scholarly journals PHA Production and PHA Synthases of the Halophilic Bacterium Halomonas sp. SF2003

2020 ◽  
Vol 7 (1) ◽  
pp. 29
Author(s):  
Tatiana Thomas ◽  
Kumar Sudesh ◽  
Alexis Bazire ◽  
Anne Elain ◽  
Hua Tiang Tan ◽  
...  
Keyword(s):  
Marine Bacterium ◽  
Carbon Sources ◽  
Halophilic Bacterium ◽  
Growth Conditions ◽  
In Silico Study ◽  
Carbon Substrates ◽  
Cupriavidus Necator H16 ◽  
Pha Production

Among the different tools which can be studied and managed to tailor-make polyhydroxyalkanoates (PHAs) and enhance their production, bacterial strain and carbon substrates are essential. The assimilation of carbon sources is dependent on bacterial strain’s metabolism and consequently cannot be dissociated. Both must wisely be studied and well selected to ensure the highest production yield of PHAs. Halomonas sp. SF2003 is a marine bacterium already identified as a PHA-producing strain and especially of poly-3-hydroxybutyrate (P-3HB) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P-3HB-co-3HV). Previous studies have identified different genes potentially involved in PHA production by Halomonas sp. SF2003, including two phaC genes with atypical characteristics, phaC1 and phaC2. At the same time, an interesting adaptability of the strain in front of various growth conditions was highlighted, making it a good candidate for biotechnological applications. To continue the characterization of Halomonas sp. SF2003, the screening of carbon substrates exploitable for PHA production was performed as well as production tests. Additionally, the functionality of both PHA synthases PhaC1 and PhaC2 was investigated, with an in silico study and the production of transformant strains, in order to confirm and to understand the role of each one on PHA production. The results of this study confirm the adaptability of the strain and its ability to exploit various carbon substrates, in pure or mixed form, for PHA production. Individual expression of PhaC1 and PhaC2 synthases in a non-PHA-producing strain, Cupriavidus necator H16 PHB¯4 (DSM 541), allows obtaining PHA production, demonstrating at the same time, functionality and differences between both PHA synthases. All the results of this study confirm the biotechnological interest in Halomonas sp. SF2003.

scholarly journals Nitric Oxide Overproduction by cue1 Mutants Differs on Developmental Stages and Growth Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1484 ◽  
Author(s):  
Tamara Lechón ◽  
Luis Sanz ◽  
Inmaculada Sánchez-Vicente ◽  
Oscar Lorenzo
Keyword(s):  
Nitric Oxide ◽  
Carbon Metabolism ◽  
Root Elongation ◽  
Developmental Stages ◽  
Primary Root ◽  
Carbon Sources ◽  
Growth Conditions ◽  
No Production

The cue1 nitric oxide (NO) overproducer mutants are impaired in a plastid phosphoenolpyruvate/phosphate translocator, mainly expressed in Arabidopsis thaliana roots. cue1 mutants present an increased content of arginine, a precursor of NO in oxidative synthesis processes. However, the pathways of plant NO biosynthesis and signaling have not yet been fully characterized, and the role of CUE1 in these processes is not clear. Here, in an attempt to advance our knowledge regarding NO homeostasis, we performed a deep characterization of the NO production of four different cue1 alleles (cue1-1, cue1-5, cue1-6 and nox1) during seed germination, primary root elongation, and salt stress resistance. Furthermore, we analyzed the production of NO in different carbon sources to improve our understanding of the interplay between carbon metabolism and NO homeostasis. After in vivo NO imaging and spectrofluorometric quantification of the endogenous NO levels of cue1 mutants, we demonstrate that CUE1 does not directly contribute to the rapid NO synthesis during seed imbibition. Although cue1 mutants do not overproduce NO during germination and early plant development, they are able to accumulate NO after the seedling is completely established. Thus, CUE1 regulates NO homeostasis during post-germinative growth to modulate root development in response to carbon metabolism, as different sugars modify root elongation and meristem organization in cue1 mutants. Therefore, cue1 mutants are a useful tool to study the physiological effects of NO in post-germinative growth.

scholarly journals Characterization of Three Small Proteins inBrucella abortusLinked to Fucose Utilization

2018 ◽  
Vol 200 (18) ◽  
Author(s):  
James A. Budnick ◽  
Lauren M. Sheehan ◽  
Lin Kang ◽  
Pawel Michalak ◽  
Clayton C. Caswell
Keyword(s):  
Brucella Abortus ◽  
Transcriptional Control ◽  
Sugar Transport ◽  
Genetic System ◽  
Growth Conditions ◽  
Content Type ◽  
Small Regulatory Rna ◽  
Small Proteins

