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Najjari A, Jabberi M, Chérif SF, Cherif A, Ouzari HI, Linares-Pastén JA, Sghaier H. Genome and pan-genome analysis of a new exopolysaccharide-producing bacterium Pyschrobacillus sp. isolated from iron ores deposit and insights into iron uptake. Front Microbiol 2024; 15:1440081. [PMID: 39238887 PMCID: PMC11376405 DOI: 10.3389/fmicb.2024.1440081] [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: 06/05/2024] [Accepted: 07/15/2024] [Indexed: 09/07/2024] Open
Abstract
Bacterial exopolysaccharides (EPS) have emerged as one of the key players in the field of heavy metal-contaminated environmental bioremediation. This study aimed to characterize and evaluate the metal biosorption potential of EPS produced by a novel Psychrobacillus strain, NEAU-3TGS, isolated from an iron ore deposit at Tamra iron mine, northern Tunisia. Genomic and pan-genomic analysis of NEAU-3TGS bacterium with nine validated published Psychrobacillus species was also performed. The results showed that the NEAU-3TGS genome (4.48 Mb) had a mean GC content of 36%, 4,243 coding sequences and 14 RNA genes. Phylogenomic analysis and calculation of nucleotide identity (ANI) values (less than 95% for new species with all strains) confirmed that NEAU-3TGS represents a potential new species. Pangenomic analysis revealed that Psychrobacillus genomic diversity represents an "open" pangenome model with 33,091 homologous genes, including 65 core, 3,738 shell, and 29,288 cloud genes. Structural EPS characterization by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy showed uronic acid and α-1,4-glycosidic bonds as dominant components of the EPS. X-ray diffraction (XRD) analysis revealed the presence of chitin, chitosan, and calcite CaCO3 and confirmed the amorphous nature of the EPS. Heavy metal bioabsorption assessment showed that iron and lead were more adsorbed than copper and cadmium. Notably, the optimum activity was observed at 37°C, pH=7 and after 3 h contact of EPS with each metal. Genomic insights on iron acquisition and metabolism in Psychrobacillus sp. NEAU-3TGS suggested that no genes involved in siderophore biosynthesis were found, and only the gene cluster FeuABCD and trilactone hydrolase genes involved in the uptake of siderophores, iron transporter and exporter are present. Molecular modelling and docking of FeuA (protein peptidoglycan siderophore-binding protein) and siderophores ferrienterobactine [Fe+3 (ENT)]-3 and ferribacillibactine [Fe+3 (BB)]-3 ligand revealed that [Fe+3 (ENT)]-3 binds to Phe122, Lys127, Ile100, Gln314, Arg215, Arg217, and Gln252. Almost the same for [Fe+3 (ENT)]-3 in addition to Cys222 and Tyr229, but not Ile100.To the best of our knowledge, this is the first report on the characterization of EPS and the adsorption of heavy metals by Psychrobacillus species. The heavy metal removal capabilities may be advantageous for using these organisms in metal remediation.
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Affiliation(s)
- Afef Najjari
- Laboratoire de Microbiologie et Biomolécules Actives (LR03ES03), Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisia
| | - Marwa Jabberi
- Laboratory "Energy and Matter for Development of Nuclear Sciences" (LR16CNSTN02), National Center for Nuclear Sciences and Technology (CNSTN), Sidi Thabet Technopark, Ariana, Tunisia
- ISBST, LR11-ES31 BVBGR, University of Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
- Biochemistry and Molecular Biology Lab of Faculty of Sciences of Bizerte, Risks Related to Environmental Stress, Struggle and Prevention (UR17ES20), University of Carthage, Bizerte, Tunisia
| | - Saïda Fatma Chérif
- Laboratoire de Matériaux, Cristallochimie et Thermodynamique Appliquée, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, Tunisia
- Institut Préparatoire aux Etudes d'Ingénieurs-El Manar, Université de Tunis El Manar, El Manar II, Tunis, Tunisia
| | - Ameur Cherif
- ISBST, LR11-ES31 BVBGR, University of Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
| | - Hadda Imene Ouzari
- Laboratoire de Microbiologie et Biomolécules Actives (LR03ES03), Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisia
| | - Javier A Linares-Pastén
- Department of Biotechnology, Faculty of Engineering, Lunds Tekniska Högskola (LTH), Lund University, Lund, Sweden
| | - Haitham Sghaier
- Laboratory "Energy and Matter for Development of Nuclear Sciences" (LR16CNSTN02), National Center for Nuclear Sciences and Technology (CNSTN), Sidi Thabet Technopark, Ariana, Tunisia
- ISBST, LR11-ES31 BVBGR, University of Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
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Long Q, Zhou W, Zhou H, Tang Y, Chen W, Liu Q, Bian X. Polyamine-containing natural products: structure, bioactivity, and biosynthesis. Nat Prod Rep 2024; 41:525-564. [PMID: 37873660 DOI: 10.1039/d2np00087c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Covering: 2005 to August, 2023Polyamine-containing natural products (NPs) have been isolated from a wide range of terrestrial and marine organisms and most of them exhibit remarkable and diverse activities, including antimicrobial, antiprotozoal, antiangiogenic, antitumor, antiviral, iron-chelating, anti-depressive, anti-inflammatory, insecticidal, antiobesity, and antioxidant properties. Their extraordinary activities and potential applications in human health and agriculture attract increasing numbers of studies on polyamine-containing NPs. In this review, we summarized the source, structure, classification, bioactivities and biosynthesis of polyamine-containing NPs, focusing on the biosynthetic mechanism of polyamine itself and representative polyamine alkaloids, polyamine-containing siderophores with catechol/hydroxamate/hydroxycarboxylate groups, nonribosomal peptide-(polyketide)-polyamine (NRP-(PK)-PA), and NRP-PK-long chain poly-fatty amine (lcPFAN) hybrid molecules.
