scholarly journals Formate-Dependent Acetogenic Utilization of Glucose by the Fecal Acetogen Clostridium bovifaecis

2020 ◽  
Vol 86 (23) ◽  
Author(s):  
Ye Yao ◽  
Bo Fu ◽  
Dongfei Han ◽  
Yan Zhang ◽  
He Liu
Keyword(s):  
Formate Dehydrogenase ◽  
Ecological Impact ◽  
Pcr Analysis ◽  
Acetyl Coa ◽  
Gene Encoding ◽  
Intestinal Environment ◽  
Acetogenic Bacteria ◽  
Metabolic Feature ◽  
Acetyl Coa Pathway ◽  
Insight Into

ABSTRACT Acetogenic bacteria are a diverse group of anaerobes that use the reductive acetyl coenzyme A (acetyl-CoA) (Wood-Ljungdahl) pathway for CO2 fixation and energy conservation. The conversion of 2 mol CO2 into acetyl-CoA by using the Wood-Ljungdahl pathway as the terminal electron accepting process is the most prominent metabolic feature for these microorganisms. However, here, we describe that the fecal acetogen Clostridium bovifaecis strain BXX displayed poor metabolic capabilities of autotrophic acetogenesis, and acetogenic utilization of glucose occurred only with the supplementation of formate. Genome analysis of Clostridium bovifaecis revealed that it contains almost the complete genes of the Wood-Ljungdahl pathway but lacks the gene encoding formate dehydrogenase, which catalyzes the reduction of CO2 to formate as the first step of the methyl branch of the Wood-Ljungdahl pathway. The lack of a gene encoding formate dehydrogenase was verified by PCR, reverse transcription-PCR analysis, enzyme activity assay, and its formate-dependent acetogenic utilization of glucose on DNA, RNA, protein, and phenotype level, respectively. The lack of a formate dehydrogenase gene may be associated with the adaption to a formate-rich intestinal environment, considering the isolating source of strain BXX. The formate-dependent acetogenic growth of Clostridium bovifaecis provides insight into a unique metabolic feature of fecal acetogens. IMPORTANCE The acetyl-CoA pathway is an ancient pathway of CO2 fixation, which converts 2 mol of CO2 into acetyl-CoA. Autotrophic growth with H2 and CO2 via the acetyl-CoA pathway as the terminal electron accepting process is the most unique feature of acetogenic bacteria. However, the fecal acetogen Clostridium bovifaecis strain BXX displayed poor metabolic capabilities of autotrophic acetogenesis, and acetogenic utilization of glucose occurred only with the supplementation of formate. The formate-dependent acetogenic growth of Clostridium bovifaecis was associated with its lack of a gene encoding formate dehydrogenase, which may result from adaption to a formate-rich intestinal environment. This study gave insight into a unique metabolic feature of fecal acetogens. Because of the requirement of formate for the acetogenic growth of certain acetogens, the ecological impact of acetogens could be more complex and important in the formate-rich environment due to their trophic interactions with other microbes.

scholarly journals Carbon Isotope Fractionation during Catabolism and Anabolism in Acetogenic Bacteria Growing on Different Substrates

2016 ◽  
Vol 82 (9) ◽  
pp. 2728-2737 ◽  
Author(s):  
Christoph Freude ◽  
Martin Blaser
Keyword(s):  
Isotope Fractionation ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Moorella Thermoacetica ◽  
Acetogenic Bacteria ◽  
Carbon Substrates ◽  
Acetyl Coa Pathway ◽  
Thermoanaerobacter Kivui ◽  
Sporomusa Sphaeroides

