Toxicological assessment of recombinant xylanase X-22 in wine

Toxicological evaluation of xylanase X-22 from Aspergillus nidulans express ed in a wine yeast strain was carried out. The safety of the X-22 intake wa s assessed by digestibility, bioinformatic, and mouse short-term repeated d osing studies, although X-22 Shows resistance to proteolytic degradation in the gastrointestinal system, is a minority protein component (<0.5 10(-6) %) of the produced wine, and shows no significant amino acid sequence homol ogy to any known food allergens. The 4-week oral toxicity study was perform ed in Swiss mice at a dose level of 0.01, 0.1, or 1 mg/kg/day (these dosage s correlate to 8, 80, and 800 times, respectively, the enzyme amount contai ned in 250 mL of wine). Body weight, food and fluid intake, urinalysis, and hematology data were obtained. Postmortem examinations and histopathology by both light and electron microscopy were performed. According to the resu lts of this study, no adverse effects were detected by oral administration of X-22.