scholarly journals High-Level Conversion of l-lysine into Cadaverine by Escherichia coli Whole Cell Biocatalyst Expressing Hafnia alvei l-lysine Decarboxylase

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1184 ◽  
Author(s):  
Kim ◽  
Baritugo ◽  
Oh ◽  
Kang ◽  
Jung ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Expression ◽  
Pyridoxal Phosphate ◽  
Lysine Decarboxylase ◽  
Hafnia Alvei ◽  
Whole Cell ◽  
E Coli ◽  
Whole Cell Biocatalyst ◽  
High Level ◽  
Whole Cell Bioconversion

Cadaverine is a C5 diamine monomer used for the production of bio-based polyamide 510. Cadaverine is produced by the decarboxylation of l-lysine using a lysine decarboxylase (LDC). In this study, we developed recombinant Escherichia coli strains for the expression of LDC from Hafnia alvei. The resulting recombinant XBHaLDC strain was used as a whole cell biocatalyst for the high-level bioconversion of l-lysine into cadaverine without the supplementation of isopropyl β-d-1-thiogalactopyranoside (IPTG) for the induction of protein expression and pyridoxal phosphate (PLP), a key cofactor for an LDC reaction. The comparison of results from enzyme characterization of E. coli and H. alvei LDC revealed that H. alvei LDC exhibited greater bioconversion ability than E. coli LDC due to higher levels of protein expression in all cellular fractions and a higher specific activity at 37 °C (1825 U/mg protein > 1003 U/mg protein). The recombinant XBHaLDC and XBEcLDC strains were constructed for the high-level production of cadaverine. Recombinant XBHaLDC produced a 1.3-fold higher titer of cadaverine (6.1 g/L) than the XBEcLDC strain (4.8 g/L) from 10 g/L of l-lysine. Furthermore, XBHaLDC, concentrated to an optical density (OD600) of 50, efficiently produced 136 g/L of cadaverine from 200 g/L of l-lysine (97% molar yield) via an IPTG- and PLP-free whole cell bioconversion reaction. Cadaverine synthesized via a whole cell biocatalyst reaction using XBHaLDC was purified to polymer grade, and purified cadaverine was successfully used for the synthesis of polyamide 510. In conclusion, an IPTG- and PLP-free whole cell bioconversion process of l-lysine into cadaverine, using recombinant XBHaLDC, was successfully utilized for the production of bio-based polyamide 510, which has physical and thermal properties similar to polyamide 510 synthesized from chemical-grade cadaverine.

scholarly journals Fecal expression of Escherichia coli lysine decarboxylase (LdcC) is downregulated in E-cadherin negative lobular breast carcinoma

2020 ◽  
Vol 107 (2) ◽  
pp. 349-358 ◽  
Author(s):  
Zs. Sári ◽  
T. Kovács ◽  
T. Csonka ◽  
M. Török ◽  
É. Sebő ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Escherichia Coli ◽  
Breast Carcinoma ◽  
Protein Expression ◽  
Lysine Decarboxylase ◽  
Metastasis Formation ◽  
Predictive Values ◽  
E Coli ◽  
Lobular Breast Carcinoma ◽  
E Cadherin

AbstractBreast cancer is characterized by oncobiosis, the abnormal composition of the microbiome in neoplastic diseases. The biosynthetic capacity of the oncobiotic flora in breast cancer is suppressed, as suggested by metagenomic studies. The microbiome synthesizes a set of cytostatic and antimetastatic metabolites that are downregulated in breast cancer, including cadaverine, a microbiome metabolite with cytostatic properties. We set out to assess how the protein expression of constitutive lysine decarboxylase (LdcC), a key enzyme for cadaverine production, changes in the feces of human breast cancer patients (n = 35). We found that the fecal expression of Escherichia coli LdcC is downregulated in lobular cases as compared to invasive carcinoma of no special type (NST) cases. Lobular breast carcinoma is characterized by low or absent expression of E-cadherin. Fecal E. coli LdcC protein expression is downregulated in E-cadherin negative breast cancer cases as compared to positive ones. Receiver operating characteristic (ROC) analysis of LdcC expression in lobular and NST cases revealed that fecal E. coli LdcC protein expression might have predictive values. These data suggest that the oncobiotic transformation of the microbiome indeed leads to the downregulation of the production of cytostatic and antimetastatic metabolites. In E-cadherin negative lobular carcinoma that has a higher potential for metastasis formation, the protein levels of enzymes producing antimetastatic metabolites are downregulated. This finding represents a new route that renders lobular cases permissive for metastasis formation. Furthermore, our findings underline the role of oncobiosis in regulating metastasis formation in breast cancer.

