An overview of the safety evaluation of the Thermomyces lanuginosus xylanase enzyme (SP 628) and the Aspergillus aculeatus xylanase enzyme (SP 578).

Xylanases SP 628 and SP 578 were produced by submerged fermentation of Aspergillus oryzae, containing a gene code originating from Thermomyces lanuginosus and Aspergillus aculeatus, respectively. Both enzymes were subject to the same series of toxicological tests to document their safety in use. The enzymes are to be applied as processing aids in the baking industry and in wheat starch separation. Neither enzyme was found to be mutagenic in the Salmonella typhimurium reverse mutation assay, nor did they cause chromosomal aberrations in cultured human peripheral lymphocytes. No evidence of inhalation toxicity or skin and eye irritation was found. The enzymes are not regarded as skin-sensitizers, although the Buehler test with guinea-pigs revealed a minor potential. Oral administration up to 10.0 ml/kg bw/day (equivalent to a Total Organic Solids amount of 13.3% for SP 628 and of 11.3% for SP 578) in 13-week rat studies did not show any adverse effect.