Combination of the CRP mutation and ptsG deletion in Escherichia coli to efficiently synthesize xylitol from corncob hydrolysates

Yuan, Xingzhong; Tu, Shuai; Lin, Johnson; Yang, Lirong; Shen, Huahao; Wu, Mianbin

doi:10.1007/s00253-019-10324-0

Cited by 31 publications

(21 citation statements)

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“…The substrate used in this study is the hydrolysate without lime treatment, while the substrate in our previous work is the hydrolysate after lime treatment. Except that, the experimental method of this work is very similar to that of the literature [ 22 ]. The results presented in Figure 2 of this study look similar to that in the previous paper; however, in this work, the strain growth level and xylitol concentration are lower than those in the literature.…”

Section: Resultsmentioning

confidence: 99%

“…On the basis of the previously constructed E. coli strain IS5-dI [ 22 ], we generated a series of strains via site-directed mutagenesis targeting Ile 127 of CRP. Then, hydrolysate was used as the substrate without ion exchange or lime treatment; the strains were screened through shaking flask fermentation experiments, and the most toxicity-tolerant strain was used as the xylitol-producing strain.…”

Section: Introductionmentioning

confidence: 99%

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Genetically Engineering Escherichia coli to Produce Xylitol from Corncob Hydrolysate without Lime Detoxification

et al. 2023

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Before fermentation with hemicellulosic hydrolysate as a substrate, it is generally necessary to detoxify the toxic substances that are harmful to microorganism growth. Cyclic AMP receptor protein (CRP) is a global regulator, and mutation of its key sites may have an important impact on E. coli virulence tolerance. Using corncob hydrolysate without ion-exchange or lime detoxification as the substrate, shake flask fermentation experiments showed that CRP mutant IS5-dG (I112L, T127G, A144T) produced 18.4 g/L of xylitol within 34 h, and the OD600 was 9.7 at 24 h; these values were 41.5% and 21.3% higher than those of the starting strain, IS5-d, respectively. This mutant produced 82 g/L of xylitol from corncob hydrolysate without ion-exchange or lime detoxification during fed-batch fermentation in a 15-L bioreactor, with a productivity of 1.04 g/L/h; these values were 173% and 174% higher than the starting strain, respectively. To our knowledge, this is the highest xylitol concentration and productivity produced by microbial fermentation using completely non-detoxified hemicellulosic hydrolysate as the substrate to date. This study also showed that alkali neutralization, high temperature sterilization, and fermentation of the hydrolysate had important effects on the xylose loss rate and xylitol production.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Genetically Engineering Escherichia coli to Produce Xylitol from Corncob Hydrolysate without Lime Detoxification

et al. 2023

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“…CCR was first studied in microorganisms such as E. coli , B. subtilis , and Salmonella typhimurium during the 1940s, and it emerged as an important gene-regulatory mechanism in bacteria, controlling the expression of approximately 10% of total bacterial genes ( Choudhury and Saini, 2017 ). The accumulation of dephosphorylated EIIA Glc is the main cause of CCR in E. coli ( Yuan et al, 2020 ), and the disruption of ptsG can relieve CCR, enabling the simultaneous utilization of mixed sugars ( Ma et al, 2017 ; Yuan et al, 2020 ). In addition to being involved in glucose transport, in some rhizosphere microorganisms (e.g., B. cereus C1L), ptsG is also involved in root colonization and the production of beneficial metabolites to induce plant systemic disease resistance ( Lin et al, 2020 ).…”

Section: Discussionmentioning

confidence: 99%

Enhancing the biosynthesis of riboflavin in the recombinant Escherichia coli BL21 strain by metabolic engineering

Ying

Chen

et al. 2023

Front. Microbiol.

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In this study, to construct the riboflavin-producing strain R1, five key genes, ribA, ribB, ribC, ribD, and ribE, were cloned and ligated to generate the plasmid pET-AE, which was overexpressed in Escherichia coli BL21. The R1 strain accumulated 182.65 ± 9.04 mg/l riboflavin. Subsequently, the R2 strain was constructed by the overexpression of zwf harboring the constructed plasmid pAC-Z in the R1 strain. Thus, the level of riboflavin in the R2 strain increased to 319.01 ± 20.65 mg/l (74.66% increase). To further enhance ribB transcript levels and riboflavin production, the FMN riboswitch was deleted from E. coli BL21 with CRISPR/Cas9 to generate the R3 strain. The R4 strain was constructed by cotransforming pET-AE and pAC-Z into the R3 strain. Compared to those of E. coli BL21, the ribB transcript levels of R2 and R4 improved 2.78 and 3.05-fold, respectively. The R4 strain accumulated 437.58 ± 14.36 mg/l riboflavin, increasing by 37.17% compared to the R2 strain. These results suggest that the deletion of the FMN riboswitch can improve the transcript level of ribB and facilitate riboflavin production. A riboflavin titer of 611.22 ± 11.25 mg/l was achieved under the optimal fermentation conditions. Ultimately, 1574.60 ± 109.32 mg/l riboflavin was produced through fed-batch fermentation with 40 g/l glucose. This study contributes to the industrial production of riboflavin by the recombinant E. coli BL21.

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“…The hydrolysate was then evaporated and concentrated using a 10 L rotary evaporation flask, which resulted in the formation of a CaSO 4 scale layer on the inner wall. 19 The pH value of the concentrated hydrolyzate is about 6.5. 39.3 g sodium gluconate was dissolved in 300 mL of deionized water and added to the evaporator.…”

Section: Methodsmentioning

confidence: 99%

Preparation of calcium carbonate microrods from the gypsum scale layer of evaporation equipment

et al. 2022

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Combination of the CRP mutation and ptsG deletion in Escherichia coli to efficiently synthesize xylitol from corncob hydrolysates

Cited by 31 publications

References 61 publications

Genetically Engineering Escherichia coli to Produce Xylitol from Corncob Hydrolysate without Lime Detoxification

Genetically Engineering Escherichia coli to Produce Xylitol from Corncob Hydrolysate without Lime Detoxification

Enhancing the biosynthesis of riboflavin in the recombinant Escherichia coli BL21 strain by metabolic engineering

Preparation of calcium carbonate microrods from the gypsum scale layer of evaporation equipment

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