Process of making cyclodextrin glucanotransferase with brevibacterium

A process for producing .gamma.-cyclodextrin glucanotransferase which comprises:

• (1) culturing Brevibacterium sp. FERM BP-4537 or a mutant thereof, in an aqueous nutrient culture medium containing assimilable sources of carbon, nitrogen and inorganic salts under conditions such that said Brevibacterium sp. FERM BP-4537 or said mutant thereof produces and secretes .gamma.-cyclodextrin glucano-transferase into said culture medium, and
• (2) collecting the resulting culture medium of step (1) containing said cyclodextrin glucanotransferase, and
• (3) purifying said .gamma.-cyclodextrin glucano-transferase from the collected culture medium of step (2), wherein when purified, the collected .gamma.-cyclodextrin glucanotransferase has the following properties:
• (a) action and substrate specificity:
• acts upon a substrate selected from the group consisting of starch, dextrin and maltooligosaccharides to produce .gamma.-cyclodextrin as a primary product and .beta.-cyclodextrin as a secondary product;
• (b) optimum reaction pH:
• about 8 to about 9;
• (c) optimum reaction temperature:
• around 45.degree. C.;
• (d) pH stability:
• about 6 to about 8;
• and
• (e) temperature stability:
• about 85% activity remains after 30 minutes at 40.degree. C. in the absence of a calcium salt, and about 100% activity remains after 30 minutes at 45.degree. C. in the presence of 20 mM of a calcium salt.