High-level l-lysine bioconversion into cadaverine with enhanced productivity using engineered Escherichia coli whole-cell biocatalyst

2020 ◽  
Vol 157 ◽  
pp. 107547 ◽  
Author(s):  
Yoong Kit Leong ◽  
Chien-Heng Chen ◽  
Shih-Fang Huang ◽  
Hung-Yi Lin ◽  
Sheng-Feng Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Whole Cell ◽  
Whole Cell Biocatalyst ◽  
Engineered Escherichia Coli ◽  
High Level

scholarly journals Development of an Autofluorescent Whole-Cell Biocatalyst by Displaying Dual Functional Moieties on Escherichia coli Cell Surfaces and Construction of a Coculture with Organophosphate-Mineralizing Activity

2008 ◽  
Vol 74 (24) ◽  
pp. 7733-7739 ◽  
Author(s):  
Chao Yang ◽  
Yaran Zhu ◽  
Jijian Yang ◽  
Zheng Liu ◽  
Chuanling Qiao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fluorescent Protein ◽  
Surface Display ◽  
Ice Nucleation Protein ◽  
Whole Cell ◽  
E Coli ◽  
Dual Functional ◽  
Whole Cell Biocatalyst ◽  
Mineralizing Activity ◽  
Green Fluorescent

ABSTRACT Surface display of the active proteins on living cells has enormous potential in the degradation of numerous toxic compounds. Here, we report the codisplay of organophosphorus hydrolase (OPH) and enhanced green fluorescent protein (GFP) on the cell surface of Escherichia coli by use of the truncated ice nucleation protein (INPNC) and Lpp-OmpA fusion systems. The surface localization of both INPNC-OPH and Lpp-OmpA-GFP was demonstrated by Western blot analysis, immunofluorescence microscopy, and a protease accessibility experiment. Anchorage of GFP and OPH on the outer membrane neither inhibits cell growth nor affects cell viability, as shown by growth kinetics of cells and stability of resting cultures. The engineered E. coli can be applied in the form of a whole-cell biocatalyst and can be tracked by fluorescence during bioremediation. This strategy of codisplay should open a new dimension for the display of multiple functional moieties on the surface of a bacterial cell. Furthermore, a coculture comprised of the engineered E. coli and a natural p-nitrophenol (PNP) degrader, Ochrobactrum sp. strain LL-1, was assembled for complete mineralization of organophosphates (OPs) with a PNP substitution. The coculture degraded OPs as well as PNP rapidly. Therefore, the coculture with autofluorescent and mineralizing activities can potentially be applied for bioremediation of OP-contaminated sites.

Expressing Xylanases in Escherichia Coli by Cell Surface Display

2013 ◽  
Vol 634-638 ◽  
pp. 965-969
Author(s):  
Mei Na Zhao ◽  
Zongbao Zheng ◽  
Tao Chen
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Consolidated Bioprocessing ◽  
Surface Display ◽  
Cell Surface Display ◽  
Whole Cell ◽  
E Coli ◽  
Metabolic Burden ◽  
Whole Cell Biocatalyst ◽  
Anchor Proteins

In this research, xylan was utilized by a recombinant whole cell biocatalyst, which was developed by expressing three xylanases — β-xylosidase, endoxylanase, and α-arabinofuranosidase — on the surface of the E. coli BL21 (DE3). The xylanases were displayed on the surface of the cells by fusing with anchor proteins, Blc. The assimilation of xylan by cell surface display was the first step in the consolidated bioprocessing (CBP). This result shows that the engineering strains could be endowed with the ability to assimilate xylan. The co-display engineering strains utilized xylan and expressed less metabolic burden than the engineering strains secreting extracellular xylanases.

