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1.
Microb Ecol ; 84(2): 325-335, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34561754

RESUMO

The scleractinian reef building coral Madracis decactis is a cosmopolitan species. Understanding host-symbiont associations is critical for assessing coral's habitat requirements and its response to environmental changes. In this study, we performed a fine grained phylogenetic analyses of Symbiodiniaceae associated with Madracis in two locations in the Southwest Atlantic Ocean (Abrolhos Bank and St. Peter and St. Paul Archipelago). Previous studies have argued that Madracis is a specialist coral, with colonies harboring a single symbiont from the genus Breviolum (formerly clade B). However, these previous studies have not precisely addressed if Madracis is colonized by several types of Symbiodiniaceae simultaneously or whether this coral is a specialist. The hypothesis that Madracis is a generalist coral host was evaluated in the present study. A total of 1.9 million reads of ITS2 nuclear ribosomal DNA were obtained by Illumina MiSeq sequencing. While Symbiodiniaceae ITS2 sequences between two sampling depths were almost entirely (62%) from the genus Breviolum (formerly clade B), shallow (10-15 m) populations in Abrolhos had a greater diversity of ITS2 sequences in comparison to deeper (25-35 m) populations of St. Peter and St. Paul Archipelago. Cladocopium (formerly clade C) and Symbiodinium (formerly clade A) were also found in Abrolhos. A single Madracis colony can host different symbiont types with > 30 Symbiodiniaceae ITS2-type profiles. Abrolhos corals presented a higher photosynthetic potential as a possible result of co-occurrence of multiple Symbiodiniaceae in a single coral colony. Multiple genera/clades of Symbiodiniaceae possibly confer coral hosts with broader environmental tolerance and ability to occupy diverse or changing habitats.


Assuntos
Antozoários , Dinoflagelados , Animais , Antozoários/fisiologia , Oceano Atlântico , Recifes de Corais , DNA Ribossômico/genética , Dinoflagelados/fisiologia , Filogenia , Simbiose
2.
Arch Microbiol ; 203(1): 399-404, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32844278

RESUMO

Description of a Gram-negative, motile, circular-shaped bacterial strain, designated A511T obtained from the skin of the pufferfish Sphoeroides spengleri (Family Tetraodontidae), collected in Arraial do Cabo, Brazil. Optimum growth occurs at 20-28 °C in the presence of 3% NaCl. The genome sequence of the novel isolate consisted of 4.36 Mb, 3,976 coding genes and G + C content of 42.5%. Genomic taxonomy analyses based on average amino acid (AAI), genome-to-genome-distance (GGDH) and phylogenetic reconstruction placed A511T (= CBAS 712T = CAIM 1939T) into a new species of the genus Vibrio (Vibrio tetraodonis sp. nov.). The genome of the novel species contains eight genes clusters (~ 183.9 Kbp in total) coding for different types of bioactive compounds that hint to several possible ecological roles in the pufferfish host.


Assuntos
Genoma Bacteriano/genética , Filogenia , Vibrio/classificação , Vibrio/genética , Composição de Bases , Brasil , RNA Ribossômico 16S/genética , Cloreto de Sódio/metabolismo , Especificidade da Espécie , Vibrio/crescimento & desenvolvimento , Vibrio/metabolismo
3.
Environ Microbiol ; 22(11): 4557-4570, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32700350

RESUMO

Cyanobacteria of the genus Synechococcus are major contributors to global primary productivity and are found in a wide range of aquatic ecosystems. This Synechococcus collective (SC) is metabolically diverse, with some lineages thriving in polar and nutrient-rich locations and others in tropical or riverine waters. Although many studies have discussed the ecology and evolution of the SC, there is a paucity of knowledge on its taxonomic structure. Thus, we present a new taxonomic classification framework for the SC based on recent advances in microbial genomic taxonomy. Phylogenomic analyses of 1085 cyanobacterial genomes demonstrate that organisms classified as Synechococcus are polyphyletic at the order rank. The SC is classified into 15 genera, which are placed into five distinct orders within the phylum Cyanobacteria: (i) Synechococcales (Cyanobium, Inmanicoccus, Lacustricoccus gen. Nov., Parasynechococcus, Pseudosynechococcus, Regnicoccus, Synechospongium gen. nov., Synechococcus and Vulcanococcus); (ii) Cyanobacteriales (Limnothrix); (iii) Leptococcales (Brevicoccus and Leptococcus); (iv) Thermosynechococcales (Stenotopis and Thermosynechococcus) and (v) Neosynechococcales (Neosynechococcus). The newly proposed classification is consistent with habitat distribution patterns (seawater, freshwater, brackish and thermal environments) and reflects the ecological and evolutionary relationships of the SC.


