Vibrio Marinus Research Articles

Investigating reconstructed inflows and pathogen infection patterns between low-relief and high-relief subtropical oyster reefs

AbstractFlood and drought events cause significant freshwater inflow fluctuations in estuaries, potentially leading to physiological stress and altered abundances of pathogens such as Vibrio vulnificus and Perkinsus marinus in oysters. To assess the effects of freshwater pulses to oyster reefs in subtropical estuaries in Texas, this study accomplished two goals: 1) reconstructed a reef-specific history of freshwater pulses through shell stable isotope analysis, 2) quantified the abundance of V. vulnificus and P. marinus through culture-dependent and culture-independent microbiology analyses. Oysters from a low-relief and high-relief reef experienced similar fluctuations in shell isotopes, indicating similar ranges of past environmental conditions. V. vulnificus and P. marinus were detected throughout the study but the abundance of these microorganisms was not correlated with environmental parameters or one another. Importantly, the P. marinus infection intensity was always lower at the high-relief reef, which suggests that high-relief reefs may experience lower infection frequencies.

Cold Adaptation of Triosephosphate Isomerase.

The main problem for enzymes from psychrophilic species, which need to work near the freezing point of liquid water, is the exponential decay of reaction rates as the temperature is decreased. Cold-adapted enzymes have solved this problem by shifting the activation enthalpy-entropy balance for the catalyzed reaction compared to those of their mesophilic orthologs. To understand the structural basis of this universal feature, it is necessary to examine pairs of such orthologous enzymes, with known three-dimensional structures, at the microscopic level. Here, we use molecular dynamics free energy calculations in combination with the empirical valence bond method to evaluate the temperature dependence of the activation free energy for differently adapted triosephosphate isomerases. The results show that the enzyme from the psychrophilic bacterium Vibrio marinus indeed displays the characteristic shift in enthalpy-entropy balance, compared to that of the yeast ortholog. The origin of this effect is found to be located in a few surface-exposed protein loops that show differential mobilities in the two enzymes. Key mutations render these loops more mobile in the cold-adapted triosephosphate isomerase, which explains both the reduced activation enthalpy contribution from the protein surface and the lower thermostability.

The relationship between Aeromonas sp. NCIMB 2263, a causative agent of skin lesions in Atlantic salmon, Vibrio marinus (Moritella marina) and Vibrio viscosus

The relationship between Aeromonas sp. NCIMB 2263, a causative agent of skin lesions in Atlantic salmon, Vibrio marinus (Moritella marina) and Vibrio viscosus

Phenotypic and genotypic characterization of Vibrio viscosus sp. nov. and Vibrio wodanis sp. nov. isolated from Atlantic salmon (Salmo salar) with 'winter ulcer'.

Two groups of Vibrio strains isolated from Atlantic salmon with 'winter ulcer' were characterized phenotypically and genotypically. The data obtained indicated that each of the two groups represented a new species in the genus Vibrio. The names Vibrio viscosus sp. nov. [type strain NVI 88/478T (= NCIMB 13584T)] and Vibrio wodanis sp. nov. [type strain NVI 88/441T (= NCIMB 13582T)] are proposed for the new species. V. viscosus strains exhibited a similar total DNA RFLP pattern and a similar plasmid DNA profile. DNA relatedness (hydroxyapatite method) of the V. viscosus type strain to nine other V. viscosus strains was 81-93% at 60 degrees C. Divergence within related sequences was 0.0-1.5% and relatedness at 75 degrees C was 74-100%. V. wodanis strains exhibited marked heterogeneity on the basis of RFLP analysis and plasmid profiles. DNA relatedness of the V. wodanis type strain to 10 other V. wodanis strains was 66-94% at 60 degrees C. Divergence within related sequences was 0.0-1.5% and relatedness at 75 degrees C was 55-97%. Relatedness between V. viscosus and V. wodanis type strains was approximately 20%. Among other Vibrio species, the closest relative of V. viscosus was Vibrio marinus (ATCC 15381T) (43% relatedness at 60 degrees C) and that of V. wodanis was Vibrio logei (ATCC 15382) (57% relatedness at 60 degrees C). These same pairs were the closest phenotypic relatives. DNA sequence analysis of the 16S rRNA gene of V. viscosus indicated an intimate relationship to V. marinus. A total evaluation of the results, however, supports V. viscosus to be a separate species in the genus Vibrio. The analysis of the sequence of the 16S rRNA gene of V. wodanis supports that V. logei (ATCC 15382) was the most related species. Ability to degrade casein, oxidative production of acid from trehalose and production of lysine decarboxylase are important biochemical tests that will differentiate between V. viscosus, V. wodanis, V. marinus (ATCC 15381T) and V. logei (ATCC 15382).

