瓦伦西亚橘烯生物转化生成圆柚酮

利用固相微萃取-气相色谱-质谱联用技术分析检测黑曲霉（Aspergillus niger）、毛霉（Mucor sp.）和解脂耶氏酵母（Yarrowia lipolytica）转化瓦伦西亚橘烯的产物，并比较3 株菌株转化瓦伦西亚橘烯生成圆柚酮的效果。结果表明，3 株菌种黑曲霉（A. niger）、毛霉（Mucor sp.）、解脂耶氏酵母（Y. lipolytica）均能对瓦伦西亚橘烯进行转化并生成圆柚酮，同时生成α-松油醇、香芹酮等物质。其中，解脂耶氏酵母转化瓦伦西亚橘烯生成圆柚酮转化量最高，达（252.52±15.79）mg/L，转化率也最高，达（27.45±1.72）%。其次为黑曲霉和毛霉，转化量分别为（140.94±30.26）mg/L和（137.67±14.02）mg/L，转化率分别为（15.32±3.29）%和（15.45±3.36）%。此外，通过正交试验对解脂耶氏酵母的发酵培养基进行条件优化，得到培养基最佳优化组合为α-乳糖40 g/L、蛋白胨15 g/L、FeSO4·7H2O 0.6 g/L。解脂耶氏酵母具有较好的生物转化瓦伦西亚橘烯生成圆柚酮的效果，优化后的该菌培养基转化生成圆柚酮质量浓度可达（457.32±76.11）mg/L，转化率为49%，较未优化的培养基相比，转化率提高21.55%。

Biotransformation of Valeneene into Nootkatone

The purpose of this study was to investigate the effect of Aspergillus nigerus, Mucor sp. and Yarrowia lipolytica on the conversion of valeneene to nootkatone using solid phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that all these three strains were capable of transforming valencene to nootkatone. Other products, such as α-terpinol and D-carvone, were also found during the biotransformation. The highest amount of nootkatone was found to be produced by Yarrowia lipolytica with a yield of (252.52 ± 15.79) mg/L and conversion rate of (27.45 ± 1.72)% followed by A. niger and Mucor sp. The amounts generated by the latter two strains were (140.94 ± 30.26) and (137.67 ± 14.02) mg/L, and the conversion rates were (15.32 ± 3.29)% and (15.45 ± 3.36)%, respectively. Using an orthogonal array design the optimal fermentation medium for Y. lipolytica was determined to consist of lactose 40 g/L, peptone 15 g/L, and FeSO4·7H2O 0.6 g/L. Using the optimized culture medium, the yield of nootkatone was up to (457.32 ± 76.11) mg/L, and the conversion rate was 49%, which increased by 21.55% compared to that before optimization.