51
|
Nady N, Salem N, Amer R, El-Shazly A, Kandil SH, Hassouna MSED. Comparison between a Conventional Anti-Biofouling Compound and a Novel Modified Low-Fouling Polyethersulfone Ultrafiltration Membrane: Bacterial Anti-Attachment, Water Quality and Productivity. MEMBRANES 2020; 10:membranes10090227. [PMID: 32927801 PMCID: PMC7558014 DOI: 10.3390/membranes10090227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 11/16/2022]
Abstract
In this work, the efficiency of a conventional chlorination pretreatment is compared with a novel modified low-fouling polyethersulfone (PES) ultrafiltration (UF) membrane, in terms of bacteria attachment and membrane biofouling reduction. This study highlights the use of membrane modification as an effective strategy to reduce bacterial attachment, which is the initial step of biofilm formation, rather than using antimicrobial agents that can enhance bacterial regrowth. The obtained results revealed that the filtration of pretreated, inoculated seawater using the modified PES UF membrane without the pre-chlorination step maintained the highest initial flux (3.27 ± 0.13 m3·m−2·h−1) in the membrane, as well as having one and a half times higher water productivity than the unmodified membrane. The highest removal of bacterial cells was achieved by the modified membrane without chlorination, in which about 12.07 × 104 and 8.9 × 104 colony-forming unit (CFU) m−2 bacterial cells were retained on the unmodified and modified membrane surfaces, respectively, while 29.4 × 106 and 0.42 × 106 CFU mL−1 reached the filtrate for the unmodified and modified membranes, respectively. The use of chlorine disinfectant resulted in significant bacterial regrowth.
Collapse
Affiliation(s)
- Norhan Nady
- Polymeric Materials Research Department, City of Scientific Research and Technological Applications (SRTA-City), Borg El-Arab City, Alexandria 21934, Egypt
- Correspondence: ; Tel.: +20-109-091-8521
| | - Noha Salem
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, Alexandria 21321, Egypt; (N.S.); (M.S.E.-D.H.)
| | - Ranya Amer
- Environment and Natural Material Research Institute (ENMRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab, Alexandria 21934, Egypt;
| | - Ahmed El-Shazly
- Chemicals and Petrochemical Engineering Department, Egypt-Japan University of Science and Technology (E-JUST), Alexandria 21934, Egypt;
| | - Sherif H. Kandil
- Department of Materials Science, Institute of Graduate Studies and Research, Alexandria University, Alexandria 21321, Egypt;
| | - Mohamed Salah El-Din Hassouna
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, Alexandria 21321, Egypt; (N.S.); (M.S.E.-D.H.)
| |
Collapse
|
52
|
Wang Y, Hao F, Lu W, Suo X, Bellenger E, Fu N, Jeantet R, Chen XD. Enhanced thermal stability of lactic acid bacteria during spray drying by intracellular accumulation of calcium. J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2020.109975] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
53
|
Yadav SK, Das J, Kumar R, Jha G. Calcium regulates the mycophagous ability of Burkholderia gladioli strain NGJ1 in a type III secretion system-dependent manner. BMC Microbiol 2020; 20:216. [PMID: 32689944 PMCID: PMC7372643 DOI: 10.1186/s12866-020-01897-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 07/12/2020] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND A rice associated bacterium Burkholderia gladioli strain NGJ1 demonstrates mycophagy, a phenomenon wherein bacteria feed on fungi. Previously, we have reported that NGJ1 utilizes type III secretion system (T3SS) to deliver a prophage tail-like protein (Bg_9562) into fungal cells to establish mycophagy. RESULTS In this study, we report that calcium ion concentration influences the mycophagous ability of NGJ1 on Rhizoctonia solani, an important fungal pathogen. The calcium limiting condition promotes mycophagy while high calcium environment prevents it. The expression of various T3SS apparatus encoding genes of NGJ1 was induced and secretion of several potential T3SS effector proteins (including Bg_9562) into extracellular milieu was triggered under calcium limiting condition. Using LC-MS/MS proteome analysis, we identified several calcium regulated T3SS effector proteins of NGJ1. The expression of genes encoding some of these effector proteins was upregulated during mycophagous interaction of NGJ1 with R. solani. Further, mutation of one of these genes (endo-β-1, 3- glucanase) rendered the mutant NGJ1 bacterium defective in mycophagy while complementation with full length copy of the gene restored its mycophagous activity. CONCLUSION Our study provides evidence that low calcium environment triggers secretion of various T3SS effectors proteins into the extracellular milieu and suggests the importance of cocktail of these proteins in promoting mycophagy.
Collapse
Affiliation(s)
- Sunil Kumar Yadav
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Joyati Das
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Rahul Kumar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
54
|
Intracellular ion concentrations and cation-dependent remodelling of bacterial MreB assemblies. Sci Rep 2020; 10:12002. [PMID: 32686735 PMCID: PMC7371711 DOI: 10.1038/s41598-020-68960-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/08/2020] [Indexed: 12/20/2022] Open
Abstract
Here, we measured the concentrations of several ions in cultivated Gram-negative and Gram-positive bacteria, and analyzed their effects on polymer formation by the actin homologue MreB. We measured potassium, sodium, chloride, calcium and magnesium ion concentrations in Leptospira interrogans, Bacillus subtilis and Escherichia coli. Intracellular ionic strength contributed from these ions varied within the 130–273 mM range. The intracellular sodium ion concentration range was between 122 and 296 mM and the potassium ion concentration range was 5 and 38 mM. However, the levels were significantly influenced by extracellular ion levels. L. interrogans, Rickettsia rickettsii and E. coli MreBs were heterologously expressed and purified from E. coli using a novel filtration method to prepare MreB polymers. The structures and stability of Alexa-488 labeled MreB polymers, under varying ionic strength conditions, were investigated by confocal microscopy and MreB polymerization rates were assessed by measuring light scattering. MreB polymerization was fastest in the presence of monovalent cations in the 200–300 mM range. MreB filaments showed high stability in this concentration range and formed large assemblies of tape-like bundles that transformed to extensive sheets at higher ionic strengths. Changing the calcium concentration from 0.2 to 0 mM and then to 2 mM initialized rapid remodelling of MreB polymers.
Collapse
|
55
|
Ryu KH. [Gut Microbiota and Pancreatobiliary System]. THE KOREAN JOURNAL OF GASTROENTEROLOGY 2020; 75:231-239. [PMID: 32448854 DOI: 10.4166/kjg.2020.75.5.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 11/03/2022]
Abstract
The gut microbiota is part of the human body that is involved in body metabolism and the occurrence of various diseases. Detecting and analyzing their genetic information (microbiome) is as important as analyzing human genes. The core microbiome, the key functional genes shared by all humans, helps better understand the physiology of the human body. Information on the gut microbiome of a diseased person can help diagnose and treat disease. The pancreatobiliary system releases functional antimicrobial substances, such as bile acids and antimicrobial peptides, which affect the gut microbiota directly. In response, the gut microbiota influences pancreatobiliary secretion by controlling the generation and emission of substances through indirect signaling. This crosstalk maintains homeostasis of the pancreatobiliary system secretion and microbiota. Dysbiosis and disease can occur if this fails to work properly. Bile acid therapy has been used widely and may affect the microbial environment in the intestine. An association of the gut microbiota has been reported in many cases of pancreatobiliary diseases, including malignant tumors. Traditionally, most pancreatobiliary diseases are accompanied by infections from the gut microbiota, which is an important target for treatment. The pancreatobiliary system can control its function through physical and drug therapy. This may be a new pioneering field in the study or treatment of the gut microbiota.
Collapse
Affiliation(s)
- Ki-Hyun Ryu
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Konyang University College of Medicine, Daejeon, Korea
| |
Collapse
|
56
|
Harirchi S, Etemadifar Z, Mahboubi A, Yazdian F, Taherzadeh MJ. The Effect of Calcium/Magnesium Ratio on the Biomass Production of a Novel Thermoalkaliphilic Aeribacillus pallidus Strain with Highly Heat-Resistant Spores. Curr Microbiol 2020; 77:2565-2574. [PMID: 32361845 DOI: 10.1007/s00284-020-02010-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 04/24/2020] [Indexed: 12/29/2022]
Abstract
Hot springs are fascinating extreme environments for the isolation of polyextremophilic microorganisms with extraordinary characteristics. Since polyextremophilic bacterial growth are not as high as routine bacteria, the objective of this study was to investigate the effect of some environmental factors on biomass and metabolites productions in the newly isolated strain, from Larijan hot spring in Iran. The strain was identified as Aeribacillus pallidus Lhs-10 and deposited as CCUG 72355 and IBRC-M 11202 in Sweden and Iran, respectively. This thermoalkaliphilic strain can grow best at 50 °C, pH 8 and in the presence of 25 g/l NaCl. The physiological characterization of this strain show that [Ca/Mg] ratio affect its growth and biomass production with the best results obtained at the ratio of 2.5. Moreover, lactic and acetic acids production by this strain was affected by pH, aeration, and temperature, where a metabolic shift was detected from lactate to acetate production when the culture was aerated. Besides, its spores could tolerate heating at 80, 85, 90, 95 and 98 °C for 30 min without any reduction in the initial spore population, whereas D-value was defined 50 min at 98 °C. This newly lactic acid-producing strain of A. pallidus can be a promising strain that can be used in the harsh conditions in industrial processes.
Collapse
Affiliation(s)
- Sharareh Harirchi
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, 8174673441, Isfahan, Iran
| | - Zahra Etemadifar
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, 8174673441, Isfahan, Iran.
| | - Amir Mahboubi
- Swedish Centre for Resource Recovery, University of Borås, 501 90, Borås, Sweden
| | - Fatemeh Yazdian
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
| | | |
Collapse
|
57
|
Pereira SA, Jesus GFA, Pereira GV, Silva BC, Sá LS, Martins ML, Mouriño JLP. The Chelating Mineral on Organic Acid Salts Modulates the Dynamics and Richness of the Intestinal Microbiota of a Silver Catfish Rhamdia quelen. Curr Microbiol 2020; 77:1483-1495. [PMID: 32236647 DOI: 10.1007/s00284-020-01962-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 03/21/2020] [Indexed: 02/01/2023]
Abstract
The aim of this study was to evaluate the influence of the chelating mineral on propionic acid, calcium or sodium on the composition, dynamics and richness of the intestinal microbiota of a native silver catfish Rhamdia quelen through high-throughput sequencing (HTS). A total of 225 fish (8.43 ± 0.18 g) were distributed in tanks, 15 fish per tank in five groups with three replicates each: Control, Ca-propionate 0.25% (Ca0.25%) Ca-propionate 1% (Ca1%), Na-propionate 0.25% (Na0.25%) and Na-propionate 1% (Na1%). The feed was provided four times a day for 60 days. After experimental period, the fish were fasted for 24 h and the intestine was aseptically collected, pooled by treatment, and fixed in pure absolute ethanol for subsequent DNA extraction and HTS. The HTS showed that the supplementation of the propionic acid chelated to the mineral calcium or sodium in the different concentrations increased the operational taxonomic units and richness in comparison to control group. The main phyla found were Fusobacteria, Firmicutes, Proteobacteria and Bacteroides. Both the fusobacteria and the genus Cetobacterium, especially C. somerae, were positively modulated with Ca0.25% and Na1% supplementation. It can be emphasized that supplementation with calcium or sodium propionate at different concentrations changed the natural microbiota of R. quelen.
