The Role of Lectin-Carbohydrate Biospecific Interactions between Medicinal Basidiomycetes Mushroom Grifola frondosa (Dicks.: Fr.) S. F. Gray and Azospirillum brasilense During Their Co-cultivation

2008 ◽  
Vol 10 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Lada V. Stepanova ◽  
Andrei V. Schelud'ko ◽  
Elena I. Katsy ◽  
Elena G. Ponomareva ◽  
Valentina E. Nikitina
Keyword(s):  
Azospirillum Brasilense ◽  
Grifola Frondosa ◽  
Biospecific Interactions

GLUTAMATE SYNTHASE FROM AZOSPIRILLUM BRASILENSE: ROLE OF FLAVINS AND IRON SULFUR CENTERS

1991 ◽  
pp. 749-754
Author(s):  
Maria A. Vanoni ◽  
Giuliana Zanetti ◽  
Bruno Curti ◽  
Dale E. Edmondson
Keyword(s):  
Azospirillum Brasilense ◽  
Glutamate Synthase ◽  
Iron Sulfur

Role of a Fasciclin domain protein in photooxidative stress and flocculation in Azospirillum brasilense Sp7

2021 ◽  
pp. 103875
Author(s):  
Ashutosh Prakash Dubey ◽  
Parul Pandey ◽  
Shivangi Mishra ◽  
Parikshit Gupta ◽  
Anil Kumar Tripathi
Keyword(s):  
Azospirillum Brasilense ◽  
Photooxidative Stress ◽  
Azospirillum Brasilense Sp7 ◽  
Domain Protein

scholarly journals Distinct Domains of CheA Confer Unique Functions in Chemotaxis and Cell Length in Azospirillum brasilense Sp7

2017 ◽  
Vol 199 (13) ◽  
Author(s):  
Jessica M. Gullett ◽  
Amber Bible ◽  
Gladys Alexandre
Keyword(s):  
Histidine Kinase ◽  
Azospirillum Brasilense ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Functional Divergence ◽  
Cell Length ◽  
Content Type ◽  
Evolutionary Event ◽  
Cellular Behaviors

ABSTRACT Chemotaxis is the movement of cells in response to gradients of diverse chemical cues. Motile bacteria utilize a conserved chemotaxis signal transduction system to bias their motility and navigate through a gradient. A central regulator of chemotaxis is the histidine kinase CheA. This cytoplasmic protein interacts with membrane-bound receptors, which assemble into large polar arrays, to propagate the signal. In the alphaproteobacterium Azospirillum brasilense, Che1 controls transient increases in swimming speed during chemotaxis, but it also biases the cell length at division. However, the exact underlying molecular mechanisms for Che1-dependent control of multiple cellular behaviors are not known. Here, we identify specific domains of the CheA1 histidine kinase implicated in modulating each of these functions. We show that CheA1 is produced in two isoforms: a membrane-anchored isoform produced as a fusion with a conserved seven-transmembrane domain of unknown function (TMX) at the N terminus and a soluble isoform similar to prototypical CheA. Site-directed and deletion mutagenesis combined with behavioral assays confirm the role of CheA1 in chemotaxis and implicate the TMX domain in mediating changes in cell length. Fluorescence microscopy further reveals that the membrane-anchored isoform is distributed around the cell surface while the soluble isoform localizes at the cell poles. Together, the data provide a mechanism for the role of Che1 in controlling multiple unrelated cellular behaviors via acquisition of a new domain in CheA1 and production of distinct functional isoforms. IMPORTANCE Chemotaxis provides a significant competitive advantage to bacteria in the environment, and this function has been transferred laterally multiple times, with evidence of functional divergence in different genomic contexts. The molecular principles that underlie functional diversification of chemotaxis in various genomic contexts are unknown. Here, we provide a molecular mechanism by which a single CheA protein controls two unrelated functions: chemotaxis and cell length. Acquisition of this multifunctionality is seemingly a recent evolutionary event. The findings illustrate a mechanism by which chemotaxis function may be co-opted to regulate additional cellular functions.