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Affiliation(s)
- Qingshan Long
- Hunan Provincial Engineering and Technology Research Center for Agricultural Microbiology Application, Hunan Institute of Microbiology, Changsha, 410009, China.
| | - Wen Zhou
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural, Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Haibo Zhou
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
| | - Ying Tang
- Hunan Provincial Engineering and Technology Research Center for Agricultural Microbiology Application, Hunan Institute of Microbiology, Changsha, 410009, China.
| | - Wu Chen
- College of Plant Protection, Hunan Agricultural University, Changsha, 410128, China.
| | - Qingshu Liu
- Hunan Provincial Engineering and Technology Research Center for Agricultural Microbiology Application, Hunan Institute of Microbiology, Changsha, 410009, China.
| | - Xiaoying Bian
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
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Verguet N, Mondange L, Nolent F, Depeille A, Garnier A, Neulat-Ripoll F, Gorgé O, Tournier JN. Assessment of calcium hypochlorite for Bacillus anthracis spore surface's decontamination. Res Microbiol 2023; 174:104053. [PMID: 36925026 DOI: 10.1016/j.resmic.2023.104053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/08/2023] [Accepted: 03/08/2023] [Indexed: 03/15/2023]
Abstract
Contamination with microorganisms occurs in laboratories but is also of high concern in the context of bioterrorism. Decontamination is a cornerstone that promotes good laboratory practices and occupational health and safety. Among the most resistant structures formed by microorganisms are spores, produced notably by Clostridium and Bacillus species. Here, we compared six products containing four different molecules (hydrogen peroxide, peracetic acid, sodium and calcium hypochlorite) on B. anthracis Sterne spores. We first selected the most efficient product based on its activity against spore suspensions using French and European standards. Four products showed sporicidal activity, of which only two did so in a time frame consistent with good laboratory practices. Then, we tested one of these two products under laboratory conditions on fully virulent B. anthracis spores, during common use and after contamination through a spill of a highly concentrated spore suspension. We, thus, robustly validated a decontaminant based on calcium hypochlorite not only on its ability to kill spores but also on its effectiveness under laboratory conditions. At the end, we were able to assure a complete disinfection in 1 min after spillover and in 2 min for common use.
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Affiliation(s)
- Noémie Verguet
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; CNR-LE Charbon, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Lou Mondange
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; Yersinia Unit, Institut Pasteur, 75015 Paris, France.
| | - Flora Nolent
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Anne Depeille
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; CNR-LE Charbon, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Annabelle Garnier
- Immunopathology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Fabienne Neulat-Ripoll
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Olivier Gorgé
- Bacteriology Unit, Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; CNR-LE Charbon, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France.
| | - Jean-Nicolas Tournier
- CNR-LE Charbon, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; Microbiology and Infectious Diseases Department, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; École du Val-de-Grâce, 75015 Paris, France.
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Yuan L, Wang D, Chen J, Lyu Y, Feng E, Zhang Y, Liu X, Wang H. Genome Sequence and Phenotypic Analysis of a Protein Lysis-Negative, Attenuated Anthrax Vaccine Strain. BIOLOGY 2023; 12:biology12050645. [PMID: 37237459 DOI: 10.3390/biology12050645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/30/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023]
Abstract
Bacillus anthracis is a Gram-positive bacterium that causes the zoonotic disease anthrax. Here, we studied the characteristic phenotype and virulence attenuation of the putative No. II vaccine strain, PNO2, which was reportedly introduced from the Pasteur Institute in 1934. Characterization of the strain showed that, compared with the control strain, A16Q1, the attenuated PNO2 (PNO2D1) was phospholipase-positive, with impaired protein hydrolysis and significantly reduced sporulation. Additionally, PNO2D1 significantly extended the survival times of anthrax-challenged mice. An evolutionary tree analysis revealed that PNO2D1 was not a Pasteur strain but was more closely related to a Tsiankovskii strain. A database comparison revealed a seven-base insertion mutation in the nprR gene. Although it did not block nprR transcription, the insertion mutation resulted in the premature termination of protein translation. nprR deletion of A16Q1 resulted in a nonproteolytic phenotype that could not sporulate. The database comparison revealed that the abs gene is also prone to mutation, and the abs promoter activity was much lower in PNO2D1 than in A16Q1. Low abs expression may be an important reason for the decreased virulence of PNO2D1.
