| Autor: |
Cajka T; UC Davis Genome Center-Metabolomics, University of California, Davis , 451 Health Sciences Drive, Davis, California 95616, United States., Garay LA; Phaff Yeast Culture Collection, Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States., Sitepu IR; Phaff Yeast Culture Collection, Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.; Bioentrepreneurship Department, Indonesia International Institute for Life Sciences , Jalan Pulo Mas Barat Kav. 88, East Jakarta, DKI Jakarta 13210, Indonesia., Boundy-Mills KL; Phaff Yeast Culture Collection, Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States., Fiehn O; UC Davis Genome Center-Metabolomics, University of California, Davis , 451 Health Sciences Drive, Davis, California 95616, United States.; Biochemistry Department, Faculty of Science, King Abdulaziz University , P.O. Box 80203, Jeddah 21589, Saudi Arabia. |
| Abstrakt: |
A multiplatform mass spectrometry-based approach was used for elucidating extracellular lipids with biosurfactant properties produced by the oleaginous yeast Rhodotorula babjevae UCDFST 04-877. This strain secreted 8.6 ± 0.1 g/L extracellular lipids when grown in a benchtop bioreactor fed with 100 g/L glucose in medium without addition of hydrophobic substrate, such as oleic acid. Untargeted reversed-phase liquid chromatography-quadrupole/time-of-flight mass spectrometry (QTOFMS) detected native glycolipid molecules with masses of 574-716 Da. After hydrolysis into the fatty acid and sugar components and hydrophilic interaction chromatography-QTOFMS analysis, the extracellular lipids were found to consist of hydroxy fatty acids and sugar alcohols. Derivatization and chiral separation gas chromatography-mass spectrometry (GC-MS) identified these components as d-arabitol, d-mannitol, (R)-3-hydroxymyristate, (R)-3-hydroxypalmitate, and (R)-3-hydroxystearate. In order to assemble these substructures back into intact glycolipids that were detected in the initial screen, potential structures were in-silico acetylated to match the observed molar masses and subsequently characterized by matching predicted and observed MS/MS fragmentation using the Mass Frontier software program. Eleven species of acetylated sugar alcohol esters of hydroxy fatty acids were characterized for this yeast strain. |
