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Rammali S, Ciobică A, El Aalaoui M, Rahim A, Kamal FZ, Dari K, Khattabi A, Romila L, Novac B, Petroaie A, Bencharki B. Exploring the antimicrobial and antioxidant properties of Lentzea flaviverrucosa strain E25-2 isolated from Moroccan forest soil. Front Microbiol 2024; 15:1429035. [PMID: 39104582 PMCID: PMC11298423 DOI: 10.3389/fmicb.2024.1429035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 07/05/2024] [Indexed: 08/07/2024] Open
Abstract
The alarming rise in antimicrobial resistance (AMR) has created a significant public health challenge, necessitating the discovery of new therapeutic agents to combat infectious diseases and oxidative stress-related disorders. The Lentzea flaviverrucosa strain E25-2, isolated from Moroccan forest soil, represents a potential avenue for such research. This study aimed to identify the isolate E25-2, obtained from soil in a cold Moroccan ecosystem, and further investigate its antimicrobial and antioxidant activities. Phylogenetic analysis based on 16S rRNA gene sequences revealed the strain's classification within the Lentzea genus, with a sequence closely resembling that of Lentzea flaviverrucosa AS4.0578 (96.10% similarity). Antimicrobial activity in solid media showed moderate to strong activity against Staphylococcus aureus ATCC 25923, Bacillus cereus strain ATCC 14579, Escherichia coli strain ATCC 25922, Candida albicans strain ATCC 60193 and 4 phytopathogenic fungi. In addition, ethyl acetate extract of this isolate demonstrated potent antimicrobial activity against 7 clinically multi-drug resistant bacteria. Furthermore, it demonstrated antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, as well as a significant increase in ferric reducing antioxidant power. A significant positive correlation was observed between antioxidant activities and total content of phenolic compounds (p < 0.0001), along with flavonoids (p < 0.0001). Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of amines, hydroxyl groups, pyridopyrazinone rings, esters and pyrrolopyrazines. The Lentzea genus could offer promising prospects in the fight against antibiotic resistance and in the prevention against oxidative stress related diseases.
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Affiliation(s)
- Said Rammali
- Laboratory of Agro-Alimentary and Health, Faculty of Sciences and Techniques, Hassan First University of Settat, Settat, Morocco
| | - Alin Ciobică
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, Iași, Romania
- Center of Biomedical Research, Romanian Academy, Iasi Branch, Iași, Romania
- Academy of Romanian Scientists, Bucharest, Romania
- CENEMED Platform for Interdisciplinary Research, “Grigore T. Popa” University of Medicine and Pharmacy of Iasi, Iasi, Romania
| | | | - Abdellatif Rahim
- Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences and Techniques, Hassan First University of Settat, Settat, Morocco
| | - Fatima Zahra Kamal
- Higher Institute of Nursing Professions and Health Technical (ISPITS), Marrakech, Morocco
- Laboratory of Physical Chemistry of Processes and Materials, Faculty of Sciences and Techniques, Hassan First University, Settat, Morocco
| | - Khadija Dari
- Laboratory of Agro-Alimentary and Health, Faculty of Sciences and Techniques, Hassan First University of Settat, Settat, Morocco
| | - Abdelkrim Khattabi
- Laboratory of Agro-Alimentary and Health, Faculty of Sciences and Techniques, Hassan First University of Settat, Settat, Morocco
| | - Laura Romila
- Department of Chemistry, “Ioan Haulica” Institute, Apollonia University, Iași, Romania
| | - Bogdan Novac
- Urology Department, Grigore T. Popa University of Medicine and Pharmacy, Iași, Romania
| | - Antoneta Petroaie
- Family Medicine Department, Grigore T. Popa University of Medicine and Pharmacy, Iași, Romania
| | - Bouchaib Bencharki
- Laboratory of Agro-Alimentary and Health, Faculty of Sciences and Techniques, Hassan First University of Settat, Settat, Morocco
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Stress Dependent Biofilm Formation and Bioactive Melanin Pigment Production by a Thermophilic Bacillus Species from Chilean Hot Spring. Polymers (Basel) 2022; 14:polym14040680. [PMID: 35215592 PMCID: PMC8880475 DOI: 10.3390/polym14040680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 12/02/2022] Open
