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Miller T, Waturangi DE, Yogiara. Antibiofilm properties of bioactive compounds from Actinomycetes against foodborne and fish pathogens. Sci Rep 2022; 12:18614. [PMID: 36329158 PMCID: PMC9633603 DOI: 10.1038/s41598-022-23455-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
In nature, bacteria can form biofilms, multi-layered structures that adhere microbial populations to solid surfaces by exopolysaccharides, proteins, and nucleic acids. In addition to causing foodborne infections, biofilms can be a major problem in aquaculture. Actinomycetes extracts have previously demonstrated antibiofilm activity against multiple foodborne and fish pathogens, and further characterization of these extracts is needed. In this study, we identified the chemical structures and antibiofilm properties of four extracts and determined the genetic similarity of the isolates to known Streptomyces isolates. We found that several extracts contained multiple antibiofilm compounds, and the antibiofilm activities of all extracts were most stable at pH 6. Furthermore, the antibiofilm inhibition and destruction activities of the isolates were stable at different temperatures. All of crude extracts demonstrated activity against biofilms formed by foodborne and fish pathogens on the surface of stainless-steel coupons as well as polystyrene that commonly used in industrial equipment. Using PCR 16S-rRNA gene and DNA sequencing analysis, the four Actinomycetes isolates were found to be 99% (1 AC), 97% (20 PM), 95% (16 PM), and 85% (18 PM) similar to Streptomyces. Biofilm structure were analyzed using Scanning Electron Microscopy coupled with Energy-Dispersive Spectrometry analysis. Coniine/(S)-2-propylpiperidine was the most active fraction of the crude extracts of the 1 AC, 20 PM, and 16 PM isolates, and piperidine, 2-(tetrahydro-2-furanyl) was most active in the 18 PM isolate.
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Affiliation(s)
- Tracy Miller
- grid.443450.20000 0001 2288 786XBiotechnology Department, Faculty of Biotechnology, Atma Jaya Catholic University of Indonesia, Jenderal Sudirman 51 Street, South Jakarta, DKI Jakarta 12930 Indonesia
| | - Diana Elizabeth Waturangi
- grid.443450.20000 0001 2288 786XBiotechnology Department, Faculty of Biotechnology, Atma Jaya Catholic University of Indonesia, Jenderal Sudirman 51 Street, South Jakarta, DKI Jakarta 12930 Indonesia
| | - Yogiara
- grid.443450.20000 0001 2288 786XBiotechnology Department, Faculty of Biotechnology, Atma Jaya Catholic University of Indonesia, Jenderal Sudirman 51 Street, South Jakarta, DKI Jakarta 12930 Indonesia
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Hu MX, He F, Zhao ZS, Guo YX, Ma XK, Tu CK, Teng H, Chen ZX, Yan H, Shao X. Electrospun Nanofibrous Membranes Accelerate Biofilm Formation and Probiotic Enrichment: Enhanced Tolerances to pH and Antibiotics. ACS APPLIED MATERIALS & INTERFACES 2022; 14:31601-31612. [PMID: 35793165 DOI: 10.1021/acsami.2c04540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Biofilms are the oldest, most successful, and most widely distributed form of microorganism life on earth, existing even in extreme environments. Presently, probiotics in biofilm phenotype are thought as the most advanced fourth-generation probiotics. However, high-efficiency and large-scale biofilm enrichment in an artificial way is difficult. Here, fibrous membranes as probiotic biofilm-enriching materials are studied. Electrospun cellulose acetate nanofibrous membranes with nano-sized fibers show outstanding superiority over fibrous membranes with micron-sized fibers in Lactobacillus paracasei biofilm enrichment. The special 3D structure of electrospun nanofibrous membranes makes other facilitating biofilm formation factors insignificant. With a suitable scaffold/culture medium ratio, nearly 100% of L. paracasei cells exist as biofilm phenotype on the membrane from the very beginning, not planktonic state. L. paracasei biofilms possess a potential for long-term survival and high tolerances toward strong acidic and alkali conditions and antibiotics. RNA sequencing results explain why L. paracasei biofilms possess high tolerances toward harsh environments as compared to planktonic L. paracasei. Electrospun nanofibrous membranes can serve as powerful biofilm-enriching scaffolds for probiotics and other valuable microbes.
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Affiliation(s)
- Meng-Xin Hu
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Fei He
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zi-Shu Zhao
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Ya-Xin Guo
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Xue-Ke Ma
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Cheng-Kai Tu
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Hui Teng
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zhe-Xin Chen
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Hong Yan
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Xin Shao
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
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Chakraborty S, Harris JM. At the Crossroads of Salinity and Rhizobium-Legume Symbiosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:540-553. [PMID: 35297650 DOI: 10.1094/mpmi-09-21-0231-fi] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Legume roots interact with soil bacteria rhizobia to develop nodules, de novo symbiotic root organs that host these rhizobia and are mini factories of atmospheric nitrogen fixation. Nodulation is a sophisticated developmental process and is sensitive to several abiotic factors, salinity being one of them. While salinity influences both the free-living partners, symbiosis is more vulnerable than other aspects of plant and microbe physiology, and the symbiotic interaction is strongly impaired even under moderate salinity. In this review, we tease apart the various known components of rhizobium-legume symbiosis and how they interact with salt stress. We focus primarily on the initial stages of symbiosis since we have a greater mechanistic understanding of the interaction at these stages.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Sanhita Chakraborty
- Department of Plant Biology, University of Vermont, Burlington, VT 05405, U.S.A
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, U.S.A
| | - Jeanne M Harris
- Department of Plant Biology, University of Vermont, Burlington, VT 05405, U.S.A
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Bulk and Spatially Resolved Extracellular Metabolome of Free-Living Nitrogen Fixation. Appl Environ Microbiol 2022; 88:e0050522. [PMID: 35652664 PMCID: PMC9238392 DOI: 10.1128/aem.00505-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Soil nitrogen (N) transformations constrain terrestrial net primary productivity and are driven by the activity of soil microorganisms. Free-living N fixation (FLNF) is an important soil N transformation and key N input to terrestrial systems, but the forms of N contributed to soil by FLNF are poorly understood. To address this knowledge gap, a focus on microorganisms and microbial scale processes is needed that links N-fixing bacteria and their contributed N sources to FLNF process rates. However, studying the activity of soil microorganisms in situ poses inherent challenges, including differences in sampling scale between microorganism and process rates, which can be addressed with culture-based studies and an emphasis on microbial-scale measurements. Culture conditions can differ significantly from soil conditions, so it also important that such studies include multiple culture conditions like liquid and solid media as proxies for soil environments like soil pore water and soil aggregate surfaces. Here we characterized extracellular N-containing metabolites produced by two common, diazotrophic soil bacteria in liquid and solid media, with or without N, across two sampling scales (bulk via GC-MS and spatially resolved via MALDI mass spec imaging). We found extracellular production of inorganic and organic N during FLNF, indicating terrestrial N contributions from FLNF occur in multiple forms not only as ammonium as previously thought. Extracellular metabolite profiles differed between liquid and solid media supporting previous work indicating environmental structure influences microbial function. Metabolite profiles also differed between sampling scales underscoring the need to quantify microbial scale conditions to accurately interpret microbial function. IMPORTANCE Free-living nitrogen-fixing bacteria contribute significantly to terrestrial nitrogen availability; however, the forms of nitrogen contributed by this process are poorly understood. This is in part because of inherent challenges to studying soil microorganisms in situ, such as vast differences in scale between microorganism and ecosystem and complexities of the soil system (e.g., opacity, chemical complexity). Thus, upscaling important ecosystem processes driven by soil microorganisms, like free-living nitrogen fixation, requires microbial-scale measurements in controlled systems. Our work generated bulk and spatially resolved measurements of nitrogen released during free-living nitrogen fixation under two contrasting growth conditions analogous to soil pores and aggregates. This work allowed us to determine that diverse forms of nitrogen are likely contributed to terrestrial systems by free-living nitrogen bacteria. We also demonstrated that microbial habitat (e.g., liquid versus solid media) alters microbial activity and that measurement of microbial activity is altered by sampling scale (e.g., bulk versus spatially resolved) highlighting the critical importance of quantifying microbial-scale processes to upscaling of ecosystem function.
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Vora SM, Ankati S, Patole C, Podile AR, Archana G. Alterations of Primary Metabolites in Root Exudates of Intercropped Cajanus cajan-Zea mays Modulate the Adaptation and Proteome of Ensifer (Sinorhizobium) fredii NGR234. MICROBIAL ECOLOGY 2022; 83:1008-1025. [PMID: 34351469 DOI: 10.1007/s00248-021-01818-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/07/2021] [Indexed: 05/22/2023]
Abstract
Legume-cereal intercropping systems, in the context of diversity, ecological function, and better yield have been widely studied. Such systems enhance nutrient phytoavailability by balancing root-rhizosphere interactions. Root exudates (RE) play an important role in the rhizospheric interactions of plant-plant and/or plant-microbiome interaction. However, the influence of the primary metabolites of RE on plant-rhizobia interactions in a legume-cereal intercrop system is not known. To understand the plant communication with rhizobia, Cajanus cajan-Zea mays intercropped plants and the broad host range legume nodulating Ensifer fredii NGR234 as the model plants and rhizobium used respectively. A metabolomics-based approach revealed a clear separation between intercropped and monocropped RE of the two plants. Intercropped C. cajan showed an increase in the myo-inositol, and proline, while intercropped Z. mays showed enhanced galactose, D-glucopyranoside, and arginine in the RE. Physiological assays of NGR234 with the RE of intercropped C. cajan exhibited a significant enhancement in biofilm formation, while intercropped Z. mays RE accelerated the bacterial growth in the late log phase. Further, using label-free proteomics, we identified a total of 2570 proteins of NGR234 covering 50% annotated protein sequences upon exposure to Z. mays RE. Furthermore, intercropped Z. mays RE upregulated bacterioferritin comigratory protein (BCP), putative nitroreductase, IlvD, LeuC, D (branched-chain amino acid proteins), and chaperonin proteins GroEL2. Identification offered new insights into the metabolome of the legume-cereal intercrop and proteome of NGR234-Z. mays interactions that underline the new molecular candidates likely to be involved in the fitness of rhizobium in the intercropping system.
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Affiliation(s)
- Siddhi M Vora
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India
| | - Sravani Ankati
- Department of Plant Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Chhaya Patole
- Institute for Stem Cell Science and Regenerative Medicine, NCBS-TIFR Campus, Bellary Road, Bangalore, Karnataka, India
| | - Appa Rao Podile
- Department of Plant Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - G Archana
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India.