Collapse
Affiliation(s)
- Scheila A Pereira
- AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (UFSC), Rod. Admar Gonzaga 1346, Florianópolis, SC, 88040-900, Brazil.
| | - Gabriel F A Jesus
- AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (UFSC), Rod. Admar Gonzaga 1346, Florianópolis, SC, 88040-900, Brazil
| | - Gabriella V Pereira
- Fish Nutrition and Health Research Group, School of Biological Sciences, Faculty of Science and Environment, Plymouth University, Plymouth, UK
| | - Bruno C Silva
- EPAGRI - Company of Agricultural Research and Rural Extension of Santa Catarina, Rua Joaquim Garcia, s/n, Camboriú, SC, 88340-000, Brazil
| | - Lúvia S Sá
- AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (UFSC), Rod. Admar Gonzaga 1346, Florianópolis, SC, 88040-900, Brazil
| | - Maurício L Martins
- AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (UFSC), Rod. Admar Gonzaga 1346, Florianópolis, SC, 88040-900, Brazil
| | - José L P Mouriño
- AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (UFSC), Rod. Admar Gonzaga 1346, Florianópolis, SC, 88040-900, Brazil
| |
Collapse
|
58
|
Benarroch JM, Asally M. The Microbiologist’s Guide to Membrane Potential Dynamics. Trends Microbiol 2020; 28:304-314. [DOI: 10.1016/j.tim.2019.12.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/25/2019] [Accepted: 12/09/2019] [Indexed: 10/25/2022]
|
59
|
Tay MF, Lee S, Xu H, Jeong K, Liu C, Cornelissen ER, Wu B, Chong TH. Impact of salt accumulation in the bioreactor on the performance of nanofiltration membrane bioreactor (NF-MBR)+Reverse osmosis (RO) process for water reclamation. WATER RESEARCH 2020; 170:115352. [PMID: 31812816 DOI: 10.1016/j.watres.2019.115352] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
The impacts of salt accumulation, through adjusting the solid retention time (SRT), in the bioreactor on the bioprocess as well as membrane performance of a high retention nanofiltration membrane bioreactor (NF-MBR) and subsequent reverse osmosis (RO) process for water reclamation are addressed in this study. The build-up of salts (i.e., Ca, Mg, PO4) is a function of SRT, hydraulic retention time (HRT) and membrane rejection. Despite the accumulation of salts, both NF-MBRs at SRT of 30 and 60 days, achieved (i) similar biodegradation efficiency; (ii) excellent organic removal (> 97%); and (iii) excellent ammonia removal (> 98%). Extending the SRT could improve the microbial bio-flocculation capability, but did not influence the microbial activity, viability, and community structure. However, more severe membrane fouling was observed in the NF-MBR with elevated salt levels, which was attributed to the greater formation of calcium phosphate scale and Ca-polysaccharides complex (i.e., irreversible fouling layer) as well as the cake-enhanced-osmotic-pressure (CEOP) effect. Although both NF-MBRs produced comparable quality of permeate, a higher RO membrane fouling rate was observed when the permeate of NF-MBR with SRT at 60 days was fed to the RO system, implying organic compositions in NF-MBR permeate may influence RO performance.
Collapse
Affiliation(s)
- Ming Feng Tay
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore; Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Seonki Lee
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Huijuan Xu
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Kwanho Jeong
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore
| | - Chang Liu
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore; School of Environment and Resource, Southwest University of Science and Technology, 621010, Mianyang, China
| | - Emile R Cornelissen
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore; KWR Watercycle Research Institute, 3433 PE, Nieuwegein, Netherlands; Particle and Interfacial Technology Group, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Bing Wu
- Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore; Faculty of Civil and Environmental Engineering, University of Iceland, Hjardarhagi 2-6, IS-107 Reykjavik, Iceland.
| | - Tzyy Haur Chong
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore; Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore.
| |
Collapse
|
60
|
Shimomura T, Yonekawa Y, Nagura H, Tateyama M, Fujiyoshi Y, Irie K. A native prokaryotic voltage-dependent calcium channel with a novel selectivity filter sequence. eLife 2020; 9:52828. [PMID: 32093827 PMCID: PMC7041947 DOI: 10.7554/elife.52828] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/07/2020] [Indexed: 12/20/2022] Open
Abstract
Voltage-dependent Ca2+ channels (Cavs) are indispensable for coupling action potentials with Ca2+ signaling in living organisms. The structure of Cavs is similar to that of voltage-dependent Na+ channels (Navs). It is known that prokaryotic Navs can obtain Ca2+ selectivity by negative charge mutations of the selectivity filter, but native prokaryotic Cavs had not yet been identified. We report the first identification of a native prokaryotic Cav, CavMr, whose selectivity filter contains a smaller number of negatively charged residues than that of artificial prokaryotic Cavs. A relative mutant whose selectivity filter was replaced with that of CavMr exhibits high Ca2+ selectivity. Mutational analyses revealed that the glycine residue of the CavMr selectivity filter is a determinant for Ca2+ selectivity. This glycine residue is well conserved among subdomains I and III of eukaryotic Cavs. These findings provide new insight into the Ca2+ selectivity mechanism that is conserved from prokaryotes to eukaryotes. Electrical signals in the brain and muscles allow animals – including humans – to think, make memories and move around. Cells generate these signals by enabling charged particles known as ions to pass through the physical barrier that surrounds all cells, the cell membrane, at certain times and in certain locations. The ions pass through pores made by various channel proteins, which generally have so-called “selectivity filters” that only allow particular types of ions to fit through. For example, the selectivity filters of a family of channels in mammals known as the Cavs only allow calcium ions to pass through. Another family of ion channels in mammals are similar in structure to the Cavs but their selectivity filters only allow sodium ions to pass through instead of calcium ions. Ion channels are found in all living cells including in bacteria. It is thought that the Cavs and sodium-selective channels may have both evolved from Cav-like channels in an ancient lifeform that was the common ancestor of modern bacteria and animals. Previous studies in bacteria found that modifying the selectivity filters of some sodium-selective channels known as BacNavs allowed calcium ions to pass through the mutant channels instead of sodium ions. However, no Cav channels had been identified in bacteria so far, representing a missing link in the evolutionary history of ion channels. Shimomura et al. have now found a Cav-like channel in a bacterium known as Meiothermus ruber. Like all proteins, ion channels are made from amino acids and comparing the selectivity filter of the M. ruber Cav with those of mammalian Cavs and the calcium-selective BacNav mutants from previous studies revealed one amino acid that plays a particularly important role. This amino acid is a glycine that helps select which ions may pass through the pore and is also present in the selectivity filters of many Cavs in mammals. Together these findings suggest that the Cav channel from M. ruber is similar to the mammal Cav channels and may more closely resemble the Cav-like channels thought to have existed in the common ancestor of bacteria and animals. Since other channel proteins from bacteria are useful genetic tools for studies in human and other animal cells, the Cav channel from M. ruber has the potential to be used to stimulate calcium signaling in experiments.
Collapse
Affiliation(s)
- Takushi Shimomura
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Nagoya, Japan.,Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Yoshiki Yonekawa
- Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hitoshi Nagura
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Nagoya, Japan
| | - Michihiro Tateyama
- Division of Biophysics and Neurobiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Yoshinori Fujiyoshi
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Nagoya, Japan.,CeSPIA Inc, Tokyo, Japan
| | - Katsumasa Irie
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Nagoya, Japan.,Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| |
Collapse
|
61
|
King MM, Kayastha BB, Franklin MJ, Patrauchan MA. Calcium Regulation of Bacterial Virulence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:827-855. [PMID: 31646536 DOI: 10.1007/978-3-030-12457-1_33] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness to both the intracellular and extracellular environments. Elaborate Ca2+ regulatory networks have been well characterized in eukaryotic cells, where Ca2+ regulates a number of essential cellular processes, ranging from cell division, transport and motility, to apoptosis and pathogenesis. However, in bacteria, the knowledge on Ca2+ signaling is still fragmentary. This is complicated by the large variability of environments that bacteria inhabit with diverse levels of Ca2+. Yet another complication arises when bacterial pathogens invade a host and become exposed to different levels of Ca2+ that (1) are tightly regulated by the host, (2) control host defenses including immune responses to bacterial infections, and (3) become impaired during diseases. The invading pathogens evolved to recognize and respond to the host Ca2+, triggering the molecular mechanisms of adhesion, biofilm formation, host cellular damage, and host-defense resistance, processes enabling the development of persistent infections. In this review, we discuss: (1) Ca2+ as a determinant of a host environment for invading bacterial pathogens, (2) the role of Ca2+ in regulating main events of host colonization and bacterial virulence, and (3) the molecular mechanisms of Ca2+ signaling in bacterial pathogens.
Collapse
Affiliation(s)
- Michelle M King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Michael J Franklin
- Department of Microbiology and Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
| |
Collapse
|
62
|
Gilabert JA. Cytoplasmic Calcium Buffering: An Integrative Crosstalk. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:163-182. [PMID: 31646510 DOI: 10.1007/978-3-030-12457-1_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Calcium (Ca2+) buffering is part of an integrative crosstalk between different mechanisms and elements involved in the control of free Ca2+ ions persistence in the cytoplasm and hence, in the Ca2+-dependence of many intracellular processes. Alterations of Ca2+ homeostasis and signaling from systemic to subcellular levels also play a pivotal role in the pathogenesis of many diseases.Compared with Ca2+ sequestration towards intracellular Ca2+ stores, Ca2+ buffering is a rapid process occurring in a subsecond scale. Any molecule (or binding site) with the ability to bind Ca2+ ions could be considered, at least in principle, as a buffer. However, the term Ca2+ buffer is applied only to a small subset of Ca2+ binding proteins containing acidic side-chain residues.Ca2+ buffering in the cytoplasm mainly relies on mobile and immobile or fixed buffers controlling the diffusion of free Ca2+ ions inside the cytosol both temporally and spatially. Mobility of buffers depends on their molecular weight, but other parameters as their concentration, affinity for Ca2+ or Ca2+ binding and dissociation kinetics next to their diffusional mobility also contribute to make Ca2+ signaling one of the most complex signaling activities of the cell.The crosstalk between all the elements involved in the intracellular Ca2+ dynamics is a process of extreme complexity due to the diversity of structural and molecular elements involved but permit a highly regulated spatiotemporal control of the signal mediated by Ca2+ ions. The basis of modeling tools to study Ca2+ dynamics are also presented.
