2019年2月28日，据欧盟食品安全局（EFSA）消息，应欧盟委员会要求，欧盟动物饲料添加剂和产品（FEEDAP）研究小组被要求就大肠杆菌CGMCC 7.248（Escherichia coli CGMCC 7.248）发酵产生的L-苏氨酸（L‐threonine）作为饲料和饮用水营养添加剂用于所有动物物种的安全性和有效性发布科学意见。
经过评估，FEEDAP研究小组认为，大肠杆菌CGMCC 7.248产生的L -苏氨酸作为添加剂对非反刍动物目标物种和消费者是安全的。
部分原文报道如下：
Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed （FEEDAP） was asked to deliver a scientific opinion on l‐tryptophan produced by fermentation with a genetically modified strain of Escherichia coli CGMCC 7.248 when used as a nutritional additive in feed and water for drinking for all animal species and categories. The production strain E. coli CGMCC 7.248 and its recombinant DNA were not detected in the final product. The product l‐tryptophan, manufactured by fermentation with E. coli CGMCC 7.248, does not give rise to any safety concern with regard to the genetic modification of the production strain. l‐Tryptophan produced by E. coli CGMCC 7.248 is safe for non‐ruminant target species. The use of unprotected l‐tryptophan in ruminant feed should be avoided. l‐Tryptophan produced by fermentation by E. coli CGMCC 7.248 is safe for the consumer. The level of endotoxins present in the product and its dusting potential indicate an inhalation risk for the user. l‐Tryptophan produced by E. coli CGMCC 7.248 is not a skin or eye irritant but it is a dermal sensitiser. The use of l‐tryptophan produced by E. coli CGMCC 7.248 in animal nutrition does not pose a risk to the environment. The product under assessment is regarded as an effective source of the amino acid l‐tryptophan for all non‐ruminant species. For the supplemental l‐tryptophan to be as efficacious in ruminants as in non‐ruminant species, it requires protection against degradation in the rumen.
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