Abstract
Thermophilic bacteria able to survive extreme temperature stress are of great biotechnological interest due to their extracellular production of bioactive molecules as a part of a survival strategy, or by intracellular modifications. In the present study, thermophilic Bacillus haynesii CamB6, isolated from a Chilean hot spring, was studied for the formation of different stress response molecules. The polymeric pigment produced by the bacterial strain was characterized by different physicochemical techniques. On exposure to ranges of temperature (50–60 °C), pH (5.0–7.0), and sources of nitrogen and carbon (1–5 g·L−1), the bacteria responded with a biofilm network formation in a hydrophobic polystyrene surface. Biofilm formation under fed-batch conditions was also statistically validated. The bacteria showed a planktonic pellicle network formation in the presence of induced hypoxia and salinity stress (19.45 g·L−1) under static conditions. Salinity stress also resulted in the intracellular response of brown pigment production. The pigment was structurally and functionally characterized by UV-Vis absorbance and the presence of different characteristic peaks via FTIR analysis (bacterial pyomelanin fingerprints) were assessed. A high thermal stability and TGA profile indicated the brown pigment was a probable pyomelanin candidate. Micropyrolysis (Py-GC/MS) showed that isoprene, pyrrole, benzene, pyridine, and their derivatives were the major components detected. In addition, acetic acid, indole, phenol, and its derivatives were observed. The absence of sulfocompounds in the pyrolyzed products agreed with those reported in the literature for pyomelanin. The pigment surface morphology was analyzed via SEM, and the elemental composition via EDS also demonstrated the similarity of the brown pigment to that of the melanin family. The pyomelanin pigment was observed to be bioactive with promising antioxidant capacity (H2O2, Fe2+) compared to the standard antioxidant molecules. In conclusion, B. haynesii CamB6 demonstrated the formation of several biomolecules as a stress response mechanism that is bioactive, showing its probable biotechnological applications in future.
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A molecular spectroscopy approach for the investigation of early phase ochronotic pigment development in Alkaptonuria. Sci Rep 2021; 11:22562. [PMID: 34799606 PMCID: PMC8605014 DOI: 10.1038/s41598-021-01670-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/22/2021] [Indexed: 12/12/2022] Open
Abstract
Alkaptonuria (AKU), a rare genetic disorder, is characterized by the accumulation of homogentisic acid (HGA) in organs due to a deficiency in functional levels of the enzyme homogentisate 1,2-dioxygenase (HGD), required for the breakdown of HGA, because of mutations in the HGD gene. Over time, HGA accumulation causes the formation of the ochronotic pigment, a dark deposit that leads to tissue degeneration and organ malfunction. Such behaviour can be observed also in vitro for HGA solutions or HGA-containing biofluids (e.g. urine from AKU patients) upon alkalinisation, although a comparison at the molecular level between the laboratory and the physiological conditions is lacking. Indeed, independently from the conditions, such process is usually explained with the formation of 1,4-benzoquinone acetic acid (BQA) as the product of HGA chemical oxidation, mostly based on structural similarity between HGA and hydroquinone that is known to be oxidized to the corresponding para-benzoquinone. To test such correlation, a comprehensive, comparative investigation on HGA and BQA chemical behaviours was carried out by a combined approach of spectroscopic techniques (UV spectrometry, Nuclear Magnetic Resonance, Electron Paramagnetic Resonance, Dynamic Light Scattering) under acid/base titration both in solution and in biofluids. New insights on the process leading from HGA to ochronotic pigment have been obtained, spotting out the central role of radical species as intermediates not reported so far. Such evidence opens the way for molecular investigation of HGA fate in cells and tissue aiming to find new targets for Alkaptonuria therapy.