Adhesion of Azospirillum brasilense: role of proteins at the cell-support interface

1996 ◽  
Vol 7 (3-4) ◽  
pp. 113-128 ◽  
Author(s):  
Yves F. Dufrêne ◽  
Christophe J.-P. Boonaert ◽  
Paul G. Rouxhet
Keyword(s):  
Azospirillum Brasilense ◽  
Cell Support

scholarly journals Role of CheB and CheR in the Complex Chemotactic and Aerotactic Pathway of Azospirillum brasilense

2006 ◽  
Vol 188 (13) ◽  
pp. 4759-4768 ◽  
Author(s):  
Bonnie B. Stephens ◽  
Star N. Loar ◽  
Gladys Alexandre
Keyword(s):  
Escherichia Coli ◽  
Steady State ◽  
Azospirillum Brasilense ◽  
Model Organism ◽  
Spatial Gradient ◽  
Wild Type ◽  
Temporal Gradient ◽  
E Coli ◽  
Significant Difference

ABSTRACT It has previously been reported that the alpha-proteobacterium Azospirillum brasilense undergoes methylation-independent chemotaxis; however, a recent study revealed cheB and cheR genes in this organism. We have constructed cheB, cheR, and cheBR mutants of A. brasilense and determined that the CheB and CheR proteins under study significantly influence chemotaxis and aerotaxis but are not essential for these behaviors to occur. First, we found that although cells lacking CheB, CheR, or both were no longer capable of responding to the addition of most chemoattractants in a temporal gradient assay, they did show a chemotactic response (albeit reduced) in a spatial gradient assay. Second, in comparison to the wild type, cheB and cheR mutants under steady-state conditions exhibited an altered swimming bias, whereas the cheBR mutant and the che operon mutant did not. Third, cheB and cheR mutants were null for aerotaxis, whereas the cheBR mutant showed reduced aerotaxis. In contrast to the swimming bias for the model organism Escherichia coli, the swimming bias in A. brasilense cells was dependent on the carbon source present and cells released methanol upon addition of some attractants and upon removal of other attractants. In comparison to the wild type, the cheB, cheR, and cheBR mutants showed various altered patterns of methanol release upon exposure to attractants. This study reveals a significant difference between the chemotaxis adaptation system of A. brasilense and that of the model organism E. coli and suggests that multiple chemotaxis systems are present and contribute to chemotaxis and aerotaxis in A. brasilense.

scholarly journals The influence of malachite green on the level of transcriptional expression of the laccase and DyP-peroxidase genes of the Azospirillum brasilense

2020 ◽  
Author(s):  
M. A. Kupryashina ◽  
T. E. Pylaev ◽  
V. E. Nikitina
Keyword(s):  
Malachite Green ◽  
Azospirillum Brasilense ◽  
Expression Level ◽  
Synthetic Dyes ◽  
Transcriptional Expression ◽  
Bacterial Enzymes ◽  
Genes Expression

Malachite green (MG), a widely-used and recalcitrant dye, has been confirmed to be carcinogenic and mutagenic against many organisms. Herein, we were aimed at the investigation of the hypothetic role of ligninolytic bacterial enzymes similar to fungal ones in the degradation of synthetic dyes. A multiple increase in the laccases and DyP-peroxidases genes expression level was recorded by RT-qPCR for bacteria of the genus Azospirillum in the presence of MG.

scholarly journals Phasin PhaP1 is involved in polyhydroxybutyrate granules morphology and in controlling early biopolymer accumulation in Azospirillum brasilense Sp7

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
María de los Angeles Martínez-Martínez ◽  
Bertha González-Pedrajo ◽  
Georges Dreyfus ◽  
Lucía Soto-Urzúa ◽  
Luis Javier Martínez-Morales
Keyword(s):  
Azospirillum Brasilense ◽  
C:N Ratio ◽  
Growth Conditions ◽  
Low Oxygen ◽  
Rt Pcr ◽  
Transmission Electron ◽  
Azospirillum Brasilense Sp7 ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Phasins are amphiphilic proteins involved in the regulation of the number and size of polyhydroxybutyrate (PHB) granules. The plant growth promoting bacterium Azospirillum brasilense Sp7 accumulates high quantities of bioplastic PHB as carbon and energy source. By analyzing the genome, we identified six genes that code for proteins with a Phasin_2 domain. To understand the role of A. brasilense Sp7 PhaP1 (PhaP1Abs) on PHB synthesis, the phaP1 gene (AMK58_RS17065) was deleted. The morphology of the PHB granules was analyzed by transmission electron microscopy (TEM) and the PHB produced was quantified under three different C:N ratios in cultures subjected to null or low-oxygen transfer. The results showed that PhaP1Abs is involved in PHB granules morphology and in controlling early biopolymer accumulation. Using RT-PCR it was found that phasin genes, except phaP4, are transcribed in accordance with the C:N ratio used for the growth of A. brasilense. phaP1, phaP2 and phaP3 genes were able to respond to the growth conditions tested. This study reports the first analysis of a phasin protein in A. brasilense Sp7.

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