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Affiliation(s)
- Lu Yuan
- College of Food Science and Technology, Shanghai Ocean University, 999 Hucheng Huan Road, Nanhui New City, Shanghai 201306, China
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Dongshu Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
- Laboratory of Advanced Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Jie Chen
- College of Food Science and Technology, Shanghai Ocean University, 999 Hucheng Huan Road, Nanhui New City, Shanghai 201306, China
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Yufei Lyu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
- Laboratory of Advanced Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Erling Feng
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Yan Zhang
- College of Food Science and Technology, Shanghai Ocean University, 999 Hucheng Huan Road, Nanhui New City, Shanghai 201306, China
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Xiankai Liu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
- Laboratory of Advanced Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
| | - Hengliang Wang
- College of Food Science and Technology, Shanghai Ocean University, 999 Hucheng Huan Road, Nanhui New City, Shanghai 201306, China
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Biotechnology, 20 Dongdajie Street, Fengtai District, Beijing 100071, China
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Ye SQ, Zhao JY, Li LL, Ling C, Zhang MY, Tang J, Liang SG, Li JY, Yang PW, Xiong J, Feng LY, Shi ZF, Ding ZG, Li MG, Tang SK. Brevibacillus daliensis sp. nov., Isolated From Soil in Machangqing Nature Reserve. Curr Microbiol 2022; 80:32. [PMID: 36480068 DOI: 10.1007/s00284-022-03127-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 11/20/2022] [Indexed: 12/13/2022]
Abstract
A new aerobic bacterial strain, designated strain YIM B02290T, was isolated from the soil of Machangqing, Dali city, Yunnan Province, China. Cells were Gram-stain-positive, sporogenous, rod-shaped, and motile with peritrichous flagella. Strain YIM B02290T showed the highest 16S rRNA gene sequence similarity with Brevibacillus laterosporus (97.6%) and Brevibacillus halotolerans (97.6%). The ANI and dDDH values between strain YIM B02290T and the two reference strains Brevibacillus laterosporus LAM00312T and Brevibacillus halotolerans DSM 25T are 72.6% and 72.2%, 20.2% and 19.5% based on the draft genome sequence, respectively. The major cellular fatty acids contain anteiso-C15: 0 and iso-C15: 0. The diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. The predominant menaquinone was identified as menaquinone-7. The main polar lipids of strain YIM B02290T were diphosphatidylglycerol, phosphatidylglycerol, phospholipid, phosphatidyl monomethylethanolamine. The genomic DNA G + C content was 40.6 mol%. All results showed that strain YIM B02290T represents a novel species of the genus Brevibacillus, for which the name Brevibacillus daliensis sp. nov. is proposed. The type strain is YIM B02290T (= CCTCC AB 2021094T = CGMCC 1.18802T = KCTC 43376T).
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Affiliation(s)
- Shi-Qiang Ye
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Jiang-Yuan Zhao
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Le-Le Li
- Department of Medicine, Qujing Vocational and Technical College, Qujing, 655000, People's Republic of China
| | - Cheng Ling
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Meng-Yu Zhang
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Jing Tang
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Song-Guo Liang
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Jian-Yu Li
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Pei-Wen Yang
- Institute of Agricultural Environmental Resources, Yunnan Academy of Agricultural Sciences, Kunming, 650205, People's Republic of China
| | - Jiao Xiong
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Lu-Yao Feng
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China
| | - Zhu-Feng Shi
- Institute of Agricultural Environmental Resources, Yunnan Academy of Agricultural Sciences, Kunming, 650205, People's Republic of China
| | - Zhang-Gui Ding
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China.
| | - Ming-Gang Li
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China.
| | - Shu-Kun Tang
- Key Laboratory for Microbial Resources of the Ministry of Education and School of Life Sciences, Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091, People's Republic of China.
