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Rahal S, Menaa B, Chekireb D. Screening of heavy metal-resistant rhizobial and non-rhizobial microflora isolated from Trifolium sp. growing in mining areas. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:283. [PMID: 38372826 DOI: 10.1007/s10661-024-12445-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 02/12/2024] [Indexed: 02/20/2024]
Abstract
Plant growth-promoting rhizobacteria (PGPR) can promote plant growth and development with several beneficial effects, especially in challenging environmental conditions, such as the presence of toxic contaminants. In this study, 49 isolates obtained from Trifolium sp. nodules growing on a Pb/Zn mine site were characterized for PGP traits including siderophores production, phosphate solubilization, extracellular enzymes production, and antifungal activity. The isolates were also screened for their ability to grow at increasing concentrations of NaCl and heavy metals, including lead, zinc, cobalt, copper, nickel, cadmium, and chromium. The findings of our study indicated that isolates Cupriavidus paucula RSCup01-RSCup08, Providencia rettgeri RSPro01, Pseudomonas putida RSPs01, Pseudomonas thivervalensis RSPs03-RSPs09, and Acinetobacter beijerinckii RSAci01 showed several key traits crucial for promoting plant growth, thus demonstrating the greatest potential. Most isolates displayed resistance to salt and heavy metals. Notably, Staphylococcus xylosus RSSta01, Pseudomonas sp. RSPs02, Micrococcus yunnanensis RSMicc01, and Kocuria dechangensis RSKoc01 demonstrated a significant capacity to grow at salt concentrations ranging from 10 to 20%, and isolates including Cupravidus paucula RSCup01-RSCup08 exhibited resistance to high levels of heavy metals, up to 1300 mg/L Pb++, 1200 mg/L Zn++, 1000 mg/L Ni++, 1000 mg/L Cd++, 500 mg/L Cu++, 400 mg/L Co++, and 50 mg/L CrVI+. Additionally, the analysis revealed that metal-resistant genes pbrA, czcD, and nccA were exclusively detected in the Cupriavidus paucula RSCup01 strain. The results of this study provide insights into the potential of plant growth-promoting rhizobacteria strains that might be used as inoculants to improve phytoremediation in heavy metal-contaminated soils.
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Affiliation(s)
- Sarah Rahal
- Laboratory of Applied Biochemistry and Microbiology (LABM), Faculty of Sciences, Department of Biochemistry, University Badji Mokhtar Annaba, B.P. 12, Sidi Amar, 23200, Annaba, Algeria.
| | - Belkis Menaa
- Laboratory of Applied Biochemistry and Microbiology (LABM), Faculty of Sciences, Department of Biochemistry, University Badji Mokhtar Annaba, B.P. 12, Sidi Amar, 23200, Annaba, Algeria
| | - Djamel Chekireb
- Laboratory of Applied Biochemistry and Microbiology (LABM), Faculty of Sciences, Department of Biochemistry, University Badji Mokhtar Annaba, B.P. 12, Sidi Amar, 23200, Annaba, Algeria
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Stoakes E, Chen X, Kalmar L, Baker D, Evans R, Rudder S, Grant AJ. Identification of Campylobacter jejuni and Campylobacter coli genes contributing to oxidative stress response using TraDIS analysis. BMC Microbiol 2024; 24:46. [PMID: 38302896 PMCID: PMC10832277 DOI: 10.1186/s12866-024-03201-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/21/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND Campylobacter jejuni and Campylobacter coli are the major causative agents of bacterial gastroenteritis worldwide and are known obligate microaerophiles. Despite being sensitive to oxygen and its reduction products, both species are readily isolated from animal food products kept under atmospheric conditions where they face high oxygen tension levels. RESULTS In this study, Transposon Directed Insertion-site Sequencing (TraDIS) was used to investigate the ability of one C. jejuni strain and two C. coli strains to overcome oxidative stress, using H2O2 to mimic oxidative stress. Genes were identified that were required for oxidative stress resistance for each individual strain but also allowed a comparison across the three strains. Mutations in the perR and ahpC genes were found to increase Campylobacter tolerance to H2O2. The roles of these proteins in oxidative stress were previously known in C. jejuni, but this data indicates that they most likely play a similar role in C. coli. Mutation of czcD decreased Campylobacter tolerance to H2O2. The role of CzcD, which functions as a zinc exporter, has not previously been linked to oxidative stress. The TraDIS data was confirmed using defined deletions of perR and czcD in C. coli 15-537360. CONCLUSIONS This is the first study to investigate gene fitness in both C. jejuni and C. coli under oxidative stress conditions and highlights both similar roles for certain genes for both species and highlights other genes that have a role under oxidative stress.