scholarly journals Tuning a bi-enzymatic cascade reaction in Escherichia coli to facilitate NADPH regeneration for ε-caprolactone production

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jinghui Xiong ◽  
Hefeng Chen ◽  
Ran Liu ◽  
Hao Yu ◽  
Min Zhuo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Regeneration System ◽  
Nadph Regeneration ◽  
Whole Cell ◽  
Cyclohexanone Monooxygenase ◽  
Ribosome Binding ◽  
Ribosome Binding Sites ◽  
Whole Cell Biocatalyst ◽  
Substrate Tolerance

Abstractε-Caprolactone is a monomer of poly(ε-caprolactone) which has been widely used in tissue engineering due to its biodegradability and biocompatibility. To meet the massive demand for this monomer, an efficient whole-cell biocatalytic approach was constructed to boost the ε-caprolactone production using cyclohexanol as substrate. Combining an alcohol dehydrogenase (ADH) with a cyclohexanone monooxygenase (CHMO) in Escherichia coli, a self-sufficient NADPH-cofactor regeneration system was obtained. Furthermore, some improved variants with the better substrate tolerance and higher catalytic ability to ε-caprolactone production were designed by regulating the ribosome binding sites. The best mutant strain exhibited an ε-caprolactone yield of 0.80 mol/mol using 60 mM cyclohexanol as substrate, while the starting strain only got a conversion of 0.38 mol/mol when 20 mM cyclohexanol was supplemented. The engineered whole-cell biocatalyst was used in four sequential batches to achieve a production of 126 mM ε-caprolactone with a high molar yield of 0.78 mol/mol.

scholarly journals Comparison of Fecal Coliform Agar and Violet Red Bile Lactose Agar for Fecal Coliform Enumeration in Foods

2002 ◽  
Vol 68 (4) ◽  
pp. 1631-1638 ◽  
Author(s):  
A. Leclercq ◽  
C. Wanegue ◽  
P. Baylac
Keyword(s):  
Escherichia Coli ◽  
Fecal Coliform ◽  
Food Samples ◽  
Fecal Coliforms ◽  
Predictive Values ◽  
Direct Plating ◽  
Hafnia Alvei ◽  
E Coli ◽  
Plating Method ◽  
Mashed Potatoes

ABSTRACT A 24-h direct plating method for fecal coliform enumeration with a resuscitation step (preincubation for 2 h at 37 ± 1°C and transfer to 44 ± 1°C for 22 h) using fecal coliform agar (FCA) was compared with the 24-h standardized violet red bile lactose agar (VRBL) method. FCA and VRBL have equivalent specificities and sensitivities, except for lactose-positive non-fecal coliforms such as Hafnia alvei, which could form typical colonies on FCA and VRBL. Recovery of cold-stressed Escherichia coli in mashed potatoes on FCA was about 1 log unit lower than that with VRBL. When the FCA method was compared with standard VRBL for enumeration of fecal coliforms, based on counting carried out on 170 different food samples, results were not significantly different (P > 0.05). Based on 203 typical identified colonies selected as found on VRBL and FCA, the latter medium appears to allow the enumeration of more true fecal coliforms and has higher performance in certain ways (specificity, sensitivity, and negative and positive predictive values) than VRBL. Most colonies clearly identified on both media were E. coli and H. alvei, a non-fecal coliform. Therefore, the replacement of fecal coliform enumeration by E. coli enumeration to estimate food sanitary quality should be recommended.

scholarly journals A Pathoadaptive Deletion in an Enteroaggregative Escherichia coli Outbreak Strain Enhances Virulence in a Caenorhabditis elegans Model

2010 ◽  
Vol 78 (9) ◽  
pp. 4068-4076 ◽  
Author(s):  
Jennifer Hwang ◽  
Lisa M. Mattei ◽  
Laura G. VanArendonk ◽  
Philip M. Meneely ◽  
Iruka N. Okeke
Keyword(s):  
Escherichia Coli ◽  
Caenorhabditis Elegans ◽  
Epithelial Cells ◽  
Genetic Material ◽  
Decarboxylase Activity ◽  
Multicopy Plasmid ◽  
Lysine Decarboxylase ◽  
Outbreak Strain ◽  
E Coli ◽  
C Elegans

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.

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