ABSTRACTElucidating the function of proteins <50 amino acids in length is no small task. Nevertheless, small proteins can play vital roles in the lifestyle of bacteria and influence the virulence of pathogens; thus, the investigation of the small proteome is warranted. Recently, our group identified theBrucella abortusprotein VtlR as a transcriptional activator of four genes, one of which is the well-studied small regulatory RNA AbcR2, while the other three genes encode hypothetical small proteins, two of which are highly conserved among the orderRhizobiales. This study provides evidence that all three genes encode authentic small proteins and that all three are highly expressed under oxidative stress, low-pH, and stationary-phase growth conditions. Fractionation of the cells revealed that the proteins are localized to the membranes ofB. abortus. We demonstrate that the small proteins under the transcriptional control of VtlR are not accountable for attenuation observed with theB. abortusvtlRdeletion strain. However, there is an association between VtlR-regulated genes and growth inhibition in the presence of the sugarl-fucose. Subsequent transcriptomic analyses revealed thatB. abortusinitiates the transcription of a locus encoding a putative sugar transport and utilization system when the bacteria are cultured in the presence ofl-fucose. Altogether, our observations characterize the role of the VtlR-controlled small proteins BAB1_0914, BAB2_0512, and BAB2_0574 in the biology ofB. abortus, particularly in the capacity of the bacteria to utilizel-fucose.IMPORTANCEDespite being one of the most common zoonoses worldwide, there is currently no human vaccine to combat brucellosis. Therefore, a better understanding of the pathogenesis and biology ofBrucellaspp., the causative agent of brucellosis, is essential for the discovery of novel therapeutics against these highly infectious bacteria. In this study, we further characterize the virulence-associated transcriptional regulator VtlR inBrucella abortus. Our findings not only shed light on our current understanding of a virulence related genetic system inBrucellaspp. but also increase our knowledge of small proteins in the field of bacteriology.

scholarly journals Resistance to pentamidine is mediated by AdeAB, regulated by AdeRS, and influenced by growth conditions inAcinetobacter baumanniiATCC 17978

2018 ◽  
Author(s):  
Felise G. Adams ◽  
Uwe H. Stroeher ◽  
Karl A. Hassan ◽  
Shashikanth Marri ◽  
Melissa H. Brown
Keyword(s):  
Signal Transduction ◽  
Antimicrobial Resistance ◽  
Carbon Sources ◽  
Growth Conditions ◽  
Multidrug Efflux ◽  
Intrinsic Resistance ◽  
Multidrug Efflux Pumps ◽  
Two Component ◽  
Two Component Signal Transduction

AbstractIn recent years, effective treatment of infections caused byAcinetobacter baumanniihas become challenging due to the ability of the bacterium to acquire or up-regulate antimicrobial resistance determinants. Two component signal transduction systems are known to regulate expression of virulence factors including multidrug efflux pumps. Here, we investigated the role of the AdeRS two component signal transduction system in regulating the AdeAB efflux system, determined whether AdeA and/or AdeB can individually confer antimicrobial resistance, and explored the interplay between pentamidine resistance and growth conditions inA. baumanniiATCC 17978. Results identified that deletion ofadeRSaffected resistance towards chlorhexidine and 4’,6-diamidino-2-phenylindole dihydrochloride, two previously defined AdeABC substrates, and also identified an 8-fold decrease in resistance to pentamidine. Examination of ΔadeA, ΔadeBand ΔadeABcells augmented results seen for ΔadeRSand identified a set of dicationic AdeAB substrates. RNA-sequencing of ΔadeRSrevealed transcription of 290 genes were ≥2-fold altered compared to the wildtype. Pentamidine shock significantly increasedadeAexpression in the wildtype, but decreased it in ΔadeRS, implying that AdeRS activatesadeABtranscription in ATCC 17978. Investigation under multiple growth conditions, including the use of Biolog phenotypic microarrays, revealed resistance to pentamidine in ATCC 17978 and mutants could be altered by bioavailability of iron or utilization of different carbon sources. In conclusion, the results of this study provide evidence that AdeAB in ATCC 17978 can confer intrinsic resistance to a subset of dicationic compounds and in particular, resistance to pentamidine can be significantly altered depending on the growth conditions.

scholarly journals Antagonism and synergism in Gardnerella vaginalis strains isolated from women with bacterial vaginosis