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Bacterial Siderophores: Structure, Functions, and Role in the Pathogenesis of Infections. PROBLEMS OF PARTICULARLY DANGEROUS INFECTIONS 2022. [DOI: 10.21055/0370-1069-2022-3-14-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This review systematizes and analyzes the data published over the past decade, devoted to the study of low-molecular-weight high affinity iron chelators – siderophores. Siderophores, which are found in bacteria, fungi and mammals, are able to extract iron from insoluble inorganic compounds, and in the host organism – from complexes with proteins that perform the function of nonspecific protection of mammals from infections. The extracted iron is delivered to cells through surface protein receptors specific for each siderophore, as well as various protein transport systems that make up membranes. Siderophores play an important role in virulence in pathogenic bacteria, performing many functions in the host organism, in addition to providing microbes with iron and other biological metals. They participate in the storage of excess iron, toxic to cells, protect bacteria from reactive oxygen compounds, compete for iron with phagocytes, and have a harmful effect on host cells, acting as secreted bacterial toxin in some cases. Bacterial siderophores perform a signaling function and regulate both, their own synthesis and the synthesis of other virulence factors. Many pathogenic bacteria produce several siderophores that are active under different conditions, against various sources of iron in the host organism and at different stages of infectious process. The review presents the results of the experimental studies aimed at elucidating the structure and diverse functions of bacterial siderophores, the mechanisms of their biosynthesis and regulation of expression, as well as the role of these molecules in the physiology and virulence of pathogenic bacteria. Special emphasis is put on siderophores of bacteria causing particularly dangerous infections.
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Production and Potential Genetic Pathways of Three Different Siderophore Types in Streptomyces tricolor Strain HM10. FERMENTATION 2022. [DOI: 10.3390/fermentation8080346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Siderophores are iron-chelating low-molecular-weight compounds that bind iron (Fe3+) with a high affinity for transport into the cell. The newly isolated strain Streptomyces tricolor HM10 secretes a pattern of secondary metabolites. Siderophore molecules are the representatives of such secondary metabolites. S. tricolor HM10 produces catechol, hydroxamate, and carboxylate types of siderophores. Under 20 μM FeCl3 conditions, S. tricolor HM10 produced up to 6.00 µg/mL of catechol siderophore equivalent of 2,3-DHBA (2,3-dihydroxybenzoic acid) after 4 days from incubation. In silico analysis of the S. tricolor HM10 genome revealed three proposed pathways for siderophore biosynthesis. The first pathway, consisting of five genes, predicted the production of catechol-type siderophore similar to petrobactin from Bacillus anthracis str. Ames. The second proposed pathway, consisting of eight genes, is expected to produce a hydroxamate-type siderophore similar to desferrioxamine B/E from Streptomyces sp. ID38640, S. griseus NBRC 13350, and/or S. coelicolor A3(2). The third pathway exhibited a pattern identical to the carboxylate xanthoferrin siderophore from Xanthomonas oryzae. Thus, Streptomyces strain HM10 could produce three different types of siderophore, which could be an incentive to use it as a new source for siderophore production in plant growth-promoting, environmental bioremediation, and drug delivery strategy.
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Senges CHR, Warmuth HL, Vázquez-Hernández M, Uzun HD, Sagurna L, Dietze P, Schmidt C, Mücher B, Herlitze S, Krämer U, Ott I, Pomorski TG, Bandow JE. Effects of 4-Br-A23187 on Bacillus subtilis cells and unilamellar vesicles reveal it to be a potent copper ionophore. Proteomics 2022; 22:e2200061. [PMID: 35666003 PMCID: PMC10140759 DOI: 10.1002/pmic.202200061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/19/2022] [Accepted: 06/03/2022] [Indexed: 11/12/2022]
Abstract
Ionophores are small molecules or peptides that transport metal ions across biological membranes. Their transport capabilities are typically characterized in vitro using vesicles and single ion species. It is difficult to infer from these data which effects ionophores have on living cells in a complex environment (e.g. culture medium), since net ion movement is influenced by many factors including ion composition of the medium, concentration gradients, pH gradient, and protein-mediated transport processes across the membrane. To gain insights into the antibacterial mechanism of action of the semisynthetic polyether ionophore 4-Br-A23187, known to efficiently transport zinc and manganese in vitro, we investigated its effects on the gram-positive model organism Bacillus subtilis. In addition to monitoring cellular ion concentrations, the physiological impact of treatment was assessed on the proteome level. 4-Br-A23187 treatment resulted in an increase in intracellular copper levels, the extent of which depended on the copper concentration of the medium. Effects of copper accumulation mirrored by the proteomic response included oxidative stress, disturbance of proteostasis, metal and sulfur homeostasis. The antibiotic effect of 4-Br-A23187 is further aggravated by a decrease in intracellular manganese and magnesium. A liposome model confirmed that 4-Br-A23187 acts as copper ionophore in vitro. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Christoph H R Senges
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Helen L Warmuth
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Melissa Vázquez-Hernández
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Huriye Deniz Uzun
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801, Bochum, Germany
| | - Leonie Sagurna
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Pascal Dietze
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Claudia Schmidt
- Inorganic and Organometallic Medicinal Chemistry, Faculty of Life Sciences, Technical University Braunschweig, 38106, Braunschweig, Germany.,Institute for Drug Research, Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - Brix Mücher
- Department of Zoology and Neurobiology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Ute Krämer
- Molecular Genetics and Physiology of Plants, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Ingo Ott