ABSTRACTHomoacetogenic bacteria are versatile microbes that use the acetyl coenzyme A (acetyl-CoA) pathway to synthesize acetate from CO2and hydrogen. Likewise, the acetyl-CoA pathway may be used to incorporate other 1-carbon substrates (e.g., methanol or formate) into acetate or to homoferment monosaccharides completely to acetate. In this study, we analyzed the fractionation of pure acetogenic cultures grown on different carbon substrates. While the fractionation ofSporomusa sphaeroidesgrown on C1compounds was strong (εC1, −49‰ to −64‰), the fractionation ofMoorella thermoaceticaandThermoanaerobacter kivuiusing glucose (εGlu= −14.1‰) was roughly one-third as strong, suggesting a contribution of less-depleted acetate from fermentative processes. ForM. thermoacetica, this could indeed be validated by the addition of nitrate, which inhibited the acetyl-CoA pathway, resulting in fractionation during fermentation (εferm= −0.4‰). In addition, we determined the fractionation into microbial biomass ofT. kivuigrown on H2/CO2(εanabol.= −28.6‰) as well as on glucose (εanabol.= +2.9‰).

scholarly journals Carbon Isotope Fractionation of 11 Acetogenic Strains Grown on H2and CO2

2012 ◽  
Vol 79 (6) ◽  
pp. 1787-1794 ◽  
Author(s):  
Martin B. Blaser ◽  
Lisa K. Dreisbach ◽  
Ralf Conrad
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Stable Carbon ◽  
Acetyl Coa ◽  
Fractionation Factor ◽  
Content Type ◽  
Carbon Isotope Fractionation ◽  
Acetogenic Bacteria ◽  
Acetyl Coa Pathway ◽  
Isotope Fractionation Factor

ABSTRACTAcetogenic bacteria are able to grow autotrophically on hydrogen and carbon dioxide by using the acetyl coenzyme A (acetyl-CoA) pathway. Acetate is the end product of this reaction. In contrast to the fermentative route of acetate production, which shows almost no fractionation of carbon isotopes, the acetyl-CoA pathway has been reported to exhibit a preference for light carbon. InAcetobacterium woodiithe isotope fractionation factor (ε) for13C and12C has previously been reported to be ε = −58.6‰. To investigate whether such a strong fractionation is a general feature of acetogenic bacteria, we measured the stable carbon isotope fractionation factor of 10 acetogenic strains grown on H2and CO2. The average fractionation factor was εTIC= −57.2‰ for utilization of total inorganic carbon and εacetate= −54.6‰ for the production of acetate. The strongest fractionation was found forSporomusa sphaeroides(εTIC= −68.3‰), the lowest fractionation forMorella thermoacetica(εTIC= −38.2‰). To investigate the reproducibility of our measurements, we determined the fractionation factor of 21 biological replicates ofThermoanaerobacter kivui. In general, our study confirmed the strong fractionation of stable carbon during chemolithotrophic acetate formation in acetogenic bacteria. However, the specific characteristics of the bacterial strain, as well as the cultural conditions, may have a moderate influence on the overall fractionation.

scholarly journals Exploration of Alternative Splicing Events in Mesenchymal Stem Cells from Human Induced Pluripotent Stem Cells

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 737
Author(s):  
Ji-Eun Jeong ◽  
Binna Seol ◽  
Han-Seop Kim ◽  
Jae-Yun Kim ◽  
Yee-Sook Cho
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Alternative Splicing ◽  
Functional Enrichment ◽  
Actin Binding ◽  
Pcr Analysis ◽  
Valuable Insight ◽  
Sequencing Analysis ◽  
Induced Pluripotent ◽  
Insight Into

Although comparative genome-wide transcriptomic analysis has provided insight into the biology of human induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), the distinct alternative splicing (AS) signatures of iMSCs remain elusive. Here, we performed Illumina RNA sequencing analysis to characterize AS events in iMSCs compared with tissue-derived MSCs. A total of 4586 differentially expressed genes (|FC| > 2) were identified between iMSCs and umbilical cord blood-derived MSCs (UCB-MSCs), including 2169 upregulated and 2417 downregulated genes. Of these, 164 differentially spliced events (BF > 20) in 112 genes were identified between iMSCs and UCB-MSCs. The predominant type of AS found in iMSCs was skipped exons (43.3%), followed by retained introns (19.5%), alternative 3′ (15.2%) and 5′ (12.8%) splice sites, and mutually exclusive exons (9.1%). Functional enrichment analysis showed that the differentially spliced genes (|FC| > 2 and BF > 20) were mainly enriched in functions associated with focal adhesion, extracellular exosomes, extracellular matrix organization, cell adhesion, and actin binding. Splice isoforms of selected genes including TRPT1, CNN2, and AP1G2, identified in sashimi plots, were further validated by RT-PCR analysis. This study provides valuable insight into the biology of iMSCs and the translation of mechanistic understanding of iMSCs into therapeutic applications.