Assuntos
Genoma Bacteriano/genética , Synechococcus/classificação , Synechococcus/genética , Ecossistema , Água Doce/microbiologia , Genômica , Ferro/metabolismo , Filogenia , Águas Salinas , Água do Mar/microbiologia , Synechococcus/metabolismo
4.
Microb Ecol ; 80(3): 546-558, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32468160

RESUMO

Prochlorococcus is the most abundant photosynthetic prokaryote on our planet. The extensive ecological literature on the Prochlorococcus collective (PC) is based on the assumption that it comprises one single genus comprising the species Prochlorococcus marinus, containing itself a collective of ecotypes. Ecologists adopt the distributed genome hypothesis of an open pan-genome to explain the observed genomic diversity and evolution patterns of the ecotypes within PC. Novel genomic data for the PC prompted us to revisit this group, applying the current methods used in genomic taxonomy. As a result, we were able to distinguish the five genera: Prochlorococcus, Eurycolium, Prolificoccus, Thaumococcus, and Riococcus. The novel genera have distinct genomic and ecological attributes.


Assuntos
Genoma Bacteriano , Traços de História de Vida , Prochlorococcus/classificação , Genômica , Prochlorococcus/genética , Prochlorococcus/fisiologia
5.
Curr Microbiol ; 77(1): 154-157, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31620811

RESUMO

We report here the novel species to encompass the isolate A649T (=CBAS 716T = CBRVS P1061T) obtained from viscera of the healthy pufferfish Sphoeroides spengleri (Family Tetraodontidae). Genomic taxonomy analysis demonstrates that the novel strain A649T had < 95% average amino acid identity/average nucleotide identity (AAI/ANI) and < 70% similarity of genome-to-genome distance (GGDH) towards its closest neighbors which places A649T into a new Enterovibrio species (Enterovibrio baiacu sp nov.). In silico phenotyping disclosed several features that may be used to differentiate related Enterovibrio species. The nearly complete genome assembly of strain A649T consisted of 5.4 Mbp and 4826 coding genes.


Assuntos
Tetraodontiformes/microbiologia , Vibrionaceae/genética , Animais , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Genoma Bacteriano/genética , Filogenia , Análise de Sequência de DNA , Vibrionaceae/classificação
7.
Microbiol Resour Announc ; 8(15)2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975799

RESUMO

Unplanned oil spills during offshore production are a serious problem for the industry and the marine environment. Here, we present the genome sequence analysis of three novel hydrocarbon-degrading bacteria, namely, "Candidatus Colwellia aromaticivorans" sp. nov., "Candidatus Halocyntiibacter alkanivorans" sp. nov., and "Candidatus Ulvibacter alkanivorans" sp. nov.

8.
Artigo em Inglês | MEDLINE | ID: mdl-30533792

RESUMO

We report here the genome sequences of the novel isolates G62T and G98T from rhodoliths. The nearly complete genomes consisted of 4.7 Mbp (4,233 coding sequences [CDS]) for G62T and 4.5 Mbp (4,085 CDS) for G98T. Genomic taxonomy places these new genomes into 2 new species.