- Inorganic and Organometallic Medicinal Chemistry, Faculty of Life Sciences, Technical University Braunschweig, 38106, Braunschweig, Germany
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801, Bochum, Germany
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
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Wang R, Gallant É, Wilson MZ, Wu Y, Li A, Gitai Z, Seyedsayamdost MR. Algal p-coumaric acid induces oxidative stress and siderophore biosynthesis in the bacterial symbiont Phaeobacter inhibens. Cell Chem Biol 2021; 29:670-679.e5. [PMID: 34437838 DOI: 10.1016/j.chembiol.2021.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 06/18/2021] [Accepted: 08/06/2021] [Indexed: 11/28/2022]
Abstract
The marine alpha-proteobacterium Phaeobacter inhibens engages in intermittent symbioses with microalgae. The symbiosis is biphasic and concludes in a parasitic phase, during which the bacteria release algaecidal metabolites in response to algal p-coumaric acid (pCA). The cell-wide effects of pCA on P. inhibens remain unknown. Herein, we report a microarray-based transcriptomic study and find that genes related to the oxidative stress response and secondary metabolism are upregulated most, while those associated with energy production and motility are downregulated in the presence of pCA. Among genes upregulated is a previously unannotated biosynthetic gene cluster and, using a combination of gene deletions and metabolic profiling, we show that it gives rise to an unreported siderophore, roseobactin. The simultaneous production of algaecides and roseobactin in the parasitic phase allows the bacteria to take up any iron that is released from dying algal cells, thereby securing a limited micronutrient.
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Affiliation(s)
- Rurun Wang
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Étienne Gallant
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Maxwell Z Wilson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yihan Wu
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Anran Li
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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10
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Négrel S, Brunel JM. Synthesis and Biological Activities of Naturally Functionalized Polyamines: An Overview. Curr Med Chem 2021; 28:3406-3448. [PMID: 33138746 DOI: 10.2174/0929867327666201102114544] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/01/2020] [Accepted: 09/16/2020] [Indexed: 11/22/2022]
Abstract
Recently, extensive researches have emphasized the fact that polyamine conjugates are becoming important in all biological and medicinal fields. In this review, we will focus our attention on natural polyamines and highlight recent progress in both fundamental mechanism studies and interests in the development and application for the therapeutic use of polyamine derivatives.
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Affiliation(s)
- Sophie Négrel
- Aix Marseille University, Faculty of Pharmacy, UMR-MD1, 27 bd Jean Moulin, 13385 Marseille, France
| | - Jean Michel Brunel
- Aix Marseille University, Faculty of Pharmacy, UMR-MD1, 27 bd Jean Moulin, 13385 Marseille, France
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11
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Huang Q, Zhang Z, Liu Q, Liu F, Liu Y, Zhang J, Wang G. SpoVG is an important regulator of sporulation and affects biofilm formation by regulating Spo0A transcription in Bacillus cereus 0-9. BMC Microbiol 2021; 21:172. [PMID: 34102998 PMCID: PMC8186074 DOI: 10.1186/s12866-021-02239-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 05/20/2021] [Indexed: 02/06/2023] Open
Abstract
Background Bacillus cereus 0–9, a Gram-positive, endospore-forming bacterium isolated from healthy wheat roots in our previous research, is considered to be an effective biocontrol strain against several soil-borne plant diseases. SpoVG, a regulator that is broadly conserved among many Gram-positive bacteria, may help this organism coordinate environmental growth and virulence to survive. This study aimed to explore the multiple functions of SpoVG in B. cereus 0–9. Methods The gene knockout strains were constructed by homologous recombination, and the sporulation process of B. cereus 0–9 and its mutants were observed by fluorescence staining method. We further determined the spore yields and biofilm formation abilities of test strains. Transcriptional fusion strains were constructed by overlapping PCR technique, and the promoter activity of the target gene was detected by measuring its fluorescence intensity. The biofilm production and colonial morphology of B. cereus 0–9 and its mutants were determined to study the functions of the target genes, and the transcription level of the target gene was determined by qRT-PCR. Results According to observation of the sporulation process of B. cereus 0–9 in germination medium, SpoVG is crucial for regulating sporulation stage V of B. cereus 0–9, which is identical to that of Bacillus subtilis but differs from that of Bacillus anthracis. In addition, SpoVG could influence biofilm formation of B. cereus 0–9. The transcription levels of two genes closely related to biofilm-formation, sipW and calY, were downregulated in a ΔspoVG mutant. The role of SpoVG in regulating biofilm formation was further explored by deleting the genes abrB and sinR in the ΔspoVG mutant, respectively, generating the double mutant strains ΔspoVGΔabrB and ΔspoVGΔsinR. The phenotypes of these double mutants were congruent with those of the single abrB and sinR deletion strains, respectively, which showed increased biofilm formation. This indicated that spoVG was located upstream of abrB and sinR in the regulatory pathway of B. cereus biofilm formation. Further, the results of qRT-PCR and the luminescence intensity of transcriptional fusion strains indicated that spoVG gene deletion could inhibit the transcription of Spo0A. Conclusions SpoVG, an important regulator in the sporulation of B. cereus, is located upstream of Spo0A and participates in regulation of biofilm formation of B. cereus 0–9 through regulating the transcription level of spo0A. Sporulation and biofilm formation are crucial mechanisms by which bacteria respond to adverse conditions. SpoVG is therefore an important regulator of Spo0A and is crucial for both sporulation and biofilm formation of B. cereus 0–9. This study provides a new insight into the regulatory mechanism of environmental adaptation in bacteria and a foundation for future studies on biofilm formation of B. cereus. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02239-6.
