Publications by authors named "Marc Vancanneyt"

112 Publications

Proposal of Henriciella barbarensis sp. nov. and Henriciella algicola sp. nov., stalked species of the genus and emendation of the genus Henriciella.

Int J Syst Evol Microbiol 2017 Aug 18;67(8):2804-2810. Epub 2017 Aug 18.

Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany.

Two Gram-negative, heterotrophic, aerobic, prosthecated, marine bacteria, designated strains MCS23T and MCS27T, were isolated from seawater samples. NaCl was required for growth. The major polar lipid detected in strain MCS27T was phosphatidylglycerol, whereas those detected in MCS23T were phosphatidylglycerol, sulfoquinovosyl diacylglycerol and 1,2-diacyl-3-α-d-glucuronopyranosyl-sn-glycerol taurineamide. The most abundant cellular fatty acids were C18 : 1ω7 and C16 : 0, hydroxyl-fatty acids were 3-OH C12 : 0 in both strains and 3-OH C11 : 0 in MCS23T. Strains MCS23T and MCS27T had DNA G+C contents of 57.0 and 55.0 mol%, respectively. The two strains shared 99.3 % 16S rRNA gene sequence similarity; levels of similarity with the type strains of species of the genus Henriciella were 99.4-97.8 % but DNA-DNA hybridizations were 53 % or lower. Besides their 16S rRNA gene sequences, the novel strains can be differentiated from other species of the genus Henriciella by cell morphology, lipid and fatty acid patterns and enzyme activities. The data obtained led to the identification of two novel species, for which the names Henriciella barbarensis sp. nov. (type strain MCS23T=LMG 28705T=CCUG 66934T) and Henriciella algicola sp. nov. (type strain MCS27T=LMG 29152T=CCUG 67844T) are proposed. As these two novel species are the first prosthecate species in the genus Henriciella, an emended genus description is also provided.
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http://dx.doi.org/10.1099/ijsem.0.002024DOI Listing
August 2017

Biodiversity of the Surface Microbial Consortia from Limburger, Reblochon, Livarot, Tilsit, and Gubbeen Cheeses.

Microbiol Spectr 2014 Feb;2(1):CM-0010-2012

Lehrstuhl für Mikrobielle Ökologie, Abteilung für Mikrobiologie, Zentralinstitut für Ernährungs-und Lebensmittelforschung, Technische Universität München, 85354 Freising, Germany.

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.
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http://dx.doi.org/10.1128/microbiolspec.CM-0010-2012DOI Listing
February 2014

Prosthecate sphingomonads: proposal of Sphingomonas canadensis sp. nov.

Int J Syst Evol Microbiol 2013 Sep 1;63(Pt 9):3214-3219. Epub 2013 Mar 1.

Laboratorium voor Microbiologie, Universiteit Gent, Belgium.

Two stalked, aerobic, catalase- and oxidase-positive rod-shaped isolates, VKM B-1508 ( = CB 258) and FWC47(T), were analysed using a polyphasic approach. While the morphology and the 16S rRNA gene sequence of strain VKM B-1508 were 100% identical to the ones of Sphingomonas leidyi DSM 4733(T), the morphology of FWC47(T) was different, and the closest recognized species were Sphingomonas oligophenolica S213(T) ( = DSM 17107(T)) and Sphingomonas leidyi DSM 4733(T) with 97.2% and 97.0% 16S rRNA gene sequence similarity, respectively. DNA-DNA hybridization studies supported the differentiation of strain FWC47(T) from S. oligophenolica and S. leidyi. Strain FWC47(T) grew optimally at 28-30 °C, and pH 6.0-8.0. The major respiratory quinone was Q10 and the major polyamine was sym-homospermidine. The major fatty acids were C(17:1)ω6c and C(18:1)ω7c and C(15:0) 2-OH was the major 2-hydroxy fatty acid. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethylamine and unidentified sphingoglycolipids. The G+C content of the genomic DNA of strain FWC47(T) was 67.1 mol%. Strain FWC47(T) differed from S. leidyi by its ability to assimilate l-alanine, maltose and sucrose, by the presence of β-galactosidase and α-chymotrypsin, and the lack of valine arylamidase and β-glucosidase activities. Contrary to S. leidyi, FWC47(T) did not reduce nitrate and could not use fructose, acetate and N-acetyl-glusosamine. In the genus Sphingomonas, the dimorphic life cycle involving a prosthecate sessile and a flagellated swarmer cell was hitherto only known from Sphingomonas leidyi. Therefore, strain FWC47(T) represents an additional distinct prosthecate species in this genus for which the name Sphingomonas canadensis is proposed. The type strain is FWC47(T) ( =LMG 27141(T) =CCUG 62982(T)).
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http://dx.doi.org/10.1099/ijs.0.048678-0DOI Listing
September 2013

Cauliform bacteria lacking phospholipids from an abyssal hydrothermal vent: proposal of Glycocaulis abyssi gen. nov., sp. nov., belonging to the family Hyphomonadaceae.

Int J Syst Evol Microbiol 2013 Jun 12;63(Pt 6):2207-2215. Epub 2012 Nov 12.

Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada.

Cauliform bacteria are prosthecate bacteria often specialized for oligotrophic environments. A polyphasic approach, comprising 16S rRNA gene sequencing, lipid analysis and salt tolerance characterizations, was used to clarify the taxonomy of one isolate, strain MCS 33(T), obtained from above the hot water plume of a deep-sea hydrothermal vent near Vancouver island, Canada. Cells contained no detectable phospholipids or sulpholipids, but did contain 1,2-di-O-acyl-3-O-α-D-glucopyranosylglycerol, 1,2-di-O-acyl-3-O-α-D-glucopyranuronosylglycerol and the novel lipid 1,2-di-O-acyl-3-[O-α-D-glucopyranuronosyl]glycerol-6'-N-glycine. It is assumed that the various glucoronosyl lipids are replacing, at least partially, the phospholipids in their various tasks in the cell cycle. The G+C content of the genomic DNA of strain MCS 33(T) was 62.8 mol%, and Q10 was the predominant respiratory ubiquinone. The 16S rRNA gene sequence of this chemoheterotrophic, aerobic, moderately halophilic strain showed only a low similarity of 94.4% to that of Oceanicaulis alexandrii C116-18(T), and both strains also differed based on their lipids. Although the novel strain was isolated from seawater sampled near a hydrothermal vent, its optimum temperature for growth was 30 °C. The main cellular fatty acids were C18:1ω7c, C18:0 and the unknown fatty acid ECL 11.798, and the main hydroxy fatty acid was C12:0 3-OH. The strain is proposed to represent a novel species of a new genus, Glycocaulis abyssi gen. nov., sp. nov. The type strain of the type species is MCS 33(T) (=LMG 27140(T)=CCUG 62981(T)).
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http://dx.doi.org/10.1099/ijs.0.047894-0DOI Listing
June 2013

