Marine Bacterium Vibrio Natriegens Research Articles

Ultrafast removal of toxic Cr(VI) by the marine bacterium Vibrio natriegens

The fastest-growing microbe Vibrio natriegens is an excellent platform for bioproduction processes. Until now, this marine bacterium has not been examined for bioremediation applications, where the production of substantial amounts of biomass would be beneficial. V. natriegens can perform extracellular electron transfer (EET) to Fe(III) via a single porin-cytochrome circuit conserved in Vibrionaceae. Electroactive microbes capable of EET to Fe(III) usually also reduce toxic metals such as carcinogenic Cr(VI), which is converted to Cr(III), thus decreasing its toxicity and mobility. Here, the performance of V. natriegens was explored for the bioremediation of Cr(VI). At a density of 100 mg/mL, V. natriegens removed 5–20 mg/L Cr(VI) within 30 s and 100 mg/L Cr(VI) within 10 min. In comparison, the model bacterium Escherichia coli grown to a comparable cell density removed Cr(VI) 36 times slower. To eliminate Cr(VI), V. natriegens had to be metabolically active, and functional outer-membrane c-type cytochromes were required. At the end of the Cr(VI) removal process, V. natriegens had reduced all of it into Cr(III) while adsorbing more than half of the metallic ions. These results demonstrate that V. natriegens, with its fast metabolism, is a viable option for the rapid treatment of aqueous pollution with Cr.

Biosensor-based isolation of amino acid-producing Vibrio natriegens strains

The marine bacterium Vibrio natriegens has recently been demonstrated to be a promising new host for molecular biology and next generation bioprocesses. V. natriegens is a Gram-negative, non-pathogenic slight-halophilic bacterium, with a high nutrient versatility and a reported doubling time of under 10 min. However, V. natriegens is not an established model organism yet, and further research is required to promote its transformation into a microbial workhorse.In this work, the potential of V. natriegens as an amino acid producer was investigated. First, the transcription factor-based biosensor LysG, from Corynebacterium glutamicum, was adapted for expression in V. natriegens to facilitate the detection of positively charged amino acids. A set of different biosensor variants were constructed and characterized, using the expression of a fluorescent protein as sensor output. After random mutagenesis, one of the LysG-based sensors was used to screen for amino acid producer strains. Here, fluorescence-activated cell sorting enabled the selective sorting of highly fluorescent cells, i.e. potential producer cells. Using this approach, individual L-lysine, L-arginine and L-histidine producers could be obtained producing up to 1 mM of the effector amino acid, extracellularly. Genome sequencing of the producer strains provided insight into the amino acid production metabolism of V. natriegens.This work demonstrates the successful expression and application of transcription factor-based biosensors in V. natriegens and provides insight into the underlying physiology, forming a solid basis for further development of this promising microbe.

Vibrio natriegens: an ultrafast-growing marine bacterium as emerging synthetic biology chassis.

The marine bacterium Vibrio natriegens is the fastest-growing non-pathogenic bacterium known to date and is gaining more and more attention as an alternative chassis organism to Escherichia coli. A recent wave of synthetic biology efforts has focused on the establishment of molecular biology tools in this fascinating organism, now enabling exciting applications - from speeding up our everyday laboratory routines to increasing the pace of biotechnological production cycles. In this review, we seek to give a broad overview on the literature on V. natriegens, spanning all the way from its initial isolation to its latest applications. We discuss its natural ecological niche and interactions with other organisms, unveil some of its extraordinary traits, review its genomic organization and give insight into its diverse metabolism - key physiological insights required to further develop this organism into a synthetic biology chassis. By providing a comprehensive overview on the established genetic tools, methods and applications we highlight the current possibilities of this organism, but also identify some of the gaps that could drive future lines of research, hopefully stimulating the growth of the V. natriegens research community.

Melanin Produced by the Fast-Growing Marine Bacterium Vibrio natriegens through Heterologous Biosynthesis: Characterization and Application.