Collapse
Affiliation(s)
- Juan A Gilabert
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain.
| |
Collapse
|
63
|
Krishnan B, Srivastava SS, Sankeshi V, Garg R, Srivastava S, Sankaranarayanan R, Sharma Y. βγ-Crystallination Endows a Novel Bacterial Glycoside Hydrolase 64 with Ca 2+-Dependent Activity Modulation. J Bacteriol 2019; 201:e00392-19. [PMID: 31527113 PMCID: PMC6832075 DOI: 10.1128/jb.00392-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 09/05/2019] [Indexed: 01/10/2023] Open
Abstract
The prokaryotic βγ-crystallins are a large group of uncharacterized domains with Ca2+-binding motifs. We have observed that a vast number of these domains are found appended to other domains, in particular, the carbohydrate-active enzyme (CAZy) domains. To elucidate the functional significance of these prospective Ca2+ sensors in bacteria and this widespread domain association, we have studied one typical example from Clostridium beijerinckii, a bacterium known for its ability to produce acetone, butanol, and ethanol through fermentation of several carbohydrates. This novel glycoside hydrolase of family 64 (GH64), which we named glucanallin, is composed of a βγ-crystallin domain, a GH64 domain, and a carbohydrate-binding module 56 (CBM56). The substrates of GH64, β-1,3-glucans, are the targets for industrial biofuel production due to their plenitude. We have examined the Ca2+-binding properties of this protein, assayed its enzymatic activity, and analyzed the structural features of the β-1,3-glucanase domain through its high-resolution crystal structure. The reaction products resulting from the enzyme reaction of glucanallin reinforce the mixed nature of GH64 enzymes, in contrast to the prevailing notion of them being an exotype. Upon disabling Ca2+ binding and comparing different domain combinations, we demonstrate that the βγ-crystallin domain in glucanallin acts as a Ca2+ sensor and enhances the glycolytic activity of glucanallin through Ca2+ binding. We also compare the structural peculiarities of this new member of the GH64 family to two previously studied members.IMPORTANCE We have biochemically and structurally characterized a novel glucanase from the less studied GH64 family in a bacterium significant for fermentation of carbohydrates into biofuels. This enzyme displays a peculiar property of being distally modulated by Ca2+ via assistance from a neighboring βγ-crystallin domain, likely through changes in the domain interface. In addition, this enzyme is found to be optimized for functioning in an acidic environment, which is in line with the possibility of its involvement in biofuel production. Multiple occurrences of a similar domain architecture suggest that such a "βγ-crystallination"-mediated Ca2+ sensitivity may be widespread among bacterial proteins.
Collapse
Affiliation(s)
- Bal Krishnan
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
- Indian Institute of Science Education and Research Berhampur, Odisha, India
| | | | - Venu Sankeshi
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Rupsi Garg
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | | | - Yogendra Sharma
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
- Indian Institute of Science Education and Research Berhampur, Odisha, India
| |
Collapse
|
64
|
Purahong W, Sadubsarn D, Tanunchai B, Wahdan SFM, Sansupa C, Noll M, Wu YT, Buscot F. First Insights into the Microbiome of a Mangrove Tree Reveal Significant Differences in Taxonomic and Functional Composition among Plant and Soil Compartments. Microorganisms 2019; 7:microorganisms7120585. [PMID: 31756976 PMCID: PMC6955992 DOI: 10.3390/microorganisms7120585] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 12/17/2022] Open
Abstract
Mangrove forest trees play important ecological functions at the interface between terrestrial and marine ecosystems. However, despite playing crucial roles in plant health and productivity, there is little information on microbiomes of the tree species in mangrove ecosystems. Thus, in this study we aimed to characterize the microbiome in soil (rhizosphere) and plant (root, stem, and leaf endosphere) compartments of the widely distributed mangrove tree Rhizophora stylosa. Surprisingly, bacterial operational taxonomic units (OTUs) were only confidently detected in rhizosphere soil, while fungal OTUs were detected in all soil and plant compartments. The major detected bacterial phyla were affiliated to Proteobacteria, Actinobacteria, Planctomycetes, and Chloroflexi. Several nitrogen-fixing bacterial OTUs were detected, and the presence of nitrogen-fixing bacteria was confirmed by nifH gene based-PCR in all rhizosphere soil samples, indicating their involvement in N acquisition in the focal mangrove ecosystem. We detected taxonomically (54 families, 83 genera) and functionally diverse fungi in the R. stylosa mycobiome. Ascomycota (mainly Dothideomycetes, Eurotiomycetes, Sordariomycetes) were most diverse in the mycobiome, accounting for 86% of total detected fungal OTUs. We found significant differences in fungal taxonomic and functional community composition among the soil and plant compartments. We also detected significant differences in fungal OTU richness (p < 0.002) and community composition (p < 0.001) among plant compartments. The results provide the first information on the microbiome of rhizosphere soil to leaf compartments of mangrove trees and associated indications of ecological functions in mangrove ecosystems.
Collapse
Affiliation(s)
- Witoon Purahong
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
- Correspondence: (W.P.); (Y.-T.W.)
| | - Dolaya Sadubsarn
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
- Department of Bio and Process Engineering, Faculty of Medical Life and Science, Furtwangen University, 78054 VS-Schwenningen, Germany
| | - Benjawan Tanunchai
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
| | - Sara Fareed Mohamed Wahdan
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
- Department of Botany, Faculty of Science, Suez Canal University, 41522 Ismailia, Egypt
| | - Chakriya Sansupa
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
- Biology Department, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
- Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Matthias Noll
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, 96450 Coburg, Germany;
| | - Yu-Ting Wu
- Department of Forestry, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: (W.P.); (Y.-T.W.)
| | - François Buscot
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, 06120 Halle (Saale), Germany; (D.S.); (B.T.); (S.F.M.W.); (C.S.); (F.B.)
- German Centre for Integrative Biodiversity Research (iDiv), 04103 Leipzig, Germany
| |
Collapse
|
65
|
Chen H, De La Fuente L. Calcium transcriptionally regulates movement, recombination and other functions of Xylella fastidiosa under constant flow inside microfluidic chambers. Microb Biotechnol 2019; 13:548-561. [PMID: 31729188 PMCID: PMC7017821 DOI: 10.1111/1751-7915.13512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 01/08/2023] Open
Abstract
Xylella fastidiosa is a xylem‐limited bacterial pathogen causing devastating diseases in many economically important crops. Calcium (Ca) is a major inorganic nutrient in xylem sap that influences virulence‐related traits of this pathogen, including biofilm formation and twitching motility. This study aimed to adapt a microfluidic system, which mimics the natural habitat of X. fastidiosa, for whole transcriptome analysis under flow conditions. A microfluidic chamber with two parallel channels was used, and RNA isolated from cells grown inside the system was analysed by RNA‐Seq. Ca transcriptionally regulated the machinery of type IV pili and other genes related to pathogenicity and host adaptation. Results were compared to our previous RNA‐Seq study in biofilm cells in batch cultures (Parker et al., 2016, Environ Microbiol 18, 1620). Ca‐regulated genes in both studies belonged to similar functional categories, but the number and tendencies (up‐/downregulation) of regulated genes were different. Recombination‐related genes were upregulated by Ca, and we proved experimentally that 2 mM Ca enhances natural transformation frequency. Taken together, our results suggest that the regulatory role of Ca in X. fastidiosa acts differently during growth in flow or batch conditions, and this can correlate to the different phases of growth (planktonic and biofilm) during the infection process.
Collapse
Affiliation(s)
- Hongyu Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
| |
Collapse
|
66
|
The Synergy of Ciprofloxacin and Carvedilol against Staphylococcus aureus-Prospects of a New Treatment Strategy? Molecules 2019; 24:molecules24224104. [PMID: 31739388 PMCID: PMC6891268 DOI: 10.3390/molecules24224104] [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: 10/13/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus infections are common and difficult to treat. The increasing number of drug-resistant staphylococcal infections has created the need to develop new strategies for the treatment of these infections. The synergistic antimicrobial activity of different pharmaceuticals seems to be an interesting alternative. The aim of this study was to assess the synergistic activity of ciprofloxacin and carvedilol against S. aureus strains. The antibacterial potential of ciprofloxacin and carvedilol was evaluated according to the CLSI guidelines. The calcium content in S. aureus cells was measured using flow cytometry and atomic absorption spectroscopy. Moreover, confocal and scanning electron microscopy were used to determine the mechanism of antibacterial synergy of ciprofloxacin and carvedilol. The antibacterial effect of ciprofloxacin was higher in the presence of carvedilol than in S. aureus cultures containing the antibiotic only. A significant increase in S. aureus membrane permeability was also observed. The simultaneous administration of the tested compounds caused damage to S. aureus cells visualized by SEM. Enhancement of the antimicrobial action of ciprofloxacin by carvedilol was correlated with an increase in free calcium content in S. aureus cells, morphological changes to the cells, and a reduction in the ability to form bacterial aggregates.
Collapse
|
67
|
De Wever A, Benzerara K, Coutaud M, Caumes G, Poinsot M, Skouri-Panet F, Laurent T, Duprat E, Gugger M. Evidence of high Ca uptake by cyanobacteria forming intracellular CaCO 3 and impact on their growth. GEOBIOLOGY 2019; 17:676-690. [PMID: 31347755 DOI: 10.1111/gbi.12358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/15/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Several species of cyanobacteria biomineralizing intracellular amorphous calcium carbonates (ACC) were recently discovered. However, the mechanisms involved in this biomineralization process and the determinants discriminating species forming intracellular ACC from those not forming intracellular ACC remain unknown. Recently, it was hypothesized that the intensity of Ca uptake (i.e., how much Ca was scavenged from the extracellular solution) might be a major parameter controlling the capability of a cyanobacterium to form intracellular ACC. Here, we tested this hypothesis by systematically measuring the Ca uptake by a set of 52 cyanobacterial strains cultured in the same growth medium. The results evidenced a dichotomy among cyanobacteria regarding Ca sequestration capabilities, with all strains forming intracellular ACC incorporating significantly more calcium than strains not forming ACC. Moreover, Ca provided at a concentration of 50 μM in BG-11 was shown to be limiting for the growth of some of the strains forming intracellular ACC, suggesting an overlooked quantitative role of Ca for these strains. All cyanobacteria forming intracellular ACC contained at least one gene coding for a mechanosensitive channel, which might be involved in Ca influx, as well as at least one gene coding for a Ca2+ /H+ exchanger and membrane proteins of the UPF0016 family, which might be involved in active Ca transport either from the cytosol to the extracellular solution or the cytosol toward an intracellular compartment. Overall, massive Ca sequestration may have an indirect role by allowing the formation of intracellular ACC. The latter may be beneficial to the growth of the cells as a storage of inorganic C and/or a buffer of intracellular pH. Moreover, high Ca scavenging by cyanobacteria biomineralizing intracellular ACC, a trait shared with endolithic cyanobacteria, suggests that these cyanobacteria should be considered as potentially significant geochemical reservoirs of Ca.