9.
Front Microbiol ; 8: 2132, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29184540

RESUMO

Cyanobacteria are major contributors to global biogeochemical cycles. The genetic diversity among Cyanobacteria enables them to thrive across many habitats, although only a few studies have analyzed the association of phylogenomic clades to specific environmental niches. In this study, we adopted an ecogenomics strategy with the aim to delineate ecological niche preferences of Cyanobacteria and integrate them to the genomic taxonomy of these bacteria. First, an appropriate phylogenomic framework was established using a set of genomic taxonomy signatures (including a tree based on conserved gene sequences, genome-to-genome distance, and average amino acid identity) to analyse ninety-nine publicly available cyanobacterial genomes. Next, the relative abundances of these genomes were determined throughout diverse global marine and freshwater ecosystems, using metagenomic data sets. The whole-genome-based taxonomy of the ninety-nine genomes allowed us to identify 57 (of which 28 are new genera) and 87 (of which 32 are new species) different cyanobacterial genera and species, respectively. The ecogenomic analysis allowed the distinction of three major ecological groups of Cyanobacteria (named as i. Low Temperature; ii. Low Temperature Copiotroph; and iii. High Temperature Oligotroph) that were coherently linked to the genomic taxonomy. This work establishes a new taxonomic framework for Cyanobacteria in the light of genomic taxonomy and ecogenomic approaches.

11.
Antonie Van Leeuwenhoek ; 109(3): 431-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26786501

RESUMO

The taxonomic position of strains Ab112(T) (CBAS 572(T)) and Ab227_MC (CBAS 573) was evaluated by means of genomic taxonomy. These isolates represent the dominant flora cultured from the healthy marine sponge Arenosclera brasiliensis, endemic to Rio de Janeiro. Strains CBAS 572(T) and CBAS 573 shared >98 % 16S rRNA sequence identity with Endozoicomonas numazuensis and Endozoicomonas montiporae. In silico DNA-DNA Hybridization, i.e. genome-to-genome distance (GGD), amino acid identity (AAI) and average nucleotide identity (ANI) further showed that these strains had <70 %, at maximum 71.1 and 78 % of identity, respectively, to their closest neighbours E. numazuensis and E. montiporae. The DNA G+C content of CBAS 572(T) and CBAS 573 were 47.6 and 47.7 mol%, respectively. Phenotypic and chemotaxonomic features also allowed a separation from the type strains of their phylogenetic neighbours. Useful phenotypic features for discriminating CBAS 572(T) and CBAS 573 from E. numazuensis and E. montiporae species include C8 esterase, N-acetyl-ß-glucosaminidase, citric acid, uridine and siderophore. The species Endozoicomonas arenosclerae sp. nov. is proposed to harbour the new isolates. The type strain is CBAS 572(T) (=Ab112(T)).


Assuntos
Código de Barras de DNA Taxonômico , Gammaproteobacteria/classificação , Gammaproteobacteria/genética , Genoma Bacteriano , Técnicas de Tipagem Bacteriana , Composição de Bases , Gammaproteobacteria/química , Estudos de Associação Genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Fenótipo , Filogenia , RNA Ribossômico 16S/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-26454874

RESUMO

A new open access database, Brazilian Marine Biodiversity (BaMBa) (https://marinebiodiversity.lncc.br), was developed in order to maintain large datasets from the Brazilian marine environment. Essentially, any environmental information can be added to BaMBa. Certified datasets obtained from integrated holistic studies, comprising physical-chemical parameters, -omics, microbiology, benthic and fish surveys can be deposited in the new database, enabling scientific, industrial and governmental policies and actions to be undertaken on marine resources. There is a significant number of databases, however BaMBa is the only integrated database resource both supported by a government initiative and exclusive for marine data. BaMBa is linked to the Information System on Brazilian Biodiversity (SiBBr, http://www.sibbr.gov.br/) and will offer opportunities for improved governance of marine resources and scientists' integration. Database URL: http://marinebiodiversity.lncc.br.


Assuntos
Organismos Aquáticos , Biota/fisiologia , Bases de Dados Factuais , Animais , Organismos Aquáticos/classificação , Organismos Aquáticos/fisiologia , Brasil
13.
Antonie Van Leeuwenhoek ; 108(5): 1257-65, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26346480

