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2.
PLoS One ; 11(1): e0146307, 2016.
Article in English | MEDLINE | ID: mdl-26745366

ABSTRACT

Axenic gametes of the marine green macroalga Ulva mutabilis Føyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseobacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the Ria Formosa lagoon (Algarve, Southern Portugal) at 20 sampling sites and tidal pools to assess their morphogenetic effects on the axenic gametes of U. mutabilis. Specifically the survey revealed that sterile-filtered seawater samples can completely recover growth and morphogenesis of U. mutabilis under axenic conditions. Morphogenetic activities of free-living and epiphytic bacteria isolated from the locally very abundant Ulva species (i.e., U. rigida) were screened using a multiwell-based testing system. The most represented genera isolated from U. rigida were Alteromonas, Pseudoalteromonas and Sulfitobacter followed by Psychrobacter and Polaribacter. Several naturally occurring bacterial species could emulate MS2 activity (= induction of cell divisions) regardless of taxonomic affiliation, whereas the MS6 activity (= induction of cell differentiation and cell wall formation) was species-specific and is probably a feature of difficult-to-culture bacteria. Interestingly, isolated bacteroidetes such as Algoriphagus sp. and Polaribacter sp. could individually trigger complete Ulva morphogenesis and thus provide a novel mode of action for bacterial-induced algal development. This study also highlights that the accumulation of algal growth factors in a shallow water body separated from the open ocean by barrier islands might have strong implications to, for example, the wide usage of natural coastal seawater in algal (land based) aquacultures of Ulva.


Subject(s)
Germ Cells/drug effects , Morphogenesis/drug effects , Plant Growth Regulators/pharmacology , Ulva/drug effects , Alteromonas/classification , Alteromonas/metabolism , Axenic Culture , Bacteroidetes/classification , Bacteroidetes/metabolism , Cell Differentiation/drug effects , Cell Division/drug effects , Cytophaga/classification , Cytophaga/metabolism , Germ Cells/growth & development , Germ Cells/microbiology , Morphogenesis/physiology , Phylogeny , Plant Growth Regulators/biosynthesis , Plant Growth Regulators/metabolism , Portugal , Psychrobacter/classification , Psychrobacter/metabolism , Roseobacter/classification , Roseobacter/metabolism , Seawater , Ulva/growth & development , Ulva/microbiology
3.
Int J Syst Evol Microbiol ; 64(Pt 4): 1351-1358, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24436065

ABSTRACT

Two facultatively anaerobic mesophilic bacteria, strains MEBiC 07026(T) and MEBiC 08903(T), were isolated from two different tidal flat sediments and both strains showed approximately 92.2 % 16S rRNA gene sequence similarity with [Cytophaga] fermentans DSM 9555(T). 16S rRNA gene sequence similarity between the two new isolates was 97.5 % but levels of DNA-DNA relatedness between the two were 31.3-31.8 %. Phylogenetic analysis revealed that the two isolates and [Cytophaga] fermentans DSM 9555(T) were affiliated with the family Marinilabiliaceae in the class Bacteroidia. The dominant fatty acids of strains MEBiC 07026(T), MEBiC 08903(T) and [Cytophaga] fermentans DSM 9555(T) were branched-type or hydroxylated C15 : 0, but [Cytophaga] fermentans DSM 9555(T) contained a higher proportion of anteiso-branched fatty acids. The two new isolates contained a markedly higher proportion of monounsaturated fatty acids than other members of the family Marinilabiliaceae. The major respiratory quinone of the strains was MK-7. Strains MEBiC07026(T) and MEBiC08903(T) utilized a wide range of carboxylic acids whereas [Cytophaga] fermentans DSM 9555(T) utilized carbohydrates rather than carboxylic acids. The DNA G+C content of the novel strains was about 44 mol% but that of [Cytophaga] fermentans DSM 9555(T) revealed from the genome sequence was 37.6 mol%. Based on evidence from this polyphasic taxonomic study, a novel genus, Carboxylicivirga gen. nov., is proposed in the family Marinilabiliaceae with two novel species, Carboxylicivirga mesophila sp. nov. with type strain MEBiC 07026(T) ( = KCCM 42978(T) = JCM 18290(T)) and Carboxylicivirga taeanensis sp. nov. with type strain MEBiC 08903(T) ( = KCCM 43024(T) = JCM 19490(T)). Additionally, [Cytophaga] fermentans DSM 9555(T) ( = ATCC 19072(T)) is reclassified as Saccharicrinis fermentans gen. nov., comb. nov.