Surface microbial consortia from Livarot, a French smear-ripened cheese.

Can J Microbiol 2011 Aug 4;57(8):651-60. Epub 2011 Aug 4.

Université de Caen Basse-Normandie, Unité des Microorganismes d'Intérêt Laitier et Alimentaire, E.A. 3213, IFR 146 ICORE, 14032 Caen CEDEX, France.

The surface microflora (902 isolates) of Livarot cheeses from three dairies was investigated during ripening. Yeasts were mainly identified by Fourier transform infrared spectroscopy. Geotrichum candidum was the dominating yeast among 10 species. Bacteria were identified using Biotype 100 strips, dereplicated by repetitive extragenic palindromic PCR (rep-PCR); 156 representative strains were identified by either BOX-PCR or (GTG)(5)-PCR, and when appropriate by 16S rDNA sequencing and SDS-PAGE analysis. Gram-positive bacteria accounted for 65% of the isolates and were mainly assigned to the genera Arthrobacter , Brevibacterium , Corynebacterium , and Staphylococcus . New taxa related to the genera Agrococcus and Leucobacter were found. Yeast and Gram-positive bacteria strains deliberately added as smearing agents were sometimes undetected during ripening. Thirty-two percent of the isolates were Gram-negative bacteria, which showed a high level of diversity and mainly included members of the genera Alcaligenes , Hafnia , Proteus , Pseudomonas , and Psychrobacter . Whatever the milk used (pasteurized or unpasteurized), similar levels of biodiversity were observed in the three dairies, all of which had efficient cleaning procedures and good manufacturing practices. It appears that some of the Gram-negative bacteria identified should now be regarded as potentially useful in some cheese technologies. The assessment of their positive versus negative role should be objectively examined.
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http://dx.doi.org/10.1139/w11-050DOI Listing
August 2011

Salinimicrobium marinum sp. nov., a halophilic bacterium of the family Flavobacteriaceae, and emended descriptions of the genus Salinimicrobium and Salinimicrobium catena.

Int J Syst Evol Microbiol 2010 Oct 13;60(Pt 10):2303-2306. Epub 2009 Nov 13.

Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, Pr. 100 Let Vladivostoku 159, 690022, Vladivostok, Russia.

Two novel heterotrophic, facultatively anaerobic, gliding and yellow-pigmented bacteria, designated strains KMM 6270(T) and KMM 6320, were isolated from different marine environments and studied using a polyphasic taxonomic approach. 16S rRNA gene sequence analysis placed the strains within the family Flavobacteriaceae. Strains KMM 6270(T) and KMM 6320 were most closely related to the type strains of recognized species of the genus Salinimicrobium (95.0-96.6 % 16S rRNA gene sequence similarity). The G+C content of the genomic DNA was 40-41 mol%. The strains grew with 0.5-15 % (w/v) NaCl (optimum 4 % NaCl) and at 4-41 °C (optimum 28-32 °C). Aesculin and gelatin were hydrolysed, but agar, casein, DNA and chitin were not. The phylogenetic data taken together with the results of the genotypic and phenotypic studies permit the classification of strains KMM 6270(T) and KMM 6320 as members of a novel species of the genus Salinimicrobium, for which the name Salinimicrobium marinum sp. nov. is proposed. The type strain is KMM 6270(T) (=KCTC 12719(T)=LMG 25395(T)).
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http://dx.doi.org/10.1099/ijs.0.019166-0DOI Listing
October 2010

Brevundimonas halotolerans sp. nov., Brevundimonas poindexterae sp. nov. and Brevundimonas staleyi sp. nov., prosthecate bacteria from aquatic habitats.

Int J Syst Evol Microbiol 2010 Aug 18;60(Pt 8):1837-1843. Epub 2009 Sep 18.

BCCM/LMG Bacteria Collection and Laboratory of Microbiology, Ghent University, Ghent, Belgium.

Eight strains of Gram-negative, bacteroid-shaped, prosthecate bacteria, isolated from brackish water (MCS24T, MCS17 and MCS35), the marine environment (CM260, CM272 and CM282) and activated sludge (FWC40T and FWC43T), were characterized using a polyphasic approach. Analysis of 16S rRNA gene sequences determined that all strains were affiliated to the alphaproteobacterial genus Brevundimonas, forming three distinct phyletic lineages within the genus. The strains grew best with 5-30 g NaCl l(-1) at 20-30 degrees C. DNA G+C contents for strains MCS24T, FWC40T and FWC43T were between 65 and 67 mol%, in accordance with values reported previously for other species of the genus. Moreover, chemotaxonomic data and physiological and biochemical tests allowed the phenotypic differentiation of three novel species within the genus Brevundimonas, for which the names Brevundimonas halotolerans sp. nov. (type strain MCS24T =LMG 25346T =CCUG 58273T), Brevundimonas poindexterae sp. nov. (type strain FWC40T =LMG 25261T =CCUG 57883T) and Brevundimonas staleyi sp. nov. (type strain FWC43T =LMG 25262T =CCUG 57884T) are proposed.
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http://dx.doi.org/10.1099/ijs.0.016832-0DOI Listing
August 2010

Reclassification of Flexibacter tractuosus (Lewin 1969) Leadbetter 1974 and 'Microscilla sericea' Lewin 1969 in the genus Marivirga gen. nov. as Marivirga tractuosa comb. nov. and Marivirga sericea nom. rev., comb. nov.