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Affiliation(s)
- Emily Stoakes
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Xuanlin Chen
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Lajos Kalmar
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Dave Baker
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Rhiannon Evans
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Steven Rudder
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Andrew J Grant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
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Sharma P, Mondal K, Kumar S, Tamang S, Najar IN, Das S, Thakur N. RNA thermometers in bacteria: Role in thermoregulation. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - GENE REGULATORY MECHANISMS 2022; 1865:194871. [DOI: 10.1016/j.bbagrm.2022.194871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/09/2022] [Accepted: 08/21/2022] [Indexed: 04/09/2023]
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Halder S, Bansal M. The effect of mutation in the stem of the MicroROSE thermometer on its thermosensing ability: insights from molecular dynamics simulation studies. RSC Adv 2022; 12:11853-11865. [PMID: 35481095 PMCID: PMC9016746 DOI: 10.1039/d2ra00169a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/05/2022] [Indexed: 01/17/2023] Open
Abstract
Mutation induced thermosensing ability of MicroROSE thermometer.
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Affiliation(s)
- Swagata Halder
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India
| | - Manju Bansal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India
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Evguenieva-Hackenberg E. Riboregulation in bacteria: From general principles to novel mechanisms of the trp attenuator and its sRNA and peptide products. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1696. [PMID: 34651439 DOI: 10.1002/wrna.1696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/25/2021] [Accepted: 09/10/2021] [Indexed: 12/26/2022]
Abstract
Gene expression strategies ensuring bacterial survival and competitiveness rely on cis- and trans-acting RNA-regulators (riboregulators). Among the cis-acting riboregulators are transcriptional and translational attenuators, and antisense RNAs (asRNAs). The trans-acting riboregulators are small RNAs (sRNAs) that bind proteins or base pairs with other RNAs. This classification is artificial since some regulatory RNAs act both in cis and in trans, or function in addition as small mRNAs. A prominent example is the archetypical, ribosome-dependent attenuator of tryptophan (Trp) biosynthesis genes. It responds by transcription attenuation to two signals, Trp availability and inhibition of translation, and gives rise to two trans-acting products, the attenuator sRNA rnTrpL and the leader peptide peTrpL. In Escherichia coli, rnTrpL links Trp availability to initiation of chromosome replication and in Sinorhizobium meliloti, it coordinates regulation of split tryptophan biosynthesis operons. Furthermore, in S. meliloti, peTrpL is involved in mRNA destabilization in response to antibiotic exposure. It forms two types of asRNA-containing, antibiotic-dependent ribonucleoprotein complexes (ARNPs), one of them changing the target specificity of rnTrpL. The posttranscriptional role of peTrpL indicates two emerging paradigms: (1) sRNA reprograming by small molecules and (2) direct involvement of antibiotics in regulatory RNPs. They broaden our view on RNA-based mechanisms and may inspire new approaches for studying, detecting, and using antibacterial compounds. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Liu H, Zhang Y, Wang Y, Xie X, Shi Q. The Connection between Czc and Cad Systems Involved in Cadmium Resistance in Pseudomonas putida. Int J Mol Sci 2021; 22:ijms22189697. [PMID: 34575861 PMCID: PMC8469834 DOI: 10.3390/ijms22189697] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 12/23/2022] Open
Abstract
Heavy metal pollution is widespread and persistent, and causes serious harm to the environment. Pseudomonas putida, a representative environmental microorganism, has strong resistance to heavy metals due to its multiple efflux systems. Although the functions of many efflux systems have been well-studied, the relationship between them remains unclear. Here, the relationship between the Czc and Cad systems that are predominantly responsible for cadmium efflux in P. putida KT2440 is identified. The results demonstrated that CzcR3, the response regulator of two-component system CzcRS3 in the Czc system, activates the expression of efflux pump genes czcCBA1 and czcCBA2 by directly binding to their promoters, thereby helping the strain resist cadmium stress. CzcR3 can also bind to its own promoter, but it has only a weak regulatory effect. The high-level expression of czcRS3 needs to be induced by Cd2+, and this relies on the regulation of CadR, a key regulator in the Cad system, which showed affinity to czcRS3 promoter. Our study indicates that the Cad system is involved in the regulation of the Czc system, and this relationship is important for maintaining the considerable resistance to cadmium in P. putida.
