This fact could be related with the metabolic burden imposed to the E. coli cell by the maintenance and replication of two plasmids Panobinostat purchase which resulted in lower cell growth and PCN values, indicating a possible increase in plasmid segregational instability, which may lead to plasmid loss . Although in some assays, it is possible to observe a positive correlation between total PCN values and resveratrol specific productivity (assays 2, 3, 13, and 25), there are others where the opposite relation is observed (assays 10 and 15). Therefore, it was not possible to establish a relation between
PCN and resveratrol productivity which can be due to the fact that this is a dual plasmid system and that resveratrol, being produced as an extracellular product, can be deteriorated by the culture conditions used as already discussed above. This study describes resveratrol production by E. coli BW27784 containing pAC-4CL1 and pUC-STS plasmids and the assessment of physiological states and plasmid segregational stability during bioreactor cultivation. Resveratrol yield was greatly influenced Dasatinib in vivo by culture conditions as a result of the possible interactions established between the culture conditions on opposite to a linear
variation for each condition tested and resveratrol yields. Cellular viability also showed to impact resveratrol production since growth conditions influenced physiological states. p-Coumaric acid played a critical role in resveratrol production, since it influenced the cellular viability due to interactions with the cell membrane, which affected the percentages of healthy cells and consequent
resveratrol volumetric yields. Monitoring resveratrol Amobarbital production is also important due to its ability to influence cellular viability caused by its inherent antimicrobial properties. The presence of two plasmids within the same cell influenced the final yield, because the metabolic burden generated might result in decreased cellular viability. Plasmid segregational stability evaluation revealed that no apparent relationship was obtained between plasmid copy number and resveratrol yields. In sum, this study indicates that these monitoring tools might be considered for a comprehensive application to resveratrol bioprocesses, in order to optimize and choose the most suitable design to create a valuable alternative to chemical synthesis. This work was partially funded by FEDER funds through Programa Operacional Factores de Competitividade–COMPETE and by National Funds through FCT – Fundação para a Ciência e Tecnologia within the scope of Project “PTDC/AGR-ALI/121876/2010”. Susana Ferreira and Filomena Silva acknowledge doctoral (SFRH/BD/66857/2009) and post-doctoral (SFRH/BPD/79250/2011) fellowships from Fundação para a Ciência e Tecnologia within the scope of QREN–POPH–Advanced Formation programs co-funded by Fundo Social Europeu and MEC.