Metabolic modelling and flux analysis of microorganisms from the Atacama Desert used in biotechnological processes

Razmilic, Valeria; Castro, Jean Franco; Marchant, Francisca; Asenjo, Juan A.; Andrews, Bárbara A.

doi:10.1007/s10482-018-1031-y

Cited by 5 publications

(1 citation statement)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The flux distribution for various intracellular biochemical reactions can also be calculated from multivariate equations after extracellular substances have been measured. This results in a metabolic flux map containing almost all relevant reactions and metabolites at steady-state ( Razmilic et al, 2018 ). Metabolic flow distribution can be analyzed under different conditions and in different mutant strains ( Soh et al, 2012 ).…”

Section: Methodsmentioning

confidence: 99%

Productivity enhancement in L-lysine fermentation using oxygen-enhanced bioreactor and oxygen vector

Wang

Zhao

et al. 2023

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

Introduction: L-lysine is a bulk product. In industrial production using high-biomass fermentation, the high density of bacteria and the intensity of production require sufficient cellular respiratory metabolism for support. Conventional bioreactors often have difficulty meeting the oxygen supply conditions for this fermentation process, which is not conducive to improving the sugar-amino acid conversion rate. In this study, we designed and developed an oxygen-enhanced bioreactor to address this problem.Methods: This bioreactor optimizes the aeration mix using an internal liquid flow guide and multiple propellers.Results: Compared with a conventional bioreactor, it improved the kLa from 367.57 to 875.64 h-1, an increase of 238.22%. The results show that the oxygen supply capacity of the oxygen-enhanced bioreactor is better than that of the conventional bioreactor. Its oxygenating effect increased the dissolved oxygen in the middle and late stages of fermentation by an average of 20%. The increased viability of Corynebacterium glutamicum LS260 in the mid to late stages of growth resulted in a yield of 185.3 g/L of L-lysine, 74.57% conversion of lysine from glucose, and productivity of 2.57 g/L/h, an increase of 11.0%, 6.01%, and 8.2%, respectively, over a conventional bioreactor. Oxygen vectors can further improve the production performance of lysine strains by increasing the oxygen uptake capacity of microorganisms. We compared the effects of different oxygen vectors on the production of L-lysine from LS260 fermentation and concluded that n-dodecane was the most suitable. Bacterial growth was smoother under these conditions, with a 2.78% increase in bacterial volume, a 6.53% increase in lysine production, and a 5.83% increase in conversion. The different addition times of the oxygen vectors also affected the final yield and conversion, with the addition of oxygen vectors at 0 h, 8 h, 16 h, and 24 h of fermentation increasing the yield by 6.31%, 12.44%, 9.93%, and 7.39%, respectively, compared to fermentation without the addition of oxygen vectors. The conversion rates increased by 5.83%, 8.73%, 7.13%, and 6.13%, respectively. The best results were achieved by adding oxygen vehicles at the 8th hour of fermentation, with a lysine yield of 208.36 g/L and a conversion rate of 83.3%. In addition, n-dodecane significantly reduced the amount of foam produced during fermentation, which is beneficial for fermentation control and equipment.Conclusion: The new oxygen-enhanced bioreactor improves oxygen transfer efficiency, and oxygen vectors enhance the ability of cells to take up oxygen, which effectively solves the problem of insufficient oxygen supply during lysine fermentation. This study provides a new bioreactor and production solution for lysine fermentation.

show abstract

Section: Methodsmentioning

confidence: 99%