title: Safety evaluation of an alpha-cyclodextrin glycosyltranferase preparation.
abstract: Alpha-cyclodextrin glucosyltransferase (alpha-CGTase, EC 2.4.1.19) is an amylolytic enzyme used for the production of alpha-cyclodextrin (alpha-CD), a novel, soluble dietary fiber, from food-grade starch. The safety of an alpha-CGTase preparation obtained by batch fermentation from a recombinant strain of Escherichia coli K12 harboring the alpha-CGTase gene from Klebsiella oxytoca strain M5a1 was examined. In a 13-week subchronic toxicity study in rats, the administration by gavage of the alpha-CGTase preparation at levels of up to 20 ml/kg bw/day, corresponding to a total organic solids dosage of 260 mg/kg bw/day, did not cause any systemic toxic effect. Some signs of irritation were observed in the respiratory tract which occurred, however, in one sex only and/or were not dose-related. Accordingly, these changes were considered to be an unspecific consequence of the reflux and aspiration of the dosing solution. There was no evidence of a genotoxic activity in Ames tests and a chromosome aberration test in cultured human lymphocytes. It is concluded that the examined alpha-CGTase preparation is safe when used for the production of alpha-CD.
authors.affiliation: Bioresco AG, Bundesstrasse 29, 4054 Basel, Switzerland. contact@bioresco.ch
authors.forename: A
authors.initials: A
authors.lastname: Bär
authors.forename: C A M
authors.initials: CA
authors.lastname: Krul
authors.forename: D
authors.initials: D
authors.lastname: Jonker
authors.forename: N
authors.initials: N
authors.lastname: de Vogel
mesh_terms: D000818:Animals; D002869:Chromosome Aberrations / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology; D005260:Female; D005503:Food Additives / Q000302:isolation & purification / Q000633:toxicity*; D005964:Glucosyltransferases / Q000302:isolation & purification / Q000633:toxicity*; D006801:Humans; D007709:Klebsiella / Q000201:enzymology / Q000235:genetics; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D009152:Mutagenicity Tests; D051381:Rats; D017208:Rats, Wistar; D018675:Toxicity Tests; D036401:Toxicity Tests, Chronic
chemical_list: D005503:Food Additives; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase