scholarly journals Cinnamic Acid, an Autoinducer of Its Own Biosynthesis, Is Processed via Hca Enzymes in Photorhabdus luminescens

2008 ◽  
Vol 74 (6) ◽  
pp. 1717-1725 ◽  
Author(s):  
Sabina Chalabaev ◽  
Evelyne Turlin ◽  
Sylvie Bay ◽  
Christelle Ganneau ◽  
Emma Brito-Fravallo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Cinnamic Acid ◽  
Aromatic Compounds ◽  
Sole Carbon Source ◽  
Biosynthetic Pathway ◽  
Phenylalanine Ammonia Lyase ◽  
Carbon Sources ◽  
Degradation Pathway ◽  
Photorhabdus Luminescens

ABSTRACT Photorhabdus luminescens, an entomopathogenic bacterium and nematode symbiont, has homologues of the Hca and Mhp enzymes. In Escherichia coli, these enzymes catalyze the degradation of the aromatic compounds 3-phenylpropionate (3PP) and cinnamic acid (CA) and allow the use of 3PP as sole carbon source. P. luminescens is not able to use 3PP and CA as sole carbon sources but can degrade them. Hca dioxygenase is involved in this degradation pathway. P. luminescens synthesizes CA from phenylalanine via a phenylalanine ammonia-lyase (PAL) and degrades it via the not-yet-characterized biosynthetic pathway of 3,5-dihydroxy-4-isopropylstilbene (ST) antibiotic. CA induces its own synthesis by enhancing the expression of the stlA gene that codes for PAL. P. luminescens bacteria release endogenous CA into the medium at the end of exponential growth and then consume it. Hca dioxygenase is involved in the consumption of endogenous CA but is not required for ST production. This suggests that CA is consumed via at least two separate pathways in P. luminescens: the biosynthesis of ST and a pathway involving the Hca and Mhp enzymes.

scholarly journals Host engineering for improved valerolactam production in Pseudomonas putida

2019 ◽  
Author(s):  
Mitchell G. Thompson ◽  
Luis E. Valencia ◽  
Jacquelyn M. Blake-Hedges ◽  
Pablo Cruz-Morales ◽  
Alexandria E. Velasquez ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Carbon Source ◽  
Pseudomonas Putida ◽  
Aromatic Compounds ◽  
Sole Carbon Source ◽  
Carbon Sources ◽  
Shotgun Proteomics ◽  
Rich Media ◽  
Amide Hydrolase

ABSTRACTPseudomonas putida is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that P. putida is able to use valerolactam as a sole carbon source, as well as degrade caprolactam. Lactams represent important nylon precursors, and are produced in quantities exceeding one million tons per year[1]. To better understand this metabolism we use a combination of Random Barcode Transposon Sequencing (RB-TnSeq) and shotgun proteomics to identify the oplBA locus as the likely responsible amide hydrolase that initiates valerolactam catabolism. Deletion of the oplBA genes prevented P. putida from growing on valerolactam, prevented the degradation of valerolactam in rich media, and dramatically reduced caprolactam degradation under the same conditions. Deletion of oplBA, as well as pathways that compete for precursors L-lysine or 5-aminovalerate, increased the titer of valerolactam from undetectable after 48 hours of production to ~90 mg/L. This work may serve as a template to rapidly eliminate undesirable metabolism in non-model hosts in future metabolic engineering efforts.

scholarly journals Mouse Intestine Selects Nonmotile flhDC Mutants of Escherichia coli MG1655 with Increased Colonizing Ability and Better Utilization of Carbon Sources

2005 ◽  
Vol 73 (12) ◽  
pp. 8039-8049 ◽  
Author(s):  
Mary P. Leatham ◽  
Sarah J. Stevenson ◽  
Eric J. Gauger ◽  
Karen A. Krogfelt ◽  
Jeremy J. Lins ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Carbon Sources ◽  
Wild Type ◽  
Flagellar Biosynthesis ◽  
Commensal Strain ◽  
Mouse Intestine ◽  
Colonizing Ability ◽  
Better Than

ABSTRACT d-Gluconate which is primarily catabolized via the Entner-Doudoroff (ED) pathway, has been implicated as being important for colonization of the streptomycin-treated mouse large intestine by Escherichia coli MG1655, a human commensal strain. In the present study, we report that an MG1655 Δedd mutant defective in the ED pathway grows poorly not only on gluconate as a sole carbon source but on a number of other sugars previously implicated as being important for colonization, including l-fucose, d-gluconate, d-glucuronate, N-acetyl-d-glucosamine, d-mannose, and d-ribose. Furthermore, we show that the mouse intestine selects mutants of MG1655 Δedd and wild-type MG1655 that have improved mouse intestine-colonizing ability and grow 15 to 30% faster on the aforementioned sugars. The mutants of MG1655 Δedd and wild-type MG1655 selected by the intestine are shown to be nonmotile and to have deletions in the flhDC operon, which encodes the master regulator of flagellar biosynthesis. Finally, we show that ΔflhDC mutants of wild-type MG1655 and MG1655 Δedd constructed in the laboratory act identically to those selected by the intestine; i.e., they grow better than their respective parents on sugars as sole carbon sources and are better colonizers of the mouse intestine.