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Hu J, Lv X, Niu X, Yu F, Zuo J, Bao Y, Yin H, Huang C, Nawaz S, Zhou W, Jiang W, Chen Z, Tu J, Qi K, Han X. Effect of nutritional and environmental conditions on biofilm formation of avian pathogenic Escherichia coli. J Appl Microbiol 2022; 132:4236-4251. [PMID: 35343028 DOI: 10.1111/jam.15543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/19/2022] [Accepted: 03/21/2022] [Indexed: 11/30/2022]
Abstract
AIMS To study the effects of environmental stress and nutrient conditions on biofilm formation of avian pathogenic Escherichia coli (APEC). METHODS AND RESULTS The APEC strain DE17 was used to study biofilm formation under various conditions of environmental stress (including different temperatures, pH, metal ions, and antibiotics) and nutrient conditions (LB and M9 media, with the addition of different carbohydrates, if necessary). The DE17 biofilm formation ability was strongest at 25°C in LB medium. Compared to incubation at 37°C, three biofilm-related genes (csgD, dgcC, and pfs) were significantly upregulated and two genes (flhC and flhD) were downregulated at 25°C, which resulted in decreased motility. However, biofilm formation was strongest in M9 medium supplemented with glucose at 37°C, and the number of live bacteria was the highest as determined by confocal laser scanning microscopy (CLSM). The bacteria in the biofilm were surrounded by a thick extracellular matrix, and honeycomb-like or rough surfaces were observed by scanning electron microscopy (SEM). Moreover, biofilm formation of the DE17 strain was remarkably inhibited under acidic conditions, whereas neutral and alkaline conditions were more suitable for biofilm formation. Biofilm formation was also inhibited at specific concentrations of cations (Na+ , K+ , Ca2+ , and Mg2+ ) and antibiotics (ampicillin, chloramphenicol, kanamycin, and spectinomycin). The qRT-PCR showed that the transcription levels of biofilm-related genes change under different environmental conditions. CONCLUSIONS Nutritional and environmental factors played an important role in DE17 biofilm development. The transcription levels of biofilm-related genes changed under different environmental and nutrient conditions. SIGNIFICANCE AND IMPACT OF THE STUDY The findings suggest that nutritional and environmental factors play an important role in APEC biofilm development. Depending on the different conditions involved in this study, it can serve as a guide to treating biofilm-related infections and to eliminating biofilms from the environment.
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Affiliation(s)
- Jiangang Hu
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, Fujian Province, College of Life Science, Longyan University, Longyan, Fujian, China.,Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China.,Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiaolong Lv
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China.,Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiangpeng Niu
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China.,Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Fangheng Yu
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China.,Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Jiakun Zuo
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
| | - Yinli Bao
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, Fujian Province, College of Life Science, Longyan University, Longyan, Fujian, China
| | - Huifang Yin
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, Fujian Province, College of Life Science, Longyan University, Longyan, Fujian, China
| | - Cuiqin Huang
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, Fujian Province, College of Life Science, Longyan University, Longyan, Fujian, China
| | - Saqib Nawaz
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
| | - Wen Zhou
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
| | - Wei Jiang
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
| | - Zhaoguo Chen
- Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
| | - Jian Tu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiangan Han
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, Fujian Province, College of Life Science, Longyan University, Longyan, Fujian, China.,Shanghai Veterinary Research Institute, the Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai, China
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Carriot N, Barry-Martinet R, Briand JF, Ortalo-Magné A, Culioli G. Impact of phosphate concentration on the metabolome of biofilms of the marine bacterium Pseudoalteromonas lipolytica. Metabolomics 2022; 18:18. [PMID: 35290545 DOI: 10.1007/s11306-022-01875-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 02/22/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Marine biofilms are the most widely distributed mode of life on Earth and drive biogeochemical cycling processes of most elements. Phosphorus (P) is essential for many biological processes such as energy transfer mechanisms, biological information storage and membrane integrity. OBJECTIVES Our aim was to analyze the effect of a gradient of ecologically relevant phosphate concentrations on the biofilm-forming capacity and the metabolome of the marine bacterium Pseudoalteromonas lipolytica TC8. METHODS In addition to the evaluation of the effect of different phosphate concentration on the biomass, structure and gross biochemical composition of biofilms of P. lipolytica TC8, untargeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS) analysis was used to determine the main metabolites impacted by P-limiting conditions. Annotation of the most discriminating and statistically robust metabolites was performed through the concomitant use of molecular networking and MS/MS fragmentation pattern interpretation. RESULTS At the lowest phosphate concentration, biomass, carbohydrate content and three-dimensional structures of biofilms tended to decrease. Furthermore, untargeted metabolomics allowed for the discrimination of the biofilm samples obtained at the five phosphate concentrations and the highlighting of a panel of metabolites mainly implied in such a discrimination. A large part of the metabolites of the resulting dataset were then putatively annotated. Ornithine lipids were found in increasing quantity when the phosphate concentration decreased, while the opposite trend was observed for oxidized phosphatidylethanolamines (PEs). CONCLUSION This study demonstrated the suitability of LC-MS-based untargeted metabolomics for evaluating the effect of culture conditions on marine bacterial biofilms. More precisely, these results supported the high plasticity of the membrane of P. lipolytica TC8, while the role of the oxidized PEs remains to be clarified.
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Affiliation(s)
- Nathan Carriot
- Laboratoire MAPIEM, Université de Toulon, EA 4323, La Garde, France
| | | | | | | | - Gérald Culioli
- Laboratoire MAPIEM, Université de Toulon, EA 4323, La Garde, France.
- Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale (IMBE), UMR CNRS-IRD-Avignon, Université-Aix-Marseille Université, Avignon, France.
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Chong P, Erable B, Bergel A. How bacteria use electric fields to reach surfaces. Biofilm 2021; 3:100048. [PMID: 33997766 PMCID: PMC8090995 DOI: 10.1016/j.bioflm.2021.100048] [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: 12/24/2020] [Revised: 03/15/2021] [Accepted: 03/28/2021] [Indexed: 11/15/2022] Open
Abstract
Electrotaxis is the property of cells to sense electric fields and use them to orient their displacement. This property has been widely investigated with eukaryotic cells but it remains unclear whether or not bacterial cells can sense an electric field. Here, a specific experimental set-up was designed to form microbial electroactive biofilms while differentiating the effect of the electric field from that of the polarised electrode surface. Application of an electric field during exposure of the electrodes to the inoculum was shown to be required for an electroactive biofilm to form afterwards. Similar biofilms were formed in both directions of the electric field. This result is attributed to the capacity of the cells to detect the K+ and Na+ ion gradients that the electric field creates at the electrode surface. This microbial property should now be considered as a key factor in the formation of electroactive biofilms and possible implications in the biomedical domain are discussed.
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Affiliation(s)
- Poehere Chong
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Benjamin Erable
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Alain Bergel
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
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Surface Properties and Adherence of Bradyrhizobium diazoefficiens to Glycine max Roots Are Altered When Grown in Soil Extracted Nutrients. NITROGEN 2021. [DOI: 10.3390/nitrogen2040031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Soybean roots are colonized and nodulated by multiple strains of compatible nitrogen-fixing rhizobia primarily belonging to the Genus Bradyrhizobium. Motility towards the root and attachment to root hairs are key determinants of competitive colonization and subsequent nodulation. Bacterial surface properties and motility are known to vary with chemical composition of the culture medium, and root adhesion and nodulation occur in a soil environment rather than laboratory medium. We asked whether the nodulation-promoting factors motility, surface hydrophobicity and surface adhesion of Bradyrhizobium are affected by growth in a soil nutrient environment. B. diazoefficiens USDA 110, 126, 3384, and B. elkanii USDA 26 were grown in mineral salt medium with peptone, yeast extract and arabinose (PSY), and in a soil extracted soluble organic matter (SESOM) medium. Surface hydrophobicity was determined by partitioning into hydrocarbon, motility by transition through soft agar, and surface-exposed saccharides by lectin profiling, followed by biofilm formation and soybean root adhesion capacity of populations. SESOM-grown populations were generally less motile and more hydrophobic. They bound fewer lectins than PSY-grown populations, indicating a simpler surface saccharide profile. SESOM populations of USDA 110 did not form detectable biofilm, but showed increased binding to soy roots. Our results indicate that growth in a soil environment impacts surface properties, motility, and subsequent soy root adhesion propensity. Hence, evaluation of Bradyrhizobium for nodulation efficiency should be performed using soil from the specific field where the soybeans are to be planted, rather than laboratory culture media.
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Zhao J, Ai G, Yang S, Zhang X, Zhang G. Detection, Structural Elucidation, and Biological Effects of Diverse N-Acyl-homoserine Lactone Signaling Molecules in the Plant-Promoting Endophytic Bacterium Rhizobium oryzihabitans M15. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9693-9705. [PMID: 34428903 DOI: 10.1021/acs.jafc.1c03895] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Quorum sensing (QS), usually performed by N-acyl-homoserine lactones (AHLs) in Gram-staining-negative bacteria, plays an important role in plant-bacteria interactions. Rhizobium oryzihabitans M15 is a plant-growth-promoting rhizobacterium (PGPR) isolated from rice roots. In this study, we found a QS system in the endogenous plasmid of R. oryzihabitans M15 and detected the activity of AHLs by a bioassay method. We identified five AHL analogues in R. oryzihabitans M15 using liquid chromatography-tandem mass spectrometry (LC-MS). The most dominant AHL analogue was N-(3R-hydroxy-7-cis-tetradecanoyl)-l-homoserine lactone according to nuclear magnetic resonance (NMR) and Mosher's reactions. Furthermore, the rosI mutant abolished AHL production and significantly decreased growth, exopolysaccharide (EPS) production, biofilm formation, and motility compared to the wild-type strain. These results lay the foundation for further investigating the QS regulation mechanism and signal pathway of R. oryzihabitans M15 and its interactions with the host plant.