Subject(s)
Bacteroidetes/classification , Cytophaga/classification , Phylogeny , Seawater/microbiology , Bacterial Typing Techniques , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Geologic Sediments/microbiology , Molecular Sequence Data , Nucleic Acid Hybridization , Phosphatidylethanolamines/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
5.
Environ Sci Pollut Res Int ; 18(3): 376-85, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20694834

ABSTRACT

UNLABELLED: BACKGROUND AIM AND SCOPE: The objective of the study was to determine the effects of ca. 35 years of pesticide contamination (pesticide dump-PD) of Lake Szelag Wielki (located in the north-eastern Poland) on changes in the microbial communities of aquatic ecosystems. In the years 2008-2009, analyses were carried out for seasonal changes in the quantity and composition of bacterioplankton in the lake examined, which is of high significance to the tourism and fishing industries and is located in the vicinity of an area subjected to reclamation after a pesticide dump. METHODS: Bacterioplankton composition was assayed by fluorescence in situ hybridisation technique for the contribution of major groups of the Bacteria domain: ά-, ß- and γ-Proteobacteria, Cytophaga-Flavobacterium and Actinobacteria as well as bacteria capable of degrading pesticides in an aquatic environment-Pseudomonas spp. Seasonal patterns of the total number of bacteria were determined by direct counting of 4',6-diamidino-2-phenylindole (DAPI)-stained cells. RESULTS: The percentage of the detected Eubacteria (EUB 338 probe) relative to all the DAPI-stained bacteria in Lake Szelag Wielki ranged from 46% to 63%. Bacteria capable of degrading pesticides in an aquatic environment-Pseudomonas spp.-were identified with a highly specific probe PEA 998. The highest mean values of this parameter reached 5.1%. In the spring, Pseudomonas spp. bacteria accounted for up to 80% of all Gamma-Proteobacteria microbes. CONCLUSION: The study showed that the qualitative and quantitative changes in the bacterioplankton of the lake can be characterised by tendencies which are typical of a eutrophic water reservoir. However, a higher contribution of microorganisms capable of degrading sparingly degradable, toxic compounds and pesticides was determined in bacterioplankton from the PD-contaminated lake, as compared to microbial communities of a lake not contaminated with pesticides.


Subject(s)
Bacteria/classification , Fresh Water/microbiology , Pesticides/toxicity , Plankton/classification , Water Pollutants, Chemical/toxicity , Actinobacteria/classification , Actinobacteria/growth & development , Bacteria/drug effects , Bacteria/growth & development , Biodegradation, Environmental , Biodiversity , Colony Count, Microbial , Cytophaga/classification , Cytophaga/growth & development , Ecosystem , Environmental Monitoring , Flavobacterium/classification , Flavobacterium/growth & development , Fresh Water/chemistry , Pesticides/analysis , Plankton/drug effects , Plankton/growth & development , Poland , Proteobacteria/classification , Proteobacteria/growth & development , Refuse Disposal , Seasons , Water Microbiology , Water Pollutants, Chemical/analysis , Water Pollution, Chemical/statistics & numerical data
6.
J Invertebr Pathol ; 100(2): 127-30, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19041326

ABSTRACT

The bacterial community associated with skin lesions of the sea urchin Tripneustes gratilla was investigated using 16S ribosomal RNA gene cloning and fluorescent in situ hybridization (FISH). All clones were classified in the Alphaproteobacteria, Gammaproteobacteria and Cytophaga-Flexibacter-Bacteroides (CFB) bacteria. Most of the Alphaproteobacteria were related to the Roseobacter lineage and to bacteria implicated in marine diseases. The majority of the Gammaproteobacteria were identified as Vibrio while CFB represented only 9% of the total clones. FISH analyses showed that Alphaproteobacteria, CFB bacteria and Gammaproteobacteria accounted respectively for 43%, 38% and 19% of the DAPI counts. The importance of the methods used is emphasized.


Subject(s)
Alphaproteobacteria/isolation & purification , Cytophaga/isolation & purification , Gammaproteobacteria/isolation & purification , Sea Urchins/microbiology , Alphaproteobacteria/classification , Alphaproteobacteria/physiology , Animals , Cloning, Molecular , Cytophaga/classification , Cytophaga/physiology , DNA, Bacterial/chemistry , Gammaproteobacteria/classification , Gammaproteobacteria/physiology , In Situ Hybridization, Fluorescence , RNA, Ribosomal, 16S/chemistry
7.
Extremophiles ; 12(5): 713-7, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18622572

ABSTRACT

Bacterial and yeast isolates recovered from a deep Antarctic ice core were screened for proteins with ice-binding activity, an indicator of adaptation to icy environments. A bacterial strain recovered from glacial ice at a depth of 3,519 m, just above the accreted ice from Subglacial Lake Vostok, was found to produce a 54 kDa ice-binding protein (GenBank EU694412) that is similar to ice-binding proteins previously found in sea ice diatoms, a snow mold, and a sea ice bacterium. The protein has the ability to inhibit the recrystallization of ice, a phenotype that has clear advantages for survival in ice.


