RESUMEN
Dry aging (DA) allows for the storage of meat without packaging at 0 to 3°C for several weeks. It enhances the production of pleasant flavors, tenderness, and juiciness in meat. Due to the long storage period and roles of indigenous microbiota in the maturation of several meat products, the microbiota of DA meat is of interest in terms of microbial contributions and food hygiene but has not yet been characterized in detail. This study identified the microbiota of pork loins during DA using culturing and culture-independent meta-16S rRNA gene sequencing and elucidated its characteristics. The amounts of free amino acids and profiles of aroma-active compounds were also monitored by high-performance liquid chromatography and gas chromatography, respectively. The meta-16S rRNA gene sequencing revealed that Pseudomonas spp. generally dominated the microbiota throughout DA; however, the culturing analysis showed marked changes in the species composition during DA. Acinetobacter spp. were the second most dominant bacteria before DA in the culture-independent analysis but became a minor population during DA. The cell numbers of yeasts showed an increased tendency during DA, and Debaryomyces hansenii was the only microorganism isolated from all meat samples throughout DA. Well-known foodborne pathogens were not observed in two microbiota analyses. The amounts of free amino acids were increased by DA, and the number of aroma-active compounds and their flavor dilution values markedly changed during DA. Most microbial isolates showed positive reactions with proteolytic and lipolytic activities, suggesting their contribution to tenderness and aroma production in DA meats.
Asunto(s)
Acinetobacter/aislamiento & purificación , Almacenamiento de Alimentos/métodos , Carne de Cerdo/microbiología , Pseudomonas/aislamiento & purificación , Saccharomycetales/aislamiento & purificación , Acinetobacter/clasificación , Acinetobacter/genética , Aminoácidos/análisis , Animales , Microbiología de Alimentos , Productos de la Carne/análisis , Productos de la Carne/microbiología , Microbiota/genética , Carne de Cerdo/análisis , Pseudomonas/clasificación , Pseudomonas/genética , ARN Ribosómico 16S/genética , Saccharomycetales/clasificación , Saccharomycetales/genética , PorcinosRESUMEN
Three Gram-stain positive, non-motile, non-spore-forming, catalase-negative and rod-shaped bacterial strains (IWT5T, IWT25T and IWT140), isolated from silage, were investigated by using a polyphasic taxonomic approach. Strains IWT5T and IWT25T grew at 10-37 °C and 30-37 °C, and at pH 4.0-7.5 and 4.0-7.0, respectively. The G+C contents of genomic DNA of strains IWT5T and IWT25T were 43.2 and 44.4 mol%, respectively. Strains IWT5T and IWT25T contained C16â:â0, C18â:â1 ω9c and summed feature 7 (unknown 18.846/C19â:â1 ω6c/C19â:â0cyclo ω10c) as the major fatty acids. Strain IWT5T was most closely related to the type strains of Lactobacillus mixtipabuli (99.9â% 16S rRNA gene sequence similarity) and Lactobacillus silagei (99.5â%). For IWT25T, the 16S rRNA gene sequence similarities with the closely related neighbour type strains L. mixtipabuli and L. silagei were 99.5 and 99.5â%, respectively. The 16S rRNA gene sequence similarities among the three novel isolates were 99.5-99.9â%. The average nucleotide identities of strains IWT5T and IWT25T to other neighbours of the genus Lactobacillus were less than 82â% and the genomes of IWT25T and IWT140 shared 97.3â% average nucleotide identity, demonstrating that the three strains were allocated to two different novel species of the genus Lactobacillus. Together with multilocus sequence analysis, phenotypic and chemotaxonomic characteristics, strains IWT5T (=JCM 31144T=DSM 102973T) and IWT25T (=JCM 31145T=DSM 102974T) are proposed as the type strains of novel species of the genus Lactobacillus, with the names Lactobacillus silagincola sp. nov. and Lactobacillus pentosiphilus sp. nov., respectively.