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Affiliation(s)
- Juanjuan Zhao
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China
| | - Guomin Ai
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, P. R. China
| | - Xiaoxia Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China
| | - Guishan Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture and Rural Affairs Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China
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Chakraborty S, Driscoll HE, Abrahante JE, Zhang F, Fisher RF, Harris JM. Salt Stress Enhances Early Symbiotic Gene Expression in Medicago truncatula and Induces a Stress-Specific Set of Rhizobium-Responsive Genes. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:904-921. [PMID: 33819071 PMCID: PMC8578154 DOI: 10.1094/mpmi-01-21-0019-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Salt stress is a major agricultural concern inhibiting not only plant growth but also the symbiotic association between legume roots and the soil bacteria rhizobia. This symbiotic association is initiated by a molecular dialogue between the two partners, leading to the activation of a signaling cascade in the legume host and, ultimately, the formation of nitrogen-fixing root nodules. Here, we show that a moderate salt stress increases the responsiveness of early symbiotic genes in Medicago truncatula to its symbiotic partner, Sinorhizobium meliloti while, conversely, inoculation with S. meliloti counteracts salt-regulated gene expression, restoring one-third to control levels. Our analysis of early nodulin 11 (ENOD11) shows that salt-induced expression is dynamic, Nod-factor dependent, and requires the ionic but not the osmotic component of salt. We demonstrate that salt stimulation of rhizobium-induced gene expression requires NSP2, which functions as a node to integrate the abiotic and biotic signals. In addition, our work reveals that inoculation with S. meliloti succinoglycan mutants also hyperinduces ENOD11 expression in the presence or absence of salt, suggesting a possible link between rhizobial exopolysaccharide and the plant response to salt stress. Finally, we identify an accessory set of genes that are induced by rhizobium only under conditions of salt stress and have not been previously identified as being nodulation-related genes. Our data suggest that interplay of core nodulation genes with different accessory sets, specific for different abiotic conditions, functions to establish the symbiosis. Together, our findings reveal a complex and dynamic interaction between plant, microbe, and environment.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Sanhita Chakraborty
- Department of Plant Biology, University of Vermont, Burlington, VT 05405, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Heather E. Driscoll
- Vermont Biomedical Research Network (VBRN), Department of Biology, Norwich University, Northfield, Vermont 05663, USA
| | - Juan E. Abrahante
- University of Minnesota Informatics Institute (UMII) (CCRB 1-210C), 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Fan Zhang
- Vermont Biomedical Research Network (VBRN), Department of Biology, University of Vermont, Burlington, Vermont 05405, USA
- Institute for Translational Research and Department of family medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107
| | - Robert F. Fisher
- Stanford University, Department of Biology, 371 Serra Mall, Stanford, California 94305-5020, USA
| | - Jeanne M. Harris
- Department of Plant Biology, University of Vermont, Burlington, VT 05405, USA
- Corresponding author: Jeanne M. Harris ()
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12
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A regulatory network involving Rpo, Gac and Rsm for nitrogen-fixing biofilm formation by Pseudomonas stutzeri. NPJ Biofilms Microbiomes 2021; 7:54. [PMID: 34210981 PMCID: PMC8249394 DOI: 10.1038/s41522-021-00230-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
Biofilm and nitrogen fixation are two competitive strategies used by many plant-associated bacteria; however, the mechanisms underlying the formation of nitrogen-fixing biofilms remain largely unknown. Here, we examined the roles of multiple signalling systems in the regulation of biofilm formation by root-associated diazotrophic P. stutzeri A1501. Physiological analysis, construction of mutant strains and microscale thermophoresis experiments showed that RpoN is a regulatory hub coupling nitrogen fixation and biofilm formation by directly activating the transcription of pslA, a major gene involved in the synthesis of the Psl exopolysaccharide component of the biofilm matrix and nifA, the transcriptional activator of nif gene expression. Genetic complementation studies and determination of the copy number of transcripts by droplet digital PCR confirmed that the regulatory ncRNA RsmZ serves as a signal amplifier to trigger biofilm formation by sequestering the translational repressor protein RsmA away from pslA and sadC mRNAs, the latter of which encodes a diguanylate cyclase that synthesises c-di-GMP. Moreover, RpoS exerts a braking effect on biofilm formation by transcriptionally downregulating RsmZ expression, while RpoS expression is repressed posttranscriptionally by RsmA. These findings provide mechanistic insights into how the Rpo/Gac/Rsm regulatory networks fine-tune nitrogen-fixing biofilm formation in response to the availability of nutrients.
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13
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Haque MM, Mosharaf MK, Haque MA, Tanvir MZH, Alam MK. Biofilm Formation, Production of Matrix Compounds and Biosorption of Copper, Nickel and Lead by Different Bacterial Strains. Front Microbiol 2021; 12:615113. [PMID: 34177820 PMCID: PMC8222582 DOI: 10.3389/fmicb.2021.615113] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 05/06/2021] [Indexed: 12/01/2022] Open
Abstract
Bacterial biofilms play a key role in metal biosorption from wastewater. Recently, Enterobacter asburiae ENSD102, Enterobacter ludwigii ENSH201, Vitreoscilla sp. ENSG301, Acinetobacter lwoffii ENSG302, and Bacillus thuringiensis ENSW401 were shown to form air–liquid (AL) and solid–air–liquid (SAL) biofilms in a static condition at 28 and 37°C, respectively. However, how environmental and nutritional conditions affect biofilm formation; production of curli and cellulose; and biosorption of copper (Cu), nickel (Ni), and lead (Pb) by these bacteria have not been studied yet. In this study, E. asburiae ENSD102, E. ludwigii ENSH201, and B. thuringiensis ENSW401 developed the SAL biofilms at pH 8, while E. asburiae ENSD102 and Vitreoscilla sp. ENSG301 constructed the SAL biofilms at pH 4. However, all these strains produced AL biofilms at pH 7. In high osmolarity and ½-strength media, all these bacteria built fragile AL biofilms, while none of these strains generated the biofilms in anaerobic conditions. Congo red binding results showed that both environmental cues and bacterial strains played a vital role in curli and cellulose production. Calcofluor binding and spectrophotometric results revealed that all these bacterial strains produced significantly lesser amounts of cellulose at 37°C, pH 8, and in high osmotic conditions as compared to the regular media, at 28°C, and pH 7. Metal biosorption was drastically reduced in these bacteria at 37°C than at 28°C. Only Vitreoscilla sp. ENSG301 and B. thuringiensis ENSW401 completely removed (100%) Cu and Ni at an initial concentration of 12.5 mg l–1, while all these bacteria totally removed (100%) Pb at concentrations of 12.5 and 25 mg l–1 at pH 7 and 28°C. At an initial concentration of 100 mg l–1, the removal of Cu (92.5 to 97.8%) and Pb (89.3 to 98.3%) was the highest at pH 6, while it was higher (84.7 to 93.9%) for Ni at pH 7. Fourier transform infrared spectroscopy results showed metal-unloaded biomass biofilms contained amino, hydroxyl, carboxyl, carbonyl, and phosphate groups. The peak positions of these groups were shifted responding to Cu, Ni, and Pb, suggesting biosorption of metals. Thus, these bacterial strains could be utilized to remove Cu, Ni, and Pb from aquatic environment.
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Affiliation(s)
- Md Manjurul Haque
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Md Khaled Mosharaf
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Md Amdadul Haque
- Department of Agro-Processing, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Md Zahid Hasan Tanvir
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Md Khairul Alam
- Soil Science Division, Bangladesh Agricultural Research Institute, Gazipur, Bangladesh
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14
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Alam S, Borthakur A, Ravi S, Gebremichael M, Mohanty SK. Managed aquifer recharge implementation criteria to achieve water sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144992. [PMID: 33736333 DOI: 10.1016/j.scitotenv.2021.144992] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Depletion of groundwater is accelerated due to an increase in water demand for applications in urbanized areas, agriculture sectors, and energy extraction, and dwindling surface water during changing climate. Managed aquifer recharge (MAR) is one of the several methods that can help achieve long-term water sustainability by increasing the natural recharge of groundwater reservoirs with water from non-traditional supplies such as excess surface water, stormwater, and treated wastewater. Despite the multiple benefits of MAR, the wide-scale implementation of MAR is lacking, partly because of challenges to select the location for MAR implementation and identify the MAR type based on site conditions and needs. In this review, we provide an overview of MAR types with a basic framework to select and implement specific MAR at a site based on water availability and quality, land use, source type, soil, and aquifer properties. Our analysis of 1127 MAR projects shows that MAR has been predominantly implemented in sites with sandy clay loam soil (soil group C) and with access to river water for recharge. Spatial analysis reveals that many regions with depleting water storage have opportunities to implement MAR projects. Analyzing data from 34 studies where stormwater was used for recharge, we show that MAR can remove dissolved organic carbon, most metals, E. coli but not efficient at removing most trace organics, and enterococci. Removal efficiency depends on the type of MAR. In the end, we highlight potential challenges for implementing MAR at a site and additional benefits such as minimizing land subsidence, flood risk, augmenting low dry-season flow, and minimizing salt-water intrusion. These results could help identify locations in the water-stressed regions to implement specific MAR for water sustainability.
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Affiliation(s)
- Sarfaraz Alam
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
| | - Annesh Borthakur
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
| | - Sujith Ravi
- Earth and Environmental Science, Temple University, PA, USA
| | | | - Sanjay K Mohanty
- Civil and Environmental Engineering, University of California Los Angeles, CA, USA.
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15
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Burgos-Garay ML, Santiago AJ, Kartforosh L, Kotay S, Donlan RM. Supplemental nutrients stimulate the amplification of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a sink drain in vitro biofilm reactor model. BIOFOULING 2021; 37:465-480. [PMID: 34210218 DOI: 10.1080/08927014.2021.1915998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 06/13/2023]
Abstract
Liquid wastes (LW) disposed in hospital handwashing sinks may affect colonization of sink P-traps by carbapenemase-producing Klebsiella pneumoniae (CPKP), causing CPKP dispersal into the patient care environment. This study aimed to determine the effect of LW on biofilm formation and CPKP colonization in a P-Trap model (PTM). PTMs containing polymicrobial biofilms grown in autoclaved municipal tap water (ATW) supplemented with 5% dextrose in water (D5W), nutritional shake (Shake), sugar-based soft drink (Soda), or ATW were inoculated with K. pneumoniae ST258 KPC+ (ST258) or K. pneumoniae CAV1016 (CAV1016) and sampled after 7, 14, and 21 d. Biofilm bio-volume, mean thickness, and heterotrophic plate counts were significantly reduced and roughness coefficient significantly increased by Soda compared with D5W, Shake, or ATW. CPKP were significantly reduced by Soda but significantly amplified by D5W (ST258; CAV1016, 7 d) and Shake (ST258) suggesting that reducing LW disposal in sinks may reduce CPKP dispersal into patient care environments.
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Affiliation(s)
- María L Burgos-Garay
- Division of Healthcare Quality Promotion, Clinical and Environmental Microbiology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ariel J Santiago
- Division of Healthcare Quality Promotion, Clinical and Environmental Microbiology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Leila Kartforosh
- Division of Healthcare Quality Promotion, Clinical and Environmental Microbiology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shireen Kotay
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
| | - Rodney M Donlan
- Division of Healthcare Quality Promotion, Clinical and Environmental Microbiology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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16
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Trabalza S, Buonaurio R, Del Pino AM, Palmerini CA, van den Burg HA, Moretti C. A Spectrofluorophotometrical Method Based on Fura-2-AM Probe to Determine Cytosolic Ca 2+ Level in Pseudomonas syringae Complex Bacterial Cells. Bio Protoc 2021; 11:e3949. [PMID: 33855111 DOI: 10.21769/bioprotoc.3949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 11/02/2022] Open
Abstract
Calcium signaling is an emerging mechanism by which bacteria respond to environmental cues. To measure the intracellular free-calcium concentration in bacterial cells, [Ca2+]i, a simple spectrofluorometric method based on the chemical probe Fura 2-acetoxy methyl ester (Fura 2-AM) is here presented using Pseudomonad bacterial cells. This is an alternative and quantitative method that can be completed in a short period of time with low costs, and it does not require the induction of heterologously expressed protein-based probes like Aequorin. Furthermore, it is possible to verify the properties of membrane channels involved in Ca2+ entry from the extracellular matrix. This method is in particular valuable for measuring [Ca2+]i in the range of 0.1-39.8 µM in small cells like those of prokaryotes.