Subject(s)
Bacterial Proteins/metabolism , Carrier Proteins/metabolism , Ice/analysis , Amino Acid Sequence , Antarctic Regions , Bacterial Proteins/chemistry , Carrier Proteins/chemistry , Cytophaga/classification , Cytophaga/genetics , Cytophaga/metabolism , DNA Primers , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Ice Cover , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Shewanella/classification , Shewanella/genetics , Shewanella/metabolism
8.
Int J Syst Evol Microbiol ; 56(Pt 9): 2223-2228, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16957125

ABSTRACT

Analysis of the 16S rRNA gene sequences of species currently assigned to the genus Flexibacter has shown extensive intrageneric phylogenetic heterogeneity. It has been shown in previous studies that the species [Flexibacter] sancti, [Flexibacter] filiformis and [Flexibacter] japonensis were most closely related to Chitinophaga pinensis. In addition, [Cytophaga] arvensicola and species of the genus Terrimonas also clustered into this phylogenetic group. Although the similarities of 16S rRNA gene sequences were low (88.5-96.4 %), there is no evidence for clear phenotypic differences between these organisms that justify assignment to different genera. A proposal is made to transfer these species to the genus Chitinophaga as Chitinophaga sancti comb. nov., Chitinophaga filiformis comb. nov., Chitinophaga japonenis comb. nov. and Chitinophaga arvensicola comb. nov. on the basis of phylogenetic and phenotypic data. Furthermore, a novel species is described within this genus, Chitinophaga skermanii sp. nov., with strain CC-SG1B(T) (=CCUG 52510(T)=CIP 109140(T)) as the type strain.


Subject(s)
Bacteroides/classification , Cytophaga/classification , DNA, Bacterial/analysis , Flexibacter/classification , RNA, Ribosomal, 16S/analysis , DNA, Ribosomal/analysis , Molecular Sequence Data , RNA, Ribosomal, 16S/genetics
9.
Appl Environ Microbiol ; 72(8): 5421-7, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16885294

ABSTRACT

Previous research in our laboratory revealed that the introduction of Bacillus cereus UW85 can increase the populations of bacteria from the Cytophaga-Flavobacterium (CF) group of the Bacteroidetes phylum in the soybean rhizosphere, suggesting that these rhizosphere microorganisms have a beneficial relationship (G. S. Gilbert, J. L. Parke, M. K. Clayton, and J. Handelsman, Ecology 74:840-854, 1993). In the present study, we determined the frequency at which CF bacteria coisolated with B. cereus strains from the soybean rhizosphere and the mechanism by which B. cereus stimulates the growth of CF rhizosphere strains in root exudate media. In three consecutive years of sampling, CF strains predominated among coisolates obtained with B. cereus isolates from field-grown soybean roots. In root exudate media, the presence of B. cereus was required for CF coisolate strains to reach high population density. However, rhizosphere isolates from the phylum Proteobacteria grew equally well in the presence and absence of B. cereus, and the presence of CF coisolates did not affect the growth of B. cereus. Peptidoglycan isolated from B. cereus cultures stimulated growth of the CF rhizosphere bacterium Flavobacterium johnsoniae, although culture supernatant from B. cereus grown in root exudate media did not. These results suggest B. cereus and CF rhizosphere bacteria have a commensal relationship in which peptidoglycan produced by B. cereus stimulates the growth of CF bacteria.