Restriction fragment length polymorphism analysis of psychrophilic and psychrotrophic Vibrio and Photobacterium from the north-western Pacific Ocean and Otsuchi Bay, Japan

Typing and identification of 60 marine psychrophilic and psychrotrophic vibrios isolated from the north-western Pacific Ocean and coastal environment of Japan were performed by restriction fragment length polymorphism analysis on the basis of polymerase chain reaction amplified 16S rDNA. We obtained 15 operational taxonomic units (OTUs) by digestion with four restriction endonucleases (HhaI, DdeI, RsaI, and Sau3AI); four large groups were obtained from the neighbor-joining method. Significant differences were observed in OTU composition between isolates from the deep sea and coastal areas. Vibrio marinus and Photobacterium species were the dominant culturable vibrios in the deep sea areas, while Vibrio splendidus like species were the dominant culturable vibrios in a coastal area of Japan.Key words: restriction analysis, Vibrio, Photobacterium, Vibrio marinus (Moritella marina), Vibrio splendidus.

Cloning and sequencing of clustered genes involved in fatty acid biosynthesis from the docosahexaenoic acid-producing bacterium, Vibrio marinus strain MP-1

A cluster of genes involved in fatty acid biosynthesis (fab) was isolated from docosahexaenoic acid (DHA)-producing Vibrio marinus strain MP-1. This fab gene cluster included five genes highly homologous to the Escherichia coli counterparts, and their order in the cluster was the same with that of the E. coli fab gene cluster except that the latter included the additional fabH gene. These fab genes should be involved in early steps of DHA biosynthesis in V. marinus strain MP-1.

Isolation of clustered genes that are notably homologous to the eicosapentaenoic acid biosynthesis gene cluster from the docosahexaenoic acid-producing bacterium Vibrio marinus strain MP-1

A 40-kbp DNA fragment was isolated from the cosmid library of Vibrio marinus strain MP-1. Among the 22 putative open reading frames (ORFs) in this fragment, ORFs 8, 9, 10 and 11 had high homology with ORFs 5, 6, 7 and 8 of the eicosapentaenoic acid biosynthesis gene cluster, respectively. Then, we speculate that these ORFs are responsible for docosahexaenoic acid biosynthesis in this bacterium.

A proposal to transfer Vibrio marinus (Russell 1891) to a new genus Moritella gen. nov. as Moritella marina comb. nov.

The taxonomic positions of Vibrio marinus and 11 related natural isolates were examined. Their phylogenetic positions on the basis of almost complete 16S rRNA sequences were determined by maximum likelihood, maximum parsimony and neighbor-joining analyses. V. marinus and the 11 isolates fell into a single cluster that was clearly distinct from other genera. There is now strong evidence that V. marinus should be reclassified as Moritella marina gen. nov., comb. nov.

A proposal to transfer Vibrio marinus (Russell 1891) to a new genus Moritella gen. nov. as Moritella marina comb. nov.

The taxonomic positions of Vibrio marinus and 11 related natural isolates were examined. Their phylogenetic positions on the basis of almost complete 16S rRNA sequences were determined by maximum likelihood, maximum parsimony and neighbor-joining analyses. V. marinus and the 11 isolates fell into a single cluster that was clearly distinct from other genera. There is now strong evidence that V. marinus should be reclassified as Moritella marina gen. nov., comb. nov.

Triose-phosphate Isomerase (TIM) of the Psychrophilic BacteriumVibrio marinus: KINETIC AND STRUCTURAL PROPERTIES

The purification and characterization of triose-phosphate isomerase from the psychrophilic bacterium Vibrio marinus (vTIM) is described. Crystal structures of the vTIM-sulfate complex and the vTIM-2-phosphoglycolate complex (at a 2.7-A resolution) are also presented. The optimal growth temperature of Vibrio marinus is 15 degrees C. Stability studies show that vTIM is an unstable protein with a half-life of only 10 min at 25 degrees C. The vTIM sequence is most closely related to the sequence of Escherichia coli TIM (eTIM) (66% identity), and several unique structural features described for eTIM are also seen in vTIM, but eTIM is considerably more stable. The Td values of vTIM and eTIM, determined by calorimetric studies, are 41 and 54 degrees C, respectively. Amino acid sequence comparison reveals that vTIM has an alanine in loop 8 (at position 238), whereas all other TIM sequences known to date have a serine. The vTIM mutant A238S was produced and characterized. Compared with wild type, the catalytic efficiency of the A238S mutant is somewhat reduced, and its stability is considerably increased.