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Affiliation(s)
- Simone Trabalza
- Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy.,Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Amsterdam, the Netherlands
| | - Roberto Buonaurio
- Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy
| | - Alberto M Del Pino
- Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy
| | - Carlo A Palmerini
- Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy
| | - Harrold A van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Amsterdam, the Netherlands
| | - Chiaraluce Moretti
- Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy
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17
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Vershinina ZR, Chubukova OV, Nikonorov YM, Khakimova LR, Lavina AM, Karimova LR, Baymiev AK, Baymiev AK. Effect of rosR Gene Overexpression on Biofilm Formation by Rhizobium leguminosarum. Microbiology (Reading) 2021. [DOI: 10.1134/s0026261721020144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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18
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Cai W, Ou F, Staehelin C, Dai W. Bradyrhizobium sp. strain ORS278 promotes rice growth and its quorum sensing system is required for optimal root colonization. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:656-666. [PMID: 32929871 DOI: 10.1111/1758-2229.12885] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 09/10/2020] [Indexed: 05/25/2023]
Abstract
Many Gram-negative bacteria communicate by using homoserine lactones (HSLs) as quorum sensing (QS) signals in a cell density-dependent manner. In addition to fatty acyl-HSL (acyl-HSL) signals, certain strains, most of them associated with plants, produce non-canonical aryl-HSLs such as cinnamoyl-HSL. However, the role of aryl-HSL in endophytic associations remained elusive. Bradyrhizobium sp. strain ORS278 possesses a LuxI-LuxR type QS system and produces cinnamoyl-HSL as a QS signal. Here, we report that strain ORS278 promotes growth of domesticated rice (Oryza sativa). QS mutants unable to produce cinnamoyl-HSL exhibited reduced plant-growth promoting activity in comparison to the parent strain ORS278. Likewise, the QS mutants were impaired in their ability to colonize rice roots. These findings suggest that genes controlled by cinnamoyl-HSL play an important role in the association between rice and ORS278. However, biofilm production was not visibly altered in these mutants. In conclusion, our study highlights the importance of aryl-HSLs in endophytic plant-bacteria interactions.
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Affiliation(s)
- Wenjie Cai
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510006, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
| | - Fuwen Ou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510006, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
| | - Christian Staehelin
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Bioresources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Weijun Dai
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510006, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
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19
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Primo E, Bogino P, Cossovich S, Foresto E, Nievas F, Giordano W. Exopolysaccharide II Is Relevant for the Survival of Sinorhizobium meliloti under Water Deficiency and Salinity Stress. Molecules 2020; 25:E4876. [PMID: 33105680 PMCID: PMC7659973 DOI: 10.3390/molecules25214876] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/12/2020] [Accepted: 10/20/2020] [Indexed: 11/16/2022] Open
Abstract
Sinorhizobium meliloti is a soil bacterium of great agricultural importance because of its ability to fix atmospheric nitrogen in symbiotic association with alfalfa (Medicago sativa) roots. We looked into the involvement of exopolysaccharides (EPS) in its survival when exposed to different environmental stressors, as well as in bacteria-bacteria and bacteria-substrate interactions. The strains used were wild-type Rm8530 and two strains that are defective in the biosynthesis of EPS II: wild-type Rm1021, which has a non-functional expR locus, and mutant Rm8530 expA. Under stress by water deficiency, Rm8530 remained viable and increased in number, whereas Rm1021 and Rm8530 expA did not. These differences could be due to Rm8530's ability to produce EPS II. Survival experiments under saline stress showed that viability was reduced for Rm1021 but not for Rm8530 or Rm8530 expA, which suggests the existence of some regulating mechanism dependent on a functional expR that is absent in Rm1021. The results of salinity-induced stress assays regarding biofilm-forming capacity (BFC) and autoaggregation indicated the protective role of EPS II. As a whole, our observations demonstrate that EPS play major roles in rhizobacterial survival.
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Affiliation(s)
| | | | | | | | | | - Walter Giordano
- Instituto de Biotecnología Ambiental y Salud (INBIAS), CONICET, Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Río Cuarto X5804BYA, Córdoba, Argentina; (E.P.); (P.B.); (S.C.); (E.F.); (F.N.)
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20
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Liu X, Zhang K, Liu Y, Zou D, Wang D, Xie Z. Effects of Calcium and Signal Sensing Systems on Azorhizobium caulinodans Biofilm Formation and Host Colonization. Front Microbiol 2020; 11:563367. [PMID: 33072026 PMCID: PMC7533552 DOI: 10.3389/fmicb.2020.563367] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/25/2020] [Indexed: 12/22/2022] Open
Abstract
Biofilm formation is important for establishing plants-microbe associations. The role of calcium on biofilm formation has been studied in many bacteria except rhizobia. In this study, we investigated the role of calcium for biofilm formation in Azorhizobium caulindans, which forms nodules in the stem and root of its host plant Sesbania rostrata. We found that calcium is essential for A. caulindans biofilm formation, in addition to the presence of extracellular matrix components, eDNA and proteins. Also, calcium-mediated biofilm formation was tested with chemotaxis, motility, cyclic di-GMP synthesis, and quorum sensing mutants. Finally, calcium was found to promote S. rostrata root colonization of A. caulinodans. In total, these results show that calcium is essential for A. caulindans biofilm formation, and it affects the interaction between A. caulinodans and host plant.
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Affiliation(s)
- Xiaolin Liu
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiye Zhang
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Yanan Liu
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Desheng Zou
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Dandan Wang
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, China
| | - Zhihong Xie
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
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21
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Chen H, De La Fuente L. Calcium transcriptionally regulates movement, recombination and other functions of Xylella fastidiosa under constant flow inside microfluidic chambers. Microb Biotechnol 2019; 13:548-561. [PMID: 31729188 PMCID: PMC7017821 DOI: 10.1111/1751-7915.13512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 01/08/2023] Open
Abstract
Xylella fastidiosa is a xylem‐limited bacterial pathogen causing devastating diseases in many economically important crops. Calcium (Ca) is a major inorganic nutrient in xylem sap that influences virulence‐related traits of this pathogen, including biofilm formation and twitching motility. This study aimed to adapt a microfluidic system, which mimics the natural habitat of X. fastidiosa, for whole transcriptome analysis under flow conditions. A microfluidic chamber with two parallel channels was used, and RNA isolated from cells grown inside the system was analysed by RNA‐Seq. Ca transcriptionally regulated the machinery of type IV pili and other genes related to pathogenicity and host adaptation. Results were compared to our previous RNA‐Seq study in biofilm cells in batch cultures (Parker et al., 2016, Environ Microbiol 18, 1620). Ca‐regulated genes in both studies belonged to similar functional categories, but the number and tendencies (up‐/downregulation) of regulated genes were different. Recombination‐related genes were upregulated by Ca, and we proved experimentally that 2 mM Ca enhances natural transformation frequency. Taken together, our results suggest that the regulatory role of Ca in X. fastidiosa acts differently during growth in flow or batch conditions, and this can correlate to the different phases of growth (planktonic and biofilm) during the infection process.
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Affiliation(s)
- Hongyu Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
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22
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Primo ED, Cossovich S, Nievas F, Bogino P, Humm EA, Hirsch AM, Giordano W. Exopolysaccharide production in Ensifer meliloti laboratory and native strains and their effects on alfalfa inoculation. Arch Microbiol 2019; 202:391-398. [PMID: 31680188 DOI: 10.1007/s00203-019-01756-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/07/2019] [Accepted: 10/22/2019] [Indexed: 01/22/2023]
Abstract
Bacterial surface molecules have an important role in the rhizobia-legume symbiosis. Ensifer meliloti (previously, Sinorhizobium meliloti), a symbiotic Gram-negative rhizobacterium, produces two different exopolysaccharides (EPSs), termed EPS I (succinoglycan) and EPS II (galactoglucan), with different functions in the symbiotic process. Accordingly, we undertook a study comparing the potential differences in alfalfa nodulation by E. meliloti strains with differences in their EPSs production. Strains recommended for inoculation as well as laboratory strains and native strains isolated from alfalfa fields were investigated. This study concentrated on EPS-II production, which results in mucoid colonies that are dependent on the presence of an intact expR gene. The results revealed that although the studied strains exhibited different phenotypes, the differences did not affect alfalfa nodulation itself. However, subtle changes in timing and efficacy to the effects of inoculation with the different strains may result because of other as-yet unknown factors. Thus, additional research is needed to determine the most effective inoculant strains and the best conditions for improving alfalfa production under agricultural conditions.
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Affiliation(s)
- Emiliano D Primo
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Sacha Cossovich
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Fiorela Nievas
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Pablo Bogino
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Ethan A Humm
- Department of Molecular, Cell and Developmental Biology, University of California-Los Angeles, Los Angeles, USA
| | - Ann M Hirsch
- Department of Molecular, Cell and Developmental Biology, University of California-Los Angeles, Los Angeles, USA.,Molecular Biology Institute, University of California-Los Angeles, Los Angeles, USA
| | - Walter Giordano
- Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
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23
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Wang H, Palmer J, Flint S. Function of pYV Plasmid on Biofilm Formation of Yersinia enterocolitica ERL032123 in the Presence of Ca 2. J Food Prot 2019; 82:1683-1687. [PMID: 31532251 DOI: 10.4315/0362-028x.jfp-19-018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The effect of the virulence plasmid pYV and calcium ions on biofilm of Yersinia enterocolitica biofilm formation was determined using a microtiter plate assay. Loss of the pYV plasmid prevented biofilm formation and the presence of Ca2+ enhanced biofilm formation in cultures containing the pYV plasmid. Scanning electron microscopy supported the result from the microtiter plate assay showing that in the presence of Ca2+, the wild-type Y. enterocolitica strain formed a strong biofilm on a polycarbonate surface. The results implied that Ca2+ promotes Y. enterocolitica biofilm formation through the function of the pYV plasmid.
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Affiliation(s)
- Haoran Wang
- School of Food and Advanced Technology, Massey University, Palmerston North 4410, New Zealand (ORCID: https://orcid.org/0000-0001-7472-2303 [H.W.])
| | - Jon Palmer
- School of Food and Advanced Technology, Massey University, Palmerston North 4410, New Zealand (ORCID: https://orcid.org/0000-0001-7472-2303 [H.W.])
| | - Steve Flint
- School of Food and Advanced Technology, Massey University, Palmerston North 4410, New Zealand (ORCID: https://orcid.org/0000-0001-7472-2303 [H.W.])
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24
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Transcriptome analysis of the fish pathogen Flavobacterium columnare in biofilm suggests calcium role in pathogenesis. BMC Microbiol 2019; 19:151. [PMID: 31272369 PMCID: PMC6610971 DOI: 10.1186/s12866-019-1533-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 06/27/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Flavobacterium columnare is the causative agent of columnaris disease that affects cultured freshwater fishes worldwide. F. columnare easily colonizes surfaces by forming biofilm, which helps the pathogen resist antibiotic and disinfectant treatments. Previously, we had shown that increasing concentrations of calcium (Ca2+) promoted biofilm formation by F. columnare. The objective of this study was to further characterize the role of Ca2+ on biofilm formation and to compare the transcriptome profiles of planktonic and biofilm cells. RESULTS RNA-Seq analysis was conducted to identify genes that were differentially expressed between the following states: i) planktonic cells in control medium (P), ii) planktonic cells in calcium-enriched medium (P/Ca), and iii) biofilm cells in calcium-enriched medium (B/Ca). Overall, we identified 441 significant (FDR-adjusted p < 0.05, fold change > 2) differentially expressed genes (DEGs) between P and B/Ca samples; 112 significant DEGs between P/Ca and B/Ca samples, and 175 significant DEGs between P/Ca and P samples, corresponding to 15.87, 4.03 and 6.30% of the total protein-coding sequences, respectively. The significant DEGs fell into different functional categories including iron acquisition, oxidative stress response, extracellular protein secretion, and respiratory metabolism. CONCLUSIONS Our results posit Ca2+ as a critical signal in regulating bacterial surface adhesion and biofilm formation in F. columnare. Living in biofilm elicited a shift in several metabolic pathways that allowed the cells to cope with oxidative stress and nutrient starvation. In addition, Ca2+ supplementation induced the expression of putative virulence factors in F. columnare, such as extracellular protein secretion and iron acquisition.