Subject(s)
Bacillus cereus/growth & development , Cytophaga/growth & development , Flavobacterium/growth & development , Glycine max/microbiology , Peptidoglycan/pharmacology , Plant Roots/microbiology , Bacillus cereus/metabolism , Culture Media , Cytophaga/classification , Cytophaga/drug effects , Cytophaga/genetics , DNA, Ribosomal/analysis , Ecosystem , Flavobacterium/classification , Flavobacterium/drug effects , Flavobacterium/genetics , Medicago sativa/microbiology , Molecular Sequence Data , Peptidoglycan/metabolism , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
10.
Res Microbiol ; 157(8): 741-51, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16690258

ABSTRACT

Microbes have been discovered in permafrost sediments for nearly a century. However, microbiological analyses of alpine permafrost are very scarce. This study is a first attempt to describe the phylogenetic diversity of a culturable bacterial community isolated from alpine permafrost in the Tianshan Mountains in northwestern China. Aerobic 2.5-6.0x10(5) CFU/gdw (CFU per 1 gram of dry weight) on modified PYGV medium were recovered from alpine permafrost samples at 4 degrees C; among these, 91 bacterial isolates with different morphotypes were characterized by phenotypic properties, such as morphology, colony pigmentation, Gram staining, endospore formation and temperature range of growth. The isolates were further categorized based on amplified rDNA restriction analysis (ARDRA), and 51 representative isolates possessing distinct ARDRA patterns selected for subsequent 16S rDNA sequencing and phylogenetic analysis. The phylogenetic trees placed the 51 isolates in four major groups: the high-G+C Gram-positives, the low-G+C Gram-positives, Proteobacteria and the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum. The most abundant and diverse isolates were members of Gram-positive bacteria, particularly the Arthrobacter as a dominant group in alpine permafrost culturable populations. Results of the Jukes-Cantor evolutionary distance matrix suggested that the vast majority of the isolates were different strains of known species, and three may represent new species within the genus Chryseobacterium of the CFB phylum. From this study, it is proposed that alpine permafrost sediments in the Tianshan Mountains provide a specific ecological niche for prolonging survival of diverse microbial lineages.


Subject(s)
Bacteria, Aerobic/classification , Gram-Positive Bacteria/classification , Soil Microbiology , Arthrobacter/classification , Arthrobacter/genetics , Bacteria, Aerobic/genetics , Base Composition , China , Chryseobacterium/classification , Chryseobacterium/genetics , Cold Climate , Cytophaga/classification , Cytophaga/genetics , DNA, Bacterial/analysis , DNA, Bacterial/genetics , DNA, Ribosomal/analysis , DNA, Ribosomal/genetics , Gram-Positive Bacteria/genetics , Phylogeny , Proteobacteria/classification , Proteobacteria/genetics
11.
Appl Environ Microbiol ; 71(12): 7799-805, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16332754

ABSTRACT

The contribution of major bacterial groups to the assimilation of extracellular polymeric substances (EPS) and glucose in the Delaware Estuary was assessed using microautoradiography and fluorescence in situ hybridization. Bacterial groups contributed to EPS and glucose assimilation in part according to their distribution in the estuary. Abundance of the phylogenetic groups explained 35% and 55% of the variation in EPS and glucose assimilation, respectively. Actinobacteria contributed 70% to glucose assimilation in freshwater, while Alphaproteobacteria assimilated 60% of this compound in saline water. In contrast, various bacterial groups dominated the assimilation of EPS. Actinobacteria and Betaproteobacteria contributed the most in the freshwater section, whereas Cytophaga-like bacteria and Alpha- and Gammaproteobacteria participated in EPS assimilation in the lower part of the estuary. In addition, we examined the fraction of bacteria in each group that assimilated glucose or EPS. Overall, the fraction of bacteria in all groups that assimilated glucose was higher than the fraction that assimilated EPS (15 to 30% versus 5 to 20%, respectively). We found no correlation between the relative abundance of a group in the estuary and the fraction of bacteria actively assimilating glucose or EPS; the more active groups were often less abundant. Our results imply that the bacterial community in the Delaware Estuary is not controlled solely by "bottom-up" factors such as dissolved organic matter.


Subject(s)
Bacteria/metabolism , Fresh Water/microbiology , Glucose/metabolism , Polysaccharides, Bacterial/metabolism , Seawater/microbiology , Actinobacteria/classification , Actinobacteria/isolation & purification , Actinobacteria/metabolism , Alphaproteobacteria/classification , Alphaproteobacteria/isolation & purification , Alphaproteobacteria/metabolism , Bacteria/classification , Bacteria/isolation & purification , Betaproteobacteria/classification , Betaproteobacteria/isolation & purification , Betaproteobacteria/metabolism , Cytophaga/classification , Cytophaga/isolation & purification , Cytophaga/metabolism , Delaware , Gammaproteobacteria/classification , Gammaproteobacteria/isolation & purification , Gammaproteobacteria/metabolism
12.
Appl Environ Microbiol ; 71(12): 8506-13, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16332841