Polyamine distribution patterns within the families Aeromonadaceae, Vibrionaceae, Pasteurellaceae, and Halomonadaceae, and related genera of the gamma subclass of the Proteobacteria.

Polyamines of the four families and the five related genera within the gamma subclass of the class Proteobacteria were analyzed by HPLC with the objective of developing a chemotaxonomic system. The production of putrescine, diaminopropane, cadaverine, and agmatine are not exactly correlated to the phylogenetic genospecies within 36 strains of the genus Aeromonas (the family Aeromonadaceae) lacking in triamines. The occurrence of norspermidine was limited but not ubiquitous within the family Vibrionaceae, including 20 strains of Vibrio, Listonella, Photobacterium, and Salinivibrio. Spermidine was not substituted for the absence of norspermidine in the family. Agmatine was detected only in Photobacterium. Salinivibrio and some strains of Vibrio were devoid of polyamines. Vibrio ("Moritella") marinus contained cadaverine. Within the family Pasteurellaceae, Haemophilus contained cadaverine only and Actinobacillus contained no polyamine. Halomonas, Chromohalobacter, and Zymobacter, belonging to the family Halomonadaceae, ubiquitously contained spermidine and sporadically cadaverine and agmatine. Shewanella contained putrescine and cadaverine; Alteromonas macleodii, putrescine, 2-hydroxyputrescine, cadaverine, 2-hydroxyspermidine, and spermidine; Pseudoalteromonas, putrescine, cadaverine, and spermidine; Marinobacter, spermidine; and Marinomonas, putrescine and spermidine. Their polyamine profiles serve as a chemotaxonomic marker within the gamma subclass.

Ferrimonas balearica gen. nov., spec. nov., a New Marine Facultative Fe(III)-reducing Bacterium

Summary The isolation of a new Fe(III)-reducing organism from a Mediterranean marine sediment at the coast of Mallorca (Spain) is described. Comparative 16S rRNA data analysis showed that the new isolate is a member of the gamma subclass of Proteobacteria and indicated a potential moderate phylogenetic affiliation to Shewanella species, Vibrio marinus and Alteromonas haloplanktis . Fe(III)-reduction was first described for members of the latter group. The low level of relatedness of the isolate to its closest relatives justifies the proposal of a new genus and species, namely Ferrimonas balearica gen. nov. spec. nov. .

Physiological Activity of Docosahexaenoic Acid and Its Production by Microbial Culture

Docosahexaenoic acid (DHA) has recently attracted nutritional attentions through its specific function in brain/retina as well as beneficial effects of (n-3) polyunsaturated fatty acids. Firstly, the physiological activity of DHA is reviewed from recent publications, and compared to the activity of icosapentaenoic acid (IPA), with respect to its incorporation into plasma/tissues, its anticoagulant/anti-inflammatory effect, its effect on brain/retina, its anticancer effect, and adverse effects of excess intake, if any.Secondly, reports on microbial lipid (single cell oil, SCO) production including DHA are reviewed, which include Crythecodinium cohnii, Thraustochytrium aureum, Vibrio marinus etc. Two trials for DHA-SCO using C. cohnii has revealed high cell/DHA productivities in a semicontinuous culture (50 g/L of cell mass) and a continuous culture (120 mg/L·h of DHA). A new strain, SR 21, isolated from the coral sea water in Yap Islands and identified as Thraustochytrium sp., showed tolerance to high concentration of glucose and to mechanical mixing and resulted in the highest DHA productivity at 4000 mg/L in a fermenter culture for 7 day.

Phylogenetic Relationships of Marine Bacteria, Mainly Members of the Family Vibrionaceae, Determined on the Basis of 16S rRNA Sequences