Mannose utilization in Escherichia coli requires cyclic AMP but not an exogenous inducer

1980 ◽  
Vol 26 (12) ◽  
pp. 1508-1511 ◽  
Author(s):  
Ann D. E. Fraser ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
Sole Carbon Source ◽  
Receptor Protein ◽  
Deficient Mutant ◽  
Phosphotransferase System ◽  
Cyclic Amp Receptor Protein ◽  
Cyclic Monophosphate

It has not been clarified whether the utilization of mannose by Escherichia coli requires adenosine 3′,5′-cyclic monophosphate (cyclic AMP). Using an adenylyl cyclase deficient mutant (CA8306B) and a cyclic AMP receptor protein (CRP) deficient mutant (5333B) we have shown that the utilization of mannose is dependent on the cyclic AMP–CRP complex. 2-Deoxyglucose (DG) is a nonmetabolizable glucose analog specific for the phosphotransferase system (PTS) which transports mannose (termed here PTSM). Growth of CA8306B on glycerol is unaffected by addition of the analog, whereas growth of the strain on glycerol plus cyclic AMP ceases im mediately upon addition of DG. These results suggest that the formation of PTSM is dependent on cyclic AMP. In addition, CA8306B grown on glycerol plus cyclic AMP can immediately utilize mannose when transferred to a medium containing mannose as a sole carbon source, whereas the same strain grown on glycerol without cyclic AMP cannot utilize mannose when so transferred. These results suggest that the formation of PTSM does not require an exogenous inducer.

scholarly journals Heterologous Production of 6-Deoxyerythronolide B in Escherichia coli through the Wood Werkman Cycle

Metabolites ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 228
Author(s):  
R. Axayacatl Gonzalez-Garcia ◽  
Lars K. Nielsen ◽  
Esteban Marcellin
Keyword(s):  
Escherichia Coli ◽  
Natural Products ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Structural Diversity ◽  
Heterologous Production ◽  
E Coli ◽  
Anticancer Properties ◽  
Defined Media ◽  
Extender Unit

Polyketides are a remarkable class of natural products with diverse functional and structural diversity. The class includes many medicinally important molecules with antiviral, antimicrobial, antifungal and anticancer properties. Native bacterial, fungal and plant hosts are often difficult to cultivate and coax into producing the desired product. As a result, Escherichia coli has been used for the heterologous production of polyketides, with the production of 6-deoxyerythronolide B (6-dEB) being the first example. Current strategies for production in E. coli require feeding of exogenous propionate as a source for the precursors propionyl-CoA and S-methylmalonyl-CoA. Here, we show that heterologous polyketide production is possible from glucose as the sole carbon source. The heterologous expression of eight genes from the Wood-Werkman cycle found in Propionibacteria, in combination with expression of the 6-dEB synthases DEBS1, DEBS2 and DEBS3 resulted in 6-dEB formation from glucose as the sole carbon source. Our results show that the Wood-Werkman cycle provides the required propionyl-CoA and the extender unit S-methylmalonyl-CoA to produce up to 0.81 mg/L of 6-dEB in a chemically defined media.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

scholarly journals Comparative metabolomics of Phialemonium curvatum as an omnipotent fungus cultivated on crude palm oil versus glucose

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Arief Izzairy Zamani ◽  
Susann Barig ◽  
Sarah Ibrahim ◽  
Hirzun Mohd. Yusof ◽  
Julia Ibrahim ◽  
...  
Keyword(s):  
Carbon Source ◽  
Organic Acids ◽  
Vegetable Oil ◽  
Carbon Metabolism ◽  
Sole Carbon Source ◽  
Carbon Sources ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
Targeted Metabolomics ◽  
Central Carbon

Abstract Background Sugars and triglycerides are common carbon sources for microorganisms. Nonetheless, a systematic comparative interpretation of metabolic changes upon vegetable oil or glucose as sole carbon source is still lacking. Selected fungi that can grow in acidic mineral salt media (MSM) with vegetable oil had been identified recently. Hence, this study aimed to investigate the overall metabolite changes of an omnipotent fungus and to reveal changes at central carbon metabolism corresponding to both carbon sources. Results Targeted and non-targeted metabolomics for both polar and semi-polar metabolites of Phialemonium curvatum AWO2 (DSM 23903) cultivated in MSM with palm oil (MSM-P) or glucose (MSM-G) as carbon sources were obtained. Targeted metabolomics on central carbon metabolism of tricarboxylic acid (TCA) cycle and glyoxylate cycle were analysed using LC–MS/MS-TripleQ and GC–MS, while untargeted metabolite profiling was performed using LC–MS/MS-QTOF followed by multivariate analysis. Targeted metabolomics analysis showed that glyoxylate pathway and TCA cycle were recruited at central carbon metabolism for triglyceride and glucose catabolism, respectively. Significant differences in organic acids concentration of about 4- to 8-fold were observed for citric acid, succinic acid, malic acid, and oxaloacetic acid. Correlation of organic acids concentration and key enzymes involved in the central carbon metabolism was further determined by enzymatic assays. On the other hand, the untargeted profiling revealed seven metabolites undergoing significant changes between MSM-P and MSM-G cultures. Conclusions Overall, this study has provided insights on the understanding on the effect of triglycerides and sugar as carbon source in fungi global metabolic pathway, which might become important for future optimization of carbon flux engineering in fungi to improve organic acids production when vegetable oil is applied as the sole carbon source.

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