A metabolic intermediate of the fructose-asparagine utilization pathway inhibits growth of a Salmonella fraB mutant

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

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Heme Binding to HupZ with a C-Terminal Tag from Group A Streptococcus

Molecules ◽

10.3390/molecules26030549 ◽

2021 ◽

Vol 26 (3) ◽

pp. 549

Author(s):

Ephrahime S. Traore ◽

Jiasong Li ◽

Tapiwa Chiura ◽

Jiafeng Geng ◽

Ankita J. Sachla ◽

...

Keyword(s):

Quaternary Structure ◽

Group A Streptococcus ◽

Heme Binding ◽

Oligomeric Structure ◽

Heme Degradation ◽

Group A ◽

Degradation Activity ◽

Ferric Heme ◽

Epr Signal ◽

Utilization Pathway

HupZ is an expected heme degrading enzyme in the heme acquisition and utilization pathway in Group A Streptococcus. The isolated HupZ protein containing a C-terminal V5-His6 tag exhibits a weak heme degradation activity. Here, we revisited and characterized the HupZ-V5-His6 protein via biochemical, mutagenesis, protein quaternary structure, UV–vis, EPR, and resonance Raman spectroscopies. The results show that the ferric heme-protein complex did not display an expected ferric EPR signal and that heme binding to HupZ triggered the formation of higher oligomeric states. We found that heme binding to HupZ was an O2-dependent process. The single histidine residue in the HupZ sequence, His111, did not bind to the ferric heme, nor was it involved with the weak heme-degradation activity. Our results do not favor the heme oxygenase assignment because of the slow binding of heme and the newly discovered association of the weak heme degradation activity with the His6-tag. Altogether, the data suggest that the protein binds heme by its His6-tag, resulting in a heme-induced higher-order oligomeric structure and heme stacking. This work emphasizes the importance of considering exogenous tags when interpreting experimental observations during the study of heme utilization proteins.

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Metabolomic Study of Heterotrophically Grown Chlorella sp. Isolated from Wastewater in Northern Sweden

Molecules ◽

10.3390/molecules26092410 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2410

Author(s):

Jean Claude Nzayisenga ◽

Anita Sellstedt

Keyword(s):

Sustainable Development ◽

Butyric Acid ◽

Lipid Production ◽

Growth Conditions ◽

Northern Sweden ◽

Metabolic Intermediate ◽

Chlorella Sp ◽

Lipid Contents ◽

New Compounds ◽

Potential Use

There are numerous strains of Chlorella with a corresponding variety of metabolic pathways. A strain we previously isolated from wastewater in northern Sweden can grow heterotrophically as well as autotrophically in light and has higher lipid contents under heterotrophic growth conditions. The aims of the present study were to characterize metabolic changes associated with the higher lipid contents in order to enhance our understanding of lipid production in microalgae and potentially identify new compounds with utility in sustainable development. Inter alia, the amino acids glutamine and lysine were 7-fold more abundant under heterotrophic conditions, the key metabolic intermediate alpha-ketoglutarate was more abundant under heterotrophic conditions with glucose, and maltose was more abundant under heterotrophic conditions with glycerol than under autotrophic conditions. The metabolite 3-hydroxy-butyric acid, the direct precursor of the biodegradable plastic PHB (poly-3-hydroxy-butyric acid), was also more abundant under heterotrophic conditions. Our metabolomic analysis has provided new insights into the alga’s lipid production pathways and identified metabolites with potential use in sustainable development, such as the production of renewable, biodegradable plastics, cosmetics, and nutraceuticals, with reduced pollution and improvements in both ecological and human health.

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A regulatory region responsible for proline-specific induction of the yeast PUT2 gene is adjacent to its TATA box.