scholarly journals Characterization of a Unique Chromosomal Copper Resistance Gene Cluster from Xanthomonas campestris pv. vesicatoria

2005 ◽  
Vol 71 (12) ◽  
pp. 8284-8291 ◽  
Author(s):  
Huseyin Basim ◽  
Gerald V. Minsavage ◽  
Robert E. Stall ◽  
Jaw-Fen Wang ◽  
Savita Shanker ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Resistance Genes ◽  
Xanthomonas Campestris ◽  
Sinorhizobium Meliloti ◽  
The United States ◽  
Copper Resistance ◽  
Pcr Analysis ◽  
Pepper Plant ◽  
Gene Encoding ◽  
Copper Resistance Genes

ABSTRACT We characterized the copper resistance genes in strain XvP26 of Xanthomonas campestris pv. vesicatoria, which was originally isolated from a pepper plant in Taiwan. The copper resistance genes were localized to a 7,652-bp region which, based on pulsed-field gel electrophoresis and Southern hybridization, was determined to be located on the chromosome. These genes hybridized only weakly, as determined by Southern analysis, to other copper resistance genes in Xanthomonas and Pseudomonas strains. We identified five open reading frames (ORFs) whose products exhibited high levels of amino acid sequence identity to the products of previously reported copper genes. Mutations in ORF1, ORF3, and ORF4 removed copper resistance, whereas mutations in ORF5 resulted in an intermediate copper resistance phenotype and insertions in ORF2 had no effect on resistance conferred to a copper-sensitive recipient in transconjugant tests. Based on sequence analysis, ORF1 was determined to have high levels of identity with the CopR (66%) and PcoR (63%) genes in Pseudomonas syringae pv. tomato and Escherichia coli, respectively. ORF2 and ORF5 had high levels of identity with the PcoS gene in E. coli and the gene encoding a putative copper-containing oxidoreductase signal peptide protein in Sinorhizobium meliloti, respectively. ORF3 and ORF4 exhibited 23% identity to the gene encoding a cation efflux system membrane protein, CzcC, and 62% identity to the gene encoding a putative copper-containing oxidoreductase protein, respectively. The latter two ORFs were determined to be induced following exposure to low concentrations of copper, while addition of Co, Cd, or Zn resulted in no significant induction. PCR analysis of 51 pepper and 34 tomato copper-resistant X. campestris pv. vesicatoria strains collected from several regions in Taiwan between 1987 and 2000 and nine copper-resistant strains from the United States and South America showed that successful amplification of DNA was obtained only for strain XvP26. The organization of this set of copper resistance genes appears to be uncommon, and the set appears to occur rarely in X. campestris pv. vesicatoria.

scholarly journals Antagonism between Aminoglycosides and β-Lactams in a Methicillin-Resistant Staphylococcus aureus Isolate Involves Induction of an Aminoglycoside-Modifying Enzyme

2002 ◽  
Vol 46 (5) ◽  
pp. 1516-1521 ◽  
Author(s):  
Takashi Ida ◽  
Ryoichi Okamoto ◽  
Masato Nonoyama ◽  
Kazuhiko Irinoda ◽  
Mizuyo Kurazono ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Activities ◽  
Hybrid Structure ◽  
Conjugative Plasmid ◽  
Pcr Analysis ◽  
Aminoglycoside Resistance ◽  
Gene Encoding ◽  
Methicillin Resistant ◽  
Aureus Isolate