Int J Syst Evol Microbiol 2010 Aug 18;60(Pt 8):1858-1863. Epub 2009 Sep 18.

Korea Research Institute of Bioscience and Biotechnology, 52 Oun-dong, Yusong, Daejon 305-333, Republic of Korea.

The taxonomic position of the misclassified strains [Flexibacter] tractuosus KCTC 2958T and '[Microscilla] sericea' LMG 13021 was studied using a polyphasic approach. The two strains shared 99.1% 16S rRNA gene sequence similarity and 28% DNA-DNA relatedness. On the basis of the phylogenetic evidence supported by genotypic and phenotypic data [Flexibacter] tractuosus KCTC 2958T and '[Microscilla] sericea' LMG 13021 are classified as two distinct species in a novel genus, Marivirga, in the family 'Flammeovirgaceae', as Marivirga tractuosa comb. nov. and Marivirga sericea nom. rev., comb. nov., with strains KCTC 2958T (=ATCC 23168T =CIP 106410T =DSM 4126T =NBRC 15989T =NCIMB 1408T =VKM B-1430T) and LMG 13021T (=ATCC 23182T =NBRC 15983T =NCIMB 1403T), respectively, as the type strains. The type species is Marivirga tractuosa.
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http://dx.doi.org/10.1099/ijs.0.016121-0DOI Listing
August 2010

Bizionia echini sp. nov., isolated from a sea urchin.

Int J Syst Evol Microbiol 2010 Apr 6;60(Pt 4):928-931. Epub 2009 Aug 6.

Department of Microbiology, School of Bioscience and Biotechnology, Chungnam National University, 220 Gung-dong, Yuseong, Daejeon 305-764, Republic of Korea.

A bacterial strain, designated KMM 6177(T), was isolated from the sea urchin Strongylocentrotus intermedius and subjected to a polyphasic taxonomic investigation. The bacterium was found to be heterotrophic, aerobic, non-motile by gliding and orange-pigmented. Comparative phylogenetic analysis based on 16S rRNA gene sequencing placed the marine isolate in the genus Bizionia, a member of the family Flavobacteriaceae, with 16S rRNA gene sequence similarity of 94.9-98.6 % with recognized Bizionia species. Strain KMM 6177(T) grew at 4-39 degrees C and with 1-8 % NaCl. It produced alkaline phosphatase, catalase and oxidase and hydrolysed aesculin, gelatin, DNA and Tween 20. The predominant fatty acids were iso-C(15 : 1), iso-C(15 : 0), iso-C(15 : 0) 3-OH, iso-C(17 : 0) 3-OH and a summed feature (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c). The DNA G+C content was 34.4 mol%. A combination of phylogenetic, genotypic and phenotypic data clearly indicated that strain KMM 6177(T) represents a novel species in the genus Bizionia, for which the name Bizionia echini sp. nov. is proposed. The type strain is KMM 6177(T) (=KCTC 22015(T)=LMG 25220(T)).
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http://dx.doi.org/10.1099/ijs.0.013193-0DOI Listing
April 2010

Leeuwenhoekiella palythoae sp. nov., a new member of the family Flavobacteriaceae.

Int J Syst Evol Microbiol 2009 Dec 30;59(Pt 12):3074-7. Epub 2009 Jul 30.

Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, Pr. 100 Let Vladivostoku 159, 690022 Vladivostok, Russia.

The taxonomic status of a novel, heterotrophic, strictly aerobic, gliding and yellow-orange-pigmented bacterium (strain KMM 6264(T)), associated with the coral Palythoa, was determined. The 16S rRNA gene sequence analysis indicated that strain KMM 6264(T) clustered with the recognized species of the genus Leeuwenhoekiella of the family Flavobacteriaceae with 96.4-98.2 % sequence similarity. DNA-DNA reassociation levels between the isolate and the type strains of Leeuwenhoekiella species were 15-22 %. The DNA G+C content was 41.2 mol%. The phylogenetic evidence and the results of genomic and phenotypic analyses showed that the isolate should be classified as a member of a novel species of the genus Leeuwenhoekiella, for which the name Leeuwenhoekiella palythoae sp. nov. is proposed. The type strain is KMM 6264(T) (=KCTC 22020(T)=LMG 24856(T)).
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http://dx.doi.org/10.1099/ijs.0.010371-0DOI Listing
December 2009

Pantoea vagans sp. nov., Pantoea eucalypti sp. nov., Pantoea deleyi sp. nov. and Pantoea anthophila sp. nov.

Int J Syst Evol Microbiol 2009 Sep 20;59(Pt 9):2339-45. Epub 2009 Jul 20.

Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa.

Bacteria isolated from eucalyptus leaves and shoots showing symptoms of blight and die-back collected in Uganda, Uruguay and Argentina and from maize displaying brown stalk rot symptoms in South Africa were tentatively placed in the genus Pantoea on the basis of phenotypic and biochemical tests. These isolates, together with two strains (LMG 2558 and LMG 2560) previously assigned to Pantoea agglomerans based on protein electrophoregrams but later excluded from this species, were further investigated using molecular techniques. 16S rRNA gene sequencing and multilocus sequence analyses (MLSA) revealed that the strains were phylogenetically closely related to Pantoea agglomerans, Pantoea stewartii and Pantoea ananatis. MLSA and amplified fragment length polymorphism analysis placed the strains into four separate clusters, not containing any of the type strains of species of the genus Pantoea. DNA-DNA hybridization confirmed the classification of the isolates into four novel species, for which the names Pantoea vagans sp. nov. (type strain R-21566T=LMG 24199T=BCC 105T=BD 765T), Pantoea eucalypti sp. nov. (type strain R-25678T=LMG 24197T=BCC 076T=BD 769T), Pantoea deleyi sp. nov. (type strain R-31523T=LMG 24200T=BCC 109T=BD 767T) and Pantoea anthophila sp. nov. (type strain LMG 2558T=BD 871T=NCPPB 1682T) are proposed.
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http://dx.doi.org/10.1099/ijs.0.009241-0DOI Listing
September 2009

Winogradskyella rapida sp. nov., isolated from protein-enriched seawater.

