The enzyme life was longer than that of immobilized cells in industrial palatinose production. Next, we conducted large-scale cultivation of MX-45 in a 2000l culture tank, and obtained culture fluid showing higher enzyme activity than that of the laboratory scale culture. Immobilized cells prepared from the large-scale culture were packed an industrial reactor, and a 40% (w/w) sucrose solution was supplied to the reactor at a flow rate of 3.9 t of sucrose per day. In this reaction, approximately 83% of the substrate was converted into trehalulose. These findings suggest that the immobilized cells of MX-45 can be used for efficient industrial production of trehalulose.