Collapse
Affiliation(s)
- Alexis De Wever
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Margot Coutaud
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Géraldine Caumes
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Mélanie Poinsot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Fériel Skouri-Panet
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Thierry Laurent
- Collection des Cyanobactéries, Institut Pasteur, Paris Cedex 15, France
| | - Elodie Duprat
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, UMR CNRS 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Muriel Gugger
- Collection des Cyanobactéries, Institut Pasteur, Paris Cedex 15, France
| |
Collapse
|
68
|
Sharma D, Sharma A, Singh B, Verma SK. Bioinformatic Exploration of Metal-Binding Proteome of Zoonotic Pathogen Orientia tsutsugamushi. Front Genet 2019; 10:797. [PMID: 31608099 PMCID: PMC6769048 DOI: 10.3389/fgene.2019.00797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/30/2019] [Indexed: 12/21/2022] Open
Abstract
Metal ions are involved in many essential biological processes and are crucial for the survival of all organisms. Identification of metal-binding proteins (MBPs) of human affecting pathogens may provide the blueprint for understanding biological metal usage and their putative roles in pathogenesis. This study is focused on the analysis of MBPs from Orientia tsutsugamushi (Ott), a causal agent of scrub typhus in humans. A total of 321 proteins were predicted as putative MBPs, based on sequence search and three-dimensional structure analysis. Majority of proteins could bind with magnesium, and the order of metal binding was Mg > Ca > Zn > Mn > Fe > Cd > Ni > Co > Cu, respectively. The predicted MBPs were functionally classified into nine broad classes. Among them, gene expression and regulation, metabolism, cell signaling, and transport classes were dominant. It was noted that the putative MBPs were localized in all subcellular compartments of Ott, but majorly found in the cytoplasm. Additionally, it was revealed that out of 321 predicted MBPs 245 proteins were putative bacterial toxins and among them, 98 proteins were nonhomologous to human proteome. Sixty putative MBPs showed the ability to interact with drug or drug-like molecules, which indicate that they may be used as broad-spectrum drug targets. These predicted MBPs from Ott could play vital role(s) in various cellular activities and virulence, hence may serve as plausible therapeutic targets to design metal-based drugs to curtail its infection.
Collapse
Affiliation(s)
- Dixit Sharma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
| | - Ankita Sharma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
| | - Birbal Singh
- ICAR-Indian Veterinary Research Institute, Regional Station, Palampur, India
| | - Shailender Kumar Verma
- Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Kangra, India
| |
Collapse
|
69
|
Development of Palm Fatty Acid Distillate-Containing Medium for Biosurfactant Production by Pseudomonas sp. LM19. Molecules 2019; 24:molecules24142613. [PMID: 31323769 PMCID: PMC6680552 DOI: 10.3390/molecules24142613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/22/2019] [Accepted: 06/28/2019] [Indexed: 11/16/2022] Open
Abstract
High production costs of biosurfactants are mainly caused by the usage of the expensive substrate and long fermentation period which undermines their potential in bioremediation processes, food, and cosmetic industries even though they, owing to the biodegradability, lower toxicity, and raise specificity traits. One way to circumvent this is to improvise the formulation of biosurfactant-production medium by using cheaper substrate. A culture medium utilizing palm fatty acid distillate (PFAD), a palm oil refinery by-product, was first developed through one-factor-at-a-time (OFAT) technique and further refined by means of the statistical design method of factorial and response surface modeling to enhance the biosurfactant production from Pseudomonas sp. LM19. The results shows that, the optimized culture medium containing: 1.148% (v/v) PFAD; 4.054 g/L KH2PO4; 1.30 g/L yeast extract; 0.023 g/L sodium-EDTA; 1.057 g/L MgSO4·7H2O; 0.75 g/L K2HPO4; 0.20 g/L CaCl2·2H2O; 0.080 g/L FeCl3·6H2O gave the maximum biosurfactant productivity. This study demonstrated that the cell concentration and biosurfactant productivity could reach up to 8.5 × 109 CFU/mL and 0.346 g/L/day, respectively after seven days of growth, which were comparable to the values predicted by an RSM regression model, i.e., 8.4 × 109 CFU/mL and 0.347 g/L/day, respectively. Eleven rhamnolipid congeners were detected, in which dirhamnolipid accounted for 58% and monorhamnolipid was 42%. All in all, manipulation of palm oil by-products proved to be a feasible substrate for increasing the biosurfactant production about 3.55-fold as shown in this study.
Collapse
|
70
|
Lee B, Lee DG. Synergistic antibacterial activity of gold nanoparticles caused by apoptosis-like death. J Appl Microbiol 2019; 127:701-712. [PMID: 31216601 DOI: 10.1111/jam.14357] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/11/2019] [Accepted: 06/14/2019] [Indexed: 01/06/2023]
Abstract
AIMS Metal nanoparticles are promising materials for the management of infectious diseases as known to have various antimicrobial activities in pathogenic micro-organisms. Among them, gold nanoparticles (AuNPs) are used in a wide range of fields such as photodynamic therapy, molecular diagnostics and drug delivery because of their unique physicochemical properties. However, little is known about the synergistic antibacterial activity and mechanism of AuNPs on pathogenic bacteria. METHODS AND RESULTS Combinations of AuNPs and cefotaxime and ciprofloxacin showed synergistic interaction against all Salmonella species, however the combination with kanamycin exhibited no interaction. We determined that AuNPs and in combinations with antibiotics exert its antibacterial effect through bacterial apoptosis-like death. AuNPs caused collapse of intracellular divalent cation homeostasis, and conventional antibiotics caused accumulation of reactive oxygen species, which induced apoptotic hallmarks such as membrane depolarization, caspase-like protein activation, cell filamentation and phosphatidylserine externalization. CONCLUSIONS The cation homeostasis disruption by AuNPs and the accumulation of reactive oxygen species by conventional antibiotics synergistically affected bacterial cell death and induced apoptosis-like death in Salmonella cells. SIGNIFICANCE AND IMPACT OF THE STUDY The synergistic activity between AuNPs and antibiotics propose that the AuNPs are a potential antibacterial agent and adjuvant for antimicrobial chemotherapy.
Collapse
Affiliation(s)
- B Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Korea
| | - D G Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Korea
| |
Collapse
|
71
|
Maraldi NM. In search of a primitive signaling code. Biosystems 2019; 183:103984. [PMID: 31201829 DOI: 10.1016/j.biosystems.2019.103984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 10/26/2022]
Abstract
Cells must have preceded by simpler chemical systems (protocells) that had the capacity of a spontaneous self-assembly process and the ability to confine chemical reaction networks together with a form of information. The presence of lipid molecules in the early Earth conditions is sufficient to ensure the occurrence of spontaneous self-assembly processes, not defined by genetic information, but related to their chemical amphiphilic nature. Ribozymes are plausible molecules for early life, being the first small polynucleotides made up of random oligomers or formed by non-enzymatic template copying. Compartmentalization represents a strategy for the evolution of ribozymes; the attachment of ribozymes to surfaces, such as formed by lipid micellar aggregates may be particular relevant if the surface itself catalyzes RNA polymerization.It is conceivable that the transition from pre-biotic molecular aggregates to cellular life required the coevolution of the RNA world, capable of synthesizing specific, instead of statistical proteins, and of the Lipid world, with a transition from micellar aggregates to semipermeable vesicles. Small molecules available in the prebiotic inventory might promote RNA stability and the evolution of hydrophobic micellar aggregates into membrane-delimited vesicles. The transition from ribozymes catalyzing the assembly of statistical polypeptides to the synthesis of proteins, required the appearance of the genetic code; the transition from hydrophobic platforms favoring the stability of ribozymes and of nascent polypeptides to the selective transport of reagents through a membrane, required the appearance of the signal transduction code.A further integration between the RNA and Lipid worlds can be advanced, taking into account the emerging roles of phospholipid aggregates not only in ensuring stability to ribozymes by compartmentalization, but also in a crucial step of evolution through natural selection mechanisms, based on signal transduction pathways that convert environmental changes into biochemical responses that could vary according to the context. Here I present evidences on the presence of traces of the evolution of a signal transduction system in extant cells, which utilize a phosphoinositide signaling system located both at nucleoplasmic level as well as at the plasma membrane, based on the very same molecules but responding to different rules. The model herewith proposed is based on the following assumptions on the biomolecules of extant organisms: i) amphiphils can be converted into structured aggregates by hydrophobic forces thus giving rise to functional platforms for the interaction of other biomolecules and to their compartmentalization; ii) fundamental biochemical pathways, including protein synthesis, can be sustained by natural ribozymes of ancient origin; iii) ribozymes and nucleotide-derived coenzymes could have existed long before protein enzymes emerged; iv) signaling molecules, both derived from phospholipids and from RNAs could have guided the evolution of complex metabolic processes before the emergence of proteins.
Collapse
Affiliation(s)
- Nadir M Maraldi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy
| |
Collapse
|
72
|
Guo G, Xu M, Chang Y, Luyten T, Seitaj B, Liu W, Zhu P, Bultynck G, Shi L, Quick M, Liu Q. Ion and pH Sensitivity of a TMBIM Ca 2+ Channel. Structure 2019; 27:1013-1021.e3. [PMID: 30930064 PMCID: PMC6560632 DOI: 10.1016/j.str.2019.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 01/25/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022]
Abstract
The anti-apoptotic transmembrane Bax inhibitor motif (TMBIM) containing protein family regulates Ca2+ homeostasis, cell death, and the progression of diseases including cancers. The recent crystal structures of the TMBIM homolog BsYetJ reveal a conserved Asp171-Asp195 dyad that is proposed in regulating a pH-dependent Ca2+ translocation. Here we show that BsYetJ mediates Ca2+ fluxes in permeabilized mammalian cells, and its interaction with Ca2+ is sensitive to protons and other cations. We report crystal structures of BsYetJ in additional states, revealing the flexibility of the dyad in a closed state and a pore-opening mechanism. Functional studies show that the dyad is responsible for both Ca2+ affinity and pH dependence. Computational simulations suggest that protonation of Asp171 weakens its interaction with Arg60, leading to an open state. Our integrated analysis provides insights into the regulation of the BsYetJ Ca2+ channel that may inform understanding of human TMBIM proteins regarding their roles in cell death and diseases.
Collapse
Affiliation(s)
- Gongrui Guo
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA; NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Min Xu
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, MA 21224, USA
| | - Yanqi Chang
- New York Consortium on Membrane Protein Structure, New York Structural Biology Center, New York, NY 10027, USA
| | - Tomas Luyten
- Laboratory Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49 3000 Leuven, Belgium
| | - Bruno Seitaj
- Laboratory Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49 3000 Leuven, Belgium
| | - Wu Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA; NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Ping Zhu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Geert Bultynck
- Laboratory Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I Bus 802, Herestraat 49 3000 Leuven, Belgium
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, MA 21224, USA.
| | - Matthias Quick
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA.
| | - Qun Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA; NSLS-II, Brookhaven National Laboratory, Upton, NY 11973, USA.
| |
Collapse
|
73
|
Moretti C, Trabalza S, Granieri L, Caballo‐Ponce E, Devescovi G, Del Pino AM, Ramos C, Venturi V, van den Burg HA, Buonaurio R, Palmerini CA. A Na + /Ca 2+ exchanger of the olive pathogen Pseudomonas savastanoi pv. savastanoi is critical for its virulence. MOLECULAR PLANT PATHOLOGY 2019; 20:716-730. [PMID: 30912619 PMCID: PMC6637891 DOI: 10.1111/mpp.12787] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In a number of compatible plant-bacterium interactions, a rise in apoplastic Ca2+ levels is observed, suggesting that Ca2+ represents an important environmental clue, as reported for bacteria infecting mammalians. We demonstrate that Ca2+ entry in Pseudomonas savastanoi pv. savastanoi (Psav) strain DAPP-PG 722 is mediated by a Na+ /Ca2+ exchanger critical for virulence. Using the fluorescent Ca2+ probe Fura 2-AM, we demonstrate that Ca2+ enters Psav cells foremost when they experience low levels of energy, a situation mimicking the apoplastic fluid. In fact, Ca2+ entry was suppressed in the presence of high concentrations of glucose, fructose, sucrose or adenosine triphosphate (ATP). Since Ca2+ entry was inhibited by nifedipine and LiCl, we conclude that the channel for Ca2+ entry is a Na+ /Ca2+ exchanger. In silico analysis of the Psav DAPP-PG 722 genome revealed the presence of a single gene coding for a Na+ /Ca2+ exchanger (cneA), which is a widely conserved and ancestral gene within the P. syringae complex based on gene phylogeny. Mutation of cneA compromised not only Ca2+ entry, but also compromised the Hypersensitive response (HR) in tobacco leaves and blocked the ability to induce knots in olive stems. The expression of both pathogenicity (hrpL, hrpA and iaaM) and virulence (ptz) genes was reduced in this Psav-cneA mutant. Complementation of the Psav-cneA mutation restored both Ca2+ entry and pathogenicity in olive plants, but failed to restore the HR in tobacco leaves. In conclusion, Ca2+ entry acts as a 'host signal' that allows and promotes Psav pathogenicity on olive plants.