RESUMO

Four lactic acid bacteria isolates obtained from fresh dromedary camel milk produced in Dakhla, a city in southern Morocco, were characterised in order to determine their taxonomic position. The four isolates had highly similar MALDI-TOF MS and RAPD fingerprints and identical 16S rRNA gene sequences. Comparative sequence analysis revealed that the 16S rRNA gene sequence of the four isolates was most similar to that of Enterococcus sulfureus ATCC 49903(T) and Enterococcus italicus DSM 15952(T) (99.33 and 98.59% similarity, respectively). However, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes revealed that the taxon represented by strain LMG 28766(T) was well separated from E. sulfureus LMG 13084(T) and E. italicus LMG 22039(T), which was further confirmed by DNA-DNA hybridization values that were clearly below the species demarcation threshold. The novel taxon was easily differentiated from its nearest neighbour species through sequence analysis of protein encoding genes, MALDI-TOF mass spectrometry and multiple biochemical tests, but had a similar percentage G+C content of about 39%. We therefore propose to formally classify these isolates as Enterococcus bulliens sp. nov., with LMG 28766(T) (=CCMM B1177(T)) as the type strain.


Assuntos
Enterococcus/classificação , Enterococcus/metabolismo , Microbiologia de Alimentos , Ácido Láctico/biossíntese , Leite/microbiologia , Animais , Composição de Bases , Camelus , DNA Bacteriano , Enterococcus/química , Enterococcus/genética , Enterococcus/isolamento & purificação , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Braz J Microbiol ; 46(2): 443-53, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26273259

RESUMO

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.


Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Bacilos Gram-Positivos/classificação , Bacilos Gram-Positivos/isolamento & purificação , Fontes Termais/microbiologia , Microbiologia do Solo , Microbiologia da Água , Bacillaceae/genética , Bacillaceae/efeitos da radiação , Biodiversidade , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bacilos Gram-Positivos/genética , Bacilos Gram-Positivos/efeitos da radiação , Dados de Sequência Molecular , Marrocos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos/citologia
15.
Braz. j. microbiol ; 46(2): 443-453, Apr-Jun/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-749707

RESUMO

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.


Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Bacilos Gram-Positivos/classificação , Bacilos Gram-Positivos/isolamento & purificação , Fontes Termais/microbiologia , Microbiologia do Solo , Microbiologia da Água , Biodiversidade , Bacillaceae/genética , Bacillaceae/efeitos da radiação , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bacilos Gram-Positivos/genética , Bacilos Gram-Positivos/efeitos da radiação , Dados de Sequência Molecular , Marrocos , Filogenia , /genética , Análise de Sequência de DNA , Esporos Bacterianos/citologia
16.
Antonie Van Leeuwenhoek ; 107(5): 1351-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25724129

RESUMO

Photobacterium species are ubiquitous in the aquatic environment and can be found in association with animal hosts including pathogenic and mutualistic associations. The traditional phenotypic characterization of Photobacterium is expensive, time-consuming and restricted to a limited number of features. An alternative is to infer phenotypic information directly from whole genome sequences. The present study evaluates the usefulness of whole genome sequences as a source of phenotypic information and compares diagnostic phenotypes of the Photobacterium species from the literature with the predicted phenotypes obtained from whole genome sequences. All genes coding for the specific proteins involved in metabolic pathways responsible for positive phenotypes of the seventeen diagnostic features were found in the majority of the Photobacterium genomes. In the Photobacterium species that were negative for a given phenotype, at least one or several genes involved in the respective biochemical pathways were absent.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Genoma Bacteriano , Photobacterium/genética , Photobacterium/isolamento & purificação , Sequência de Bases , Dados de Sequência Molecular , Fenótipo , Photobacterium/classificação , Filogenia
17.
Antonie Van Leeuwenhoek ; 107(2): 503-10, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25491120

RESUMO

Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain.


Assuntos
Leite/microbiologia , Streptococcus/classificação , Streptococcus/isolamento & purificação , Animais , Proteínas de Bactérias/análise , Técnicas de Tipagem Bacteriana , Composição de Bases , Camelus , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Marrocos , Filogenia , Proteoma/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Streptococcus/química , Streptococcus/genética
18.
Arch Microbiol ; 197(3): 359-70, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25533848

RESUMO

Microbial taxonomy should provide adequate descriptions of bacterial, archaeal, and eukaryotic microbial diversity in ecological, clinical, and industrial environments. Its cornerstone, the prokaryote species has been re-evaluated twice. It is time to revisit polyphasic taxonomy, its principles, and its practice, including its underlying pragmatic species concept. Ultimately, we will be able to realize an old dream of our predecessor taxonomists and build a genomic-based microbial taxonomy, using standardized and automated curation of high-quality complete genome sequences as the new gold standard.