ABSTRACT

Sequence analysis of environmental DNA promises to provide new insights into the ecology and biogeochemistry of uncultured marine microbes. In this study we used the Sargasso Sea Whole Genome Sequence (WGS) data set to search for hydrolases used by Cytophaga-like bacteria to degrade biopolymers such as polysaccharides and proteins. Analysis of the Sargasso WGS data for contigs bearing both the 16S rRNA genes of Cytophaga-like bacteria and hydrolase genes revealed a cellulase gene (celM) most similar to the gene found in Cytophaga hutchinsonii. A BLAST search of the entire Sargasso Sea WGS data set indicated that celM was the most abundant cellulase-like gene in the Sargasso Sea. However, the similarity between CelM-like cellulases and peptidases belonging to metalloprotease family M42 led us to question whether CelM is involved in the degradation of polysaccharides or proteins. PCR primers were designed for the celM genes in the Sargasso Sea WGS data set and used to identify celM in a fosmid library constructed with prokaryotic DNA from the western Arctic Ocean. Expression analysis of the Cytophaga-like Arctic CelM, which is 63% identical and 77% similar to CelM in C. hutchinsonii, indicated that there was peptidase activity, whereas cellulase activity was not detected. Our analysis suggests that the celM gene plays a role in the degradation of protein by Cytophaga-like bacteria. The abundance of peptidase genes in the Cytophaga-like fosmid clone provides further evidence for the importance of Cytophaga-like bacteria in the degradation of protein in high-molecular-weight dissolved organic matter.


Subject(s)
Cytophaga/genetics , Genomic Library , Hydrolases/genetics , Arctic Regions , Base Sequence , Cytophaga/classification , Cytophaga/enzymology , DNA Primers , Gene Expression Regulation, Bacterial , Gene Expression Regulation, Enzymologic , Molecular Sequence Data , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Seawater/microbiology
13.
Can J Microbiol ; 51(11): 910-23, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16333330

ABSTRACT

Bacterial diversity was assessed in water samples collected from several uranium mining wastes in Ger many and in the United States by using 16S rDNA and ribosomal intergenic spacer amplification retrievals. The results obtained using the 16S rDNA retrieval showed that the samples collected from the uranium mill tailings of Schlema/Alberoda, Germany, were predominated by Nitrospina-like bacteria, whereas those from the mill tailings of Shiprock, New Mexico, USA, were predominated by gamma-Pseudomonas and Frauteria spp. Additional smaller populations of the Cytophaga-Flavobacterium-Bacteroides group and alpha- and delta-Proteobacteria were identified in the Shiprock samples as well. Proteobacteria and Cytophaga-Flavobacterium-Bacteroides were also found in the third uranium mill tailings studied, Gittersee/Coschütz, Germany, but the groups of the predominant clones were rather small. Most of the clones of the Gittersee/Coschütz samples represented individual sequences, which indicates a high level of bacterial diversity. The samples from the fourth uranium waste studied, Steinsee Deponie B1, Germany, were predominantly occupied by Acinetobacter spp. The ribosomal intergenic spacer amplification retrieval provided results complementary to those obtained by the 16S rDNA analyses. For instance, in the Shiprock samples, an additional predominant bacterial group was identified and affiliated with Nitrosomonas sp., whereas in the Gittersee/Coschütz samples, anammox populations were identified that were not retrieved by the applied 16S rDNA approach.


Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Biodiversity , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal/genetics , Industrial Waste , RNA, Ribosomal, 16S/genetics , Uranium , Water Microbiology , Bacteria/genetics , Bacteroides/classification , Bacteroides/isolation & purification , Cytophaga/classification , Cytophaga/isolation & purification , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal Spacer/chemistry , Flavobacterium/classification , Flavobacterium/isolation & purification , Germany , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Proteobacteria/classification , Proteobacteria/isolation & purification , Pseudomonas/classification , Pseudomonas/cytology , Pseudomonas/isolation & purification , Radioactive Pollutants , Sequence Analysis, DNA , United States , Waste Disposal, Fluid
14.
Can J Microbiol ; 51(11): 897-909, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16333329