Collapse
Affiliation(s)
- Chiaraluce Moretti
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Simone Trabalza
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Letizia Granieri
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Eloy Caballo‐Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea La MayoraUniversidad de Málaga‐Consejo Superior de Investigaciones Científicas (IHSM‐UMACSIC)Área de GenéticaMálagaSpain
| | - Giulia Devescovi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Alberto Marco Del Pino
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Cayo Ramos
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Vittorio Venturi
- Bacteriology Group, International Centre for Genetic Engineering and BiotechnologyTriesteItaly
| | - Harrold A. van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences (SILS)University of AmsterdamAmsterdamNetherlands
| | - Roberto Buonaurio
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| | - Carlo Alberto Palmerini
- Department of Agricultural, Food and Environmental ScienceUniversity of PerugiaBorgo XX Giugno 74, Perugia06121Italy
| |
Collapse
|
74
|
Lee YS, Park W. Enhanced calcium carbonate-biofilm complex formation by alkali-generating Lysinibacillus boronitolerans YS11 and alkaliphilic Bacillus sp. AK13. AMB Express 2019; 9:49. [PMID: 30976947 PMCID: PMC6459448 DOI: 10.1186/s13568-019-0773-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022] Open
Abstract
Microbially induced calcium carbonate (CaCO3) precipitation (MICP) is a process where microbes induce condition favorable for CaCO3 formation through metabolic activities by increasing the pH or carbonate ions when calcium is near. The molecular and ecological basis of CaCO3 precipitating (CCP) bacteria has been poorly illuminated. Here, we showed that increased pH levels by deamination of amino acids is a driving force toward MICP using alkalitolerant Lysinibacillus boronitolerans YS11 as a model species of non-ureolytic CCP bacteria. This alkaline generation also facilitates the growth of neighboring alkaliphilic Bacillus sp. AK13, which could alter characteristics of MICP by changing the size and shape of CaCO3 minerals. Furthermore, we showed CaCO3 that precipitates earlier in an experiment modifies membrane rigidity of YS11 strain via upregulation of branched chain fatty acid synthesis. This work closely examines MICP conditions by deamination and the effect of MICP on cell membrane rigidity and crystal formation for the first time.
Collapse
|
75
|
Amato P, Besaury L, Joly M, Penaud B, Deguillaume L, Delort AM. Metatranscriptomic exploration of microbial functioning in clouds. Sci Rep 2019; 9:4383. [PMID: 30867542 PMCID: PMC6416334 DOI: 10.1038/s41598-019-41032-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 02/27/2019] [Indexed: 01/19/2023] Open
Abstract
Clouds constitute the uppermost layer of the biosphere. They host diverse communities whose functioning remains obscure, although biological activity potentially participates to atmospheric chemical and physical processes. In order to gain information on the metabolic functioning of microbial communities in clouds, we conducted coordinated metagenomics/metatranscriptomics profiling of cloud water microbial communities. Samples were collected from a high altitude atmospheric station in France and examined for biological content after untargeted amplification of nucleic acids. Living microorganisms, essentially bacteria, maintained transcriptional and translational activities and expressed many known complementary physiological responses intended to fight oxidants, osmotic variations and cold. These included activities of oxidant detoxification and regulation, synthesis of osmoprotectants/cryoprotectants, modifications of membranes, iron uptake. Consistently these energy-demanding processes were fueled by central metabolic routes involved in oxidative stress response and redox homeostasis management, such as pentose phosphate and glyoxylate pathways. Elevated binding and transmembrane ion transports demonstrated important interactions between cells and their cloud droplet chemical environments. In addition, polysaccharides, potentially beneficial for survival like exopolysaccharides, biosurfactants and adhesins, were synthesized. Our results support a biological influence on cloud physical and chemical processes, acting notably on the oxidant capacity, iron speciation and availability, amino-acids distribution and carbon and nitrogen fates.
Collapse
Affiliation(s)
- Pierre Amato
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000, Clermont-Ferrand, France.
| | - Ludovic Besaury
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000, Clermont-Ferrand, France
| | - Muriel Joly
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000, Clermont-Ferrand, France
| | - Benjamin Penaud
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000, Clermont-Ferrand, France
| | | | - Anne-Marie Delort
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000, Clermont-Ferrand, France
| |
Collapse
|
76
|
Tian B, Shah M, Choi MH, Rho JK, Lee SY, Yoon SC. Calcium Involved Directional Organization of Polymer Chains in Polyester Nanogranules in Bacterial Cells. Sci Rep 2019; 9:3429. [PMID: 30837614 PMCID: PMC6401383 DOI: 10.1038/s41598-019-40097-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 02/06/2019] [Indexed: 12/04/2022] Open
Abstract
Soil bacteria accumulate polyesters (typically poly([R]-3-hydroxybutyrate (PHB), in which one end of the chain terminates with a carboxyl group) in the form of hydrated, amorphous nanogranules in cells. However, it is not clear what drives the structure of these biomaterials inside bacterial cells. Here, we determined that calcium guides intracellular formation of PHB nanogranules. Our systematic study using the surface zeta potential measurement and the carboxyl-specific SYTO-62 dye binding assay showed that the terminal carboxyl is not exposed to the granule surface but is buried inside native “unit-granules” comprising the mature granule. Extracellular Ca2+ was found to mediate the formation of these PHB unit-granules, with uptaken Ca2+ stored inside the granules. Comparative [Ca2+]-dependent fluorescence spectroscopy revealed that the native granules in Cupriavidus necator H16 act as a Ca2+ storage system, presumably for the regulation of its cytosolic Ca2+ level, but those from recombinant Escherichia coli do not. This study reveals intimate links between Ca2+ and native granule formation, and establishes a novel mechanism that intracellular PHB granules function as Ca2+ storage in order to relieve soil bacteria from Ca2+ stress.
Collapse
Affiliation(s)
- Baoxia Tian
- Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea.,Faculty of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 23003, People's Republic of China
| | - Mohsin Shah
- Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea.,Department of Physiology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, 40000, Pakistan
| | - Mun Hwan Choi
- Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Jong Kook Rho
- Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Sang Yeol Lee
- Systems & Synthetic Agrobiotech Center, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Sung Chul Yoon
- Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea. .,Systems & Synthetic Agrobiotech Center, Gyeongsang National University, Jinju, 52828, Republic of Korea.
| |
Collapse
|
77
|
Lee H, Lee DG. SOS genes contribute to Bac8c induced apoptosis-like death in Escherichia coli. Biochimie 2019; 157:195-203. [DOI: 10.1016/j.biochi.2018.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/03/2018] [Indexed: 01/12/2023]
|
78
|
Li JZ, Zhou LY, Peng YL, Fan J. Pseudomonas bacteriocin syringacin M released upon desiccation suppresses the growth of sensitive bacteria in plant necrotic lesions. Microb Biotechnol 2019; 13:134-147. [PMID: 30672132 PMCID: PMC6922522 DOI: 10.1111/1751-7915.13367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/01/2018] [Accepted: 12/13/2018] [Indexed: 12/12/2022] Open
Abstract
Bacteriocins are regarded as important factors mediating microbial interactions, but their exact role in community ecology largely remains to be elucidated. Here, we report the characterization of a mutant strain, derived from Pseudomonas syringae pv. tomato DC3000 (Pst), that was incapable of growing in plant extracts and causing disease. Results showed that deficiency in a previously unannotated gene saxE led to the sensitivity of the mutant to Ca2+ in leaf extracts. Transposon insertions in the bacteriocin gene syrM, adjacent to saxE, fully rescued the bacterial virulence and growth of the ΔsaxE mutant in plant extracts, indicating that syrM‐saxE encode a pair of bacteriocin immunity proteins in Pst. To investigate whether the syrM‐saxE system conferred any advantage to Pst in competition with other SyrM‐sensitive pathovars, we compared the growth of a SyrM‐sensitive strain co‐inoculated with Pst strains with or without the syrM gene and observed a significant syrM‐dependent growth reduction of the sensitive bacteria on plate and in lesion tissues upon desiccation–rehydration treatment. These findings reveal an important biological role of SyrM‐like bacteriocins and help to understand the complex strategies used by P. syringae in adaptation to the phyllosphere niche in the context of plant disease.
Collapse
Affiliation(s)
- Jun-Zhou Li
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Li-Ying Zhou
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - You-Liang Peng
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100193, China
| | - Jun Fan
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China.,Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| |
Collapse
|
79
|
Hansen TH, Thomassen MT, Madsen ML, Kern T, Bak EG, Kashani A, Allin KH, Hansen T, Pedersen O. The effect of drinking water pH on the human gut microbiota and glucose regulation: results of a randomized controlled cross-over intervention. Sci Rep 2018; 8:16626. [PMID: 30413727 PMCID: PMC6226457 DOI: 10.1038/s41598-018-34761-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/25/2018] [Indexed: 01/07/2023] Open
Abstract
Studies in rodent models have shown that alterations in drinking water pH affect both the composition of the gut microbiota and host glucose regulation. To explore a potential impact of electrochemically reduced alkaline (pH ≈ 9) versus neutral (pH ≈ 7) drinking water (2 L/day) on human intestinal microbiota and host glucose metabolism we conducted a randomized, non-blinded, cross-over study (two 2-week intervention periods, separated by a 3-week wash-out) in 29 healthy, non-smoking Danish men, aged 18 to 35 years, with a body mass index between 20.0 to 27.0 kg m-2. Volunteers were ineligible if they had previously had abdominal surgery, had not been weight stabile for at least two months, had received antibiotic treatment within 2 months, or had a habitual consumption of caloric or artificially sweetened beverages in excess of 1 L/week or an average intake of alcohol in excess of 7 units/week. Microbial DNA was extracted from faecal samples collected at four time points, before and after each intervention, and subjected to 16S rRNA gene amplicon sequencing (Illumina MiSeq, V4 region). Glycaemic regulation was evaluated by means of an oral glucose tolerance test.No differential effect of alkaline versus neutral drinking water was observed for the primary outcome, overall gut microbiota diversity as represented by Shannon's index. Similarly, neither a differential effect on microbiota richness or community structure was observed. Nor did we observe a differential effect on the abundance of individual operational taxonomic units (OTUs) or genera. However, analyses of within period effects revealed a significant (false discovery rate ≤5%) increase in the relative abundance of 9 OTUs assigned to order Clostridiales, family Ruminococcaceae, genus Bacteroides, and species Prevotella copri, indicating a potential effect of quantitative or qualitative changes in habitual drinking habits. An increase in the concentration of plasma glucose at 30 minutes and the incremental area under the curve of plasma glucose from 0 30 and 0 120 minutes, respectively, was observed when comparing the alkaline to the neutral intervention. However, results did not withstand correction for multiplicity. In contrast to what has been reported in rodents, a change in drinking water pH had no impact on the composition of the gut microbiota or glucose regulation in young male adults. The study is registered at www.clinicaltrials.gov (NCT02917616).