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Affiliation(s)
- Qiubin Huang
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China.,Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng, 475004, China
| | - Zhen Zhang
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China
| | - Qing Liu
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China
| | - Fengying Liu
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China.,Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng, 475004, China
| | - Yupeng Liu
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China.,Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng, 475004, China
| | - Juanmei Zhang
- Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng, 475004, China. .,School of Pharmaceutical, Henan Univeristy, Kaifeng, 475004, China.
| | - Gang Wang
- Institute of Microbial Engineering, Laboratory of Bioresource and Applied Microbiology, School of Life Sciences, Henan University, Jinming Street, Kaifeng, 475004, China. .,Engineering Research Center for Applied Microbiology of Henan Province, Kaifeng, 475004, China.
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Rhizobiales-Specific RirA Represses a Naturally "Synthetic" Foreign Siderophore Gene Cluster To Maintain Sinorhizobium-Legume Mutualism. mBio 2021; 13:e0290021. [PMID: 35130720 PMCID: PMC8822346 DOI: 10.1128/mbio.02900-21] [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] [Indexed: 12/14/2022] Open
Abstract
Iron homeostasis is strictly regulated in cellular organisms. The Rhizobiales order enriched with symbiotic and pathogenic bacteria has evolved a lineage-specific regulator, RirA, responding to iron fluctuations. However, the regulatory role of RirA in bacterium-host interactions remains largely unknown. Here, we report that RirA is essential for mutualistic interactions of Sinorhizobium fredii with its legume hosts by repressing a gene cluster directing biosynthesis and transport of petrobactin siderophore. Genes encoding an inner membrane ABC transporter (fat) and the biosynthetic machinery (asb) of petrobactin siderophore are sporadically distributed in Gram-positive and Gram-negative bacteria. An outer membrane siderophore receptor gene (fprA) was naturally assembled with asb and fat, forming a long polycistron in S. fredii. An indigenous regulation cascade harboring an inner membrane protease (RseP), a sigma factor (FecI), and its anti-sigma protein (FecR) were involved in direct activation of the fprA-asb-fat polycistron. Operons harboring fecI and fprA-asb-fat, and those encoding the indigenous TonB-ExbB-ExbD complex delivering energy to the outer membrane transport activity, were directly repressed by RirA under iron-replete conditions. The rirA deletion led to upregulation of these operons and iron overload in nodules, impaired intracellular persistence, and symbiotic nitrogen fixation of rhizobia. Mutualistic defects of the rirA mutant can be rescued by blocking activities of this naturally "synthetic" circuit for siderophore biosynthesis and transport. These findings not only are significant for understanding iron homeostasis of mutualistic interactions but also provide insights into assembly and integration of foreign machineries for biosynthesis and transport of siderophores, horizontal transfer of which is selected in microbiota. IMPORTANCE Iron is a public good explored by both eukaryotes and prokaryotes. The abundant ferric form is insoluble under neutral and basic pH conditions, and many bacteria secrete siderophores forming soluble ferric siderophore complexes, which can be then taken up by specific receptors and transporters. Siderophore biosynthesis and uptake machineries can be horizontally transferred among bacteria in nature. Despite increasing attention on the importance of siderophores in host-microbiota interactions, the regulatory integration process of transferred siderophore biosynthesis and transport genes is poorly understood in an evolutionary context. By focusing on the mutualistic rhizobium-legume symbiosis, here, we report how a naturally synthetic foreign siderophore gene cluster was integrated with the rhizobial indigenous regulation cascade, which is essential for maintaining mutualistic interactions.