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Pyomelanin produced by Streptomyces sp. ZL-24 and its protective effects against SH-SY5Y cells injury induced by hydrogen peroxide. Sci Rep 2021; 11:16649. [PMID: 34404820 PMCID: PMC8371117 DOI: 10.1038/s41598-021-94598-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 07/12/2021] [Indexed: 02/07/2023] Open
Abstract
A soluble melanin pigment produced by Streptomyces sp. ZL-24 was purified and named StrSM. The elemental analysis of StrSM showed it consists of carbon, hydrogen, and oxygen. The spectrum analysis, including ultraviolet-visible absorption spectrum, Fourier-transform infrared spectrum, and pyrolysis-gas chromatography-mass spectrometry, indicated that StrSM might be pyomelanin. High performance liquid chromatography and liquid chromatography-mass spectra analysis of intermediate metabolite showed the presence of homogentisic acid (HGA). Moreover, the enzyme 4-hydroxyphenylpyruvate dioxygenase, involved in HGA biosynthesis, showed high activity during melanin production. Subsequently, a tyrosinase gene (melC2) and hydroxyphenylpyruvate dioxygenase gene double mutant demonstrated StrSM is pyomelanin. In vitro bioactivity assay showed that StrSM had excellent protective capability against SH-SY5Y cell oxidative injury. To our knowledge, the results firstly provide comprehensive data on Streptomyces pyomelanin identification and a promising candidate compound to treat oxidative injury of neurocytes.
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Donoso RA, Ruiz D, Gárate-Castro C, Villegas P, González-Pastor JE, de Lorenzo V, González B, Pérez-Pantoja D. Identification of a self-sufficient cytochrome P450 monooxygenase from Cupriavidus pinatubonensis JMP134 involved in 2-hydroxyphenylacetic acid catabolism, via homogentisate pathway. Microb Biotechnol 2021; 14:1944-1960. [PMID: 34156761 PMCID: PMC8449657 DOI: 10.1111/1751-7915.13865] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 11/28/2022] Open
Abstract
The self-sufficient cytochrome P450 RhF and its homologues belonging to the CYP116B subfamily have attracted considerable attention due to the potential for biotechnological applications based in their ability to catalyse an array of challenging oxidative reactions without requiring additional protein partners. In this work, we showed for the first time that a CYP116B self-sufficient cytochrome P450 encoded by the ohpA gene harboured by Cupriavidus pinatubonensis JMP134, a β-proteobacterium model for biodegradative pathways, catalyses the conversion of 2-hydroxyphenylacetic acid (2-HPA) into homogentisate. Mutational analysis and HPLC metabolite detection in strain JMP134 showed that 2-HPA is degraded through the well-known homogentisate pathway requiring a 2-HPA 5-hydroxylase activity provided by OhpA, which was additionally supported by heterologous expression and enzyme assays. The ohpA gene belongs to an operon including also ohpT, coding for a substrate-binding subunit of a putative transporter, whose expression is driven by an inducible promoter responsive to 2-HPA in presence of a predicted OhpR transcriptional regulator. OhpA homologues can be found in several genera belonging to Actinobacteria and α-, β- and γ-proteobacteria lineages indicating a widespread distribution of 2-HPA catabolism via homogentisate route. These results provide first time evidence for the natural function of members of the CYP116B self-sufficient oxygenases and represent a significant input to support novel kinetic and structural studies to develop cytochrome P450-based biocatalytic processes.
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Affiliation(s)
- Raúl A Donoso
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana, Santiago, Chile.,Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Daniela Ruiz
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile.,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Carla Gárate-Castro
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana, Santiago, Chile.,Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Pamela Villegas
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana, Santiago, Chile
| | - José Eduardo González-Pastor
- Laboratory of Molecular Adaptation, Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - Víctor de Lorenzo
- Systems and Synthetic Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Campus de Cantoblanco, Madrid, Spain
| | - Bernardo González
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile.,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Danilo Pérez-Pantoja
- Programa Institucional de Fomento a la Investigación, Desarrollo e Innovación (PIDi), Universidad Tecnológica Metropolitana, Santiago, Chile
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Pavan ME, López NI, Pettinari MJ. Melanin biosynthesis in bacteria, regulation and production perspectives. Appl Microbiol Biotechnol 2019; 104:1357-1370. [PMID: 31811318 DOI: 10.1007/s00253-019-10245-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/25/2019] [Accepted: 11/04/2019] [Indexed: 12/26/2022]
Abstract
The production of black pigments in bacteria was discovered more than a century ago and related to tyrosine metabolism. However, their diverse biological roles and the control of melanin synthesis in different bacteria have only recently been investigated. The broad distribution of these pigments suggests that they have an important role in a variety of organisms. Melanins protect microorganisms from many environmental stress conditions, ranging from ultraviolet radiation and toxic heavy metals to oxidative stress. Melanins can also affect bacterial interactions with other organisms and are important in pathogenesis and survival in many environments. Bacteria produce several types of melanin through dedicated pathways or as a result of enzymatic imbalances in altered metabolic routes. The control of the melanin synthesis in bacteria involves metabolic and transcriptional regulation, but many aspects remain still largely unknown. The diverse properties of melanins have spurred a large number of applications, and recent efforts have been done to produce the pigment at biotechnologically relevant scales.