Collapse
Affiliation(s)
- Tue H Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Department of Cardiology and Endocrinology, Slagelse Hospital, Slagelse, Denmark.
| | - Mette T Thomassen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mia L Madsen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Timo Kern
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emilie G Bak
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alireza Kashani
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristine H Allin
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
80
|
Nishino K, Morita Y, Takahashi S, Okumura M, Shiratani S, Umemura K, Narumi I, Kondo C, Ochiai R, Oshima T, Nishida H. Enlargement of Deinococcus grandis spheroplasts requires Mg 2+ or Ca 2. MICROBIOLOGY-SGM 2018; 164:1361-1371. [PMID: 30222092 DOI: 10.1099/mic.0.000716] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
While the cell wall strictly controls cell size and morphology in bacteria, spheroplasts lack cell walls and can become enlarged in growth medium under optimal conditions. Optimal conditions depend on the bacterial species. We frequently observed extreme enlargement of spheroplasts of the radiation-resistant bacterium Deinococcus grandis in Difco Marine Broth 2216, but not in TGY broth (a commonly used growth medium for Deinococcus). Thorough investigation of media components showed that the presence of Mg2+ or Ca2+ promoted extreme spheroplast enlargement, synthesizing the outer membrane. Our findings strongly suggest that Mg2+ or Ca2+ enlarges spheroplasts, which could change the lipid composition of the spheroplast membrane.
Collapse
Affiliation(s)
- Koki Nishino
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Yusuke Morita
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Sawako Takahashi
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Mai Okumura
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Shusaku Shiratani
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Kosuke Umemura
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Issay Narumi
- 2Radiation Microbiology Laboratory, Department of Life Sciences, Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Gunma 374-0193, Japan
| | - Chie Kondo
- 3Pharmaceuticals and Life Sciences Division, Shimadzu Techno-Research, Inc., 1 Nishinokyoushimoaicho, Nakagyouku, Kyoto 604-8436, Japan
| | - Ryosuke Ochiai
- 3Pharmaceuticals and Life Sciences Division, Shimadzu Techno-Research, Inc., 1 Nishinokyoushimoaicho, Nakagyouku, Kyoto 604-8436, Japan
| | - Taku Oshima
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Hiromi Nishida
- 1Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| |
Collapse
|
81
|
Gulyuk AV, LaJeunesse DR, Collazo R, Ivanisevic A. Characterization of Pseudomonas aeruginosa Films on Different Inorganic Surfaces before and after UV Light Exposure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10806-10815. [PMID: 30122052 DOI: 10.1021/acs.langmuir.8b02079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The changes of the surface properties of Au, GaN, and SiO x after UV light irradiation were used to actively influence the process of formation of Pseudomonas aeruginosa films. The interfacial properties of the substrates were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. The changes in the P. aeruginosa film properties were accessed by analyzing adhesion force maps and quantifying the intracellular Ca2+ concentration. The collected analysis indicates that the alteration of the inorganic materials' surface chemistry can lead to differences in biofilm formation and variable response from P. aeruginosa cells.
Collapse
Affiliation(s)
- Alexey V Gulyuk
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Dennis R LaJeunesse
- Joint School of Nanoscience and Nanoengineering , University of North Carolina-Greensboro and North Carolina A&T State University , Greensboro , North Carolina 27401 , United States
| | - Ramon Collazo
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Albena Ivanisevic
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| |
Collapse
|
82
|
Lee H, Lee DG. Arenicin-1-induced apoptosis-like response requires RecA activation and hydrogen peroxide against Escherichia coli. Curr Genet 2018; 65:167-177. [DOI: 10.1007/s00294-018-0855-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 12/25/2022]
|
83
|
The Antibacterial Mechanism of Terpinen-4-ol Against Streptococcus agalactiae. Curr Microbiol 2018; 75:1214-1220. [DOI: 10.1007/s00284-018-1512-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
84
|
Nurfarahin AH, Mohamed MS, Phang LY. Culture Medium Development for Microbial-Derived Surfactants Production-An Overview. Molecules 2018; 23:molecules23051049. [PMID: 29723959 PMCID: PMC6099601 DOI: 10.3390/molecules23051049] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/22/2018] [Accepted: 04/24/2018] [Indexed: 12/14/2022] Open
Abstract
Surfactants are compounds that can reduce the surface tension between two different phases or the interfacial tension of the liquid between water and oil, possessing both hydrophilic and hydrophobic moieties. Biosurfactants have traits that have proven to be advantageous over synthetic surfactants, but these compounds do not compete economically with synthetic surfactants. Different alternatives increase the yield of biosurfactants; development of an economical production process and the usage of cheaper substrates during process have been employed. One of the solutions relies on the suitable formulation of a production medium by including alternative raw materials sourced from agro-wastes, hydrocarbons, or by-products of a process might help in boosting the biosurfactant production. Since the nutritional factors required will be different among microorganisms, the establishment of a suitable formulation for biosurfactant production will be challenging. The present review describes various nutrients and elements considered in the formulation of a production medium with an approach focusing on the macronutrient (carbon, nitrogen source, and C/N ratio), minerals, vitamins, metabolic regulators, and salinity levels which may aid in the study of biosurfactant production in the future.
Collapse
Affiliation(s)
- Abdul Hamid Nurfarahin
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM, Malaysia.
| | - Mohd Shamzi Mohamed
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM, Malaysia.
- Bioprocessing and Biomanufacturing Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM, Malaysia.
| | - Lai Yee Phang
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400 UPM, Malaysia.
| |
Collapse
|
85
|
Lee B, Lee DG. Depletion of reactive oxygen species induced by chlorogenic acid triggers apoptosis-like death in Escherichia coli. Free Radic Res 2018; 52:605-615. [DOI: 10.1080/10715762.2018.1456658] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Bin Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Korea
| | - Dong Gun Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, Korea
| |
Collapse
|
86
|
Li ZH, Zhu YM, Zhang J, Yang CJ, Zhang TY, Yu HQ. Evaluation of robustness of activated sludge using calcium-induced enhancement of respiration. BIORESOURCE TECHNOLOGY 2018; 253:55-63. [PMID: 29328935 DOI: 10.1016/j.biortech.2018.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/28/2017] [Accepted: 01/03/2018] [Indexed: 06/07/2023]
Abstract
Robustness of an activated sludge system, describing uncertainty and operational risk, was evaluated using the absence or presence of calcium-induced enhancement of respiration (CaER) effect. Generally, the fast-growing system was susceptible to external environmental variations, of which the sludge exhibited significant CaER effect under normal operational conditions, while the slow growing system showed less significant CaER effect. However, sludge in both systems exhibited CaER effect under stressed conditions of decreasing temperature or ammonia shocking. Therefore, the absence of CaER effect indicates a more robust system, while the presence of CaER effect indicates a susceptible system. Additionally, a method to identify safe and dangerous shocking was established by a hybrid usage of absence or presence of CaER effect and recovery index (RI) curve type. The evaluation of robustness could help determining when adjustment should be really taken to cope with the uncertainty, and thus holds a high promise for field application.
Collapse
Affiliation(s)
- Zhi-Hua Li
- Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Yuan-Mo Zhu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Jing Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Cheng-Jian Yang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Tian-Yu Zhang
- Department of Mathematical Sciences, Montana State University, Bozeman, MT 59717-2400, USA
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| |
Collapse
|
87
|
Acidocalcisome-Mitochondrion Membrane Contact Sites in Trypanosoma brucei. Pathogens 2018; 7:pathogens7020033. [PMID: 29565282 PMCID: PMC6027259 DOI: 10.3390/pathogens7020033] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 12/13/2022] Open
Abstract
Membrane contact sites are regions of close apposition between two organelles, typically less than 30 nanometers apart, that facilitate transfer of biomolecules. The presence of contact sites has been demonstrated in yeast, plants, and mammalian cells. Here, we investigated the presence of such contact sites in Trypanosoma brucei. In mammalian cells, endoplasmic reticulum-mitochondria contact sites facilitate mitochondrial uptake of Ca2+ released by the ER-located inositol 1,4,5-trisphosphate receptor (InsP3R). However, the InsP3R in trypanosomes localizes to acidocalcisomes, which serve as major Ca2+ stores in these parasites. In this work, we have used super-resolution structured illumination microscopy and electron microscopy to identify membrane contact sites that exist between acidocalcisomes and mitochondria. Furthermore, we have confirmed the close association of these organelles using proximity ligation assays. Characterization of these contact sites may be a necessary starting point towards unraveling the role of Ca2+ in regulating trypanosome bioenergetics.
Collapse
|
88
|
The Complex Interplay between Chronic Inflammation, the Microbiome, and Cancer: Understanding Disease Progression and What We Can Do to Prevent It. Cancers (Basel) 2018; 10:cancers10030083. [PMID: 29558443 PMCID: PMC5876658 DOI: 10.3390/cancers10030083] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 12/12/2022] Open
Abstract
Cancer is a multifaceted condition, in which a senescent cell begins dividing in an irregular manner due to various factors such as DNA damage, growth factors and inflammation. Inflammation is not typically discussed as carcinogenic; however, a significant percentage of cancers arise from chronic microbial infections and damage brought on by chronic inflammation. A hallmark cancer-inducing microbe is Helicobacter pylori and its causation of peptic ulcers and potentially gastric cancer. This review discusses the recent developments in understanding microbes in health and disease and their potential role in the progression of cancer. To date, microbes can be linked to almost every cancer, including colon, pancreatic, gastric, and even prostate. We discuss the known mechanisms by which these microbes can induce cancer growth and development and how inflammatory cells may contribute to cancer progression. We also discuss new treatments that target the chronic inflammatory conditions and their associated cancers, and the impact microbes have on treatment success. Finally, we examine common dietary misconceptions in relation to microbes and cancer and how to avoid getting caught up in the misinterpretation and over inflation of the results.
Collapse
|
89
|
Tal N, Rudnick-Glick S, Grinberg I, Natan M, Banin E, Margel S. Engineering of a New Bisphosphonate Monomer and Nanoparticles of Narrow Size Distribution for Antibacterial Applications. ACS OMEGA 2018; 3:1458-1469. [PMID: 30023805 PMCID: PMC6044825 DOI: 10.1021/acsomega.7b01686] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
In recent years, many bacteria have developed resistance to commonly used antibiotics. It is well-known that calcium is essential for bacterial function and cell wall stability. Bisphosphonates (BPs) have high affinity to calcium ions and are effective calcium chelators. Therefore, BPs could potentially be used as antibacterial agents. This article provides a detailed description regarding the synthesis of a unique BP vinylic monomer MA-Glu-BP (methacrylate glutamate bisphosphonate) and polyMA-Glu-BP nanoparticles (NPs) for antibacterial applications. polyMA-Glu-BP NPs were synthesized by dispersion copolymerization of the MA-Glu-BP monomer with the primary amino monomer N-(3-aminopropyl)methacrylamide hydrochloride (APMA) and the cross-linker monomer tetra ethylene glycol diacrylate, to form cross-linked NPs with a narrow size distribution. The size and size distribution of polyMA-Glu-BP NPs were controlled by changing various polymerization parameters. Near-infrared fluorescent polyMA-Glu-BP NPs were prepared by covalent binding of the dye cyanine7 N-hydroxysuccinimide to the primary amino groups belonging to the APMA monomeric units on the polyMA-Glu-BP NPs. The affinity of the near-infrared fluorescent polyMA-Glu-BP NPs toward calcium was demonstrated in vitro by a coral model. Cytotoxicity, cell uptake, and antibacterial properties of the polyMA-Glu-BP NPs against two common bacterial pathogens representing Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, and two representing Gram-positive bacteria, Listeria innocua and Staphylococcus aureus, were then demonstrated.