Melanin is a pigment produced by organisms throughout all domains of life. Due to its unique physicochemical properties, biocompatibility, and biostability, there has been an increasing interest in the use of melanin for broad applications. In the vast majority of studies, melanin has been either chemically synthesized or isolated from animals, which has restricted its use to small-scale applications. Using bacteria as biocatalysts is a promising and economical alternative for the large-scale production of biomaterials. In this study, we engineered the marine bacterium Vibrio natriegens, one of the fastest-growing organisms, to synthesize melanin by expressing a heterologous tyrosinase gene and demonstrated that melanin production was much faster than in previously reported heterologous systems. The melanin of V. natriegens was characterized as a polymer derived from dihydroxyindole-2-carboxylic acid (DHICA) and, similarly to synthetic melanin, exhibited several characteristic and useful features. Electron microscopy analysis demonstrated that melanin produced from V. natriegens formed nanoparticles that were assembled as "melanin ghost" structures, and the photoprotective properties of these particles were validated by their protection of cells from UV irradiation. Using a novel electrochemical reverse engineering method, we observed that melanization conferred redox activity to V. natriegens Moreover, melanized bacteria were able to quickly adsorb the organic compound trinitrotoluene (TNT). Overall, the genetic tractability, rapid division time, and ease of culture provide a set of attractive properties that compare favorably to current E. coli production strains and warrant the further development of this chassis as a microbial factory for natural product biosynthesis.IMPORTANCE Melanins are macromolecules that are ubiquitous in nature and impart a large variety of biological functions, including structure, coloration, radiation resistance, free radical scavenging, and thermoregulation. Currently, in the majority of investigations, melanins are either chemically synthesized or extracted from animals, which presents significant challenges for large-scale production. Bacteria have been used as biocatalysts to synthesize a variety of biomaterials due to their fast growth and amenability to genetic engineering using synthetic biology tools. In this study, we engineered the extremely fast-growing bacterium V. natriegens to synthesize melanin nanoparticles by expressing a heterologous tyrosinase gene with inducible promoters. Characterization of the melanin produced from V. natriegens-produced tyrosinase revealed that it exhibited physical and chemical properties similar to those of natural and chemically synthesized melanins, including nanoparticle structure, protection against UV damage, and adsorption of toxic compounds. We anticipate that producing and controlling melanin structures at the nanoscale in this bacterial system with synthetic biology tools will enable the design and rapid production of novel biomaterials for multiple applications.

Synthetic Biology Tools for the Fast-Growing Marine Bacterium Vibrio natriegens.

The fast-growing nonmodel marine bacterium Vibrio natriegens has recently garnered attention as a host for molecular biology and biotechnology applications. In order to further its capabilities as a synthetic biology chassis, we have characterized a wide range of genetic parts and tools for use in V. natriegens. These parts include many commonly used resistance markers, promoters, ribosomal binding sites, reporters, terminators, degradation tags, origin of replication sequences, and plasmid backbones. We have characterized the behavior of these parts in different combinations and have compared their functionality in V. natriegens and Escherichia coli. Plasmid stability over time, plasmid copy numbers, and production load on the cells were also evaluated. Additionally, we tested constructs for chemical and optogenetic induction and characterized basic engineered circuit behavior in V. natriegens. The results indicate that, while most parts and constructs work similarly in the two organisms, some deviate significantly. Overall, these results will serve as a primer for anyone interested in engineering V. natriegens and will aid in developing more robust synthetic biology principles and approaches for this nonmodel chassis.

Cell-free Protein Expression Using the Rapidly Growing Bacterium Vibrio natriegens.

The marine bacterium Vibrio natriegens has garnered considerable attention as an emerging microbial host for biotechnology due to its fast growth rate. A general protocol is described for the preparation of V. natriegens crude cell extracts using common laboratory equipment. This high yielding protocol has been specifically optimized for user accessibility and reduced cost. Cell-free protein synthesis (CFPS) can be carried out in small scale 10 μL batch reactions in either a 96- or 384-well format and reproducibly yields concentrations of > 260 μg/mL super folder GFP (sfGFP) within 3 h. Overall, crude cell extract preparation and CFPS can be achieved in 1-2 full days by a single user. This protocol can be easily integrated into existing protein synthesis pipelines to facilitate advances in bio-production and synthetic biology applications.