ABSTRACT

A microbial consortium (AM) obtained by sequential enrichment in liquid culture with a polycyclic aromatic hydrocarbon (PAH) mixture of three- and four-ringed PAHs as a sole source of carbon and energy was examined using a triple-approach method based on various cultivation strategies, denaturing gradient gel electrophoresis (DGGE), and the screening of 16S and 18S rRNA gene clone libraries. Eleven different sequences by culture-dependent techniques and seven by both DGGE and clone libraries were obtained. The comparison of three variable regions (V3-V5) of the 16S rRNA gene between the sequences obtained yielded 19 different microbial components. Proteobacteria were the dominant group, representing 83% of the total, while the Cytophaga-Flexibacter-Bacteroides group (CFB) was 11% and the Ascomycota fungi 6%. Beta-proteobacteria were predominant in the DGGE and clone library methods, whereas they were a minority in culturable strains. The highest diversity and number of noncoincident sequences were achieved by the cultivation method that showed members of the alpha-, beta-, and gamma-Proteobacteria; CFB bacterial group; and Ascomycota fungi. Only six of the 11 strains isolated showed PAH-degrading capability. The bacterial strain (AMS7) and the fungal strain (AMF1), which were similar to Sphingomonas sp. and Fusarium sp., respectively, achieved the greatest PAH depletion. The results indicate that polyphasic assessment is necessary for a proper understanding of the composition of a microbial consortium.


Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Biodiversity , Fungi/classification , Fungi/isolation & purification , Polycyclic Aromatic Hydrocarbons/metabolism , Ascomycota/classification , Ascomycota/genetics , Ascomycota/isolation & purification , Ascomycota/metabolism , Bacteria/genetics , Bacteria/metabolism , Bacteroides/classification , Bacteroides/genetics , Bacteroides/isolation & purification , Bacteroides/metabolism , Biodegradation, Environmental , Cytophaga/classification , Cytophaga/genetics , Cytophaga/isolation & purification , Cytophaga/metabolism , DNA Fingerprinting , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Electrophoresis, Polyacrylamide Gel , Flexibacter/classification , Flexibacter/genetics , Flexibacter/isolation & purification , Flexibacter/metabolism , Fungi/genetics , Fungi/metabolism , Molecular Sequence Data , Phylogeny , Proteobacteria/classification , Proteobacteria/genetics , Proteobacteria/isolation & purification , Proteobacteria/metabolism , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 18S/chemistry , RNA, Ribosomal, 18S/genetics , Sequence Homology, Nucleic Acid , Soil Microbiology
15.
Appl Environ Microbiol ; 71(11): 6799-807, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16269712

ABSTRACT

Dilution culture experiments were conducted in western North Pacific coastal regions to determine growth and grazing mortality rates of bacterial phylogenetic groups (alpha-, beta-, and gamma-proteobacteria and the Cytophaga-Flavobacter cluster) detected by fluorescent in situ hybridization. Growth rates varied greatly (1.2- to 4.0-fold) among different groups, and they were related to environmental variables (chlorophyll a concentrations and temperature) in a group-specific fashion. Growth rates of alpha-proteobacteria, the most abundant group in all the samples examined, were generally lower than those of less abundant groups, including the Cytophaga-Flavobacter cluster and gamma-proteobacteria. Grazing mortality rates and mean cell volumes varied little among different groups. These results provide insights into factors that affect distributions of different groups, but growth and grazing mortality alone did not fully explain bacterial community compositions at a broad phylogenetic level.


Subject(s)
Alphaproteobacteria/growth & development , Cytophaga/growth & development , Gammaproteobacteria/growth & development , Phylogeny , Plankton/growth & development , Seawater/microbiology , Alphaproteobacteria/classification , Alphaproteobacteria/genetics , Animals , Behavior, Animal , Cytophaga/classification , Cytophaga/genetics , Ecosystem , Feeding Behavior , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Plankton/classification , Plankton/genetics
16.
J Eukaryot Microbiol ; 52(3): 191-200, 2005.
Article in English | MEDLINE | ID: mdl-15926994

ABSTRACT

The toxic dinoflagellate Alexandrium catenella isolated from fjords in Southern Chile produces several analogues of saxitoxin and has been associated with outbreaks of paralytic shellfish poisoning. Three bacterial strains, which remained in close association with this dinoflagellate in culture, were isolated by inoculating the dinoflagellate onto marine agar. The phenotypically different cultivable bacterial colonies were purified. Their genetic identification was done by polymerase chain reaction amplification of the 16S rRNA genes. Partial sequence analysis suggested that the most probable affiliations were to two bacterial phyla: Proteobacteria and the Cytophaga group. The molecular identification was complemented by morphological data and biochemical profiling. The three bacterial species, when grown separately from phytoplankton cells in high-nutrient media, released algal-lytic compounds together with aminopeptidase, lipase, glucosaminidase, and alkaline phosphatase. When the same bacteria, free of organic nutrients, were added back to the algal culture they displayed no detrimental effects on the dinoflagellate cells and recovered their symbiotic characteristics. This observation is consistent with phylogenetic analysis that reveals that these bacteria correspond to species distinct from other bacterial strains previously classified as algicidal bacteria. Thus, bacterial-derived lytic activities are expressed only in the presence of high-nutrient culture media and it is likely that in situ environmental conditions may modulate their expression.