Collapse
Affiliation(s)
- Nimrod Tal
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Safra Rudnick-Glick
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Igor Grinberg
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Michal Natan
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Ehud Banin
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Shlomo Margel
- The Institute of Nanotechnology
and Advanced Materials, Department
of Chemistry, and The Mina and Everard Goodman Faculty of Life Sciences, The Institute
for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| |
Collapse
|
90
|
Liu K, Ding X, Tang X, Wang J, Li W, Yan Q, Liu Z. Macro and Microelements Drive Diversity and Composition of Prokaryotic and Fungal Communities in Hypersaline Sediments and Saline-Alkaline Soils. Front Microbiol 2018. [PMID: 29535703 PMCID: PMC5835090 DOI: 10.3389/fmicb.2018.00352] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Understanding the effects of environmental factors on microbial communities is critical for microbial ecology, but it remains challenging. In this study, we examined the diversity (alpha diversity) and community compositions (beta diversity) of prokaryotes and fungi in hypersaline sediments and salinized soils from northern China. Environmental variables were highly correlated, but they differed significantly between the sediments and saline soils. The compositions of prokaryotic and fungal communities in the hypersaline sediments were different from those in adjacent saline–alkaline soils, indicating a habitat-specific microbial distribution pattern. The macroelements (S, P, K, Mg, and Fe) and Ca were, respectively, correlated closely with the alpha diversity of prokaryotes and fungi, while the macronutrients (e.g., Na, S, P, and Ca) were correlated with the prokaryotic and fungal beta-diversity (P ≤ 0.05). And, the nine microelements (e.g., Al, Ba, Co, Hg, and Mn) and micronutrients (Ba, Cd, and Sr) individually shaped the alpha diversity of prokaryotes and fungi, while the six microelements (e.g., As, Ba, Cr, and Ge) and only the trace elements (Cr and Cu), respectively, influenced the beta diversity of prokaryotes and fungi (P < 0.05). Variation-partitioning analysis (VPA) showed that environmental variables jointly explained 55.49% and 32.27% of the total variation for the prokaryotic and fungal communities, respectively. Together, our findings demonstrate that the diversity and community composition of the prokaryotes and fungi were driven by different macro and microelements in saline habitats, and that geochemical elements could more widely regulate the diversity and community composition of prokaryotes than these of fungi.
Collapse
Affiliation(s)
- Kaihui Liu
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Xiaowei Ding
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Xiaofei Tang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
| | - Wenjun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Qingyun Yan
- Environmental Microbiome Research Center and School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Zhenghua Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
| |
Collapse
|
91
|
Ca 2+-Induced Two-Component System CvsSR Regulates the Type III Secretion System and the Extracytoplasmic Function Sigma Factor AlgU in Pseudomonas syringae pv. tomato DC3000. J Bacteriol 2018; 200:JB.00538-17. [PMID: 29263098 DOI: 10.1128/jb.00538-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 12/12/2017] [Indexed: 11/20/2022] Open
Abstract
Two-component systems (TCSs) of bacteria regulate many different aspects of the bacterial life cycle, including pathogenesis. Most TCSs remain uncharacterized, with no information about the signal(s) or regulatory targets and/or role in bacterial pathogenesis. Here, we characterized a TCS in the plant-pathogenic bacterium Pseudomonas syringae pv. tomato DC3000 composed of the histidine kinase CvsS and the response regulator CvsR. CvsSR is necessary for virulence of P. syringae pv. tomato DC3000, since ΔcvsS and ΔcvsR strains produced fewer symptoms than the wild type (WT) and demonstrated reduced growth on multiple hosts. We discovered that expression of cvsSR is induced by Ca2+ concentrations found in leaf apoplastic fluid. Thus, Ca2+ can be added to the list of signals that promote pathogenesis of P. syringae pv. tomato DC3000 during host colonization. Through chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) and global transcriptome analysis (RNA-seq), we discerned the CvsR regulon. CvsR directly activated expression of the type III secretion system regulators, hrpR and hrpS, that regulate P. syringae pv. tomato DC3000 virulence in a type III secretion system-dependent manner. CvsR also indirectly repressed transcription of the extracytoplasmic sigma factor algU and production of alginate. Phenotypic analysis determined that CvsSR inversely regulated biofilm formation, swarming motility, and cellulose production in a Ca2+-dependent manner. Overall, our results show that CvsSR is a key regulatory hub critical for interaction with host plants.IMPORTANCE Pathogenic bacteria must be able to react and respond to the surrounding environment, make use of available resources, and avert or counter host immune responses. Often, these abilities rely on two-component systems (TCSs) composed of interacting proteins that modulate gene expression. We identified a TCS in the plant-pathogenic bacterium Pseudomonas syringae that responds to the presence of calcium, which is an important signal during the plant defense response. We showed that when P. syringae is grown in the presence of calcium, this TCS regulates expression of factors contributing to disease. Overall, our results provide a better understanding of how bacterial pathogens respond to plant signals and control systems necessary for eliciting disease.
Collapse
|
92
|
Leitão TJ, Cury JA, Tenuta LMA. Kinetics of calcium binding to dental biofilm bacteria. PLoS One 2018; 13:e0191284. [PMID: 29385163 PMCID: PMC5791987 DOI: 10.1371/journal.pone.0191284] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/02/2018] [Indexed: 11/19/2022] Open
Abstract
Dental biofilm bacteria can bind calcium ions and release them during a pH drop, which could decrease the driving force for dental demineralization (i.e. hydroxyapatite dissolution) occurring at reduced pHs. However, the kinetics of this binding and release is not completely understood. Here we validated a method to evaluate the kinetics of calcium binding and release to/from Streptococcus mutans, and estimated the importance of this reservoir as a source of ions. The kinetics of calcium binding was assessed by measuring the amount of bound calcium in S. mutans Ingbrit 1600 pellets treated with PIPES buffer, pH 7.0, containing 1 or 10 mM Ca; for the release kinetics, bacterial pellets previously treated with 1 mM or 10 mM Ca were exposed to the calcium-free or 1 mM Ca PIPES buffer, pH 7.0, for up to 60 min. Binding and release curves were constructed and parameters of kinetics were calculated. Also, calcium release was assessed by exposing pellets previously treated with calcium to a pH 5.0 buffer for 10 min. Calcium binding to bacteria was concentration-dependent and rapid, with maximum binding reached at 5 min. On the other hand, calcium release was slower, and according to the calculations, would never be complete in the groups pretreated with 10 mM Ca. Decreasing pH from 7.0 to 5.0 caused a release of calcium able to increase the surrounding fluid calcium concentration in 2 mM. The results suggest that dental biofilm bacteria may act as a calcium reservoir, rapidly binding ions from surrounding fluids, releasing them slowly at neutral pH and promptly during a pH drop.
Collapse
Affiliation(s)
- Tarcísio Jorge Leitão
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
- Department of Dentistry II, Federal University of Maranhão, São Luis, Maranhão, Brazil
| | - Jaime Aparecido Cury
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
| | - Livia Maria Andaló Tenuta
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, United States of America
- * E-mail:
| |
Collapse
|
93
|
TIR Domain Proteins Are an Ancient Family of NAD +-Consuming Enzymes. Curr Biol 2018; 28:421-430.e4. [PMID: 29395922 DOI: 10.1016/j.cub.2017.12.024] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/02/2017] [Accepted: 12/12/2017] [Indexed: 11/22/2022]
Abstract
The Toll/interleukin-1 receptor (TIR) domain is the signature signaling domain of Toll-like receptors (TLRs) and their adaptors, serving as a scaffold for the assembly of protein complexes for innate immune signaling [1, 2]. TIR domain proteins are also expressed in plants, where they mediate disease resistance [3, 4], and in bacteria, where they have been associated with virulence [5-9]. In pursuing our work on axon degeneration [10], we made the surprising discovery that the TIR domain of SARM1 (sterile alpha and TIR motif containing 1), a TLR adaptor protein, has enzymatic activity [11]. Upon axon injury, the SARM1 TIR domain cleaves nicotinamide adenine dinucleotide (NAD+), destroying this essential metabolic co-factor to trigger axon destruction [11, 12]. Whereas current studies of TIR domains focus on their scaffolding function, our findings with SARM1 inspired us to ask whether this enzymatic activity is the primordial function of the TIR domain. Here we show that ancestral prokaryotic TIR domains constitute a new family of NADase enzymes. Using purified proteins from a cell-free translation system, we find that TIR domain proteins from both bacteria and archaea cleave NAD+ into nicotinamide and ADP-ribose (ADPR), with catalytic cleavage executed by a conserved glutamic acid. A subset of bacterial and archaeal TIR domains generates a non-canonical variant cyclic ADPR (cADPR) molecule, and the full-length TIR domain protein from pathogenic Staphylococcus aureus induces NAD+ loss in mammalian cells. These findings suggest that the primordial function of the TIR domain is the enzymatic cleavage of NAD+ and establish TIR domain proteins as a new class of metabolic regulatory enzymes.
Collapse
|
94
|
Skouri-Panet F, Benzerara K, Cosmidis J, Férard C, Caumes G, De Luca G, Heulin T, Duprat E. In Vitro and in Silico Evidence of Phosphatase Diversity in the Biomineralizing Bacterium Ramlibacter tataouinensis. Front Microbiol 2018; 8:2592. [PMID: 29375498 PMCID: PMC5768637 DOI: 10.3389/fmicb.2017.02592] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/12/2017] [Indexed: 11/13/2022] Open
Abstract
Microbial phosphatase activity can trigger the precipitation of metal-phosphate minerals, a process called phosphatogenesis with global geochemical and environmental implications. An increasing diversity of phosphatases expressed by diverse microorganisms has been evidenced in various environments. However, it is challenging to link the functional properties of genomic repertoires of phosphatases with the phosphatogenesis capabilities of microorganisms. Here, we studied the betaproteobacterium Ramlibacter tataouinensis (Rta), known to biomineralize Ca-phosphates in the environment and the laboratory. We investigated the functional repertoire of this biomineralization process at the cell, genome and molecular level. Based on a mineralization assay, Rta is shown to hydrolyse the phosphoester bonds of a wide range of organic P molecules. Accordingly, its genome has an unusually high diversity of phosphatases: five genes belonging to two non-homologous families, phoD and phoX, were detected. These genes showed diverse predicted cis-regulatory elements. Moreover, they encoded proteins with diverse structural properties according to molecular models. Heterologously expressed PhoD and PhoX in Escherichia coli had different profiles of substrate hydrolysis. As evidenced for Rta cells, recombinant E. coli cells induced the precipitation of Ca-phosphate mineral phases, identified as poorly crystalline hydroxyapatite. The phosphatase genomic repertoire of Rta (containing phosphatases of both the PhoD and PhoX families) was previously evidenced as prevalent in marine oligotrophic environments. Interestingly, the Tataouine sand from which Rta was isolated showed similar P-depleted, but Ca-rich conditions. Overall, the diversity of phosphatases in Rta allows the hydrolysis of a broad range of organic P substrates and therefore the release of orthophosphates (inorganic phosphate) under diverse trophic conditions. Since the release of orthophosphates is key to the achievement of high saturation levels with respect to hydroxyapatite and the induction of phosphatogenesis, Rta appears as a particularly efficient driver of this process as shown experimentally.