Molecular and Cellular Biology ◽

10.1128/mcb.8.11.4634 ◽

1988 ◽

Vol 8 (11) ◽

pp. 4634-4641 ◽

Cited By ~ 15

Author(s):

A H Siddiqui ◽

M C Brandriss

Keyword(s):

Gene Fusion ◽

Regulatory Gene ◽

Regulatory Region ◽

Tata Box ◽

Homologous Gene ◽

Lacz Gene ◽

Proline Utilization ◽

Constitutive Mutation ◽

Necessary And Sufficient ◽

Utilization Pathway

Deletion analysis of the promoter of the PUT2 gene that functions in the proline utilization pathway of Saccharomyces cerevisiae identified a PUT2 upstream activation site (UAS). It is contained within a single 40-base-pair (bp) region located immediately upstream of the TATA box and is both necessary and sufficient for proline induction. When placed upstream of a CYC7-lacZ gene fusion, the 40-bp sequence conferred proline regulation on CYC7-lacZ. A 35-bp deletion within the PUT2 UAS in an otherwise intact PUT2 promoter resulted in noninducible expression of a PUT2-lacZ gene fusion. When a plasmid bearing this UAS-deleted promoter was placed in a strain carrying a constitutive mutation in the positive regulatory gene PUT3, expression of PUT2-lacZ was not constitutive but occurred at levels below those found under noninducing conditions. In heterologous as well as homologous gene fusions, the PUT2 UAS appeared to be responsible for uninduced as well as proline-induced levels of expression. Although located immediately adjacent to the PUT2 UAS, the TATA box did not appear to play a regulatory role, as indicated by the results of experiments in which it was replaced by the CYC7 TATA box. A 26-bp sequence containing this TATA box was critical to the expression of PUT2, since a deletion of this region completely abolished transcriptional activity of the gene under both inducing and noninducing conditions. Our results indicate that the PUT2 promoter has a comparatively simple structure, requiring UAS and TATA sequences as well as the PUT3 gene product (directly or indirectly) for its expression.

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Nitrate reductases and hemoglobins control nitrogen-fixing symbiosis by regulating nitric oxide accumulation

Journal of Experimental Botany ◽

10.1093/jxb/eraa403 ◽

2020 ◽

Author(s):

Antoine Berger ◽

Alexandre Boscari ◽

Alain Puppo ◽

Renaud Brouquisse

Keyword(s):

Nitric Oxide ◽

Defense Responses ◽

Nodule Formation ◽

No Production ◽

Degradation Pathways ◽

Atmospheric Nitrogen ◽

Metabolic Intermediate ◽

Hypoxic Environment ◽

Nitrate Reductases

Abstract The interaction between legumes and rhizobia leads to the establishment of a symbiotic relationship between plant and bacteria. This is characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Nitric oxide (NO) accumulates at each stage of the symbiotic process. NO is involved in defense responses, nodule organogenesis and development, nitrogen fixation metabolism, and senescence induction. During symbiosis, either successively or simultaneously, NO regulates gene expression, modulates enzyme activities, and acts as a metabolic intermediate in energy regeneration processes via phytoglobin-NO respiration and the bacterial denitrification pathway. Due to the transition from normoxia to hypoxia during nodule formation, and the progressive presence of the bacterial partner in the growing nodules, NO production and degradation pathways change during the symbiotic process. This review analyzes the different source and degradation pathways of NO, and highlights the role of nitrate reductases and hemoproteins of both the plant and bacterial partners in the control of NO accumulation.

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Aspergillus niger upregulated glycerolipid metabolism and ethanol utilization pathway under ethanol stress

MicrobiologyOpen ◽

10.1002/mbo3.948 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Nawaporn Vinayavekhin ◽

Wimonsiri Kongchai ◽

Jittra Piapukiew ◽

Warinthorn Chavasiri

Keyword(s):

Aspergillus Niger ◽

Ethanol Stress ◽

Utilization Pathway

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Maintenance Role of a Glutathionyl-Hydroquinone Lyase (PcpF) in Pentachlorophenol Degradation by Sphingobium chlorophenolicum ATCC 39723

Journal of Bacteriology ◽

10.1128/jb.00489-08 ◽

2008 ◽

Vol 190 (23) ◽

pp. 7595-7600 ◽

Cited By ~ 21

Author(s):

Yan Huang ◽

Randy Xun ◽

Guanjun Chen ◽

Luying Xun

Keyword(s):