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Moretti C, Trabalza S, Granieri L, Caballo‐Ponce E, Devescovi G, Del Pino AM, Ramos C, Venturi V, van den Burg HA, Buonaurio R, Palmerini CA. A Na + /Ca 2+ exchanger of the olive pathogen Pseudomonas savastanoi pv. savastanoi is critical for its virulence. MOLECULAR PLANT PATHOLOGY 2019; 20:716-730. [PMID: 30912619 PMCID: PMC6637891 DOI: 10.1111/mpp.12787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In a number of compatible plant-bacterium interactions, a rise in apoplastic Ca2+ levels is observed, suggesting that Ca2+ represents an important environmental clue, as reported for bacteria infecting mammalians. We demonstrate that Ca2+ entry in Pseudomonas savastanoi pv. savastanoi (Psav) strain DAPP-PG 722 is mediated by a Na+ /Ca2+ exchanger critical for virulence. Using the fluorescent Ca2+ probe Fura 2-AM, we demonstrate that Ca2+ enters Psav cells foremost when they experience low levels of energy, a situation mimicking the apoplastic fluid. In fact, Ca2+ entry was suppressed in the presence of high concentrations of glucose, fructose, sucrose or adenosine triphosphate (ATP). Since Ca2+ entry was inhibited by nifedipine and LiCl, we conclude that the channel for Ca2+ entry is a Na+ /Ca2+ exchanger. In silico analysis of the Psav DAPP-PG 722 genome revealed the presence of a single gene coding for a Na+ /Ca2+ exchanger (cneA), which is a widely conserved and ancestral gene within the P. syringae complex based on gene phylogeny. Mutation of cneA compromised not only Ca2+ entry, but also compromised the Hypersensitive response (HR) in tobacco leaves and blocked the ability to induce knots in olive stems. The expression of both pathogenicity (hrpL, hrpA and iaaM) and virulence (ptz) genes was reduced in this Psav-cneA mutant. Complementation of the Psav-cneA mutation restored both Ca2+ entry and pathogenicity in olive plants, but failed to restore the HR in tobacco leaves. In conclusion, Ca2+ entry acts as a 'host signal' that allows and promotes Psav pathogenicity on olive plants.
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Affiliation(s)
- Chiaraluce Moretti
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Simone Trabalza
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Letizia Granieri
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Eloy Caballo‐Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea La MayoraUniversidad de Málaga‐Consejo Superior de Investigaciones Científicas (IHSM‐UMACSIC)Área de GenéticaMálagaSpain
| | - Giulia Devescovi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Alberto Marco Del Pino
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Cayo Ramos
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Vittorio Venturi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Harrold A. van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamNetherlands
| | - Roberto Buonaurio
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Carlo Alberto Palmerini
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
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Eze EC, Chenia HY, El Zowalaty ME. Acinetobacter baumannii biofilms: effects of physicochemical factors, virulence, antibiotic resistance determinants, gene regulation, and future antimicrobial treatments. Infect Drug Resist 2018; 11:2277-2299. [PMID: 30532562 PMCID: PMC6245380 DOI: 10.2147/idr.s169894] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acinetobacter baumannii is a leading cause of nosocomial infections due to its increased antibiotic resistance and virulence. The ability of A. baumannii to form biofilms contributes to its survival in adverse environmental conditions including hospital environments and medical devices. A. baumannii has undoubtedly propelled the interest of biomedical researchers due to its broad range of associated infections especially in hospital intensive care units. The interplay among microbial physicochemistry, alterations in the phenotype and genotypic determinants, and the impact of existing ecological niche and the chemistry of antimicrobial agents has led to enhanced biofilm formation resulting in limited access of drugs to their specific targets. Understanding the triggers to biofilm formation is a step towards limiting and containing biofilm-associated infections and development of biofilm-specific countermeasures. The present review therefore focused on explaining the impact of environmental factors, antimicrobial resistance, gene alteration and regulation, and the prevailing microbial ecology in A. baumannii biofilm formation and gives insights into prospective anti-infective treatments.
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Affiliation(s)
- Emmanuel C Eze
- Virology and Microbiology Research Group, School of Health Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa,
| | - Hafizah Y Chenia
- Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Mohamed E El Zowalaty
- Virology and Microbiology Research Group, School of Health Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa,
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In Vitro Formation of Dickeya zeae MS1 Biofilm. Curr Microbiol 2018; 76:100-107. [PMID: 30390102 DOI: 10.1007/s00284-018-1593-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 10/29/2018] [Indexed: 10/28/2022]
Abstract
Bacterial soft rot caused by Dickeya zeae MS1 (Erwinia chrysanthemi) is one of the most devastating banana diseases worldwide. However, knowledge of the development and ecological interactions of D. zeae MS1 biofilm is limited. Here, we visualized the development and architecture of D. zeae MS1 biofilm using confocal laser scanning microscopy, and we evaluated the ability of D. zeae MS1 to form biofilms under different environmental conditions (carbon sources, temperatures, pH levels and mineral elements) using a microtiter plate assay. We found that the development of D. zeae MS1 biofilm could be categorized into four phases and that mature biofilm consisted of a highly organized architecture of both bacterial cells and a self-produced matrix of extracellular polysaccharides. Furthermore, sucrose was the most suitable carbon source for supporting the growth of biofilm cells and that 32 °C and pH 7.0 were the most favorable of the temperatures and pH levels examined. Meanwhile, the addition of Ca2+, Fe2+, K+ and Na+ enhanced the formation of biofilm in minimal medium cultures, whereas 2.5 mM Cu2+ and Mn2+ was inhibitory. A better understanding of biofilm formation under different environmental parameters will improve our knowledge of the growth kinetics of D. zeae MS1 biofilm.
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Ponomareva AL, Buzoleva LS, Bogatyrenko EA. Abiotic Environmental Factors Affecting the Formation of Microbial Biofilms. BIOL BULL+ 2018. [DOI: 10.1134/s106235901805014x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Mosharaf MK, Tanvir MZH, Haque MM, Haque MA, Khan MAA, Molla AH, Alam MZ, Islam MS, Talukder MR. Metal-Adapted Bacteria Isolated From Wastewaters Produce Biofilms by Expressing Proteinaceous Curli Fimbriae and Cellulose Nanofibers. Front Microbiol 2018; 9:1334. [PMID: 29988579 PMCID: PMC6026672 DOI: 10.3389/fmicb.2018.01334] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Bacterial biofilm plays a pivotal role in bioremediation of heavy metals from wastewaters. In this study, we isolated and identified different biofilm producing bacteria from wastewaters. We also characterized the biofilm matrix [i.e., extracellular polymeric substances (EPS)] produced by different bacteria. Out of 40 isolates from different wastewaters, only 11 (27.5%) isolates (static condition at 28°C) and 9 (22.5%) isolates (agitate and static conditions at 28 and 37°C) produced air–liquid (AL) and solid–air–liquid (SAL) biofilms, respectively, only on salt-optimized broth plus 2% glycerol (SOBG) but not in other media tested. Biomass biofilms and bacteria coupled with AL biofilms were significantly (P ≤ 0.001) varied in these isolates. Escherichia coli (isolate ENSD101 and ENST501), Enterobacter asburiae (ENSD102), Enterobacter ludwigii (ENSH201), Pseudomonas fluorescens (ENSH202 and ENSG304), uncultured Vitreoscilla sp. (ENSG301 and ENSG305), Acinetobacter lwoffii (ENSG302), Klebsiella pneumoniae (ENSG303), and Bacillus thuringiensis (ENSW401) were identified based on 16S rRNA gene sequencing. Scanning electron microscope (SEM) images revealed that biofilm matrix produced by E. asburiae ENSD102, uncultured Vitreoscilla sp. ENSG301, A. lwoffii ENSG302, and K. pneumoniae ENSG303 are highly fibrous, compact, and nicely interlinked as compared to the biofilm developed by E. ludwigii ENSH201 and B. thuringiensis ENSW401. X-ray diffraction (XRD) results indicated that biofilm matrix produced by E. asburiae ENSD102, uncultured Vitreoscilla sp. ENSG301, and A. lwoffii ENSG302 are non-crystalline amorphous nature. Fourier transform infrared (FTIR) spectroscopy showed that proteins and polysaccharides are the main components of the biofilms. Congo red binding results suggested that all these bacteria produced proteinaceous curli fimbriae and cellulose-rich polysaccharide. Production of cellulose was also confirmed by Calcofluor binding- and spectrophotometric assays. E. asburiae ENSD102, Vitreoscilla sp. ENSG301, and A. lwoffii ENSG302 were tested for their abilities to form the biofilms exposure to 0 to 2000 mg/L of copper sulfate (for Cu), zinc sulfate (for Zn), lead nitrate (for Pb), nickel chloride (for Ni), and potassium dichromate (for Cr), several concentrations of these metals activated the biofilm formation. The polysaccharides is known to sequester the heavy metals thus, these bacteria might be applied to remove the heavy metals from wastewater.