2010 ◽  
Vol 59 (8) ◽  
pp. 891-897 ◽  
Author(s):  
G. S. Teixeira ◽  
K. L. K. Soares-Brandão ◽  
K. M. G. R. Branco ◽  
J. L. M. Sampaio ◽  
R. M. D. Nardi ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Chemical Nature ◽  
Growth Conditions ◽  
Antagonistic Activity ◽  
Gardnerella Vaginalis ◽  
Ecological Role ◽  
Micro Organisms

Antagonistic and synergistic substances are important for interactions between micro-organisms associated with human body surfaces, either in healthy or in diseased conditions. In the present study, such compounds produced by Gardnerella vaginalis strains isolated from women with bacterial vaginosis (BV) were detected in vitro and the antagonistic ones were partially characterized. Among 11 G. vaginalis strains tested, all showed antagonistic activity against at least one of the 22 indicator bacteria assayed. Interestingly, for some of these strains, antagonism reverted to synergism, favouring one of the indicator strains (Peptostreptococcus anaerobius) when the growth medium was changed. Partial characterization of antagonistic substances suggested a bacteriocin-like chemical nature. Depending on growth conditions, G. vaginalis isolated from women with BV produced antagonistic or synergistic compounds for other bacterial components of the vaginal ecosystem. This is the first report to our knowledge of the production of antagonistic and/or synergistic substances by G. vaginalis. This ability may be a pivotal factor in understanding BV and the ecological role of this bacterium in the vaginal environment.

Marine Biosurfactants, II. Production and Characterization of an Anionic Trehalose Tetraester from the Marine Bacterium Arthrobacter sp. EK 1

1991 ◽  
Vol 46 (3-4) ◽  
pp. 204-209 ◽  
Author(s):  
A. Passeri ◽  
S. Lang ◽  
F. Wagner ◽  
Victor Wray
Keyword(s):  
Fatty Acids ◽  
Nitrogen Limitation ◽  
Marine Bacterium ◽  
Thick Layer ◽  
Growth Conditions ◽  
Main Fraction ◽  
Exact Position ◽  
Chain Lengths ◽  
Layer Chromatography

Within a screening for biosurfactants we could isolate various n-alkanes utilizing marine bacteria which were capable of synthesizing glycolipids. One strain was identified as Arthrobacter sp. EK 1 which produced trehalose lipids. After purification by column and thick layer chromatography the main fraction, an anionic 2,3,4,2′-trehalose tetraester, was obtained. The chain lengths of fatty acids ranged from 8 up to 14, furthermore succinate could be detected. Since the place of substitution of succinate has so far not been cited in literature, a definitive structural elucidation was carried out chemically by hydroboration and by 1H, 2 D1H, 13C and 13C - 1H correlation NMR measurements. All investigations confirmed the exact position of succinate at C2 atom of trehalose. After improvement of growth conditions the production of the trehalose tetraester increased up to 4.8 g/1 during a fermentation in a 20 1 bioreactor under nitrogen limitation.

Characterization of Azomonas macrocytogenes strains isolated from Alberta soils

1987 ◽  
Vol 33 (9) ◽  
pp. 830-833 ◽  
Author(s):  
William J. Page ◽  
S. Karen Collinson
Keyword(s):  
Nitrogen Fixation ◽  
Agrobacterium Tumefaciens ◽  
Cell Morphology ◽  
Carbon Sources ◽  
Erwinia Carotovora ◽  
Growth Conditions ◽  
Dihydroxybenzoic Acid ◽  
Fluorescent Compound ◽  
Good Agreement

Five strains of Azomonas macrocytogenes were identified from a collection of aerobic nitrogen-fixing organisms obtained from Alberta soils. The cell morphology, colony appearance, and growth conditions of these five isolates and their use of nitrogen and carbon sources were in good agreement with four standard Azomonas macrocytogenes strains. The new strains did not produce N,N,N′,N′-tetramethyl-p-phenylenediamine-dependent cytochrome oxidase, were unable to form true cysts, formed blue–white fluorescent compound(s) under iron-limited conditions, and excreted 3,4-dihydroxybenzoic acid into culture fluids. The detection of this catechol proved to be more reliable and convenient than the observation of the red–violet colour of its ferrated form, which was a variable occurrence in older cultures. Four of the new strains were antagonistic to Agrobacterium tumefaciens and two strains stimulated Erwinia carotovora growth. The new strains also demonstrated nitrogen fixation under molybdate-deficient conditions, which suggested the presence of an alternative molybdate-independent nitrogenase.

scholarly journals Role of Siderophore Biosynthesis in Virulence of Staphylococcus aureus: Identification and Characterization of Genes Involved in Production of a Siderophore