Degradation Rate ◽

Tricarboxylic Acid Cycle ◽

Degradation Pathway ◽

Tricarboxylic Acid ◽

Metabolic Intermediate ◽

Reductive Dehalogenase ◽

Cell Extracts ◽

Toxic Pollutant ◽

Sphingobium Chlorophenolicum

ABSTRACT Pentachlorophenol (PCP) is a toxic pollutant. Its biodegradation has been extensively studied in Sphingobium chlorophenolicum ATCC 39723. All enzymes required to convert PCP to a common metabolic intermediate before entering the tricarboxylic acid cycle have been characterized. One of the enzymes is tetrachloro-p-hydroquinone (TeCH) reductive dehalogenase (PcpC), which is a glutathione (GSH) S-transferase (GST). PcpC catalyzes the GSH-dependent conversion of TeCH to trichloro-p-hydroquinone (TriCH) and then to dichloro-p-hydroquinone (DiCH) in the PCP degradation pathway. PcpC is susceptible to oxidative damage, and the damaged PcpC produces glutathionyl (GS) conjugates, GS-TriCH and GS-DiCH, which cannot be further metabolized by PcpC. The fate and effect of GS-hydroquinone conjugates were unknown. A putative GST gene (pcpF) is located next to pcpC on the bacterial chromosome. The pcpF gene was cloned, and the recombinant PcpF was purified. The purified PcpF was able to convert GS-TriCH and GS-DiCH conjugates to TriCH and DiCH, respectively. The GS-hydroquinone lyase reactions catalyzed by PcpF are rather unusual for a GST. The disruption of pcpF in S. chlorophenolicum made the mutant lose the GS-hydroquinone lyase activities in the cell extracts. The mutant became more sensitive to PCP toxicity and had a significantly decreased PCP degradation rate, likely due to the accumulation of the GS-hydroquinone conjugates inside the cell. Thus, PcpF played a maintenance role in PCP degradation and converted the GS-hydroquinone conjugates back to the intermediates of the PCP degradation pathway.

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Response of enzyme activities and metabolic intermediate concentrations to glucagon administration in hepatopancreas and muscle of carp +

Fisheries Science ◽

10.1046/j.1444-2906.2001.00212.x ◽

2001 ◽

Vol 67 (1) ◽

pp. 157-162 ◽

Cited By ~ 9

Author(s):

Tsuyoshi Sugita ◽

Sadao Shimeno ◽

Yasunori Ohkubo ◽

Hidetsuyo Hosokawa ◽

Toshiro Masumoto

Keyword(s):

Enzyme Activities ◽

Metabolic Intermediate

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Pyrolysis of Furfural Residues and Possible Utilization Pathway

10.5772/intechopen.98734 ◽

2021 ◽

Author(s):

George Ngusale

Keyword(s):

Nitrogen Content ◽

Minor Component ◽

Pure Nitrogen ◽

Thermogravimetric Analyzer ◽

Furfural Residues ◽

Furfural Residue ◽

Ftir Spectrometer ◽

A Minor ◽

Utilization Pathway ◽

Low Nitrogen

The manuscript attempts to understand the evolution of NOx precursors: NH3 and HCN from Pyrolysis of furfural residue (FR). The pyrolysis process was carried out in a thermogravimetric analyzer (TGA) coupled to Fourier-transform infrared (FTIR) spectrometer. The combination revealed insightful information on the evolution of NH3 and HCN. This could help us better understand the characteristics of FR derived from furfural production especially with regard to NH3 and HCN. Nitrogen is considered a minor component in biomass wastes; in this study nitrogen content is about 0.57%. However, the pollution potential poised by low nitrogen content is huge through both direct and indirect processes. Thus, this study presents results that were found with regard to FR pyrolysis in pure nitrogen environment. At the heating rate of 40°C/min−1, the only NOx precursor detected was HCN at 713 cm−1 as per the database provided by National Institute of Standards and Technology (NIST). NH3 was not detected. The particle size of FR used ranged between 0.15–0.25 mm.

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Alkylation of Cellular Macromolecules by Reactive Metabolic Intermediate of DBCP

Journal of Pesticide Science ◽

10.1584/jpestics.5.45 ◽

1980 ◽

Vol 5 (1) ◽

pp. 45-53 ◽

Cited By ~ 13

Author(s):

Yasuhiro KATO ◽

Kiyoshi SATO ◽

Osami MATANO ◽

Shinko GOTO

Keyword(s):

Metabolic Intermediate

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