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Affiliation(s)
- María Elisa Pavan
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nancy I López
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. .,IQUIBICEN-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - M Julia Pettinari
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. .,IQUIBICEN-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Latino L, Midoux C, Vergnaud G, Pourcel C. Investigation of Pseudomonas aeruginosa strain PcyII-10 variants resisting infection by N4-like phage Ab09 in search for genes involved in phage adsorption. PLoS One 2019; 14:e0215456. [PMID: 30990839 PMCID: PMC6467409 DOI: 10.1371/journal.pone.0215456] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/02/2019] [Indexed: 12/20/2022] Open
Abstract
Bacteria and their bacteriophages coexist and coevolve for the benefit of both in a mutualistic association. Multiple mechanisms are used by bacteria to resist phages in a trade-off between survival and maintenance of fitness. In vitro studies allow inquiring into the fate of virus and host in different conditions aimed at mimicking natural environment. We analyse here the mutations emerging in a clinical Pseudomonas aeruginosa strain in response to infection by Ab09, a N4-like lytic podovirus and describe a variety of chromosomal deletions and mutations conferring resistance. Some deletions result from illegitimate recombination taking place during long-term maintenance of the phage genome. Phage variants with mutations in a tail fiber gene are selected during pseudolysogeny with the capacity to infect resistant cells and produce large plaques. These results highlight the complex host/phage association and suggest that phage Ab09 promotes bacterial chromosome rearrangements. Finally this study points to the possible role of two bacterial genes in Ab09 phage adhesion to the cell, rpsB encoding protein S2 of the 30S ribosomal subunit and ORF1587 encoding a Wzy-like membrane protein involved in LPS biosynthesis.
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Affiliation(s)
- Libera Latino
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Cédric Midoux
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Gilles Vergnaud
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Christine Pourcel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
- * E-mail: ,
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Tan TT, Zhang XD, Miao Z, Yu Y, Du SL, Hou XY, Cai J. A single point mutation in hmgA leads to melanin accumulation in Bacillus thuringiensis BMB181. Enzyme Microb Technol 2019; 120:91-97. [DOI: 10.1016/j.enzmictec.2018.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/25/2018] [Accepted: 10/17/2018] [Indexed: 10/28/2022]
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4-Hydroxyphenylpyruvate Dioxygenase Thermolability Is Responsible for Temperature-Dependent Melanogenesis in Aeromonas salmonicida subsp. salmonicida. Appl Environ Microbiol 2019; 85:AEM.01926-18. [PMID: 30341077 DOI: 10.1128/aem.01926-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/09/2018] [Indexed: 12/17/2022] Open
Abstract
Aeromonas salmonicida subsp. salmonicida is a major pathogen affecting fisheries worldwide and is a well-known pigmented member of the Aeromonas genus. This subspecies produces melanin at ≤22°C. However, melanogenesis decreases as the culture temperature increases and is completely suppressed at 30°C to 35°C, while bacterial growth is unaffected. The mechanism and biological significance of this temperature-dependent melanogenesis remain unclear. Heterologous expression of an A. salmonicida subsp. salmonicida 4-hydroxyphenylpyruvate dioxygenase (HppD), the most critical enzyme in the homogentisic acid (HGA)-melanin synthesis pathway, results in thermosensitive pigmentation in Escherichia coli, suggesting that HppD plays a key role in this process. In this study, we demonstrated that the thermolability of HppD is responsible for the temperature-dependent melanization of A. salmonicida subsp. salmonicida Substitutions of three residues, S18T, P103Q, and L119P, in A. salmonicida subsp. salmonicida HppD increased the thermostability of this enzyme and resulted in temperature-independent melanogenesis. Moreover, the replacement of the corresponding residues in HppD from Aeromonas media strain WS, which forms pigment independent of temperature, with those of A. salmonicida subsp. salmonicida HppD resulted in thermosensitive melanogenesis. A structural analysis suggested that mutations at these sites, especially at position P103, strengthen the secondary structure of HppD and