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Affiliation(s)
- M K Mosharaf
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - M Z H Tanvir
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - M M Haque
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - M A Haque
- Department of Agro-Processing, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - M A A Khan
- Department of Plant Pathology, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - A H Molla
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - Mohammad Z Alam
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
| | - M S Islam
- Bangladesh Jute Research Institute, Dhaka, Bangladesh
| | - M R Talukder
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh
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Egamberdieva D, Jabborova D, Wirth SJ, Alam P, Alyemeni MN, Ahmad P. Interactive Effects of Nutrients and Bradyrhizobium japonicum on the Growth and Root Architecture of Soybean ( Glycine max L.). Front Microbiol 2018; 9:1000. [PMID: 29875740 PMCID: PMC5974200 DOI: 10.3389/fmicb.2018.01000] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/27/2018] [Indexed: 01/20/2023] Open
Abstract
Understanding the symbiotic performance of rhizobia and responses of plant root systems to mineral nutrient supply will facilitate the development of strategies to enhance effective rhizobia-legume symbioses. Interactive effect of nitrogen (N), phosphorus (P), and magnesium (Mg) on the symbiotic performance of soybean (Glycine max L.) with Bradyrhizobium japonicum, nodulation, root architecture, and the N concentration in plant tissue under hydroponic conditions were studied. Plant growth was significantly higher under a high N supply combined with Mg (HNHMg) than in combination with P (HNHP), which was attributed to the interaction between N and Mg ions. The plants grown at a low N concentration combined with either high or low P or Mg (LNHP, LNHMg, LNLP, and LNLMg) showed a higher nodule dry weight compared to those grown under a high N supply. We observed that the N content in the roots and shoots of soybean plants was significantly lower under LNHP or LNLP, but it was higher under HNHMg or LNHMg, indicating that Mg promotes N acquisition by the plant tissues. Neither root nor shoot growth responded significantly to P availability regardless of the N supply. We observed significant positive relationships between the number of nodules, the N content in plant tissues and the root system architecture of soybean plants grown with a variable supply of Mg combined with N, which highlights the importance of N and Mg availability in the growth medium in regulating root system architecture and nodule formation. The number of rhizobial cells colonizing soybean roots was highest under the HNHMg treatment (6.78 × 104 CFUs/cm of root tip), followed by the HNLMg (4.72 × 104 CFUs/cm of root tip) and LNHMg (4.10 × 104 CFU/cm of root tip) treatments, and lowest under the LNLMg (1.84 × 104 CFUs/cm of root tip) nutrient conditions. The results of this study contribute to new insights for the improvement of the root system and the symbiotic performance of rhizobia inoculated on legumes, stressing the importance of a balanced supply of nutrients.
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Affiliation(s)
| | - Dilfuza Jabborova
- Institute of Genetics and Plant Experimental Biology, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan
| | - Stephan J. Wirth
- Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany
| | - Pravej Alam
- Biology Department, College of Science and Humanities, Prince Sattam bin Abdulaziz University, Alkharj, Saudi Arabia
| | - Mohammed N. Alyemeni
- Department of Botany and Microbiology, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
| | - Parvaiz Ahmad
- Department of Botany and Microbiology, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Botany, S.P. College, Srinagar, India
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31
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Ullah S, Khan MY, Asghar HN, Akhtar MJ, Zahir ZA. Differential response of single and co-inoculation of Rhizobium leguminosarum and Mesorhizobium ciceri for inducing water deficit stress tolerance in wheat. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1302-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Zhou G, Peng H, Wang YS, Huang XM, Xie XB, Shi QS. Complete genome sequence of Citrobacter werkmanii strain BF-6 isolated from industrial putrefaction. BMC Genomics 2017; 18:765. [PMID: 29017450 PMCID: PMC5635574 DOI: 10.1186/s12864-017-4157-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/04/2017] [Indexed: 11/10/2022] Open
Abstract
Background In our previous study, Citrobacter werkmanii BF-6 was isolated from an industrial spoilage sample and demonstrated an excellent ability to form biofilms, which could be affected by various environmental factors. However, the genome sequence of this organism has not been reported so far. Results We report the complete genome sequence of C. werkmanii BF-6 together with the description of the genome features and its annotation. The size of the complete chromosome is 4,929,789 bp with an average coverage of 137×. The chromosome exhibits an average G + C content of 52.0%, and encodes 4570 protein coding genes, 84 tRNA genes, 25 rRNA operons, 3 microsatellite sequences and 34 minisatellite sequences. A previously unknown circular plasmid designated as pCW001 was also found with a length of 212,549 bp and a G + C content of 48.2%. 73.5%, 75.6% and 92.6% of the protein coding genes could be assigned to GO Ontology, KEGG Pathway, and COG (Clusters of Orthologous Groups) categories respectively. C. werkmanii BF-6 and C. werkmanii NRBC 105721 exhibited the closest evolutionary relationships based on 16S ribosomal RNA and core-pan genome assay. Furthermore, C. werkmanii BF-6 exhibits typical bacterial biofilm formation and development. In the RT-PCR experiments, we found that a great number of biofilm related genes, such as bsmA, bssR, bssS, hmsP, tabA, csgA, csgB, csgC, csgD, csgE, and csgG, were involved in C. werkmanii BF-6 biofilm formation. Conclusions This is the first complete genome of C. werkmanii. Our work highlights the potential genetic mechanisms involved in biofilm formation and paves a way for further application of C. werkmanii in biofilms research. Electronic supplementary material The online version of this article (10.1186/s12864-017-4157-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gang Zhou
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Hong Peng
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Ying-Si Wang
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Xiao-Mo Huang
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Xiao-Bao Xie
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Qing-Shan Shi
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China. .,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China. .,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China. .,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.
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Haque MM, Oliver MMH, Nahar K, Alam MZ, Hirata H, Tsuyumu S. CytR Homolog of Pectobacterium carotovorum subsp. carotovorum Controls Air-Liquid Biofilm Formation by Regulating Multiple Genes Involved in Cellulose Production, c-di-GMP Signaling, Motility, and Type III Secretion System in Response to Nutritional and Environmental Signals. Front Microbiol 2017; 8:972. [PMID: 28620360 PMCID: PMC5449439 DOI: 10.3389/fmicb.2017.00972] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/15/2017] [Indexed: 01/22/2023] Open
Abstract
Pectobacterium carotovorum subsp. carotovorum [Pcc (formerly Erwinia carotovora subsp. carotovora)] PC1 causes soft-rot disease in a wide variety of plant species by secreting multiple pathogenicity-related traits. In this study, regulatory mechanism of air-liquid (AL) biofilm formation was studied using a cytR homolog gene deletion mutant (ΔcytR) of Pcc PC1. Compared to the wild type (Pcc PC1), the ΔcytR mutant produced fragile and significantly (P < 0.001) lower amounts of AL biofilm on salt-optimized broth plus 2% glycerol (SOBG), yeast peptone dextrose adenine, and also on King’s B at 27°C after 72 h incubation in static condition. The wild type also produced significantly higher quantities of AL biofilm on SOBGMg– (magnesium deprived) containing Cupper (Cu2+), Zinc (Zn2+), Manganese (Mn2+), Magnesium (Mg2+), and Calcium (Ca2+) compared to the ΔcytR mutant. Moreover, the wild type was produced higher amounts of biofilms compared to the mutant while responding to pH and osmotic stresses. The ΔfliC (encoding flagellin), flhD::Tn5 (encoding a master regulator) and ΔmotA (a membrane protein essential for flagellar rotation) mutants produced a lighter and more fragile AL biofilm on SOBG compared to their wild counterpart. All these mutants resulted in having weak bonds with the cellulose specific dye (Calcofluor) producing lower quantities of cellulose compared to the wild type. Gene expression analysis using mRNA collected from the AL biofilms showed that ΔcytR mutant significantly (P < 0.001) reduced the expressions of multiple genes responsible for cellulose production (bcsA, bcsE, and adrA), motility (flhD, fliA, fliC, and motA) and type III secretion system (hrpX, hrpL, hrpA, and hrpN) compared to the wild type. The CytR homolog was therefore, argued to be able to regulate the AL biofilm formation by controlling cellulose production, motility and T3SS in Pcc PC1. In addition, all the mutants exhibited poorer attachment to radish sprouts and AL biofilm cells of the wild type was resistant than stationary-phase and planktonic cells to acidity and oxidative stress compared to the same cells of the ΔcytR mutant. The results of this study therefore suggest that CytR homolog is a major determinant of Pcc PC1’s virulence, attachment and its survival mechanism.
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Affiliation(s)
- M M Haque
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural UniversityGazipur, Bangladesh
| | - M M H Oliver
- Department of Agricultural Engineering, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural UniversityGazipur, Bangladesh
| | - Kamrun Nahar
- Plant Breeding Division, Bangladesh Agricultural Research InstituteGazipur, Bangladesh
| | - Mohammad Z Alam
- Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural UniversityGazipur, Bangladesh
| | - Hisae Hirata
- Faculty of Agriculture, Shizuoka UniversityShizuoka, Japan
| | - Shinji Tsuyumu
- Faculty of Agriculture, Shizuoka UniversityShizuoka, Japan
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Velmourougane K, Prasanna R, Saxena AK. Agriculturally important microbial biofilms: Present status and future prospects. J Basic Microbiol 2017; 57:548-573. [PMID: 28407275 DOI: 10.1002/jobm.201700046] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 11/07/2022]
Abstract
Microbial biofilms are a fascinating subject, due to their significant roles in the environment, industry, and health. Advances in biochemical and molecular techniques have helped in enhancing our understanding of biofilm structure and development. In the past, research on biofilms primarily focussed on health and industrial sectors; however, lately, biofilms in agriculture are gaining attention due to their immense potential in crop production, protection, and improvement. Biofilms play an important role in colonization of surfaces - soil, roots, or shoots of plants and enable proliferation in the desired niche, besides enhancing soil fertility. Although reports are available on microbial biofilms in general; scanty information is published on biofilm formation by agriculturally important microorganisms (bacteria, fungi, bacterial-fungal) and their interactions in the ecosystem. Better understanding of agriculturally important bacterial-fungal communities and their interactions can have several implications on climate change, soil quality, plant nutrition, plant protection, bioremediation, etc. Understanding the factors and genes involved in biofilm formation will help to develop more effective strategies for sustainable and environment-friendly agriculture. The present review brings together fundamental aspects of biofilms, in relation to their formation, regulatory mechanisms, genes involved, and their application in different fields, with special emphasis on agriculturally important microbial biofilms.
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Affiliation(s)
| | - Radha Prasanna
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Anil Kumar Saxena
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau Nath Bhanjan, Uttar Pradesh, India
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Hawkins JP, Oresnik IJ. Characterisation of a gene encoding a membrane protein that affects exopolysaccharide production and intracellular Mg2+ concentrations in Ensifer meliloti. FEMS Microbiol Lett 2017; 364:3072829. [DOI: 10.1093/femsle/fnx061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/15/2017] [Indexed: 12/30/2022] Open
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Schmidt J, Fester T, Schulz E, Michalzik B, Buscot F, Gutknecht J. Effects of plant-symbiotic relationships on the living soil microbial community and microbial necromass in a long-term agro-ecosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 581-582:756-765. [PMID: 28082056 DOI: 10.1016/j.scitotenv.2017.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/30/2016] [Accepted: 01/01/2017] [Indexed: 06/06/2023]
Abstract
We examined the impact of arbuscular mycorrhizal fungi and rhizobia on the living microbial community and microbial necromass under different long-term fertilization treatments at the long-term Static Fertilization Experiment Bad Lauchstädt (Germany). Phospholipid fatty acids (PLFA) and amino sugars plus muramic acid, were used as biomarkers for soil microbial bio- and necromass, respectively, and analyzed from six treatments imposed on two crop rotations, varying only in the inclusion/non-inclusion of a legume. Treatments included: two levels of only farmyard manure (FYM), only mineral fertilizer (NPK), the combined application of both fertilizer types and a non-fertilized control. PLFA profiles differed clearly between the investigated crop rotations and were significantly related to labile C, mineral N, and soil pH. This emphasizes the role of carbon, and of mycorrhizal and rhizobial symbioses, as driver for changes in the microbial community composition due to effects on the living conditions in soil. We found some evidence that legume associated symbiosis with arbuscular mycorrhizal fungi and rhizobia act as a buffer, reducing the impact of varying inputs of mineral nutrients on the decomposer community. While our results support former findings that living microbial populations vary within short-term periods and are reflective of a given crop grown in a given year, soil necromass composition indicates longer term changes across the two crop rotation types, mainly shaped by fertilizer related effects on the community composition and C turnover. However, there was some evidence that specifically the presence of a legume, affects the soil necromass composition not only over the whole crop rotation but even in the short-term.
