2019年1月21日,欧盟食品安全局发布关于来自转基因枯草芽孢杆菌(XAS菌株)的食品酶1,4-β-内切木聚糖酶(endo‐1,4‐β‐xylanase)安全性的评估结果。
据了解这种食物酶拟用于烘焙过程。根据烘焙过程中推荐的最大使用量和欧盟食品安全局综合欧洲食品消费数据库中的个人消费数据,估计欧洲人口每天膳食暴露于食物酶-总有机固体( TOS )的量为0.014mg TOS / kg体重。最终专家组得出结论,在预期的使用条件下,不能排除因饮食接触而引起过敏和诱发反应的风险,但发生的可能性很低。由于食物酶中不存在活细胞尚未得到充分证实,因此专家组无法得出这种转基因菌株可能带来的相关风险。
部分原文报道如下:
The food enzyme is an endo‐1,4‐β‐xylanase (4‐β‐d‐xylan xylanohydrolase; EC 3.2.1.8) produced with the genetically modified Bacillus subtilis strain XAS. Antibiotic resistance genes are present in the production organism on a self‐replicative vector. The endo‐1,4‐β‐xylanase is intended to be used in baking processes. based on the maximum use levels, dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.014 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no‐observed‐adverse‐effect level (NOAEL) of 55 mg TOS/kg bw per day that, compared with the estimated dietary exposure, results in a sufficiently high margin of exposure (MOE) (of at least 3,600)。 Similarity of the amino acid sequence to those of known allergens was searched and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood to occur is considered to be low. Since the absence of viable cells in the food enzyme has not been adequately demonstrated, the Panel cannot conclude on the risks associated with the possible spread of a genetically modified bacterial strain carrying antimicrobial resistance determinants.