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Torres Manno MA, Repizo GD, Magni C, Dunlap CA, Espariz M. The assessment of leading traits in the taxonomy of the Bacillus cereus group. Antonie van Leeuwenhoek 2020; 113:2223-2242. [PMID: 33179199 DOI: 10.1007/s10482-020-01494-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022]
Abstract
Bacillus cereus sensu lato strains (B. cereus group) are widely distributed in nature and have received interest for decades due to their importance in insect pest management, food production and their positive and negative repercussions in human health. Consideration of practical uses such as virulence, physiology, morphology, or ill-defined features have been applied to describe and classify species of the group. However, current comparative studies have exposed inconsistencies between evolutionary relatedness and biological significance among genomospecies of the B. cereus group. Here, the combined analyses of core-based phylogeny and all versus all Average Nucleotide Identity values based on 2116 strains were conducted to update the genomospecies circumscriptions within B. cereus group. These analyses suggested the existence of 57 genomospecies, 37 of which are novel, thus indicating that the taxonomic identities of more than 39% of the analyzed strains should be revised or updated. In addition, we found that whole-genome in silico analyses were suitable to differentiate genomospecies such as B. anthracis, B. cereus and B. thuringiensis. The prevalence of toxin and virulence factors coding genes in each of the genomospecies of the B. cereus group was also examined, using phylogeny-aware methods at wide-genome scale. Remarkably, Cry and emetic toxins, commonly assumed to be associated with B. thuringiensis and emetic B. paranthracis, respectively, did not show a positive correlation with those genomospecies. On the other hand, anthrax-like toxin and capsule-biosynthesis coding genes were positively correlated with B. anthracis genomospecies, despite not being present in all strains, and with presumably non-pathogenic genomospecies. Hence, despite these features have been so far considered relevant for industrial or medical classification of related species of the B. cereus group, they were inappropriate for their circumscription. In this study, genomospecies of the group were accurately affiliated and representative strains defined, generating a rational framework that will allow comparative analysis in epidemiological or ecological studies. Based on this classification the role of specific markers such as Type VII secretion system, cytolysin, bacillolysin, and siderophores such as petrobactin were pointed out for further analysis.
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Affiliation(s)
- Mariano A Torres Manno
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Santa Fe, Argentina
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR - CONICET), sede FCByF - UNR, Rosario, Santa Fe, Argentina
- Área Estadística y Procesamiento de Datos, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Guillermo D Repizo
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina
- Laboratorio de Resistencia bacteriana a antimicrobianos, Instituto de Biología Molecular y Celular de Rosario (IBR), sede FCByF - UNR, Rosario, Santa Fe, Argentina
| | - Christian Magni
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Santa Fe, Argentina
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR - CONICET), sede FCByF - UNR, Rosario, Santa Fe, Argentina
| | - Christopher A Dunlap
- United States Department of Agriculture, Crop Bioprotection Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, 1815 North University Street, Peoria, IL, 61604, USA
| | - Martín Espariz
- Laboratorio de Biotecnología e Inocuidad de los Alimentos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Municipalidad de Granadero Baigorria, Sede Suipacha 590, Rosario, Santa Fe, Argentina.
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR - CONICET), sede FCByF - UNR, Rosario, Santa Fe, Argentina.
- Área Estadística y Procesamiento de Datos, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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Assoni L, Milani B, Carvalho MR, Nepomuceno LN, Waz NT, Guerra MES, Converso TR, Darrieux M. Resistance Mechanisms to Antimicrobial Peptides in Gram-Positive Bacteria. Front Microbiol 2020; 11:593215. [PMID: 33193264 PMCID: PMC7609970 DOI: 10.3389/fmicb.2020.593215] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023] Open
Abstract
With the alarming increase of infections caused by pathogenic multidrug-resistant bacteria over the last decades, antimicrobial peptides (AMPs) have been investigated as a potential treatment for those infections, directly through their lytic effect or indirectly, due to their ability to modulate the immune system. There are still concerns regarding the use of such molecules in the treatment of infections, such as cell toxicity and host factors that lead to peptide inhibition. To overcome these limitations, different approaches like peptide modification to reduce toxicity and peptide combinations to improve therapeutic efficacy are being tested. Human defense peptides consist of an important part of the innate immune system, against a myriad of potential aggressors, which have in turn developed different ways to overcome the AMPs microbicidal activities. Since the antimicrobial activity of AMPs vary between Gram-positive and Gram-negative species, so do the bacterial resistance arsenal. This review discusses the mechanisms exploited by Gram-positive bacteria to circumvent killing by antimicrobial peptides. Specifically, the most clinically relevant genera, Streptococcus spp., Staphylococcus spp., Enterococcus spp. and Gram-positive bacilli, have been explored.