ABSTRACT We encountered three clinical isolates of methicillin-resistant Staphylococcus aureus which were susceptible to netilmicin and arbekacin in the absence of β-lactam antibiotics but which were resistant to them in the presence of β-lactam antibiotics. One of these strains, KU5801, was used to further investigate the antagonism between aminoglycosides and β-lactam antibiotics. β-Lactam antibiotics induced bacterial synthesis of aminoglycoside-6′-N-acetyltransferase and 2"-O-phosphotransferase [AAC(6′)-APH(2")] in association with decreased antimicrobial activities of aminoglycosides. A 14.4-kb EcoRI fragment that included the genes that control for β-lactam-inducible aminoglycoside resistance was cloned from a 31-kb conjugative plasmid present in KU5801. Restriction fragment mapping and PCR analysis suggested that a Tn4001-like element containing a gene encoding AAC(6′)-APH(2") was located downstream from a truncated blaZ gene. The DNA sequence between blaR1 and a Tn4001-like element was determined. The Tn4001-IS257 hybrid structure was cointegrated into the blaZ gene, and the typical sequences for the termination of transcription were not found between these regions. We deduced that antagonism of aminoglycosides by β-lactam antibiotics in isolate KU5801 involved transcription of the aac(6′)-Ie-aph(2")-Ia gene under the influence of the system regulating penicillinase production.

scholarly journals A Deeply Branching Thermophilic Bacterium with an Ancient Acetyl-CoA Pathway Dominates a Subsurface Ecosystem

PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e30559 ◽  
Author(s):  
Hideto Takami ◽  
Hideki Noguchi ◽  
Yoshihiro Takaki ◽  
Ikuo Uchiyama ◽  
Atsushi Toyoda ◽  
...  
Keyword(s):  
Thermophilic Bacterium ◽  
Acetyl Coa ◽  
Acetyl Coa Pathway

Discovery and Characterization of Differentially Expressed Soybean MiRNAs and Their Targets During Soybean Mosaic Virus Infection Unveils Novel Insight Into Soybean-SMV Interaction

2021 ◽  
Author(s):  
Bowen Li ◽  
Adhimoolam Karthikeyan ◽  
Liqun Wang ◽  
Jinlong Yin ◽  
Tongtong Jin ◽  
...  
Keyword(s):  
Virus Infection ◽  
Mosaic Virus ◽  
Target Genes ◽  
Soybean Mosaic Virus ◽  
Expression Patterns ◽  
Defense Responses ◽  
Pcr Analysis ◽  
Functional Annotations ◽  
Additional Information ◽  
Insight Into

Abstract Background: Soybean mosaic virus (SMV) is the most devastating pathogen of soybean. MicroRNAs (miRNAs) are a class of non-coding RNAs (21-24 nucleotides) and play important roles in regulating defense responses against pathogens. However, miRNA's response to SMV in soybean is not as well documented. Result: In this study, we analyzed 18 miRNA libraries, including three biological replicates from two soybean lines (Resistant and susceptible lines to SMV strain SC3 selected from the near-isogenic lines of Qihuang No. 1× Nannong1138-2) after virus infection at three different time intervals (0 dpi, 7 dpi, and 14 dpi). A total of 1,092 miRNAs, including 608 known miRNAs and 484 novel miRNAs were detected. Differential expression analyses identified the miRNAs responded during soybean-SMV interaction. Then, miRNAs potential target genes were predicted via data mining, and functional annotation was done by Gene Ontology (GO) analysis. Eventually, the expression patterns of several miRNAs validated by quantitative real-time PCR analysis are consistent with sequencing results. Conclusion: We have identified a large number of miRNAs and their target genes and also functional annotations. Our study provides additional information on soybean miRNAs and an insight into the role of miRNAs during SMV-infection in soybean.

scholarly journals Overproduction of SecA Suppresses the Export Defect Caused by a Mutation in the Gene Encoding the Escherichia coli Export Chaperone SecB

1999 ◽  
Vol 181 (10) ◽  
pp. 3010-3017 ◽  
Author(s):  
Heather A. Cook ◽  
Carol A. Kumamoto
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane Proteins ◽  
Protein A ◽  
In Vivo Studies ◽  
Wild Type ◽  
Gene Encoding ◽  
Precursor Proteins ◽  
Additional Support ◽  
Insight Into