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Garg N, Taylor AJ, Pastorelli F, Flannery SE, Jackson PJ, Johnson MP, Kelly DJ. Genes Linking Copper Trafficking and Homeostasis to the Biogenesis and Activity of the cbb 3-Type Cytochrome c Oxidase in the Enteric Pathogen Campylobacter jejuni. Front Microbiol 2021; 12:683260. [PMID: 34248902 PMCID: PMC8267372 DOI: 10.3389/fmicb.2021.683260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/26/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial C-type haem-copper oxidases in the cbb 3 family are widespread in microaerophiles, which exploit their high oxygen-binding affinity for growth in microoxic niches. In microaerophilic pathogens, C-type oxidases can be essential for infection, yet little is known about their biogenesis compared to model bacteria. Here, we have identified genes involved in cbb 3-oxidase (Cco) assembly and activity in the Gram-negative pathogen Campylobacter jejuni, the commonest cause of human food-borne bacterial gastroenteritis. Several genes of unknown function downstream of the oxidase structural genes ccoNOQP were shown to be essential (cj1483c and cj1486c) or important (cj1484c and cj1485c) for Cco activity; Cj1483 is a CcoH homologue, but Cj1484 (designated CcoZ) has structural similarity to MSMEG_4692, involved in Qcr-oxidase supercomplex formation in Mycobacterium smegmatis. Blue-native polyacrylamide gel electrophoresis of detergent solubilised membranes revealed three major bands, one of which contained CcoZ along with Qcr and oxidase subunits. Deletion of putative copper trafficking genes ccoI (cj1155c) and ccoS (cj1154c) abolished Cco activity, which was partially restored by addition of copper during growth, while inactivation of cj0369c encoding a CcoG homologue led to a partial reduction in Cco activity. Deletion of an operon encoding PCu A C (Cj0909) and Sco (Cj0911) periplasmic copper chaperone homologues reduced Cco activity, which was partially restored in the cj0911 mutant by exogenous copper. Phenotypic analyses of gene deletions in the cj1161c-1166c cluster, encoding several genes involved in intracellular metal homeostasis, showed that inactivation of copA (cj1161c), or copZ (cj1162c) led to both elevated intracellular Cu and reduced Cco activity, effects exacerbated at high external Cu. Our work has therefore identified (i) additional Cco subunits, (ii) a previously uncharacterized set of genes linking copper trafficking and Cco activity, and (iii) connections with Cu homeostasis in this important pathogen.
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Affiliation(s)
- Nitanshu Garg
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Aidan J Taylor
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Federica Pastorelli
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Sarah E Flannery
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Phillip J Jackson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, United Kingdom
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Park M, Hwang S, Ryu S, Jeon B. CosR Regulation of perR Transcription for the Control of Oxidative Stress Defense in Campylobacter jejuni. Microorganisms 2021; 9:microorganisms9061281. [PMID: 34208393 PMCID: PMC8231278 DOI: 10.3390/microorganisms9061281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress resistance is an important mechanism to sustain the viability of oxygen-sensitive microaerophilic Campylobacter jejuni. In C. jejuni, gene expression associated with oxidative stress defense is modulated by PerR (peroxide response regulator) and CosR (Campylobacter oxidative stress regulator). Iron also plays an important role in the regulation of oxidative stress, as high iron concentrations reduce the transcription of perR. However, little is known about how iron affects the transcription of cosR. The level of cosR transcription was increased when the defined media MEMα (Minimum Essential Medium) was supplemented with ferrous (Fe2+) and ferric (Fe3+) iron and the Mueller-Hinton (MH) media was treated with an iron chelator, indicating that iron upregulates cosR transcription. However, other divalent cationic ions, such as Zn2+, Cu2+, Co2+, and Mn2+, did not affect cosR transcription, suggesting that cosR transcription is regulated specifically by iron. Interestingly, the level of perR transcription was increased when CosR was overexpressed. The positive regulation of perR transcription by CosR was observed both in the presence or in the absence of iron. The results of the electrophoretic mobility shift assay showed that CosR directly binds to the perR promoter. DNase I footprinting assays revealed that the CosR binding site in the perR promoter overlaps with the PerR box. In the study, we demonstrated that cosR transcription is increased in iron-rich conditions, and CosR positively regulates the transcription of PerR, another important regulator of oxidative stress defense in C. jejuni. These results provide new insight into how C. jejuni regulates oxidative stress defense by coordinating the transcription of perR and cosR in response to iron.
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Affiliation(s)
- Myungseo Park
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Sunyoung Hwang
- Department of Food and Animal Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
- Center for Food Bioconvergence, Seoul National University, Seoul 08826, Korea
- Correspondence: (S.R.); (B.J.)
| | - Byeonghwa Jeon
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN 55455, USA;
- Correspondence: (S.R.); (B.J.)
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