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Affiliation(s)
- J Schmidt
- UFZ - Helmholtz Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Str. 4, D-06120 Halle, Germany.
| | - T Fester
- UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstr. 15, D-04318 Leipzig, Germany
| | - E Schulz
- UFZ - Helmholtz Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Str. 4, D-06120 Halle, Germany
| | - B Michalzik
- Friedrich-Schiller-University of Jena, Institute of Geography, Löbdergraben 32, D-07743 Jena, Germany
| | - F Buscot
- UFZ - Helmholtz Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Str. 4, D-06120 Halle, Germany; German Centre of Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, D-04103 Leipzig, Germany
| | - J Gutknecht
- UFZ - Helmholtz Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Str. 4, D-06120 Halle, Germany; University of Minnesota, Twin Cities, Department of Soil, Water, and Climate, 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN 55108, USA
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Tallawi M, Opitz M, Lieleg O. Modulation of the mechanical properties of bacterial biofilms in response to environmental challenges. Biomater Sci 2017; 5:887-900. [DOI: 10.1039/c6bm00832a] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this review, we highlight recent research on the relationship between biofilm matrix composition, biofilm mechanics and environmental stimuli.
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Affiliation(s)
- Marwa Tallawi
- Department of Mechanical Engineering and Munich School of Bioengineering
- Technische Universität München
- Garching
- Germany
| | - Madeleine Opitz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - Oliver Lieleg
- Department of Mechanical Engineering and Munich School of Bioengineering
- Technische Universität München
- Garching
- Germany
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Taktek S, St-Arnaud M, Piché Y, Fortin JA, Antoun H. Igneous phosphate rock solubilization by biofilm-forming mycorrhizobacteria and hyphobacteria associated with Rhizoglomus irregulare DAOM 197198. MYCORRHIZA 2017; 27:13-22. [PMID: 27541158 PMCID: PMC5203815 DOI: 10.1007/s00572-016-0726-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/08/2016] [Indexed: 05/22/2023]
Abstract
Biofilm formation on abiotic and biotic surfaces was studied with two hyphobacteria, strongly attached to the surface of the arbuscular mycorrhizal fungus (AMF) Rhizoglomus irregulare (Ri) DAOM 197198 and two mycorrhizobacteria, loosely attached to the roots of different mycorrhizal plants. When the sparingly soluble igneous phosphate rock (PR) from Quebec, or when the chemical hydroxyapatite were used as sole phosphorus (P) source, hyphobacteria Rhizobium miluonense Rm3 and Burkholderia anthina Ba8 produced significantly more biofilms than mycorrhizobacteria Rahnella sp. Rs11 and Burkholderia phenazinium Bph12, as indicated by the crystal violet assay or by quantifying biofilm exopolysaccharides. As previously observed with planktonic bacteria, biofilms mobilized P by lowering the pH and releasing gluconic acid. The high efficiency of P mobilization by the hyphobacteria Ba8 was linked to the presence of more viable cells in its biofilm as revealed by the hydrolysis of fluorescein diacetate. Scanning electron microscopy micrographs showed a high adherence of the best P-solubilizer hyphobacteria Ba8 on the surface of Quebec PR. Hydroxyapatite porous structure did not allow a good adherence of Ba8. Ba8 formed an important biofilm on the hyphae of Ri DAOM 197198 with low reactive Quebec PR while no biofilm was observed with the high reactive hydroxyapatite. Results confirm the possible presence of specificity between the Ri DAOM 197198 and the hyphobacteria and suggest that the interaction would be regulated by the availability of P.
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Affiliation(s)
- Salma Taktek
- Centre de recherche en innovation sur les végétaux and Département des sols et de génie agroalimentaire, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, 2480 Boulevard Hochelaga, Québec, QC, G1V 0A6, Canada
| | - Marc St-Arnaud
- Institut de recherche en biologie végétale, Université de Montréal and Jardin botanique de Montréal, Montréal, H1X 2B2, QC, Canada
| | - Yves Piché
- Centre d'étude de la forêt and Département des sciences du bois et de la forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, G1V 0A6, QC, Canada
| | - J André Fortin
- Centre d'étude de la forêt and Département des sciences du bois et de la forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, G1V 0A6, QC, Canada
| | - Hani Antoun
- Centre de recherche en innovation sur les végétaux and Département des sols et de génie agroalimentaire, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, 2480 Boulevard Hochelaga, Québec, QC, G1V 0A6, Canada.
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Nocelli N, Bogino PC, Banchio E, Giordano W. Roles of Extracellular Polysaccharides and Biofilm Formation in Heavy Metal Resistance of Rhizobia. MATERIALS 2016; 9:ma9060418. [PMID: 28773540 PMCID: PMC5456807 DOI: 10.3390/ma9060418] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/09/2016] [Accepted: 05/17/2016] [Indexed: 12/04/2022]
Abstract
Bacterial surface components and extracellular compounds, particularly flagella, lipopolysaccharides (LPSs), and exopolysaccharides (EPSs), in combination with environmental signals and quorum-sensing signals, play crucial roles in bacterial autoaggregation, biofilm development, survival, and host colonization. The nitrogen-fixing species Sinorhizobium meliloti (S. meliloti) produces two symbiosis-promoting EPSs: succinoglycan (or EPS I) and galactoglucan (or EPS II). Studies of the S.meliloti/alfalfa symbiosis model system have revealed numerous biological functions of EPSs, including host specificity, participation in early stages of host plant infection, signaling molecule during plant development, and (most importantly) protection from environmental stresses. We evaluated functions of EPSs in bacterial resistance to heavy metals and metalloids, which are known to affect various biological processes. Heavy metal resistance, biofilm production, and co-culture were tested in the context of previous studies by our group. A range of mercury (Hg II) and arsenic (As III) concentrations were applied to S. meliloti wild type strain and to mutant strains defective in EPS I and EPS II. The EPS production mutants were generally most sensitive to the metals. Our findings suggest that EPSs are necessary for the protection of bacteria from either Hg (II) or As (III) stress. Previous studies have described a pump in S. meliloti that causes efflux of arsenic from cells to surrounding culture medium, thereby protecting them from this type of chemical stress. The presence of heavy metals or metalloids in culture medium had no apparent effect on formation of biofilm, in contrast to previous reports that biofilm formation helps protect various microorganism species from adverse environmental conditions. In co-culture experiments, EPS-producing heavy metal resistant strains exerted a protective effect on AEPS-non-producing, heavy metal-sensitive strains; a phenomenon termed “rescuing” of the non-resistant strain.
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Affiliation(s)
- Natalia Nocelli
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba X5804BYA, Argentina.
| | - Pablo C Bogino
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba X5804BYA, Argentina.
| | - Erika Banchio
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba X5804BYA, Argentina.
| | - Walter Giordano
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba X5804BYA, Argentina.
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40
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Copper-induced modifications in early symbiotic signaling factors of Ensifer (Sinorhizobium)–Medicago interactions. Arch Microbiol 2016; 198:701-9. [DOI: 10.1007/s00203-016-1242-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 03/07/2016] [Accepted: 05/09/2016] [Indexed: 12/18/2022]
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41
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42
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Horváthová T, Babik W, Bauchinger U. Biofilm feeding: Microbial colonization of food promotes the growth of a detritivorous arthropod. Zookeys 2016:25-41. [PMID: 27110187 PMCID: PMC4829882 DOI: 10.3897/zookeys.577.6149] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 02/22/2016] [Indexed: 01/12/2023] Open
Abstract
Feeding on plant material is common among animals, but how different animals overcome the dietary deficiencies imposed by this feeding strategy is not well understood. Microorganisms are generally considered to play a vital role in the nutritional ecology of plant feeding animals. Commonly microbes living inside animal bodies are considered more important, but recent studies suggest external microbes significantly shape plant-feeding strategies in invertebrates. Here we investigate how external microbes that typically form biofilm on primary plant material affect growth rates in a terrestrial isopod species Porcellio scaber. We experimentally manipulated the amount of biofilm on three different primary diet sources and quantified growth and survival of individuals that fed on food with either a small or large amount of biofilm. In addition, we tested how dietary manipulation shapes the composition of bacterial communities in the gut. The presence of visible biofilm significantly affected the growth of isopods: individuals that fed on the primary diet source with a large amount of biofilm gained more mass than individuals feeding on a diet with marginal biofilm. Diet also significantly affected the bacterial gut community. The primary diet source mainly determined the taxonomic composition of the bacterial community in the isopod gut, whereas the amount of biofilm affected the relative abundance of bacterial taxa. Our study suggests that terrestrial isopods may cope with low-quality plant matter by feeding on biofilm, with decomposition of plant material by organisms outside of the feeding organism (here a terrestrial isopod) probably playing a major role. Future investigations may be directed towards the primary diet source, plant matter, and the secondary diet source, biofilm, and should assess if both components are indeed uptaken in detritivorous species.
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Affiliation(s)
- Terézia Horváthová
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Wiesław Babik
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
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43
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Parker JK, Chen H, McCarty SE, Liu LY, De La Fuente L. Calcium transcriptionally regulates the biofilm machinery of Xylella fastidiosa to promote continued biofilm development in batch cultures. Environ Microbiol 2016; 18:1620-34. [PMID: 26913481 DOI: 10.1111/1462-2920.13242] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 01/21/2016] [Indexed: 11/29/2022]
Abstract
The functions of calcium (Ca) in bacteria are less characterized than in eukaryotes, where its role has been studied extensively. The plant-pathogenic bacterium Xylella fastidiosa has several virulence features that are enhanced by increased Ca concentrations, including biofilm formation. However, the specific mechanisms driving modulation of this feature are unclear. Characterization of biofilm formation over time showed that 4 mM Ca supplementation produced denser biofilms that were still developing at 96 h, while biofilm in non-supplemented media had reached the dispersal stage by 72 h. To identify changes in global gene expression in X. fastidiosa grown in supplemental Ca, RNA-Seq of batch culture biofilm cells was conducted at three 24-h time intervals. Results indicate that a variety of genes are differentially expressed in response to Ca, including genes related to attachment, motility, exopolysaccharide synthesis, biofilm formation, peptidoglycan synthesis, regulatory functions, iron homeostasis, and phages. Collectively, results demonstrate that Ca supplementation induces a transcriptional response that promotes continued biofilm development, while biofilm cells in nonsupplemented media are driven towards dispersion of cells from the biofilm structure. These results have important implications for disease progression in planta, where xylem sap is the source of Ca and other nutrients for X. fastidiosa.