ABSTRACT SecB is a cytosolic protein required for rapid and efficient export of particular periplasmic and outer membrane proteins inEscherichia coli. SecB promotes export by stabilizing newly synthesized precursor proteins in a nonnative conformation and by targeting the precursors to the inner membrane. Biochemical studies suggest that SecB facilitates precursor targeting by binding to the SecA protein, a component of the membrane-embedded translocation apparatus. To gain more insight into the functional interaction of SecB and SecA, in vivo, mutations in the secA locus that compensate for the export defect caused by the secBmissense mutation secBL75Q were isolated. Two suppressors were isolated, both of which led to the overproduction of wild-type SecA protein. In vivo studies demonstrated that the SecBL75Q mutant protein releases precursor proteins at a lower rate than does wild-type SecB. Increasing the level of SecA protein in the cell was found to reverse this slow-release defect, indicating that overproduction of SecA stimulates the turnover of SecBL75Q-precursor complexes. These findings lend additional support to the proposed pathway for precursor targeting in which SecB promotes targeting to the translocation apparatus by binding to the SecA protein.

scholarly journals The extended reductive acetyl-CoA pathway: ATPases in metal cluster maturation and reductive activation

2014 ◽  
Vol 395 (5) ◽  
pp. 545-558 ◽  
Author(s):  
Jae-Hun Jeoung ◽  
Sebastian Goetzl ◽  
Sandra Elisabeth Hennig ◽  
Jochen Fesseler ◽  
Christina Wörmann ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Metal Cluster ◽  
Potential Gradient ◽  
Reductive Activation ◽  
Acetyl Coa ◽  
Oxygen Sensitive ◽  
Metal Organic ◽  
Acetyl Group ◽  
Acetyl Coa Pathway ◽  
Atp Binding And Hydrolysis

Abstract The reductive acetyl-coenzyme A (acetyl-CoA) pathway, also known as the Wood-Ljungdahl pathway, allows reduction and condensation of two molecules of carbon dioxide (CO2) to build the acetyl-group of acetyl-CoA. Productive utilization of CO2 relies on a set of oxygen sensitive metalloenzymes exploiting the metal organic chemistry of nickel and cobalt to synthesize acetyl-CoA from activated one-carbon compounds. In addition to the central catalysts, CO dehydrogenase and acetyl-CoA synthase, ATPases are needed in the pathway. This allows the coupling of ATP binding and hydrolysis to electron transfer against a redox potential gradient and metal incorporation to (re)activate one of the central players of the pathway. This review gives an overview about our current knowledge on how these ATPases achieve their tasks of maturation and reductive activation.

scholarly journals The Erwinia chrysanthemi 3937 PhoQ Sensor Kinase Regulates Several Virulence Determinants

2006 ◽  
Vol 188 (8) ◽  
pp. 3088-3098 ◽  
Author(s):  
Balakrishnan Venkatesh ◽  
Lavanya Babujee ◽  
Hui Liu ◽  
Pete Hedley ◽  
Takashi Fujikawa ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Regulatory System ◽  
Soft Rot ◽  
Erwinia Chrysanthemi ◽  
Pcr Analysis ◽  
Sensor Kinase ◽  
Virulence Determinants ◽  
Gene Encoding ◽  
Reverse Transcription Pcr ◽  
Two Component

ABSTRACT The PhoPQ two-component system regulates virulence factors in Erwinia chrysanthemi, a pectinolytic enterobacterium that causes soft rot in several plant species. We characterized the effect of a mutation in phoQ, the gene encoding the sensor kinase PhoQ of the PhoPQ two-component regulatory system, on the global transcriptional profile of E. chrysanthemi using cDNA microarrays and further confirmed our results by quantitative reverse transcription-PCR analysis. Our results indicate that a mutation in phoQ affects transcription of at least 40 genes, even in the absence of inducing conditions. Enhanced expression of several genes involved in iron metabolism was observed in the mutant, including that of the acs operon that is involved in achromobactin biosynthesis and transport. This siderophore is required for full virulence of E. chrysanthemi, and its expression is governed by the global repressor protein Fur. Changes in gene expression were also observed for membrane transporters, stress-related genes, toxins, and transcriptional regulators. Our results indicate that the PhoPQ system governs the expression of several additional virulence factors and may also be involved in interactions with other regulatory systems.

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