title: High-titer production and strong antimicrobial activity of sophorolipids from Rhodotorula bogoriensis.
abstract: Rhodotorula bogoriensis produces sophorolipids (SLs) that contain 13-hydroxydocosanoic acid (OH-C22 ) as the lipid moiety. A systematic study was conducted to further understand the fermentative production of SLs containing OH-C22 (C22 -SL) by R. bogoriensis. Shake-flask studies showed that R. bogoriensis consumed glucose at a slow pace. HPLC analysis of the C22 -SL products from shake-flask fermentations at different glucose concentrations showed a correlation between glucose depletion and the extent of C22 -SL deacetylation. A large-scale bioreactor fermentation resulted in the isolation of C22 -SL at a volumetric product yield of 51 g/L. HPLC analysis of C22 -SL product from the bioreactor fermentation corroborated the finding that glucose depletion correlated with extensive deacetylation of C22 -SL. The antimicrobial activity of C22 -SL was established for the first time to be stronger than the C18 -SL from Candida bombicola against Propionibacterium acnes in a plate assay.
authors.affiliation: Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture, Wyndmoor, PA, 19038.
authors.forename: Daniel K Y
authors.initials: DK
authors.lastname: Solaiman
authors.affiliation: Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture, Wyndmoor, PA, 19038.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Ashby
authors.affiliation: Biobased and Other Animal Co-Products Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Dept. of Agriculture, Wyndmoor, PA, 19038.
authors.forename: Nicole V
authors.initials: NV
authors.lastname: Crocker
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D011425:Propionibacterium acnes / Q000187:drug effects; D012248:Rhodotorula / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D005227:Fatty Acids; C035513:13-hydroxydocosanoic acid; D005947:Glucose
keywords: Propionibacterium acnes; antimicrobial activity; biosurfactant; poly(hydroxyalkanoate); very-long-chain sophorolipid