Int J Syst Evol Microbiol 2009 Sep 15;59(Pt 9):2180-4. Epub 2009 Jul 15.

Marine Microbiology, Department of Pure and Applied Natural Sciences, University of Kalmar, SE-39182 Kalmar, Sweden.

Flavobacteria are emerging as an important group of organisms associated with the degradation of complex organic matter in aquatic environments. A novel Gram-reaction-negative, heterotrophic, rod-shaped, aerobic, yellow-pigmented and gliding bacterium, strain SCB36T, was isolated from a protein-enriched seawater sample, collected at Scripps Pier, Southern California Bight (Eastern Pacific). Analysis of the 16S rRNA gene sequence showed that the bacterium was related to members of the genus Winogradskyella within the family Flavobacteriaceae, phylum Bacteroidetes. 16S rRNA gene sequence similarity to the other Winogradskyella species was 94.5-97.1%. DNA-DNA relatedness between strain SCB36T and Winogradskyella thalassocola KMM 3907T, its closest relative in terms of 16S rRNA gene sequence similarity, was 20%. On the basis of the phylogenetic and phenotypic data, strain SCB36T represents a novel species of the genus Winogradskyella, for which the name Winogradskyella rapida sp. nov. is proposed. The type strain is SCB36T (=CECT 7392T=CCUG 56098T).
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http://dx.doi.org/10.1099/ijs.0.008334-0DOI Listing
September 2009

Winogradskyella echinorum sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from the sea urchin Strongylocentrotus intermedius.

Int J Syst Evol Microbiol 2009 Jun;59(Pt 6):1465-8

Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, Pr. 100 Let Vladivostoku 159, 690022 Vladivostok, Russia.

The taxonomic position of a novel marine, yellow-pigmented bacterium, designated strain KMM 6211(T), was examined by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 6211(T) is a member of the family Flavobacteriaceae, phylum Bacteroidetes. The closest relative of strain KMM 6211(T) was Winogradskyella eximia KMM 3944(T), the sequence similarity being 97.1 %. The DNA G+C content of KMM 6211(T) was 33.6 mol%. The strain was motile by gliding and grew with 1-6 % NaCl and at 4-37 degrees C. Aesculin, casein and gelatin were hydrolysed, but agar, starch, DNA and chitin were not degraded. On the basis of phylogenetic data and phenotypic differences between the isolate and recognized Winogradskyella species, strain KMM 6211(T) represents a novel species of the genus Winogradskyella, for which the name Winogradskyella echinorum sp. nov. is proposed. The type strain is KMM 6211(T) (=KCTC 22026(T)=LMG 24757(T)).
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http://dx.doi.org/10.1099/ijs.0.005421-0DOI Listing
June 2009

Pediococcus argentinicus sp. nov. from Argentinean fermented wheat flour and identification of Pediococcus species by pheS, rpoA and atpA sequence analysis.

Int J Syst Evol Microbiol 2008 Dec;58(Pt 12):2909-16

Laboratory of Microbiology, Ghent University, Ghent, Belgium.

A Gram-positive, small coccus-shaped lactic acid bacterium, strain LMG 23999(T), was isolated from Argentinean wheat flour. 16S rRNA gene sequence analysis revealed that the phylogenetic position of the novel strain was within the genus Pediococcus, with Pediococcus stilesii, Pediococcus pentosaceus and Pediococcus acidilactici as its closest relatives (97.7, 97.3 and 96.9 % gene sequence similarity, respectively). Fluorescent amplified fragment length polymorphism fingerprinting of whole genomes and whole-cell protein electrophoresis confirmed the unique taxonomic status of the novel strain. DNA-DNA hybridizations, DNA G+C content determination, comparative sequence analysis of the pheS, rpoA and atpA genes and physiological and biochemical characterization demonstrated that strain LMG 23999(T) (=CCUG 54535(T)=CRL 776(T)) represents a novel species for which the name Pediococcus argentinicus sp. nov. is proposed. Multi-locus sequence analysis based on pheS, rpoA and atpA genes was found to be a suitable method for the identification of species of the genus Pediococcus.
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http://dx.doi.org/10.1099/ijs.0.65833-0DOI Listing
December 2008

Mycetocola reblochoni sp. nov., isolated from the surface microbial flora of Reblochon cheese.

Int J Syst Evol Microbiol 2008 Dec;58(Pt 12):2687-93

School of Biology, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.

Four Gram-positive, aerobic, non-sporulating, rod-shaped bacteria isolated from the surface microflora of Reblochon cheese at the late stage of ripening had chemotaxonomic properties characteristic of members of the family Microbacteriaceae. The isolates had virtually identical SDS-PAGE whole-organism protein patterns, shared many chemical and phenotypic characteristics and formed an independent branch in the Microbacteriaceae 16S rRNA gene tree that was most closely related to the type strains of Mycetocola species. The new isolates had chemotaxonomic properties consistent with their classification in the genus Mycetocola but were readily distinguished from recognized members of this taxon based on DNA-DNA relatedness, whole-organism protein and phenotypic data. The combined genotypic and phenotypic data indicate that the isolates should be classified in the genus Mycetocola as members of a novel species, for which the name Mycetocola reblochoni sp. nov. is proposed. The type strain is LMG 22367(T) (=R-20377(T) =BRB-1L41(T) =DSM 18580(T)).
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http://dx.doi.org/10.1099/ijs.0.64201-0DOI Listing
December 2008

Phylogeny and identification of Pantoea species associated with plants, humans and the natural environment based on multilocus sequence analysis (MLSA).

Syst Appl Microbiol 2008 Dec 12;31(6-8):447-60. Epub 2008 Nov 12.

Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa.

