scholarly journals Co-Production of Isoprene and Lactate by Engineered Escherichia coli in Microaerobic Conditions

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7173
Author(s):  
Tao Cheng ◽  
Xiuhong Liang ◽  
Yaqun Wang ◽  
Ningning Chen ◽  
Dexin Feng ◽  
...  

Lactate and isoprene are two common monomers for the industrial production of polyesters and synthetic rubbers. The present study tested the co-production of D-lactate and isoprene by engineered Escherichia coli in microaerobic conditions. The deletion of alcohol dehydrogenase (adhE) and acetate kinase (ackA) genes, along with the supplementation with betaine, improved the co-production of lactate and isoprene from the substrates of glucose and mevalonate. In fed-batch studies, microaerobic fermentation significantly improved the isoprene concentration in fermentation outlet gas (average 0.021 g/L), compared with fermentation under aerobic conditions (average 0.0009 g/L). The final production of D-lactate and isoprene can reach 44.0 g/L and 3.2 g/L, respectively, through fed-batch microaerobic fermentation. Our study demonstrated a dual-phase production strategy in the co-production of isoprene (gas phase) and lactate (liquid phase). The increased concentration of gas-phase isoprene could benefit the downstream process and decrease the production cost to collect and purify the bio-isoprene from the fermentation outlet gas. The proposed microaerobic process can potentially be applied in the production of other volatile bioproducts to benefit the downstream purification process.

2006 ◽  
Vol 28 (20) ◽  
pp. 1695-1700 ◽  
Author(s):  
Geoffrey M. Smith ◽  
Sarah A. Lee ◽  
Kevin C. Reilly ◽  
Mark A. Eiteman ◽  
Elliot Altman

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 269
Author(s):  
Lijuan Zhong ◽  
Zheng Liu ◽  
Yinghua Lu

The aim of this study was to analyze the major influence factors of culture medium on the expression level of β-1,3-1,4-glucanase, and to further develop an optimized process for the extracellular production of β-glucanase at a bioreactor scale (7 L) with a genetically engineered Escherichia coli (E. coli) JM109-pLF3. In this study, batch cultivation and fed-batch cultivation including the constant rate feeding strategy and the DO-stat (DO: Dissolved Oxygen) feeding strategy were conducted. At a 7 L bioreactor scale for batch cultivation, biomass reached 3.14 g/L and the maximum β-glucanase activity was 506.94 U/mL. Compared with batch cultivation, the addition of glycerol, complex nitrogen and complete medium during fed-batch cultivation increased the production of biomass and β-1,3-1,4-glucanase. The maximum biomass and β-glucanase activity, which were 7.67 g/L and 1680 U/mL, respectively, that is, 2.45 and 3.31 times higher than those obtained with batch cultivation, were obtained by feeding a complex nitrogen source at a constant rate of 1.11 mL/min. Therefore, these nutritional supplements and strategies can be used as a reference to enhance the production of other bioproducts from E. coli.


2019 ◽  
Vol 103 (14) ◽  
pp. 5627-5639 ◽  
Author(s):  
Mariel Perez-Zabaleta ◽  
Mónica Guevara-Martínez ◽  
Martin Gustavsson ◽  
Jorge Quillaguamán ◽  
Gen Larsson ◽  
...  

RSC Advances ◽  
2018 ◽  
Vol 8 (54) ◽  
pp. 30851-30859
Author(s):  
Chang Qi ◽  
Hongwei Zhao ◽  
Wenyang Li ◽  
Xing Li ◽  
Haiying Xiang ◽  
...  

A sustainable technology for gamma (γ)-terpinene was constructed in an engineered Escherichia coli. In-depth analysis at translation level for the engineered strain and intermediate metabolites were analyzed. The fed-batch fermentation of γ-terpinene was 275.41 mg L−1.


Author(s):  
Zhijian Ni ◽  
Jinyong Wu ◽  
Zhongkui Li ◽  
Lixia Yuan ◽  
Yu Wang ◽  
...  

Abstract 3-fucosyllactose (3-FL) and 2′-fucosyllactose (2′-FL), are two important fucosylated oligosaccharides in human milk. Extensive studies on 2'-FL enabled its official approval for use in infant formula. However, commercialization of 3-FL seems to be a bit sluggish due to its low content in human milk and poor yield in enlarged production. Here, an α-1,3-fucosyltransferase mutant was expressed in an engineered E. coli able to produce GDP-L-fucose, and gave a promising 3-FL titer in a 5.0-L bioreactor. To increase the availability of cofactors (NADPH and GTP) for optimized 3-FL production, zwf, pntAB, and gsk genes were successively overexpressed, finally resulting in a high 3-FL level with a titer of 35.72 g/L, a yield of 0.82 mol 3-FL/mol lactose, and a specific productivity of 0.46 g/L*h. Unexpectedly, the deletion of pfkA gene led to a much lower performance of 3-FL production than the control strain. Taken together, our production strategy finally achieved the highest 3-FL level in E. coli to date.


2020 ◽  
Vol 14 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Maryam Ahankoub ◽  
Gashtasb Mardani ◽  
Payam Ghasemi-Dehkordi ◽  
Ameneh Mehri-Ghahfarrokhi ◽  
Abbas Doosti ◽  
...  

Background: Genetically engineered microorganisms (GEMs) can be used for bioremediation of the biological pollutants into nonhazardous or less-hazardous substances, at lower cost. Polycyclic aromatic hydrocarbons (PAHs) are one of these contaminants that associated with a risk of human cancer development. Genetically engineered E. coli that encoded catechol 2,3- dioxygenase (C230) was created and investigated its ability to biodecomposition of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC) measurement. We revised patents documents relating to the use of GEMs for bioremediation. This approach have already been done in others studies although using other genes codifying for same catechol degradation approach. Objective: In this study, we investigated biodecomposition of phenanthrene and pyrene by a genetically engineered Escherichia coli. Methods: Briefly, following the cloning of C230 gene (nahH) into pUC18 vector and transformation into E. coli Top10F, the complementary tests, including catalase, oxidase and PCR were used as on isolated bacteria from spiked soil. Results: The results of HPLC measurement showed that in spiked soil containing engineered E. coli, biodegradation of phenanthrene and pyrene comparing to autoclaved soil that inoculated by wild type of E. coli and normal soil group with natural microbial flora, were statistically significant (p<0.05). Moreover, catalase test was positive while the oxidase tests were negative. Conclusion: These findings indicated that genetically manipulated E. coli can provide an effective clean-up process on PAH compounds and it is useful for bioremediation of environmental pollution with petrochemical products.


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