| Title: | Metabolism of L-methionine linked to the biosynthesis of volatile organic sulfur-containing compounds during the submerged fermentation of Tuber melanosporum |
| Author(s): | Liu RS; Zhou H; Li HM; Yuan ZP; Chen T; Tang YJ; |
| Address: | "Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China" |
| Journal Title: | Appl Microbiol Biotechnol |
| DOI: | 10.1007/s00253-013-5224-z |
| ISSN/ISBN: | 1432-0614 (Electronic) 0175-7598 (Linking) |
| Abstract: | "Tuber melanosporum, known as the black diamond of cuisine, is highly appreciated for its unique and characteristic aroma, which is mainly due to its volatile organic sulfur-containing compounds (VOSCs). In this work, by adding 5 g/L L-methionine to the fermentation medium, the activities of aminotransferase and alpha-ketoacid decarboxylase were significantly enhanced by 103 and 250%, respectively, while the activities of alcohol dehydrogenase and demethiolase were decreased by 277 and 39%. Then, the six VOSCs, i.e., methanethiol (MTL), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 3-(methylthio)propanal (methional), and 3-(methylthio)-1-propanol (methionol), were first detected in the submerged fermentation of T. melanosporum. These results indicated that the biosynthesis of VOSCs was triggered by aminotransferase and alpha-ketoacid decarboxylase. The production of methional and methionol increased with the increased concentrations of L-methionine (i.e., 5, 10, 15, and 20 g/L) before day 4 of the culture protocol, and methionol was the major product in the Ehrlich pathway. The production of MTL was significantly decreased after day 4 with a significantly increased DMDS, and DMDS was the major product of the demethiolation pathway. Compared with the demethiolation pathway with a total flux of sulfur of 11.33-24.32 muM, the Ehrlich pathway with a total flux of sulfur of 6,149-10,330 muM was considered the major pathway for the biosynthesis of VOSCs. This is the first report linking the metabolism of L-methionine to the biosynthesis of VOSCs by the Ehrlich and demethiolation pathways during the submerged fermentation of T. melanosporum" |
| Keywords: | Ascomycota/chemistry/*metabolism Fermentation Industrial Microbiology Methionine/*metabolism Sulfur/*metabolism Volatile Organic Compounds/chemistry/*metabolism; |
| Notes: | "MedlineLiu, Rui-Sang Zhou, Huan Li, Hong-Mei Yuan, Zhan-Peng Chen, Tao Tang, Ya-Jie eng Research Support, Non-U.S. Gov't Germany 2013/10/05 Appl Microbiol Biotechnol. 2013 Dec; 97(23):9981-92. doi: 10.1007/s00253-013-5224-z. Epub 2013 Oct 5" |