greatly improve its thermal stability. Additionally, we found that the HppD sequences of all A. salmonicida subsp. salmonicida isolates were identical and that two of the three residues were clearly distinct from those of other Aeromonas strains.IMPORTANCE Aeromonas salmonicida subsp. salmonicida is the causative agent of furunculosis, a bacterial septicemia of cold-water fish of the Salmonidae family. Although other Aeromonas species can produce melanin, A. salmonicida subsp. salmonicida is the only member of this genus that has been reported to exhibit temperature-dependent melanization. Here, we demonstrated that thermosensitive melanogenesis in A. salmonicida subsp. salmonicida strains is due to the thermolability of 4-hydroxyphenylpyruvate dioxygenase (HppD). Additionally, we confirmed that this thermolabile HppD exhibited higher activity at low temperatures than its mesophilic homologues, suggesting this as an adaptive strategy of this enzyme to the psychrophilic lifestyle of A. salmonicida subsp. salmonicida The strictly conserved hppD sequences among A. salmonicida subsp. salmonicida isolates and the specific possession of P103 and L119 residues could be used as a reference for the identification of A. salmonicida subsp. salmonicida isolates.
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Yang W, Ruan L, Tao J, Peng D, Zheng J, Sun M. Single Amino Acid Substitution in Homogentisate Dioxygenase Affects Melanin Production in Bacillus thuringiensis. Front Microbiol 2018; 9:2242. [PMID: 30364256 PMCID: PMC6193087 DOI: 10.3389/fmicb.2018.02242] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022] Open
Abstract
Bacillus thuringiensis formulation losing its activity under field conditions due to UV radiation and photoprotection of B. thuringiensis based on melanin has attracted the attention of researchers for many years. Here, a single amino acid substitution (G272E) in homogentisate 1,2-dioxygenase was found to be responsible for pigment overproduction in B. thuringiensis BMB181, a derivative of BMB171. Disrupting the gene encoding homogentisate dioxygenase in BMB171 induced the accumulation of the homogentisic acid and provoked an increased pigment formation. To gain insights into homogentisate 1,2-dioxygenase in B. thuringiensis, we constructed a total of 14 mutations with a single amino acid substitution, and six of the mutant proteins were found to affect the melanin production when substituted by alanine. This study provides a new way to construct pigment-overproducing strains by impairing the homogentisate dioxygenase with a single mutation in B. thuringiensis, and the findings will facilitate a better understanding of this enzyme.
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Affiliation(s)
- Wenjun Yang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Lifang Ruan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jiangming Tao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Zeng Z, Guo XP, Cai X, Wang P, Li B, Yang JL, Wang X. Pyomelanin from Pseudoalteromonas lipolytica reduces biofouling. Microb Biotechnol 2017; 10:1718-1731. [PMID: 28834245 PMCID: PMC5658579 DOI: 10.1111/1751-7915.12773] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/14/2017] [Accepted: 06/15/2017] [Indexed: 01/11/2023] Open
Abstract
Members of the marine bacterial genus Pseudoalteromonas are efficient producers of antifouling agents that exert inhibitory effects on the settlement of invertebrate larvae. The production of pigmented secondary metabolites by Pseudoalteromonas has been suggested to play a role in surface colonization. However, the physiological characteristics of the pigments produced by Pseudoalteromonas remain largely unknown. In this study, we identified and characterized a genetic variant that hyperproduces a dark‐brown pigment and was generated during Pseudoalteromonas lipolytica biofilm formation. Through whole‐genome resequencing combined with targeted gene deletion and complementation, we found that a point mutation within the hmgA gene, which encodes homogentisate 1,2‐dioxygenase, is solely responsible for the overproduction of the dark‐brown pigment pyomelanin. In P. lipolytica, inactivation of the hmgA gene led to the formation of extracellular pyomelanin and greatly reduced larval settlement and metamorphosis of the mussel Mytilus coruscus. Additionally, the extracted pyomelanin from the hmgA deletion mutant and the in vitro‐synthesized pyomelanin also reduced larval settlement and metamorphosis of M. coruscus, suggesting that extracellular pyomelanin released from marine Pseudoalteromonas biofilm can inhibit the settlement of fouling organisms.