Construction of a bioreporter by heterogeneously expressing a Vibrio natriegens recA::luxCDABE fusion in Escherichia coli, and genotoxicity assessments of petrochemical-contaminated groundwater in northern China.

Here, we constructed an Escherichia coli recA::luxCDABE bioreporter for genotoxicity assessments. The recA promoter was cloned from the marine bacterium Vibrio natriegens. This bioreporter showed a dose-response relationship following induction by mitomycin C, and other pollutants or environmental samples could be calculated as mitomycin C equivalents, which provided a way to quantitatively compare the genotoxicities of different environmental samples. This bioreporter was used to evaluate the genotoxicity under a wide range of external environmental conditions, like temperatures ranging from 15 °C to 42 °C, pH between 4.0 and 9.0, and salinity ranging from 0% to 3%. This successfully extended its application from the laboratory to the field, and allowed the bioreporter to assess the genotoxicity and bioavailability of genotoxins in various environmental media, including surface water, groundwater, seawater, and soil matrix. Expression of V. natriegens recA in E. coli indicated a LexA-like regulator in V. natriegens, and the putative SOS box of V. natriegens recA was similar to that of E. coli. The genotoxicities of groundwater samples from a petrochemical-contaminated site in northern China were evaluated by this bioreporter assay, and the genotoxic levels were in accordance with contamination levels obtained by chemical analyses.

Microscopical Observation of the Marine Bacterium Vibrio Natriegeus Growth on Metallic Corrosion

Biofilm formation and the adsorption of nonsulfate-reducing marine bacterium Vibrio natriegens (V. natriegens) to different metallic surfaces have been studied by atomic force microscopy (AFM). The nature of extracellular polymeric substance (EPS) has been monitored through the force-distance curve. EPS may act as adhesive binding adjacent cells and thus further enhance the aggregation of microbes during cluster formation due to its adhesiveness in nature. The AFM images supplied the change of the morphology of microbial cells and colonies, the distribution of microbial colonies, and the presence of EPS on the surfaces with immersion. Results showed that the biofilms formed on the surfaces increased in thickness and heterogeneity with time and that 3–7 days was the proliferation period of the bacteria on metallic surfaces. The corrosion type of the metals by V. natriegens could be confirmed as typical pitting attack through scanning electron microscopy (SEM) observation.

Investigations on reducing microbiologically-influenced corrosion of aluminum by using super-hydrophobic surfaces

Electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy were carried out to determine the effect of super-hydrophobic surfaces on the marine bacterium Vibrio natriegens ( V . natriegens ) adhesion. Four different samples were prepared in order to investigate the anti-biocorrosion mechanism of super-hydrophobic surfaces. Potentiodynamic polarization suggested that the V . natriegens attached on the surface mainly enhanced the reaction kinetics of the anodic reaction and accelerated the dissolution of aluminum. EIS results were interpreted with different equivalent circuits to model the physicoelectric characteristics of the electrode/biofilm/solution interface. The results showed that neither anodization nor chemical modification could decrease the bacterial adhesion and corrosion rate individually. V . natriegens showed only weak attachment to the super-hydrophobic surface, and the biocorrosion mechanism was closely associated with surface energy and surface topography.

Microbially Influenced Corrosion of Copper by Marine Bacterium <i>Vibrio natriegens</i>

The microbially influenced corrosion of copper by marine bacterium Vibrio natriegens (V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). AFM images corroborated the results from the EIS models which show biofilm attachment over time. The electrochemical results showed that the corrosion of copper was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance (Rct) obtained from EIS.

Microbially influenced corrosion of stainless steel by marine bacterium Vibrio natriegens: (I) Corrosion behavior

The microbially influenced corrosion of stainless steel (SS) by marine bacterium Vibrio natriegens ( V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA)) and electrochemical techniques (the open circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves ). AFM images corroborated the results from the EIS models which show biofilm attachment and subsequent detachment over time. The SEM images revealed the occurrence of micro-pitting corrosion underneath the biofilms on the metal surface after the biofilm removal. The presence of carbon, oxygen, phosphor and sulfur obtained from EDXA proved the formation of biofilm. The electrochemical results showed that the corrosion of SS was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance ( R ct) obtained from EIS and the increase in corrosion current densities obtained from potentiodynamic polarization curves.

