Cell adaptation to solvent, substrate and product: a successful strategy to overcome product inhibition in a bioconversion system.
Carvone has previously been found to highly inhibit its own production at concentrations above 50 mM during conversion of a diastereomeric mixture of (-)-carveol by whole cells of Rhodococcus erythropolis. Adaptation of the cells to the presence of increasing concentrations of carveol and carvone in n-dodecane prior to biotransformation proved successful in overcoming carvone inhibition. By adapting R. erythropolis cells for 197 h, an 8.3-fold increase in carvone production rate compared to non-adapted cells was achieved in an air-driven column reactor. After an incubation period of 268 h, a final carvone concentration of 1.03 M could be attained, together with high productivity [0.19 mg carvone h(-1) (ml organic phase)(-1)] and high yield (0.96 g carvone g carveol(-1)).
de Carvalho
Carla C C R
CC
Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal. ccarvalho@ist.utl.pt
Poretti
Alessandro
A
da Fonseca
M Manuela R
MM
D000222:Adaptation, Physiological / Q000502:physiology*; D018407:Bacterial Physiological Phenomena; D019149:Bioreactors; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D000081005:Cyclohexane Monoterpenes; D004305:Dose-Response Relationship, Drug; D039821:Monoterpenes / Q000378:metabolism / Q000494:pharmacology*; D012240:Rhodococcus / Q000201:enzymology / Q000378:metabolism*; D012997:Solvents / Q000009:adverse effects / Q000737:chemistry; D013379:Substrate Specificity; D014867:Water / Q000737:chemistry
D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; D012997:Solvents; D014867:Water; C006923:carvone