Subject(s)
Bacteria/classification , Dinoflagellida/microbiology , Animals , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/ultrastructure , Bacterial Typing Techniques , Cytophaga/classification , Cytophaga/genetics , Cytophaga/isolation & purification , Cytotoxins/analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Dinoflagellida/ultrastructure , Enzymes/analysis , Eukaryota/microbiology , Molecular Sequence Data , Phylogeny , Pseudoalteromonas/classification , Pseudoalteromonas/isolation & purification , RNA, Ribosomal, 16S/genetics , Rhodobacteraceae/classification , Rhodobacteraceae/isolation & purification , Seawater/microbiology , Sequence Analysis, DNA
17.
Int J Syst Evol Microbiol ; 55(Pt 3): 1033-1038, 2005 May.
Article in English | MEDLINE | ID: mdl-15879230

ABSTRACT

Five heterotrophic, aerobic, halotolerant and pigmented bacterial strains with gliding motility were isolated from Antarctic sea water; one other isolate was collected from the sea urchin Strongylocentrotus intermedius in the Gulf of Peter the Great in the Sea of Japan. 16S rRNA gene sequence analysis indicated that the strains are members of the family Flavobacteriaceae, the nearest neighbour (with 97.1 % sequence similarity) being the misclassified species [Cytophaga] marinoflava. DNA-DNA hybridization experiments and chemotaxonomic and phenotypic analyses demonstrated that the six novel isolates represent a single species distinct from [C.] marinoflava. On the basis of its separate phylogenetic lineage (the nearest neighbours show 92 % sequence similarity), [C.] marinoflava is reclassified as Leeuwenhoekiella marinoflava gen. nov., comb. nov. A second species of this new genus, Leeuwenhoekiella aequorea sp. nov., is proposed for the six novel isolates, with strain LMG 22550(T) (=CCUG 50091(T)) as the type strain.


Subject(s)
Cytophaga/classification , Flavobacteriaceae/classification , Flavobacteriaceae/isolation & purification , Seawater/microbiology , Strongylocentrotus/microbiology , Animals , Antarctic Regions , Bacterial Typing Techniques , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Fatty Acids/analysis , Flavobacteriaceae/cytology , Flavobacteriaceae/physiology , Genes, rRNA , Japan , Molecular Sequence Data , Nucleic Acid Hybridization , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Water Microbiology
18.
Syst Appl Microbiol ; 28(3): 242-64, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15900971

ABSTRACT

A taxonomic survey was conducted to determine the microbial diversity held within the Harbor Branch Oceanographic Marine Microbial Culture Collection (HBMMCC). The collection consists of approximately 17,000 microbial isolates, with 11,000 from a depth of greater than 150 ft seawater. A total of 2273 heterotrophic bacterial isolates were inventoried using the DNA fingerprinting technique amplified rDNA restriction analysis on approximately 750-800 base pairs (bp) encompassing hypervariable regions in the 5' portion of the small subunit (SSU) 16S rRNA gene. Restriction fragment length polymorphism patterns obtained from restriction digests with RsaI, HaeIII, and HhaI were used to infer taxonomic similarity. SSU 16S rDNA fragments were sequenced from a total of 356 isolates for more definitive taxonomic analysis. Sequence results show that this subset of the HBMMCC contains 224 different phylotypes from six major bacterial clades (Proteobacteria (Alpha, Beta, Gamma), Cytophaga, Flavobacteria, and Bacteroides (CFB), Gram + high GC content, Gram + low GC content). The 2273 microorganisms surveyed encompass 834 alpha-Proteobacteria (representing 60 different phylotypes), 25 beta-Proteobacteria (3 phylotypes), 767 gamma-Proteobacteria (77 phylotypes), 122 CFB (17 phylotypes), 327 Gram + high GC content (43 phylotypes), and 198 Gram + low GC content isolates (24 phylotypes). Notably, 11 phylotypes were < or =93% similar to the closest sequence match in the GenBank database even after sequencing a larger portion of the 16S rRNA gene (approximately 1400 bp), indicating the likely discovery of novel microbial taxa. Furthermore, previously reported "uncultured" microbes, such as sponge-specific isolates, are part of the HBMMCC. The results of this research will be available online as a searchable taxonomic database (www.hboi.edu/dbmr/dbmr_hbmmd.html).