The phylogenetic relationships of 50 reference strains, mostly marine bacteria which require Na+ for growth, were determined on the basis of 600 16S rRNA nucleotides by using reverse transcriptase sequencing. Strains belonging to 10 genera were included (four genera of the family Vibrionaceae, the genus Aeromonas of the family Aeromonadaceae, and the genera Alteromonas, Marinomonas, Shewanella, Pseudomonas, and Deleya). The sequences were aligned, the similarity values and evolutionary distance values were determined, and a phylogenetic tree was constructed by using the neighbor-joining method. On the basis of our results, the family Vibrionaceae was separated into at least seven groups (genera and families). Vibrio marinus clearly was on a line of descent that was remote from other vibrios. As determined by the similarity and evolutionary distance values, V. marinus is more distantly related to the family Vibrionaceae than the members of the Aeromonadaceae are. Also, Vibrio cholerae strains formed a separate group with Vibrio mimicus at the genus level. Of 30 species of the Vibrionaceae, 17 formed a large phylogenetic cluster. The genus Listonella was found to be a heterogeneous group, and the species were distributed in various subgroups of the Vibrionaceae. The separation of the family Aeromonadaceae from the family Vibrionaceae and the separation of the genera Marinomonas and Shewanella from the genus Alteromonas were confirmed in this phylogenetic study. However, a marine Pseudomonas species, Pseudomonas nautica, was clearly separated from two terrestrial Pseudomonas species. Each group that was separated by the phylogenetic analysis had characteristic 16S rRNA sequence patterns that were common only to species in that group. Therefore, the characteristic sequences described in this paper may be useful for identification purposes.

Properties of lactate dehydrogenase in a psychrophilic marine bacterium

Lactate dehydrogenase (EC 1.1.1.27) from Vibrio marinus MP-1 was purified 15-fold and ammonium activated. The optimum pH for pyruvate reduction was 7.4. Maximum lactate dehydrogenase activity occurred at 10 to 15 degrees C, and none occurred at 40 degrees C. The crude-extract enzyme was stable between 15 and 20 degrees C and lost 50% of its activity after 60 min at 45 degrees C. The partially purified enzyme was stable between 8 and 15 degrees C and lost 50% of its activity after 60 min at 30 degrees C. The thermal stability of lactate dehydrogenase was increased by mercaptoethanol, with 50% remaining activity at 42 degrees C.

AN OBLIGATELY PSYCHROPHILIC BACTERIUM ISOLATED ON THE HOKKAIDO COAST

An attempt was made to elucidate whether any psychrophilic bacteria inhabited on the Hokkaido coast in winter, and consequently an obligately psychrophilic strain of bacteria was isolated from sea water several meters off shore in the suburbs of Abashiri city in Hokkaido. This strain resembled Vibrio marinus in many morphological and physiological properties. Optimum and maximum temperatures for growth were about 15° and below 25°, respectively. This psychrophile was also halophilic and required about 0.4M NaCl for the maximum growth. Furthermore, morphological change was observed in the cultures at 10°, 15°, and 20°, particularly in the young stage at 20°.

Hydrostatic pressure effects upon cellular leakage and active transport by Vibrio marinus

AbstractHydrostatic pressures greater than ca. 400 atm cause release of cellular components of Vibrio marinus MP‐1 in the order protein > RNA > malate dehydrogenase > DNA > amino acids. Increased pressures also slow the rate of cycloleucine (non‐metabolizable analogue of l‐leucine and l‐valine) uptake but increase its efflux rate. LINEWEAVER‐BURK plots (1/V versus 1/[S]) of cycloleucine uptake indicate that the Km increases with compression which suggests a decrease in affinity of the transport system for substrate at increased pressures.

Hydrostatic pressure effects upon cellular leakage and active transport by Vibrio marinus.

Hydrostatic pressures greater than ca. 400 atm cause release of cellular components of Vibrio marinus MP-1 in the order protein greater than RNA greater than malate dehydrogenase greater than DNA greater than amino acids. Increased pressures also slow the rate of cycloleucine (non-metabolizable analogue of L-leucine acid L-valine) uptake but increase its efflux rate. Lineweaver-Burk plots (1/V versus 1/[S]) of cycloleucine uptake indicate that the Km increases with compression which suggests a decrease in affinity of the transport system for substrate at increased pressures.

Some physical and chemical parameters affecting the formation and retention of glutamate pools in a marine psychrophilic bacterium.

The release of glutamic acid from the obligate marine psychrophilic bacterium Vibrio marinus MP-1 under various physical conditions has shown that at least two glutamate pools are potentially present. One, designated amino acid pool one, is loosely bound to the cell and is not found in cells accumulating glutamate by de novo synthesis. The second amino acid pool is more stable and is present in cells that are grown on a minimal salts-sugar medium.

Some physical and chemical parameters affecting the formation and retention of glutamate pools in a marine psychrophilic bacterium

AbstractThe release of glutamic acid from the obligate marine psychrophilic bacterium Vibrio marinus MP‐1 under various physical conditions has shown that at least two glutamate pools are potentially present. One, designated amino acid pool one, is loosely bound to the cell and is not found in cells accumulating glutamate by de novo synthesis. The second amino acid pool is more stable and is present in cells that are grown on a minimal salts‐sugar medium.