Species belonging to the genus of Pantoea are commonly isolated from plants, humans and the natural environment. The species of the genus are phenotypically closely related, making rapid identification of Pantoea strains to the species level difficult. Multilocus sequence analysis (MLSA) was evaluated as a means for rapid classification and identification of Pantoea strains. Four housekeeping genes, gyrB, rpoB, atpD and infB, were sequenced for strains assigned to the genus. Included in the study were (1) reference strains from the seven currently recognized species of Pantoea, (2) strains belonging to Brenner DNA groups II, IV and V, previously isolated from clinical samples and difficult to identify because of high phenotypic similarity to P. agglomerans or P. ananatis and (3) isolates from diseased Eucalyptus, maize and onion, assigned to the genus on the basis of phenotypic tests. Phylogenetic trees were constructed from the sequences of the four housekeeping genes. The "core"Pantoea species formed a cluster separate from the "Japanese" species which formed a tight cluster that included the genus Tatumella when the tree was based on concatenated sequences of the four genes. The MLSA data further suggested the existence of ten potential novel species, phylogenetically related to the currently recognized Pantoea species and the possible inclusion of Pectobacterium cypripedii in the genus Pantoea. When compared with DNA-DNA hybridization data, a good congruence was observed between both methods, with gyrB sequence data being the most consistent. In conclusion, MLSA of partial nucleotide sequences of the genes gyrB, rpoB, atpD and infB can be used for classification, identification and phylogenetic analyses of Pantoea strains.
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http://dx.doi.org/10.1016/j.syapm.2008.09.004DOI Listing
December 2008

Phylogeny by a polyphasic approach of the order Caulobacterales, proposal of Caulobacter mirabilis sp. nov., Phenylobacterium haematophilum sp. nov. and Phenylobacterium conjunctum sp. nov., and emendation of the genus Phenylobacterium.

Int J Syst Evol Microbiol 2008 Aug;58(Pt 8):1939-49

Helmholtz Center for Infection Research, Chemical Microbiology, Inhoffenstrasse 7, Braunschweig, Germany.

Three strains of Gram-negative, rod-shaped, non-spore-forming bacteria were isolated from fresh water and human blood. As determined by analyses of 16S rRNA gene sequences, the prosthecate strain FWC 38T was affiliated to the alphaproteobacterial genus Caulobacter, with Caulobacter henricii (96.8 %) and Caulobacter fusiformis (96.8 %) as its closest relatives. The non-prosthecate strain LMG 11050T and the prosthecate strain FWC 21T both belonged to the genus Phenylobacterium with Phenylobacterium koreense (96.9 %) and Phenylobacterium immobile (96.3 %) as the closest relatives. This affiliation was supported by chemotaxonomic data (polar lipids and cellular fatty acids). Physiological and biochemical tests allowed genotypic and phenotypic differentiation of the novel strains from all hitherto recognized species of the genera Caulobacter and Phenylobacterium. The strains therefore represent novel species, for which the names Caulobacter mirabilis sp. nov. (type strain FWC 38T=LMG 24261T=CCUG 55073T), Phenylobacterium conjunctum (type strain FWC 21T=LMG 24262T=CCUG 55074T), the first described prosthecate Phenylobacterium species, and Phenylobacterium haematophilum sp. nov. (type strain LMG 11050T=CCUG 26751T) are proposed. Marker nucleotides within the 16S rRNA genes were determined for the genera Asticcacaulis, Brevundimonas, Caulobacter and Phenylobacterium and the description of the genus Phenylobacterium is emended.
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http://dx.doi.org/10.1099/ijs.0.65567-0DOI Listing
August 2008

Genotypic diversity, antimicrobial resistance, and virulence factors of human isolates and probiotic cultures constituting two intraspecific groups of Enterococcus faecium isolates.

Appl Environ Microbiol 2008 Jul 16;74(14):4247-55. Epub 2008 May 16.

Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.

The intraspecific relationships among a collection of Enterococcus faecium isolates comprising probiotic cultures and human clinical isolates were investigated through the combined use of two high-resolution DNA-fingerprinting techniques. In addition, the incidences of antimicrobial resistance and virulence traits were investigated. A total of 128 E. faecium isolates from human clinical or nonclinical sources or used as probiotic cultures were subjected to fluorescent amplified fragment length polymorphism (FAFLP) fingerprinting and pulsed-field gel electrophoresis (PFGE) analysis of SmaI macrorestriction patterns. Susceptibilities to 16 antimicrobial agents were tested using broth microdilution, and the presence of the corresponding resistance genes was investigated using PCR. Multiplex PCR was used to detect the presence of the enterococcal virulence genes asa1, gelE, cylA, esp, and hyl. The results of the study showed that two intraspecific genomic groups (I and II) were obtained in FAFLP analysis. PFGE analysis demonstrated high variability within these two groups but also indicated that some probiotic cultures were indistinguishable and that a number of clinical isolates may be reisolations of commercial probiotic cultures. Compared to group II, which contained the majority of the probiotic isolates and fewer human clinical isolates, higher phenotypic and genotypic resistance frequencies were observed in group I. Two probiotic isolates were phenotypically resistant to erythromycin, one of which contained an erm(B) gene that was not transferable to enterococcal recipients. None of the probiotic E. faecium isolates demonstrated the presence of the tested virulence genes. The previously reported observation that E. faecium consists of two intraspecific genomic groups was further substantiated by FAFLP fingerprinting of 128 isolates. In combination with antimicrobial resistance and virulence testing, this grouping might represent an additional criterion in assessing the safety of new potential probiotic E. faecium isolates.
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http://dx.doi.org/10.1128/AEM.02474-07DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493176PMC
July 2008

alpha-Chitinase activity among lactic acid bacteria.

Syst Appl Microbiol 2008 Jun;31(2):151-6

Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Grønnegårdsvej 15, 1870 Frederiksberg C., Denmark.

Chitin is a polysaccharide widely distributed in nature. Among 115 strains from 29 species of lactic acid bacteria only strains belonging to Carnobacterium divergens and Carnobacterium maltaromaticum hydrolyzed alpha-chitin. This activity was not affected by temperature (10 degrees C versus 30 degrees C) and in most cases not subject to glucose catabolite repression.
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http://dx.doi.org/10.1016/j.syapm.2008.03.003DOI Listing
June 2008

Taxonomic structure and stability of the bacterial community in belgian sourdough ecosystems as assessed by culture and population fingerprinting.