Subject(s)
Bacteria/classification , Bacteria/genetics , Invertebrates/microbiology , Seawater , Alphaproteobacteria/classification , Alphaproteobacteria/genetics , Alphaproteobacteria/isolation & purification , Animals , Bacteria/isolation & purification , Bacteroides/classification , Bacteroides/genetics , Bacteroides/isolation & purification , Betaproteobacteria/classification , Betaproteobacteria/genetics , Betaproteobacteria/isolation & purification , Cytophaga/classification , Cytophaga/genetics , Cytophaga/isolation & purification , DNA Fingerprinting , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Flavobacteriaceae/classification , Flavobacteriaceae/genetics , Flavobacteriaceae/isolation & purification , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Gammaproteobacteria/isolation & purification , Genes, rRNA , Geologic Sediments/microbiology , Molecular Sequence Data , Phylogeny , Polymorphism, Restriction Fragment Length , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
19.
Lett Appl Microbiol ; 40(4): 274-7, 2005.
Article in English | MEDLINE | ID: mdl-15752217

ABSTRACT

AIMS: The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream larvae (Sparus aurata). METHODS AND RESULTS: Six bacterial strains isolated from well-performing live food cultures were identified by sequencing fragments of their 16s rDNA genome to the genus level as Cytophaga sp., Roseobacter sp., Ruergeria sp., Paracoccus sp., Aeromonas sp. and Shewanella sp. Survival rates of gilthead sea bream larvae transferred to seawater added these bacterial strains at concentrations of 6 +/- 0.3 x 10(5) bacteria ml(-1) were similar to those of larvae transferred to sterilized seawater and showed an average of 86% at 9 days after hatching, whereas, survival rates of larvae transferred to filtered seawater were lower (P < 0.05), and showed an average of 39%, 9 days after hatching. CONCLUSION: Several bacterial strains isolated from well-performing live food cultures showed a positive effect for sea bream larvae when compared with filtered seawater. SIGNIFICANCE AND IMPACT OF THE STUDY: The approach used in this study could be applied as an in vivo evaluation method of candidate probiotic strains used in the rearing of marine fish larvae.


Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Probiotics , Sea Bream/growth & development , Sea Bream/microbiology , Aeromonas/classification , Aeromonas/isolation & purification , Aquaculture/methods , Cytophaga/classification , Cytophaga/isolation & purification , DNA, Bacterial/chemistry , DNA, Bacterial/isolation & purification , DNA, Ribosomal/chemistry , DNA, Ribosomal/isolation & purification , Genes, rRNA/genetics , Paracoccus/classification , Paracoccus/isolation & purification , RNA, Ribosomal, 16S/genetics , Roseobacter/classification , Roseobacter/isolation & purification , Sequence Analysis, DNA , Shewanella/classification , Shewanella/isolation & purification , Water Microbiology
20.
Int J Syst Evol Microbiol ; 55(Pt 1): 225-229, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15653878

ABSTRACT

The taxonomic position of three novel sea-water isolates was determined. The strains studied were strictly aerobic, heterotrophic, pigmented, motile by gliding, Gram-negative and oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive. 16S rRNA gene sequence phylogenetic analysis indicated that the strains KMM 6020T, KMM 6021 and KMM 6028 occupied a distinct lineage within the family Flavobacteriaceae. The major respiratory quinone was MK-6. The predominant fatty acids were i15 : 0, i15 : 1, i15 : 0 3-OH, i17 : 1omega9c and i17 : 0 3-OH. On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacteria were assigned to the genus Aquimarina gen. nov., as Aquimarina muelleri gen. nov., sp. nov. The type strain is KMM 6020T (=KCTC 12285T=LMG 22569T). From the results of the 16S rRNA gene sequence analysis and phenotypic features, the species [Cytophaga] latercula Lewin 1969 is proposed to be reclassified in the new genus Stanierella as Stanierella latercula gen. nov., comb. nov., with type strain CIP 104806T (=ATCC 23177T=NCIMB 1399T=LMG 1343T).


Subject(s)
Flavobacteriaceae/classification , Bacterial Typing Techniques , Cytophaga/classification , DNA, Bacterial/analysis , DNA, Ribosomal/analysis , Flavobacteriaceae/chemistry , Flavobacteriaceae/genetics , Flavobacteriaceae/physiology , Genes, rRNA , Genotype , Molecular Sequence Data , Phenotype , Phylogeny , RNA, Ribosomal, 16S/genetics , Seawater/microbiology , Sequence Analysis, DNA
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