Microbially influenced corrosion of 303 stainless steel by marine bacterium Vibrio natriegens: (II) Corrosion mechanism

Electrochemical techniques (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves) and surface analysis (scanning electron microscopy (SEM)) were carried out to determine the possible mechanism of the microbially influenced corrosion of 303 stainless steel (303 SS) by marine bacterium Vibrio natriegens ( V. natriegens). In order to clarify the mechanism, 303 SS coupons were immersed in four different mediums. EIS results were interpreted with different equivalent circuits to model the physicoelectric characteristics of the electrode/biofilm/solution interface. The results showed that N 2-fixation actually promoted the corrosion of 303 SS; however, the influence of the produced NH 3 was negligible. It can be speculated that the electron transfer and/or the nitrogenase catalyzing the process may influence the corrosion.

The Influence of the Marine Bacterium <i>Vibrio Natriegens</i> Growth on Metallic Corrosion as Studied by Microscope Technologies

Biofilm formation and the adsorption of nonsulfate-reducing marine bacterium Vibrio natriegens (V. natriegen) to different metallic surfaces have been studied by atomic force microscopy (AFM). The nature of extracellular polymeric substance (EPS) has been monitored through the force-distance curve. EPS may act as adhesive binding adjacent cells and thus further enhance the aggregation of microbes during cluster formation due to its adhesiveness in nature. The AFM images supply the change of the morphology of microbial cells and colonies, the distribution of microbial colonies and the presence of EPS on the surfaces with immersion. Results show that the biofilms formed on the surfaces increase in thickness and heterogeneity with time and that 3~7 days is the proliferation period of the bacteria on metallic surfaces. The corrosion type of the metals by V. natriegens could be confirmed as typical pitting attack through scanning electron microscopy (SEM) observation.

RecA Expression in Response to Solar UVR in the Marine Bacterium Vibrio natriegens.

Solar ultraviolet radiation may produce daily stress on marine and estuarine communities as cells are damaged and repair that damage. Reduction in the earth's stratospheric ozone layer has increased awareness of the potential effects that ultraviolet radiation may have in the environment, including how marine bacteria respond to changes in solar radiation. We examined the use of the bacterial RecA protein as an indicator of the potential of bacteria to repair DNA damage caused by solar UV irradiation using the marine bacterium Vibrio natriegens as a model. RecA is universally present in bacteria and is a regulator protein for the so-called Dark Repair Systems, which include excision repair, postreplication recombinational repair, and mutagenic or SOS repair. Solar UVB and UVA both reduced V. natriegens viability in seawater microcosms. After exposure to unfiltered solar radiation or radiation in which UVB was blocked, survival dropped below 1%, whereas visible light from which UVA and UVB had been filtered had no effect on survival. Using a RecA-specific antibody for detection, RecA protein was induced by solar radiation in a diel pattern in marine microcosms conducted in the Gulf of Mexico. Peak induction was observed at dusk each day. Although RecA expression was correlated with the formation of UVB-induced cyclobutyl pyrimidine dimers, longer wavelength UVA radiation also induced recA gene expression. Our results demonstrate that RecA-regulated, light-independent repair is an important component in the ability of marine bacteria to survive exposure to solar ultraviolet radiation and that RecA expression is a useful monitor of bacterial repair after exposure to solar UVR.

Stable isotope dynamics of nitrogen recycled during interactions among marine bacteria and protists