Assuntos
Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Classificação/métodos , Genômica , Microbiologia/tendências , Simulação por Computador
19.
PeerJ ; 2: e427, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25024905

RESUMO

Five novel strains of Photobacterium (A-394T, A-373, A-379, A-397 and A-398) were isolated from bleached coral Madracis decactis (scleractinian) in the remote St Peter & St Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil. Healthy M. decactis specimens were also surveyed, but no strains were related to them. The novel isolates formed a distinct lineage based on the 16S rRNA, recA, and rpoA gene sequences analysis. Their closest phylogenetic neighbours were Photobacterium rosenbergii, P. gaetbulicola, and P. lutimaris, sharing 96.6 to 95.8% 16S rRNA gene sequence similarity. The novel species can be differentiated from the closest neighbours by several phenotypic and chemotaxonomic markers. It grows at pH 11, produces tryptophane deaminase, presents the fatty acid C18:0, but lacks C16:0 iso. The whole cell protein profile, based in MALDI-TOF MS, distinguished the strains of the novel species among each other and from the closest neighbors. In addition, we are releasing the whole genome sequence of the type strain. The name Photobacterium sanctipauli sp. nov. is proposed for this taxon. The G + C content of the type strain A-394(T) (= LMG27910(T) = CAIM1892(T)) is 48.2 mol%.

20.
Microbiol Spectr ; 2(1): CM-0010-2012, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26082119

RESUMO

Comprehensive collaborative studies from our laboratories reveal the extensive biodiversity of the microflora of the surfaces of smear-ripened cheeses. Two thousand five hundred ninety-seven strains of bacteria and 2,446 strains of yeasts from the surface of the smear-ripened cheeses Limburger, Reblochon, Livarot, Tilsit, and Gubbeen, isolated at three or four times during ripening, were identified; 55 species of bacteria and 30 species of yeast were found. The microfloras of the five cheeses showed many similarities but also many differences and interbatch variation. Very few of the commercial smear microorganisms, deliberately inoculated onto the cheese surface, were reisolated and then mainly from the initial stages of ripening, implying that smear cheese production units must have an adventitious "house" flora. Limburger cheese had the simplest microflora, containing two yeasts, Debaryomyces hansenii and Geotrichum candidum, and two bacteria, Arthrobacter arilaitensis and Brevibacterium aurantiacum. The microflora of Livarot was the most complicated, comprising 10 yeasts and 38 bacteria, including many gram-negative organisms. Reblochon also had a very diverse microflora containing 8 yeasts and 13 bacteria (excluding gram-negative organisms which were not identified), while Gubbeen had 7 yeasts and 18 bacteria and Tilsit had 5 yeasts and 9 bacteria. D. hansenii was by far the dominant yeast, followed in order by G. candidum, Candida catenulata, and Kluyveromyces lactis. B. aurantiacum was the dominant bacterium and was found in every batch of the 5 cheeses. The next most common bacteria, in order, were Staphylococcus saprophyticus, A. arilaitensis, Corynebacterium casei, Corynebacterium variabile, and Microbacterium gubbeenense. S. saprophyticus was mainly found in Gubbeen, and A. arilaitensis was found in all cheeses but not in every batch. C. casei was found in most batches of Reblochon, Livarot, Tilsit, and Gubbeen. C. variabile was found in all batches of Gubbeen and Reblochon but in only one batch of Tilsit and in no batch of Limburger or Livarot. Other bacteria were isolated in low numbers from each of the cheeses, suggesting that each of the 5 cheeses has a unique microflora. In Gubbeen cheese, several different strains of the dominant bacteria were present, as determined by pulsed-field gel electrophoresis, and many of the less common bacteria were present as single clones. The culture-independent method, denaturing gradient gel electrophoresis, resulted in identification of several bacteria which were not found by the culture-dependent (isolation and rep-PCR identification) method. It was thus a useful complementary technique to identify other bacteria in the cheeses. The gross composition, the rate of increase in pH, and the indices of proteolysis were different in most of the cheeses.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Queijo/microbiologia , Consórcios Microbianos , Leveduras/classificação , Leveduras/isolamento & purificação
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