Immobilization of Streptomyces flavochromogenes pullulanase on tannic acid and TEAE--cellulose

Pullulanase was immobilized successfully by simple, inexpensive methods that may be useful for industrial application of this enzyme. A tannin--pullulanase(TP) complex was obtained by addition of tannic acid to the culture filtrate of thermophilic Streptomyces flavochromogenes. TP could be bound to TEAE--cellulose (TTCP). Immobilization in this manner took place with quantitative retention of activity. The immobilized enzymes were stable for more than six months. The optimum temperatures of the native enzyme and TP were both 50 degrees C; that of TTCP was 45 degrees C. In the presence of 5mM Ca2+, the activity of TTCP was increased approximately twofold and the optimum temperature was raised to 50--60 degrees C. Pullulanase was not significantly eluted from TP or TTCP by NaCl solution (0.1--0.5M).