Collapse
Affiliation(s)
- Fériel Skouri-Panet
- Centre National de la Recherche Scientifique, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, UMR 7590, Muséum National d'Histoire Naturelle, Université Pierre et Marie Curie, IRD 206, Paris, France
| | - Karim Benzerara
- Centre National de la Recherche Scientifique, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, UMR 7590, Muséum National d'Histoire Naturelle, Université Pierre et Marie Curie, IRD 206, Paris, France
| | - Julie Cosmidis
- Department of Geological Sciences, University of Colorado, Boulder, CO, United States
| | - Céline Férard
- Centre National de la Recherche Scientifique, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, UMR 7590, Muséum National d'Histoire Naturelle, Université Pierre et Marie Curie, IRD 206, Paris, France
| | - Géraldine Caumes
- Centre National de la Recherche Scientifique, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, UMR 7590, Muséum National d'Histoire Naturelle, Université Pierre et Marie Curie, IRD 206, Paris, France
| | - Gilles De Luca
- Laboratoire d'Écologie Microbienne de la Rhizosphère et Environnements Extrêmes, UMR 7265, Aix Marseille Univ, Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Saint-Paul-lez-Durance, France
| | - Thierry Heulin
- Laboratoire d'Écologie Microbienne de la Rhizosphère et Environnements Extrêmes, UMR 7265, Aix Marseille Univ, Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Saint-Paul-lez-Durance, France
| | - Elodie Duprat
- Centre National de la Recherche Scientifique, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Universités, UMR 7590, Muséum National d'Histoire Naturelle, Université Pierre et Marie Curie, IRD 206, Paris, France
| |
Collapse
|
95
|
Purification of therapeutic proteins mediated by in vivo polyester immobilized sortase. Biotechnol Lett 2017; 40:369-373. [DOI: 10.1007/s10529-017-2473-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 10/30/2017] [Indexed: 10/18/2022]
|
96
|
How prokaryotes 'encode' their environment: Systemic tools for organizing the information flow. Biosystems 2017; 164:26-38. [PMID: 28987781 DOI: 10.1016/j.biosystems.2017.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 01/04/2023]
Abstract
An important issue related to code biology concerns the cell's informational relationships with the environment. As an open self-producing system, a great variety of inputs and outputs are necessary for the living cell, not only consisting of matter and energy but also involving information flows. The analysis here of the simplest cells will involve two basic aspects. On the one side, the molecular apparatuses of the prokaryotic signaling system, with all its variety of environmental signals and component pathways (which have been called 1-2-3 Component Systems), including the role of a few second messengers which have been pointed out in bacteria too. And in the other side, the gene transcription system as depending not only on signaling inputs but also on a diversity of factors. Amidst the continuum of energy, matter, and information flows, there seems to be evidence for signaling codes, mostly established around the arrangement of life-cycle stages, in large metabolic changes, or in the relationships with conspecifics (quorum sensing) and within microbial ecosystems. Additionally, and considering the complexity growth of signaling systems from prokaryotes to eukaryotes, four avenues or "roots" for the advancement of such complexity would come out. A comparative will be established in between the signaling strategies and organization of both kinds of cellular systems. Finally, a new characterization of "informational architectures" will be proposed in order to explain the coding spectrum of both prokaryotic and eukaryotic signaling systems. Among other evolutionary aspects, cellular strategies for the construction of novel functional codes via the intermixing of informational architectures could be related to the persistence of retro-elements with obvious viral ancestry.
Collapse
|
97
|
Urdaneta V, Casadesús J. Interactions between Bacteria and Bile Salts in the Gastrointestinal and Hepatobiliary Tracts. Front Med (Lausanne) 2017; 4:163. [PMID: 29043249 PMCID: PMC5632352 DOI: 10.3389/fmed.2017.00163] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/19/2017] [Indexed: 12/25/2022] Open
Abstract
Bile salts and bacteria have intricate relationships. The composition of the intestinal pool of bile salts is shaped by bacterial metabolism. In turn, bile salts play a role in intestinal homeostasis by controlling the size and the composition of the intestinal microbiota. As a consequence, alteration of the microbiome-bile salt homeostasis can play a role in hepatic and gastrointestinal pathological conditions. Intestinal bacteria use bile salts as environmental signals and in certain cases as nutrients and electron acceptors. However, bile salts are antibacterial compounds that disrupt bacterial membranes, denature proteins, chelate iron and calcium, cause oxidative damage to DNA, and control the expression of eukaryotic genes involved in host defense and immunity. Bacterial species adapted to the mammalian gut are able to endure the antibacterial activities of bile salts by multiple physiological adjustments that include remodeling of the cell envelope and activation of efflux systems and stress responses. Resistance to bile salts permits that certain bile-resistant pathogens can colonize the hepatobiliary tract, and an outstanding example is the chronic infection of the gall bladder by Salmonella enterica. A better understanding of the interactions between bacteria and bile salts may inspire novel therapeutic strategies for gastrointestinal and hepatobiliary diseases that involve microbiome alteration, as well as novel schemes against bacterial infections.
Collapse
Affiliation(s)
- Verónica Urdaneta
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Josep Casadesús
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| |
Collapse
|
98
|
Wedekind JE, Dutta D, Belashov IA, Jenkins JL. Metalloriboswitches: RNA-based inorganic ion sensors that regulate genes. J Biol Chem 2017; 292:9441-9450. [PMID: 28455443 DOI: 10.1074/jbc.r117.787713] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Divalent ions fulfill essential cellular roles and are required for virulence by certain bacteria. Free intracellular Mg2+ can approach 5 mm, but at this level Mn2+, Ni2+, or Co2+ can be growth-inhibitory, and magnesium fluoride is toxic. To maintain ion homeostasis, many bacteria have evolved ion sensors embedded in the 5'-leader sequences of mRNAs encoding ion uptake or efflux channels. Here, we review current insights into these "metalloriboswitches," emphasizing ion-specific binding by structured RNA aptamers and associated conformational changes in downstream signal sequences. This riboswitch-effector interplay produces a layer of gene regulatory feedback that has elicited interest as an antibacterial target.
Collapse
Affiliation(s)
- Joseph E Wedekind
- From the Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Debapratim Dutta
- From the Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Ivan A Belashov
- From the Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Jermaine L Jenkins
- From the Department of Biochemistry & Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| |
Collapse
|
99
|
Zhu Y, Ma N, Jin W, Wu S, Sun C. Genomic and Transcriptomic Insights into Calcium Carbonate Biomineralization by Marine Actinobacterium Brevibacterium linens BS258. Front Microbiol 2017; 8:602. [PMID: 28428780 PMCID: PMC5382220 DOI: 10.3389/fmicb.2017.00602] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 03/23/2017] [Indexed: 01/31/2023] Open
Abstract
Calcium carbonate (CaCO3) biomineralization has been investigated due to its wide range of scientific and technological implications, however, the molecular mechanisms of this important geomicrobiological process are largely unknown. Here, a urease-positive marine actinobacterium Brevibacterium linens BS258 was demonstrated to effectively form CaCO3 precipitates. Surprisingly, this bacterium could also dissolve the formed CaCO3 with the increase of the Ca2+ concentration. To disclose the mechanisms of biomineralization, the genome of B. linens BS258 was further completely sequenced. Interestingly, the expression of three carbonic anhydrases was significantly up-regulated along with the increase of Ca2+ concentration and the extent of calcite dissolution. Moreover, transcriptome analyses revealed that increasing concentration of Ca2+ induced KEGG pathways including quorum sensing (QS) in B. linens BS258. Notably, most up-regulated genes related to QS were found to encode peptide/nickel ABC transporters, which suggested that nickel uptake and its associated urease stimulation were essential to boost CaCO3 biomineralization. Within the genome of B. linens BS258, there are both cadmium and lead resistance gene clusters. Therefore, the sequestration abilities of Cd2+ and Pb2+ by B. linens BS258 were checked. Consistently, Pb2+ and Cd2+ could be effectively sequestered with the precipitation of calcite by B. linens BS258. To our knowledge, this is the first study investigating the microbial CaCO3 biomineralization from both genomic and transcriptomic insights, which paves the way to disclose the relationships among bacterial metabolisms and the biomineralization.
Collapse
Affiliation(s)
- Yuying Zhu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
- College of Earth Science, University of Chinese Academy of SciencesBeijing, China
| | - Ning Ma
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
- College of Earth Science, University of Chinese Academy of SciencesBeijing, China
| | - Weihua Jin
- College of Biotechnology and Bioengineering, Zhejiang University of TechnologyHangzhou, China
| | - Shimei Wu
- College of Life Sciences, Qingdao UniversityQingdao, China
| | - Chaomin Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of SciencesQingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
| |
Collapse
|
100
|
Biochemical characterization of the bacterial peroxidase from the human pathogen Neisseria gonorrhoeae. J Inorg Biochem 2017; 171:108-119. [PMID: 28388513 DOI: 10.1016/j.jinorgbio.2017.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/21/2017] [Accepted: 03/19/2017] [Indexed: 10/19/2022]
Abstract
Neisseria gonorrhoeae is an obligate human pathogen that expresses an array of molecular systems to detoxify reactive oxygen species as defense mechanisms during colonization and infection. One of these is the bacterial peroxidase that reduces H2O2 to water in its periplasm. The soluble form of this enzyme was heterologously expressed in E. coli in the holo-form binding two c-types hemes, a high-potential E heme and a low-potential P heme, with redox potentials of (+310mV) and (-190mV/-300mV), respectively in the presence of calcium ions, at pH7.5. Visible and EPR spectroscopic analysis together with activity assays indicate the presence of a calcium dependent reductive activation mechanism in thgonorrhoeaeNeisseria gonorrhoeae bacterial peroxidase, in which P heme is bis-His coordinated low-spin in the fully oxidized state of the enzyme, and becomes penta-coordinated high-spin upon reduction of E heme in the presence of calcium ions. The activated enzyme has a high affinity for H2O2 (KM of 4±1μM), with maximum activity being attained at pH7.0 and 37°C, with the rate-limiting step in the catalytic cycle being the electron transfer between the two hemes. In this enzyme, dimer formation is not promoted at high ionic strength, thus differing from the classical bacterial peroxidases. These results contribute to the understanding of the involvement of Neisseria gonorrhoeae bacterial peroxidase has a first line defense mechanism against exogenously produced hydrogen peroxide in the host environment.
Collapse
|