Appl Environ Microbiol 2008 Apr 29;74(8):2414-23. Epub 2008 Feb 29.

Laboratory of Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.

A total of 39 traditional sourdoughs were sampled at 11 bakeries located throughout Belgium which were visited twice with a 1-year interval. The taxonomic structure and stability of the bacterial communities occurring in these traditional sourdoughs were assessed using both culture-dependent and culture-independent methods. A total of 1,194 potential lactic acid bacterium (LAB) isolates were tentatively grouped and identified by repetitive element sequence-based PCR, followed by sequence-based identification using 16S rRNA and pheS genes from a selection of genotypically unique LAB isolates. In parallel, all samples were analyzed by denaturing gradient gel electrophoresis (DGGE) of V3-16S rRNA gene amplicons. In addition, extensive metabolite target analysis of more than 100 different compounds was performed. Both culturing and DGGE analysis showed that the species Lactobacillus sanfranciscensis, Lactobacillus paralimentarius, Lactobacillus plantarum, and Lactobacillus pontis dominated the LAB population of Belgian type I sourdoughs. In addition, DGGE band sequence analysis demonstrated the presence of Acetobacter sp. and a member of the Erwinia/Enterobacter/Pantoea group in some samples. Overall, the culture-dependent and culture-independent approaches each exhibited intrinsic limitations in assessing bacterial LAB diversity in Belgian sourdoughs. Irrespective of the LAB biodiversity, a large majority of the sugar and amino acid metabolites were detected in all sourdough samples. Principal component-based analysis of biodiversity and metabolic data revealed only little variation among the two samples of the sourdoughs produced at the same bakery. The rare cases of instability observed could generally be linked with variations in technological parameters or differences in detection capacity between culture-dependent and culture-independent approaches. Within a sampling interval of 1 year, this study reinforces previous observations that the bakery environment rather than the type or batch of flour largely determines the development of a stable LAB population in sourdoughs.
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http://dx.doi.org/10.1128/AEM.02771-07DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2293155PMC
April 2008

Commercial ripening starter microorganisms inoculated into cheese milk do not successfully establish themselves in the resident microbial ripening consortia of a South german red smear cheese.

Appl Environ Microbiol 2008 Apr 15;74(7):2210-7. Epub 2008 Feb 15.

Abteilung Mikrobiologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, D-85350 Freising, Germany.

Production of smear-ripened cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. These microorganisms often originate from the cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. While commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. Thus, the fate of the smear starters of a German Limburger cheese subjected to the "old-young" smearing technique was investigated during ripening. The cheese milk was supplemented with a commercial smear starter culture containing Debaryomyces hansenii, Galactomyces geotrichum, Arthrobacter arilaitensis, and Brevibacterium aurantiacum. Additionally, the cheese surface was inoculated with an extremely stable in-house microbial consortium. A total of 1,114 yeast and 1,201 bacterial isolates were identified and differentiated by Fourier transform infrared spectroscopy. Furthermore, mitochondrial DNA restriction fragment length polymorphism, random amplified polymorphic DNA, repetitive PCR, and pulsed field gel electrophoresis analyses were used to type selected isolates below the species level. The D. hansenii starter strain was primarily found early in the ripening process. The G. geotrichum starter strain in particular established itself after relocation to a new ripening room. Otherwise, it occurred at low frequencies. The bacterial smear starters could not be reisolated from the cheese surface at all. It is concluded that none of the smear starter strains were able to compete significantly and in a stable fashion against the resident microbial consortia, a result which might have been linked to the method of application. This finding raises the issue of whether addition of starter microorganisms during production of this type of cheese is actually necessary.
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http://dx.doi.org/10.1128/AEM.01663-07DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2292584PMC
April 2008

Leuconostoc holzapfelii sp. nov., isolated from Ethiopian coffee fermentation and assessment of sequence analysis of housekeeping genes for delineation of Leuconostoc species.

Int J Syst Evol Microbiol 2007 Dec;57(Pt 12):2952-2959

Laboratory of Microbiology, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium.

A Gram-positive, ovoid lactic acid bacterium, strain LMG 23990(T), was isolated from Ethiopian coffee fermentation. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc citreum and Leuconostoc lactis as the closest neighbours (99.6 and 99.0 % 16S rRNA gene sequence similarity, respectively). Genotypic fingerprinting by fluorescent amplified fragment length polymorphism, whole-cell protein electrophoresis, DNA-DNA hybridizations, comparative sequence analysis of pheS, rpoA, atpA, and physiological and biochemical tests allowed us to differentiate strain LMG 23990(T) from all established Leuconostoc species. Strain LMG 23990(T) (=CCUG 54536(T)) therefore represents a novel species, for which the name Leuconostoc holzapfelii sp. nov. is proposed.
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http://dx.doi.org/10.1099/ijs.0.65292-0DOI Listing
December 2007

Maribacter polysiphoniae sp. nov., isolated from a red alga.

Int J Syst Evol Microbiol 2007 Dec;57(Pt 12):2840-2843

Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, Pr. 100 Let Vladivostoku 159, 690022 Vladivostok, Russia.

A novel gliding, heterotrophic, Gram-negative, yellow-orange-pigmented, aerobic, oxidase- and catalase-positive bacterium, designated strain KMM 6151(T), was isolated from the Pacific red alga Polysiphonia japonica. Analysis of the 16S rRNA gene sequence of the strain revealed that it formed a distinct lineage within the genus Maribacter, family Flavobacteriaceae, with sequence similarities in the range 94.6-96.9 %. On the basis of phenotypic, genotypic and phylogenetic data, strain KMM 6151(T) represents a novel species of the genus Maribacter, for which the name Maribacter polysiphoniae sp. nov. is proposed. The type strain is KMM 6151(T) (=KCTC 22021(T)=LMG 23671(T)).
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http://dx.doi.org/10.1099/ijs.0.65181-0DOI Listing
December 2007

Identification of lactobacilli by pheS and rpoA gene sequence analyses.