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Affiliation(s)
- Lucas Assoni
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Barbara Milani
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Marianna Ribeiro Carvalho
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lucas Natanael Nepomuceno
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Natalha Tedeschi Waz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Maria Eduarda Souza Guerra
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Thiago Rojas Converso
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
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15
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SpoVG is Necessary for Sporulation in Bacillus anthracis. Microorganisms 2020; 8:microorganisms8040548. [PMID: 32290166 PMCID: PMC7232415 DOI: 10.3390/microorganisms8040548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/01/2020] [Accepted: 04/08/2020] [Indexed: 01/24/2023] Open
Abstract
The Bacillus anthracis spore constitutes the infectious form of the bacterium, and sporulation is an important process in the organism’s life cycle. Herein, we show that disruption of SpoVG resulted in defective B. anthracis sporulation. Confocal microscopy demonstrated that a ΔspoVG mutant could not form an asymmetric septum, the first morphological change observed during sporulation. Moreover, levels of spoIIE mRNA were reduced in the spoVG mutant, as demonstrated using β-galactosidase activity assays. The effects on sporulation of the ΔspoVG mutation differed in B. anthracis from those in B. subtilis because of the redundant functions of SpoVG and SpoIIB in B. subtilis. SpoVG is highly conserved between B. anthracis and B. subtilis. Conversely, BA4688 (the protein tentatively assigned as SpoIIB in B. anthracis) and B. subtilis SpoIIB (SpoIIBBs) share only 27.9% sequence identity. On complementation of the B. anthracis ΔspoVG strain with spoIIBBs, the resulting strain pBspoIIBBs/ΔspoVG could not form resistant spores, but partially completed the prespore engulfment stage. In agreement with this finding, mRNA levels of the prespore engulfment gene spoIIM were significantly increased in strain pBspoIIBBs/ΔspoVG compared with the ΔspoVG strain. Transcription of the coat development gene cotE was similar in the pBspoIIBBs/ΔspoVG and ΔspoVG strains. Thus, unlike in B. subtilis, SpoVG appears to be required for sporulation in B. anthracis, which provides further insight into the sporulation mechanisms of this pathogen.
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16
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Malmquist JA, Rogan MR, McGillivray SM. Galleria mellonella as an Infection Model for Bacillus anthracis Sterne. Front Cell Infect Microbiol 2019; 9:360. [PMID: 31681636 PMCID: PMC6813211 DOI: 10.3389/fcimb.2019.00360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/04/2019] [Indexed: 01/09/2023] Open
Abstract
Understanding bacterial virulence provides insight into the molecular basis behind infection and could identify new drug targets. However, assessing potential virulence determinants relies on testing in an animal model. The mouse is a well-validated model but it is constrained by the ethical and logistical challenges of using vertebrate animals. Recently the larva of the greater wax moth Galleria mellonella has been explored as a possible infection model for a number of pathogens. In this study, we developed G. mellonella as an infection model for Bacillus anthracis Sterne. We first validated two different infection assays, a survival assay and a competition assay, using mutants containing disruptions in known B. anthracis virulence genes. We next tested the utility of G. mellonella to assess the virulence of transposon mutants with unknown mutations that had increased susceptibility to hydrogen peroxide in in vitro assays. One of these transposon mutants also displayed significantly decreased virulence in G. mellonella. Further investigation revealed that this mutant had a disruption in the petrobactin biosynthesis operon (asbABCDEF), which has been previously implicated in both virulence and defense against oxidative stress. We conclude that G. mellonella can detect attenuated virulence of B. anthracis Sterne in a manner consistent with that of mammalian infection models. Therefore, G. mellonella could serve as a useful alternative to vertebrate testing, especially for early assessments of potential virulence genes when use of a mammalian model may not be ethical or practical.
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Affiliation(s)
- Jacob A Malmquist
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
| | - Madison R Rogan
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
| | - Shauna M McGillivray
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
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17
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Qin Y, He Y, She Q, Larese-Casanova P, Li P, Chai Y. Heterogeneity in respiratory electron transfer and adaptive iron utilization in a bacterial biofilm. Nat Commun 2019; 10:3702. [PMID: 31420537 PMCID: PMC6697725 DOI: 10.1038/s41467-019-11681-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/26/2019] [Indexed: 11/16/2022] Open
Abstract
In Bacillus subtilis, robust biofilm formation requires large quantities of ferric iron. Here we show that this process requires preferential production of a siderophore precursor, 2,3-dihydroxybenzoate, instead of the siderophore bacillibactin. A large proportion of iron is associated extracellularly with the biofilm matrix. The biofilms are conductive, with extracellular iron potentially acting as electron acceptor. A relatively small proportion of ferric iron is internalized and boosts production of iron-containing enzymes involved in respiratory electron transfer and establishing strong membrane potential, which is key to biofilm matrix production. Our study highlights metabolic diversity and versatile energy generation strategies within B. subtilis biofilms. Biofilm formation in Bacillus subtilis requires high levels of ferric iron. Here, Qin et al. show that iron accumulation requires production of dihydroxybenzoate (a precursor in siderophore biosynthesis), and matrix-associated iron may be acting as extracellular electron acceptor during respiratory electron transfer.
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Affiliation(s)
- Yuxuan Qin
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.,Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Yinghao He
- Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Qianxuan She
- Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Philip Larese-Casanova
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, 02115, USA
| | - Pinglan Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA, 02115, USA.
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