2004 ◽  
Vol 72 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Suzanne E. Dale ◽  
Amanda Doherty-Kirby ◽  
Gilles Lajoie ◽  
David E. Heinrichs
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Conditions ◽  
Siderophore Production ◽  
Coagulase Negative Staphylococci ◽  
Iron Restriction ◽  
Growth Deficiency ◽  
Molecular Determinants ◽  
Identification And Characterization

ABSTRACT Molecular determinants underlying the production of siderophores in the human and animal pathogen Staphylococcus aureus and the contribution of siderophore production to the virulence of this bacterium have, until now, remained undefined. Here, we show that S. aureus strains RN6390 and Newman produce siderophore when the cells are starved for iron. We further identified and characterized a nine-gene, iron-regulated operon, designated sbn and situated between sirABC and galE on the S. aureus chromosome, that is involved in the production of a siderophore. Mutation of the sbnE gene, in both RN6390 and Newman, eliminates the ability of these strains to produce a siderophore under iron-limited growth conditions, while introduction of multicopy sbnE into sbnE mutants complemented the inability of the mutants to produce the siderophore. sbnE mutants, in both the RN6390 and Newman backgrounds, displayed a drastic growth deficiency, compared to the wild type, in iron-restricted growth medium, whereas no such deficiency was observed during growth in iron-replete medium. Complemented mutants showed a restored ability to grow under iron restriction. We further showed that an sbnE mutant was compromised in a murine kidney abscess model of S. aureus infection, illustrating the importance of siderophore production to the pathogenicity of S. aureus. sbn genes were present in all S. aureus strains tested (and all S. aureus genome sequences) but were undetectable in any of the 13 coagulase-negative staphylococci tested, including Staphylococcus epidermidis.

scholarly journals Characterization of Polyhydroxyalkanoates Produced by Contaminated Soil Bacteria using Wastewater and Glucose as Carbon Sources

2015 ◽  
Vol 14 (9) ◽  
pp. 1605-1611
Author(s):  
S Munir ◽  
N Jamil
Keyword(s):  
Carbon Source ◽  
Contaminated Soil ◽  
Volatile Fatty Acids ◽  
Carbon Sources ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
Different Types ◽  
Pha Production ◽  
Different Sources

Purpose: To isolate polyhydroxyalkanoates (PHA)-producing bacterial strains from contaminated soil using industrial wastewater and glucose as carbon soured by Macrogen sequencing. Two different sources, namely, glucose and wastewater were used to ces.Methods: The strains were isolated and identified as Pseudomonas, Bacillus, Enterobacter, Exiguobacterium and Stenotrophomonas using biochemical tests and further confirmevaluate and  compare the use of wastewater as a carbon source for PHA production. The biomass obtained was analyzed by Fourier transform infra-red (FTIR) to identify the presence of PHA in it. Afterwards, PHA extraction was carried out and then gas chromatography (GC) performed to identify PHA monomers.Results: Utilization of glucose resulted in the production of PHB, while wastewater yielded copolymers poly-3 hydroxybutyrate-co-3hydroxyvalerate P(3HB-co-3HV) due to its content of volatile fatty acids such as acetic acid, propionic acid and butyric acid, which led to the production of different types of polymers. The maximum PHA production was 41 ± 0.22 % obtained for Stenotrophomonas (SM03) using 2 % glucose as carbon source while for wastewater, maximum production was achieved by the Pseudomonas strain (SM01).Conclusion: Wastewater is produced in large quantities daily during various activities and therefore can be used as a cheap carbon source for the production of valuable products such as PHA.Keywords: Polyhydroxyalkanoates, Wastewater, Glucose, Pseudomonas strain, Stenotrophomonas

Characterization of polar membrane lipids of the extremely halophilic bacterium Salinibacter ruber and possible role of cardiolipin

2009 ◽  
Vol 1791 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Veronica M.T. Lattanzio ◽  
Maristella Baronio ◽  
Aharon Oren ◽  
Nicholas J. Russell ◽  
Angela Corcelli
Keyword(s):  
Membrane Lipids ◽  
Halophilic Bacterium

Novel insights into nickel import in Staphylococcus aureus: the positive role of free histidine and structural characterization of a new thiazolidine-type nickel chelator

Metallomics ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 613-621 ◽  
Author(s):  
H. Lebrette ◽  
E. Borezée-Durant ◽  
L. Martin ◽  
P. Richaud ◽  
E. Boeri Erba ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Structural Characterization ◽  
Growth Conditions ◽  
Positive Role ◽  
Type Nickel

Staphylococcus aureuspossesses two canonical ABC-importers dedicated to nickel acquisition: the NikABCDE and the CntABCDF systems, active under different growth conditions.

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