Extractive Bioconversion Using Solid Adsorbent in Plant Cell Suspension cultures

초록

For the enhanced production of a cardiac glycoside, digoxin, using in situ adsorption by bioconversion from digitoxin in plant cell suspension cultures, selection of proper resins was attempted and the culture conditions were optimized. Among various kinds of resins tested, Amberlite XAD-8 was found to be the best for digoxin production in considering adsorption characteristics as well as the effect on cell growth. Adequate time for resin addition was determined to be the 36th hour from the beginning of the bioconversion and the presence of resins should be as short as possible to increase the productivity. In addition, to prevent the cells from direct contact with resin particles, immobilized systems were designed and examined. Immobilization improved the advantages of in situ adsorption further. It was confirmed that the increase of contact area for mass transfer was an important factor in utilizing immobilized system to enhance digoxin productivity.