Int J Syst Evol Microbiol 2007 Dec;57(Pt 12):2777-2789

BCCMTM/LMG Bacteria Collection, Ghent University, K.L. Ledeganckstraat 35, Ghent 9000, Belgium.

The aim of this study was to evaluate the use of the phenylalanyl-tRNA synthase alpha subunit (pheS) and the RNA polymerase alpha subunit (rpoA) partial gene sequences for species identification of members of the genus Lactobacillus. Two hundred and one strains representing the 98 species and 17 subspecies were examined. The pheS gene sequence analysis provided an interspecies gap, which in most cases exceeded 10 % divergence, and an intraspecies variation of up to 3 %. The rpoA gene sequences revealed a somewhat lower resolution, with an interspecies gap normally exceeding 5 % and an intraspecies variation of up to 2 %. The combined use of pheS and rpoA gene sequences offers a reliable identification system for nearly all species of the genus Lactobacillus. The pheS and rpoA gene sequences provide a powerful tool for the detection of potential novel Lactobacillus species and synonymous taxa. In conclusion, the pheS and rpoA gene sequences can be used as alternative genomic markers to 16S rRNA gene sequences and have a higher discriminatory power for reliable identification of species of the genus Lactobacillus.
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http://dx.doi.org/10.1099/ijs.0.64711-0DOI Listing
December 2007

Methods for extracting biochemical information from bacterial Raman spectra: focus on a group of structurally similar biomolecules--fatty acids.

Anal Chim Acta 2007 Nov 29;603(2):167-75. Epub 2007 Sep 29.

Ghent University, Department of Analytical Chemistry, Proeftuinstraat 86, B-9000 Ghent, Belgium.

In this paper we explore the possibilities of Raman spectroscopy in order to deduce information on the fatty acid composition of bacterial cells. Therefore, representative strains of two bacterial taxa were each cultured in different conditions and in parallel analyzed by Raman spectroscopy and gaschromatographic FAME analysis. Raman spectra of pure fatty acids were recorded and used as reference spectra. The culturing conditions for each strain could be easily distinguished by the fatty acid information retrieved from bacterial Raman spectra. Chemometric techniques such as EMSC and PCA allowed to extract information about groups of fatty acids, that was consistent with the results from FAME analysis. Although the information retrieved from Raman spectroscopy is not as refined as that from FAME analysis, the presented methods could be useful to obtain basic information on the fatty acid present in bacteria when performing Raman spectroscopic analysis for fast whole cell profiling, which provides information for different types of cell components (fatty acids, amino acids, primary metabolites, etc.).
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http://dx.doi.org/10.1016/j.aca.2007.09.049DOI Listing
November 2007

Validation of the (GTG)(5)-rep-PCR fingerprinting technique for rapid classification and identification of acetic acid bacteria, with a focus on isolates from Ghanaian fermented cocoa beans.

Int J Food Microbiol 2008 Jun 4;125(1):79-90. Epub 2007 Sep 4.

Research Group of Industrial Microbiology and Food Biotechnology, Department of Applied Biological Sciences and Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.

Amplification of repetitive bacterial DNA elements through the polymerase chain reaction (rep-PCR fingerprinting) using the (GTG)(5) primer, referred to as (GTG)(5)-PCR fingerprinting, was found a promising genotypic tool for rapid and reliable speciation of acetic acid bacteria (AAB). The method was evaluated with 64 AAB reference strains, including 31 type strains, and 132 isolates from Ghanaian, fermented cocoa beans, and was validated with DNA:DNA hybridization data. Most reference strains, except for example all Acetobacter indonesiensis strains and Gluconacetobacter liquefaciens LMG 1509, grouped according to their species designation, indicating the usefulness of this technique for identification to the species level. Moreover, exclusive patterns were obtained for most strains, suggesting that the technique can also be used for characterization below species level or typing of AAB strains. The (GTG)(5)-PCR fingerprinting allowed us to differentiate four major clusters among the fermented cocoa bean isolates, namely A. pasteurianus (cluster I, 100 isolates), A. syzygii- or A. lovaniensis-like (cluster II, 23 isolates), and A. tropicalis-like (clusters III and IV containing 4 and 5 isolates, respectively). A. syzygii-like and A. tropicalis-like strains from cocoa bean fermentations were reported for the first time. Validation of the method and indications for reclassifications of AAB species and existence of new Acetobacter species were obtained through 16S rRNA sequencing analyses and DNA:DNA hybridizations. Reclassifications refer to A. aceti LMG 1531, Ga. xylinus LMG 1518, and Ga. xylinus subsp. sucrofermentans LMG 18788(T).
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http://dx.doi.org/10.1016/j.ijfoodmicro.2007.02.030DOI Listing
June 2008

Algibacter mikhailovii sp. nov., a novel marine bacterium of the family Flavobacteriaceae, and emended description of the genus Algibacter.

Int J Syst Evol Microbiol 2007 Sep;57(Pt 9):2147-2150

Korean Collection for Type Cultures, Genetic Resources Center, Korea Institute of Bioscience and Biotechnology, Yusong, Daejon 305-333, Republic of Korea.

A novel marine bacterium, designated strain KMM 6171(T), was subjected to taxonomic analysis by using a polyphasic approach. Colonies were yellow-pigmented and cells were Gram-negative, heterotrophic rods displaying slow gliding motility. 16S rRNA gene sequence analysis indicated that strain KMM 6171(T) was closely related to the genus Algibacter, a member of the family Flavobacteriaceae, with sequence similarity of 96.7-96.8 %. The predominant cellular fatty acids were iso-C15 : 1, iso-C15 : 0, anteiso-C15 : 0, C15 : 0, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH and summed feature 3, comprising C16 : 1omega7c and/or iso-C15 : 0 2-OH. The DNA G+C content was 35.1 mol%. On the basis of the phenotypic, genotypic, chemotaxonomic and phylogenetic data, strain KMM 6171(T) represents a novel species of the genus Algibacter, for which the name Algibacter mikhailovii sp. nov. is proposed. The type strain is KMM 6171(T) (=KCTC 12710(T)=LMG 23988(T)). An emended description of the genus Algibacter based on the new data is also given.
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http://dx.doi.org/10.1099/ijs.0.65165-0DOI Listing
September 2007

Influence of geographical origin and flour type on diversity of lactic acid bacteria in traditional Belgian sourdoughs.

