超嗜热古菌Sulfolobus tokodaii尿嘧啶营养缺陷型筛选条件的最适化及初步筛选

超嗜热古菌Sulfolobus tokodaii隶属于古菌中的泉古菌（Crenarchaea），硫化叶菌属（Sulfolobus）。野生型S.tokodaii尿嘧啶相关基因表达的乳清核苷酸转移酶和乳清苷单磷酸脱羧酶可以将5-氟乳清酸(5-FOA)转化成有毒物质5-氟尿嘧啶核苷酸，导致野生型S.tokodaii无法正常生长。根据此原理，通过对筛选条件如5-FOA的质量浓度、紫外诱变时间等的最适化，运用微生物的自发突变或对其进行紫外照射等诱变方法，初步筛选出S.tokodaii的尿嘧啶营养缺陷型菌株。

Optimization of selective conditions for the selection of uracil auxotrophs of thermophilic archaea Sulfolobus tokodaii

Thermophilic archaea Sulfolobus tokodaii was recognized as a species of the genus Sulfolobus, which belongs to Crenarchaea of Archaea. Orotate phosphoribosyl transferase and orotidine monophosphate decarboxylase, expressed by a uracil-related gene in the wild type of Sulfolobus tokodaii, could transform 5-fluoroorotic acid (5-FOA) to the toxic substance 5-fluorouridine monophosphate. Therefore, the wild-type strain could not grow normally. The selective condition was optimized based on this theory, such as the effective concentration of 5-FOA and the time of UV irradiation, and several uracil auxotrophs mutants of S.tokodaii were primarily obtained by spontaneous change or UV mutagenesis.