Lower Citrinin Production by Gene Disruption of ctnB Involved in Citrinin Biosynthesis in Monascus aurantiacus Li AS3.4384
Lower Citrinin Production by Gene Disruption of ctnB Involved in Citrinin Biosynthesis in Monascus aurantiacus Li AS3.4384
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通过破坏参与橙红红曲 Li AS3.4384 橘霉素生物合成的 ctnB 基因来降低橘霉素产量
DOI：
10.1021/jf400879s
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发表时间：
2013-07-31
影响因子：
6.1
通讯作者：
He, Qing-Hua
中科院分区：
文献类型：
--
作者：
Li, Yan-Ping;Pan, Yi-Feng;He, Qing-Hua
丝状真菌Monoclusspp.在亚洲，1000多年来一直用于食品着色剂和保健品的生产。然而，人们更加关注Monastery产品的安全性，因为它们含有对肝脏和肾脏系统有害的桔霉素。桔霉素生物合成基因簇已在Monasucs aurantiacus中得到表征。编码氧化还原酶的ctnB基因位于pksCT和ctnA之间。本研究以潮霉素抗性基因作为选择标记，构建了ctnB置换载体（pCTNB-HPH），以破坏ctnB基因。将线性载体转化为M.原生质体CaCl2/PEG法对柑橘属植物的原生质体进行了初步研究。通过同源重组获得了3株ctnB基因缺失菌株。与亲本菌株相比，Delta ctnB突变体几乎不产生桔霉素。这些数据证实ctnB基因直接参与桔霉素生物合成。此外，两个干扰菌株的色素产量与野生型菌株相似，但另一个突变体的产量略高于后者。这些结果表明，通过基因工程成功地消除了霉菌毒素桔霉素的产生。
The filamentous fungi Monascus spp. have been used in the production of food colorants and health remedies for more than 1000 years in Asia. However, greater attention has been given to the safety of Monascus products because they contain citrinin, which is harmful to the hepatic and renal systems. The citrinin biosynthetic gene cluster has been characterized in Monasucs aurantiacus. The ctnB gene encoding an oxidoreductase is located between pksCT and ctnA. In this study, a ctnB replacement vector (pCTNB-HPH) was constructed to disrupt the ctnB gene with a hygromycin resistance gene as the selection marker. The linear vector was transformed into M. aurantiacus using the protoplast CaCl2/polyethylene glycol (PEG) method. Three ctnB-disrupted strains were obtained by homologous recombination. In comparison to the parental strain, the Delta ctnB mutants barely produced citrinin. These data confirmed that the ctnB gene is directly involved in citrinin biosynthesis. Moreover, the yields of the pigments of two disruptants were similar to that of the wild-type strain, but the yield of another mutant was slightly higher than that of the latter strain. These results indicate that the production of the mycotoxin citrinin was successfully eliminated through genetic engineering.