CAJ | 학술논문

该研究通过硫胺素（ VB1）营养缺陷型负选择法，从中国淄博食用油污染的土壤中获得一株酵母属菌株 R6。该菌株具有累积胞外α-酮戊二酸(α-KG)的能力。生理学和生物化学实验表明该 R6菌株与已测试的 API 20 C AUX酵母鉴别系统中的胶红酵母具有共同特征。此外，R6菌株的18S rDNA 基因已经获得并测序，基于该序列以及同源菌属所得到的系统进化学分析表明菌株 R6与胶红酵母属成员具有99%的同源性。因此，菌株 R6被鉴别为胶红酵母属的一员。随后，本实验通过控制单一发酵变量以及高效液相色谱法(HPLC)检测优化了R6累积α-KG的发酵条件。当发酵培养基中添加的 VB1和 CaCO3的浓度分别为0.03 mg/L和60 g/L时，α-KG达到6.035 g/L的最高产量。天然营养缺陷型的 R6菌株的发现不仅丰富了通过发酵生产α-KG的微生物来源，而且为进一步的发酵调控奠定了基础，从而实现过量的α-KG的累积。
해연구통과류알소（ VB1）영양결함형부선택법，종중국치박식용유오염적토양중획득일주효모속균주 R6。해균주구유루적포외α-동무이산(α-KG)적능력。생이학화생물화학실험표명해 R6균주여이측시적 API 20 C AUX효모감별계통중적효홍효모구유공동특정。차외，R6균주적18S rDNA 기인이경획득병측서，기우해서렬이급동원균속소득도적계통진화학분석표명균주 R6여효홍효모속성원구유99%적동원성。인차，균주 R6피감별위효홍효모속적일원。수후，본실험통과공제단일발효변량이급고효액상색보법(HPLC)검측우화료R6루적α-KG적발효조건。당발효배양기중첨가적 VB1화 CaCO3적농도분별위0.03 mg/L화60 g/L시，α-KG체도6.035 g/L적최고산량。천연영양결함형적 R6균주적발현불부봉부료통과발효생산α-KG적미생물래원，이차위진일보적발효조공전정료기출，종이실현과량적α-KG적루적。
A yeast strain R6 was obtained by the method of thiamine(VB1) auxotroph-ic negative selection from the edible oil-pol uted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared common feature with Rhodotorula mucilaginosa according to the API 20 C AUX yeast identification sys-tem which has been tested previously. Furthermore, the 18S rDNA gene of strain R6 was amplified and sequenced. Phylogenetic analysis based on the 18S rDNA sequence and the relatives indicated that R6 shared 99% homologies with the members of R. mucilaginosa, suggesting that strain R6 belonged to R. mucilaginosa. Investigation showed that strain R6 possessed the capacity of accumulating exocel-lular alpha-ketoglutaric acid (alpha-KG). Final y, the fermentation conditions of R6 to accumulate alpha-KG was optimized by control ing each single fermenting variable and detected through high performance liquid chromatography (HPLC). Results showed that both VB1 and CaCO3 in fermentation medium were the key factors in-fluencing the cumulant of alpha-KG. The discovery of natural auxotrophic strain R6 not only broadened the microbial resource which can achieve lots of alpha-KG pro-duction through fermentation, but also laid a foundation for further fermentation regu-lation to achieve excessive alpha-KG accumulation.