Appl Environ Microbiol 2007 Oct 3;73(19):6262-9. Epub 2007 Aug 3.

Laboratory of Microbiology, Department of Biochemistry, Physiology and Microbiology, Ghent University, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium.

A culture-based approach was used to investigate the diversity of lactic acid bacteria (LAB) in Belgian traditional sourdoughs and to assess the influence of flour type, bakery environment, geographical origin, and technological characteristics on the taxonomic composition of these LAB communities. For this purpose, a total of 714 LAB from 21 sourdoughs sampled at 11 artisan bakeries throughout Belgium were subjected to a polyphasic identification approach. The microbial composition of the traditional sourdoughs was characterized by bacteriological culture in combination with genotypic identification methods, including repetitive element sequence-based PCR fingerprinting and phenylalanyl-tRNA synthase (pheS) gene sequence analysis. LAB from Belgian sourdoughs belonged to the genera Lactobacillus, Pediococcus, Leuconostoc, Weissella, and Enterococcus, with the heterofermentative species Lactobacillus paralimentarius, Lactobacillus sanfranciscensis, Lactobacillus plantarum, and Lactobacillus pontis as the most frequently isolated taxa. Statistical analysis of the identification data indicated that the microbial composition of the sourdoughs is mainly affected by the bakery environment rather than the flour type (wheat, rye, spelt, or a mixture of these) used. In conclusion, the polyphasic approach, based on rapid genotypic screening and high-resolution, sequence-dependent identification, proved to be a powerful tool for studying the LAB diversity in traditional fermented foods such as sourdough.
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http://dx.doi.org/10.1128/AEM.00894-07DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2075033PMC
October 2007

Infectivity of Lactobacillus rhamnosus and Lactobacillus paracasei isolates in a rat model of experimental endocarditis.

J Med Microbiol 2007 Aug;56(Pt 8):1017-1024

Department of Fundamental Microbiology, University of Lausanne, Switzerland.

The potential pathogenicity of selected (potentially) probiotic and clinical isolates of Lactobacillus rhamnosus and Lactobacillus paracasei was investigated in a rat model of experimental endocarditis. In addition, adhesion properties of the lactobacilli for fibrinogen, fibronectin, collagen and laminin, as well as the killing activity of the platelet-microbicidal proteins fibrinopeptide A (FP-A) and connective tissue activating peptide 3 (CTAP-3), were assessed. The 90 % infective dose (ID(90)) of the L. rhamnosus endocarditis isolates varied between 10(6) and 10(7) c.f.u., whereas four of the six (potentially) probiotic L. rhamnosus isolates showed an ID(90) that was at least 10-fold higher (10(8) c.f.u.) (P<0.001). In contrast, the two other probiotic L. rhamnosus isolates exhibited an ID(90) (10(6) and 10(7) c.f.u.) comparable to the ID(90) of the clinical isolates of this species investigated (P>0.05). Importantly, these two probiotic isolates shared the same fluorescent amplified fragment length polymorphism cluster type as the clinical isolate showing the lowest ID(90) (10(6) c.f.u.). L. paracasei tended to have a lower infectivity than L. rhamnosus (ID(90) of 10(7) to > or =10(8) c.f.u.). All isolates had comparable bacterial counts in cardiac vegetations (P>0.05). Except for one L. paracasei strain adhering to all substrates, all tested lactobacilli adhered only weakly or not at all. The platelet peptide FP-A did not show any microbicidal activity against the tested lactobacilli, whereas CTAP-3 killed the majority of the isolates. In general, these results indicate that probiotic lactobacilli display a lower infectivity in experimental endocarditis compared with true endocarditis pathogens. However, the difference in infectivity between L. rhamnosus endocarditis and (potentially) probiotic isolates could not be explained by differences in adherence or platelet microbicidal protein susceptibility. Other disease-promoting factors may exist in these organisms and warrant further investigation.
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http://dx.doi.org/10.1099/jmm.0.46929-0DOI Listing
August 2007

Lactobacillus crustorum sp. nov., isolated from two traditional Belgian wheat sourdoughs.

Int J Syst Evol Microbiol 2007 Jul;57(Pt 7):1461-1467

BCCM/LMG Bacteria Collection, Department of Biochemistry, Physiology and Microbiology, Ghent University, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium.

A polyphasic taxonomic study of the lactic acid bacteria (LAB) population in three traditional Belgian sourdoughs, sampled between 2002 and 2004, revealed a group of isolates that could not be assigned to any recognized LAB species. Initially, sourdough isolates were screened by means of (GTG)(5)-PCR fingerprinting. Four isolates displaying unique (GTG)(5)-PCR patterns were further investigated by means of phenylalanyl-tRNA synthase (pheS) gene sequence analysis and represented a bifurcated branch that could not be allocated to any LAB species present in the in-house pheS database. Their phylogenetic affiliation was determined using 16S rRNA gene sequence analysis and showed that the four sourdough isolates belong to the Lactobacillus plantarum group with Lactobacillus mindensis, Lactobacillus farciminis and Lactobacillus nantensis as closest relatives. Further genotypic and phenotypic studies, including whole-cell protein analysis (SDS-PAGE), amplified fragment length polymorphism (AFLP) fingerprinting, DNA-DNA hybridization, DNA G+C content analysis, growth characteristics and biochemical features, demonstrated that the new sourdough isolates represent a novel Lactobacillus species for which the name Lactobacillus crustorum sp. nov. is proposed. The type strain of the new species is LMG 23699(T) (=CCUG 53174(T)).
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http://dx.doi.org/10.1099/ijs.0.64836-0DOI Listing
July 2007