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Affiliation(s)
- Zhenshun Zeng
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Xing-Pan Guo
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, International Research Center for Marine Biosciences, Shanghai Ocean University, Shanghai, China
| | - Xingsheng Cai
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Pengxia Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Baiyuan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Jin-Long Yang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, International Research Center for Marine Biosciences, Shanghai Ocean University, Shanghai, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
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Characterization of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione resistance in pyomelanogenic Pseudomonas aeruginosa DKN343. PLoS One 2017; 12:e0178084. [PMID: 28570601 PMCID: PMC5453437 DOI: 10.1371/journal.pone.0178084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 05/07/2017] [Indexed: 01/11/2023] Open
Abstract
Pyomelanin is a reddish-brown pigment that provides bacteria and fungi protection from oxidative stress, and is reported to contribute to infection persistence. Production of this pigment can be inhibited by the anti-virulence agent 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC). The Pseudomonas aeruginosa clinical isolate DKN343 exhibited high levels of resistance to NTBC, and the mechanism of pyomelanin production in this strain was uncharacterized. We determined that pyomelanin production in the clinical Pseudomonas aeruginosa isolate DKN343 was due to a loss of function in homogentisate 1,2-dioxygenase (HmgA). Several potential resistance mechanisms were investigated, and the MexAB-OprM efflux pump is required for resistance to NTBC. DKN343 has a frameshift mutation in NalC, which is a known indirect repressor of the mexAB-oprM operon. This frameshift mutation may contribute to the increased resistance of DKN343 to NTBC. Additional studies investigating the prevalence of resistance in pyomelanogenic microbes are necessary to determine the future applications of NTBC as an anti-virulence therapy.
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Ahmad S, Lee SY, Kong HG, Jo EJ, Choi HK, Khan R, Lee SW. Genetic Determinants for Pyomelanin Production and Its Protective Effect against Oxidative Stress in Ralstonia solanacearum. PLoS One 2016; 11:e0160845. [PMID: 27513990 PMCID: PMC4981395 DOI: 10.1371/journal.pone.0160845] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/26/2016] [Indexed: 11/18/2022] Open
Abstract
Ralstonia solanacearum is a soil-borne plant pathogen that infects more than 200 plant species. Its broad host range and long-term survival under different environmental stress conditions suggest that it uses a variety of mechanisms to protect itself against various types of biotic and abiotic stress. R. solanacearum produces a melanin-like brown pigment in the stationary phase when grown in minimal medium containing tyrosine. To gain deeper insight into the genetic determinants involved in melanin production, transposon-inserted mutants of R. solanacearum strain SL341 were screened for strains with defective melanin-producing capability. In addition to one mutant already known to be involved in pyomelanin production (viz., strain SL341D, with disruption of the hydroxphenylpyruvate dioxygenase gene), we identified three other mutants with disruption in the regulatory genes rpoS, hrpG, and oxyR, respectively. Wild-type SL341 produced pyomelanin in minimal medium containing tyrosine whereas the mutant strains did not. Likewise, homogentisate, a major precursor of pyomelanin, was detected in the culture filtrate of the wild-type strain but not in those of the mutant strains. A gene encoding hydroxyphenylpyruvate dioxygenase exhibited a significant high expression in wild type SL341 compared to other mutant strains, suggesting that pyomelanin production is regulated by three different regulatory proteins. However, analysis of the gene encoding homogentisate dioxygenase revealed no significant difference in its relative expression over time in the wild-type SL341 and mutant strains, except for SL341D, at 72 h incubation. The pigmented SL341 strain also exhibited a high tolerance to hydrogen peroxide stress compared with the non-pigmented SL341D strain. Our study suggests that pyomelanin production is controlled by several regulatory factors in R. solanacearum to confer protection under oxidative stress.
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Affiliation(s)
- Shabir Ahmad
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Seung Yeup Lee
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Hyun Gi Kong
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Eun Jeong Jo
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Hye Kyung Choi
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Raees Khan
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Seon-Woo Lee
- Department of Applied Biosciences, Dong-A University, Busan, 49315, Republic of Korea
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