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 132:229-239 (1996) - doi:10.3354/meps132229 Stable isotope dynamics of nitrogen recycled during interactions among marine bacteria and protists Hoch MP, Snyder RA, Cifuentes LA, Coffin RB Variation in the distribution of stable nitrogen isotopes among different size classes of particulate organic nitrogen (PON) in aquatic environments may be partly explained by isotope effects associated with regeneration of NH4+ by the microbial food web. Protists fed the marine bacterium Vibrio natriegens were grown in batch and continuous culture to define the isotope discrimination between NH4+, microbial biomass, and dissolved organic nitrogen (DON) for culture systems closed or open to exogenous nutrient inputs. In batch cultures of a flagellate Pseudobodo sp. and a scuticociliate Uronema sp., the nitrogen isotope discrimination between biomass and NH4+ was 3 to 5 o/oo during exponential growth of protists corresponding to the highest rates of biomass-specific NH4+ release. The delta15N of DON, calculated by mass balance, was very depleted in 15N relative to NH4+ and biomass during exponential and early stationary growth when DON and dissolved free amino acid (DFAA) concentrations increased. In contrast to batch culture results, for continuous culture of the flagellate the isotope discrimination between biomass and NH4+ and the change in the calculated delta15N of DON were small: 1 to 2 o/oo. Based on rates of thymidine incorporation and turnover of DFAA, protist excretion and bacterial uptake of DON were less coupled for exponentially growing protists fed starved bacteria in batch cultures than for the flagellate fed active bacteria growing in a 2-stage continuous culture. Coupling between release and utilization of DON, as well as isotope effects associated with protist metabolism, are proposed to constrain the nitrogen isotope dynamics of NH4+ suspended PON, and DON within marine ecosystems, especially those environments dominated by regenerated primary production. Stable nitrogen isotopes . Protist grazing . Marine bacteria . Ammonium regeneration . Dissolved organic nitrogen Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 132. Publication date: February 29, 1996 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1996 Inter-Research.

CO2 production, O2 consumption and isocitrate dehydrogenase in the marine bacterium Vibrio natriegens

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 09:211-217 (1995) - DOI: https://doi.org/10.3354/ame009211 CO2 production, O2 consumption and isocitrate dehydrogenase in the marine bacterium Vibrio natriegens Berdalet E, Packard T, Lagacé B, Roy S, St-Amand L, Gagné JP The respiratory metabolism of the marine bacterium Vibrio natriegens growing in batch cultures with acetate and pyruvate as carbon sources was studied. In particular, the relationship of the activity of the enzyme isocitrate dehydrogenase (IDH) to physiological CO2 production and O2 consumption was examined. Gas measurements were performed by a new type of respirometer that combined O2 detection by a Pb-O fuel cell and CO2 detection by infrared absorption. Two different respiratory patterns were observed. On pyruvate, CO2 production and O2 consumption rates paralleled each other during the exponential and the stationary phases. On acetate, they did not. Growth based on acetate was characterized by a higher O2 consumption, lower CO2 production, lower respiratory quotient and lower IDH activity than on pyruvate. In both culture media, the in vitro IDH activity remained elevated after the in vivo CO2 production had decreased when the carbon source was exhausted. The range of the respiratory quotient obtained in the acetate cultures suggests that the acetate is partitioned between the Krebs cycle and the glyoxylate bypass in the proportions of 1:4 to 1:2. In the pyruvate cultures, the range of the respiratory quotients indicates that, in the course of the different growth phases, the partitioning of the carbon source between the Krebs cycle and the anaplerotic pathways is variable. CO2 production rates . O2 consumption rates . Isocitrate dehydrogenase activity . Vibrio natriegens . Micro-Oxymax Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 09, No. 3. Publication date: December 21, 1995 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 1995 Inter-Research.

Reversible Acceleration of the Corrosion of AISI 304 Stainless Steel Exposed to Seawater Induced by Growth and Secretions of the Marine BacteriumVibrio Natriegens

Abstract Growth of the nonsulfate-reducing marine bacterium Vibrio natriegens increased the corrosion current density (CD) of AISI 304 stainless steel (SS) coupons when grown in a marine medium. The corrosion rate, estimated as the corrosion CD (Icorr), calculated from the Tafel constants and polarization resistance, increased from 230 to 2900 nA/cm2 during a 6-day incubation period with V. natriegens. Just before the rapid increase in the corrosion CD, bacterial cells were seen by epifluorescent microscopy after acridine orange staining to colonize the SS surface. On the third day of exposure to seawater, the rapid increase in the corrosion CD correlated with the appearance of extracellular material from the colonizing bacteria, as observed by (1) epifluorescent microscopy, (2) scanning electron microscopy (SEM), and (3) nondestructive analysis of lyophilized biofilms by Fourier transform-infrared spectroscopy (FT-IR) using diffuse reflectance. The extracellular products from the colonizing bacteria corr...