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Affiliation(s)
- Jennifer K Parker
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | - Hongyu Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | - Sara E McCarty
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | - Lawrence Y Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
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44
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Zhou G, Shi QS, Huang XM, Xie XB. Proteome responses of Citrobacter werkmanii BF-6 planktonic cells and biofilms to calcium chloride. J Proteomics 2016; 133:134-143. [DOI: 10.1016/j.jprot.2015.12.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/24/2015] [Accepted: 12/14/2015] [Indexed: 11/27/2022]
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45
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Pan M, Zhao J, Zhen S, Heng S, Wu J. Effects of the combination of aeration and biofilm technology on transformation of nitrogen in black-odor river. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2016; 74:655-662. [PMID: 27508370 DOI: 10.2166/wst.2016.212] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excess nitrogen in urban river networks leading to eutrophication has become one of the most urgent environmental problems. Combinations of different aeration and biofilm techniques was designed to remove nitrogen from rivers. In laboratory water tank simulation experiments, we assessed the removal efficiency of nitrogen in both the overlying water and sediments by using the combination of the aeration and biofilm techniques, and then analyzed the transformation of nitrogen during the experiments. Aeration (especially sediment aeration) combined with the biofilms techniques was proved efficient in removing nitrogen from polluted rivers. Results indicated that the combination of sediment aeration and biofilms, with the highest nitrogen removal rate from the overlying water and sediments, was the most effective combined process, which especially inhibited the potential release of nitrogen from sediments by reducing the enzyme activity. It was found that the content of dissolved oxygen in water could be restored on the basis of the application of aeration techniques ahead, and the biofilm technique would be effective in purifying water in black-odor rivers.
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Affiliation(s)
- Mei Pan
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng 224003, China E-mail: ; College of Environment, Hohai University, Nanjing 210098, China
| | - Jun Zhao
- Nanjing University of Information Science & Technology, Ningliu Road #219, Nanjing 210044, China
| | - Shucong Zhen
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng 224003, China E-mail:
| | - Sheng Heng
- College of Environmental Science and Engineering, Yancheng Institute of Technology, Yingbin Road #9, Yancheng 224003, China E-mail:
| | - Jie Wu
- Zhenjiang Urban Planning Design Institute, NanXu Road #669, Zhenjiang 212034, China
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46
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Murugan K, Selvanayaki K, Al-Sohaibani S. Urinary catheter indwelling clinical pathogen biofilm formation, exopolysaccharide characterization and their growth influencing parameters. Saudi J Biol Sci 2016; 23:150-9. [PMID: 26858552 PMCID: PMC4705282 DOI: 10.1016/j.sjbs.2015.04.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 04/15/2015] [Accepted: 04/27/2015] [Indexed: 12/23/2022] Open
Abstract
Self-reproducing microbial biofilm community mainly involved in the contamination of indwelling medical devices including catheters play a vital role in nosocomial infections. The catheter-associated urinary tract infection (CA-UTI) causative Staphylococcus aureus, Enterobacter faecalis, and Pseudomonas aeruginosa were selectively isolated, their phenotypic as well as genotypic biofilm formation, production and monomeric sugar composition of EPS as well as sugar, salt, pH and temperature influence on their in vitro biofilm formation were determined. From 50 culture positive urinary catheters S. aureus (24%), P. aeruginosa (18%), E. faecalis (14%) and others (44%) were isolated. The performed assays revealed their varying biofilm forming ability. The isolated S. aureus ica, E. faecalis esp, and P. aeruginosa cup A gene sequencing and phylogenetic analysis showed their close branching and genetic relationship. The analyzed sugar, salt, pH, and temperature showed that the degree of CA-UTI isolates biofilm formation is an environmentally sensitive process. EPS monosaccharide HPLC analysis showed the presence of neutral sugars (ng/μl) as follows: glucose (P. aeruginosa: 44.275; E. faecalis: 4.23), lactose (P. aeruginosa: 7.29), mannitol (P. aeruginosa: 2.53; S. aureus: 2.62; E. faecalis: 2.054) and maltose (E. faecalis: 7.0042) revealing species-specific presence and variation. This study may have potential clinical relevance for the easy diagnosis and management of CA-UTI.
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Affiliation(s)
- Kasi Murugan
- Department of Botany and Microbiology, College of Science, P.O. Box 2455, King Saud University, Riyadh 11451, Saudi Arabia
| | - Krishnasamy Selvanayaki
- P.G. and Research Department of Microbiology, K. S. Rangasamy College of Arts and Science, Tiruchengode, Namakkal 637 215, Tamilnadu, India
| | - Saleh Al-Sohaibani
- Department of Botany and Microbiology, College of Science, P.O. Box 2455, King Saud University, Riyadh 11451, Saudi Arabia
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47
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Machado D, Palmeira-de-Oliveira A, Cerca N. Optimization of culture conditions for Gardnerella vaginalis biofilm formation. J Microbiol Methods 2015; 118:143-6. [PMID: 26381661 DOI: 10.1016/j.mimet.2015.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/10/2015] [Accepted: 09/10/2015] [Indexed: 11/25/2022]
Abstract
Bacterial vaginosis is the leading vaginal disorder in women in reproductive age. Although bacterial vaginosis is related with presence of a biofilm composed predominantly by Gardnerella vaginalis, there has not been a detailed information addressing the environmental conditions that influence the biofilm formation of this bacterial species. Here, we evaluated the influence of some common culture conditions on G. vaginalis biofilm formation, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that culture conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, using a fed-batch system and supplementing the growth medium with maltose.
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Affiliation(s)
- Daniela Machado
- Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Ana Palmeira-de-Oliveira
- CICS-UBI, Health Sciences Research Center, Faculty of Health Sciences, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal; Labfit - HPRD: Health Products Research and Development Lda, Edificio UBIMEDICAL, Estrada Municipal 506, 6200-284 Covilhã, Portugal
| | - Nuno Cerca
- Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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48
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Biofilm formation and extracellular polymeric substances (EPS) production by Bacillus subtilis depending on nutritional conditions in the presence of polyester film. Folia Microbiol (Praha) 2015; 61:91-100. [PMID: 26139336 DOI: 10.1007/s12223-015-0406-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
The influence of biofilm formation as the mode of microorganism growth on degradation of synthetic polymers represents an important research topic. This study focuses on the effect of biofilm developed by Bacillus subtilis (BS) cultivated submerged under various nutrition conditions on biodeterioration of poly(ε-caprolactone) film. Polymer in the film form (thickness 0.7 mm) was incubated for 21 days either continuously or by regularly renewed system. The scission of polyester chain bonds took place in all biotic media and was enhanced by biofilm formation in nutrient-rich media.
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49
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Zhang W, Sun J, Ding W, Lin J, Tian R, Lu L, Liu X, Shen X, Qian PY. Extracellular matrix-associated proteins form an integral and dynamic system during Pseudomonas aeruginosa biofilm development. Front Cell Infect Microbiol 2015; 5:40. [PMID: 26029669 PMCID: PMC4429628 DOI: 10.3389/fcimb.2015.00040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/27/2015] [Indexed: 12/13/2022] Open
Abstract
Though the essential role of extracellular matrix in biofilm development has been extensively documented, the function of matrix-associated proteins is elusive. Determining the dynamics of matrix-associated proteins would be a useful way to reveal their functions in biofilm development. Therefore, we applied iTRAQ-based quantitative proteomics to evaluate matrix-associated proteins isolated from different phases of Pseudomonas aeruginosa ATCC27853 biofilms. Among the identified 389 proteins, 54 changed their abundance significantly. The increased abundance of stress resistance and nutrient metabolism-related proteins over the period of biofilm development was consistent with the hypothesis that biofilm matrix forms micro-environments in which cells are optimally organized to resist stress and use available nutrients. Secreted proteins, including novel putative effectors of the type III secretion system were identified, suggesting that the dynamics of pathogenesis-related proteins in the matrix are associated with biofilm development. Interestingly, there was a good correlation between the abundance changes of matrix-associated proteins and their expression. Further analysis revealed complex interactions among these modulated proteins, and the mutation of selected proteins attenuated biofilm development. Collectively, this work presents the first dynamic picture of matrix-associated proteins during biofilm development, and provides evidences that the matrix-associated proteins may form an integral and well regulated system that contributes to stress resistance, nutrient acquisition, pathogenesis and the stability of the biofilm.
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Affiliation(s)
- Weipeng Zhang
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Jin Sun
- Department of Biology, Hong Kong Baptist University Hong Kong, China
| | - Wei Ding
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Jinshui Lin
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Renmao Tian
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Liang Lu
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Xiaofen Liu
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Pei-Yuan Qian
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
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50
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Amaya-Gómez CV, Hirsch AM, Soto MJ. Biofilm formation assessment in Sinorhizobium meliloti reveals interlinked control with surface motility. BMC Microbiol 2015; 15:58. [PMID: 25887945 PMCID: PMC4381460 DOI: 10.1186/s12866-015-0390-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 02/18/2015] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Swarming motility and biofilm formation are opposite, but related surface-associated behaviors that allow various pathogenic bacteria to colonize and invade their hosts. In Sinorhizobium meliloti, the alfalfa endosymbiont, these bacterial processes and their relevance for host plant colonization are largely unexplored. Our previous work demonstrated distinct swarming abilities in two S. meliloti strains (Rm1021 and GR4) and revealed that both environmental cues (iron concentration) and bacterial genes (fadD, rhb, rirA) play crucial roles in the control of surface motility in this rhizobial species. In the current study, we investigate whether these factors have an impact on the ability of S. meliloti to establish biofilms and to colonize host roots. RESULTS We found that strain GR4, which is less prone to translocate on solid surfaces than strain Rm1021, is more efficient in developing biofilms on glass and plant root surfaces. High iron conditions, known to prevent surface motility in a wild-type strain of S. meliloti, promote biofilm development in Rm1021 and GR4 strains by inducing the formation of more structured and thicker biofilms than those formed under low iron levels. Moreover, three different S. meliloti mutants (fadD, rhb, and rirA) that exhibit an altered surface translocation behavior compared with the wild-type strain, establish reduced biofilms on both glass and alfalfa root surfaces. Iron-rich conditions neither rescue the defect in biofilm formation shown by the rhb mutant, which is unable to produce the siderophore rhizobactin 1021 (Rhb1021), nor have any impact on biofilms formed by the iron-response regulator rirA mutant. On the other hand, S. meliloti FadD loss-of-function mutants do not establish normal biofilms irrespective of iron levels. CONCLUSIONS Our studies show that siderophore Rhb1021 is not only required for surface translocation, but also for biofilm formation on glass and root surfaces by strain Rm1021. In addition, we present evidence for the existence of control mechanisms that inversely regulate swarming and biofilm formation in S. meliloti, and that contribute to efficient plant root colonization. One of these mechanisms involves iron levels and the iron global regulator RirA. The other mechanism involves the participation of the fatty acid metabolism-related enzyme FadD.
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Affiliation(s)
- Carol V Amaya-Gómez
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008, Granada, Spain.
| | - Ann M Hirsch
- Department of Molecular, Cell, and Developmental Biology and Molecular Biology Institute, University of California-Los Angeles, Los Angeles, CA, 90095-1606, USA.
| | - María J Soto
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, 18008, Granada, Spain.
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