Asunto(s)
Lactobacillus/clasificación , Filogenia , Ensilaje/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Most lactic acid bacteria are non-motile but some of them are flagellated and exhibit motility. So far, motile lactobacilli have rarely been studied, and characteristics of their flagellins are poorly understood. In this study, a highly motile strain of Lactobacillus agilis was recruited for transcriptional analysis and characterization of its flagellins. RESULTS: Unlike another motile lactic acid bacteria of intestinal isolate, Lactobacillus ruminis, flagellar filaments of the L. agilis strain probably consist of two homologous but distinct flagellins. Glycosylation of the flagellar filaments and their resistance to heat, acid and SDS were also observed. The immunological activity of the flagellins was evaluated through the stimulation of Caco-2 cells. The results show that TLR5-stimulating activity of the protein is attenuated, likely due to an incomplete TLR5-recognition site. CONCLUSIONS: The flagella filaments of L. agilis BKN88 consist of two homologous glycosylated flagellins, which likely have an incomplete TLR5-recognition site. The characteristics of the flagellin are presumably a consequence of adaptation as a commensal microbe in the gastrointestinal tract.
Asunto(s)
Proteínas Bacterianas/metabolismo , Flagelina/metabolismo , Lactobacillus/citología , Lactobacillus/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Flagelina/química , Flagelina/genética , Glicosilación , Humanos , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Alineación de SecuenciaRESUMEN
Six strains of anaerobic bacteria, C13EG70T, C13EG118, C13EG186T, C13GAMG5, C13GAMG28 and C13GAMG40, were isolated from the caecum of a healthy chicken bred in Bogor, Indonesia. Phylogenetic analysis showed the isolates were separated into two groups. Group I (C13EG70T and C13EG118) showed nearly identical 16S rRNA gene sequences (99.9 % sequence similarity). Group II (C13EG186T, C13GAMG5, C13GAMG28 and C13GAMG40) showed nearly identical 16S rRNA gene sequences (>99.4 % sequence similarity). The isolates showed low 16S rRNA gene sequence similarities to recognized species of the genus Bacteroides. High gene sequence similarities were found between type strains (C13EG70T and C13EG186T) and Bacteroides salanitronis JCM 13657T (87.9, 91.5 %, respectively). Physiological, biochemical and genotypic characteristics demonstrated that these strains could be separated from the type strain of B. salanitronis. It is concluded that Group I and Group II represent novel species. Two novel species of the genus Bacteroides are proposed as Bacteroides caecicola sp. nov. (type strain C13EG70T = LIPI12-4-Ck732T = JSAT12-4-Ck732T = InaCC B449T = NBRC 110958T) and Bacteroides gallinaceum sp. nov. (type strain C13EG186T = LIPI12-4-Ck844T = JSAT12-4-Ck884T = InaCC B451T = NBRC 110963T).
RESUMEN
Synonymy of Gibbsiella dentisursi DSM 23818T ( = NUM 1720T) and Gibbsiella papilionis JCM 18389T ( = LEN33T) was suspected following multilocus sequence analysis (MLSA) of both type strains in a previous classification study, where they were found to share >99.6â% gene sequence similarity. The taxonomic relationship between these two strains was re-examined here using a polyphasic approach. A DNA-DNA hybridization value of 98â% confirmed that the two type strains belong to a single taxon, while the phenotypic profiles were found to be nearly identical. Therefore we propose Gibbsiella papilionis as a later heterotypic synonym of Gibbsiella dentisursi, with the type strain as NUM 1720T ( = DSM 23818T = JCM 17201T).
Asunto(s)
Enterobacteriaceae/clasificación , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Enterobacteriaceae/genética , Ácidos Grasos/análisis , Genes Bacterianos , Datos de Secuencia Molecular , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Three strains of anaerobic Gram-stain-negative, short to longer rod-shaped bacteria isolated from the caecum of chicken in Indonesia were studied using a polyphasic taxonomic approach. These strains belonged to the genus Bacteroides, based on sequence analysis of 16S rRNA and hsp60 (groEL) genes, with similarities of 93.2-94.1 and 89.8-90.8 %, respectively, to the closest recognized species, Bacteroides coprocola JCM 17929T. Sugar fermentation and enzyme characteristics, cellular fatty acid profiles, menaquinone profiles and metabolic end products were also investigated. Furthermore, DNA-DNA hybridization studies confirmed that the three novel strains are different from the closest related species. The strains were also found to be distinct from each other on the basis of ribotype profiles. The DNA G+C contents of the three strains were 41.1-41.8âmol%. Based on phenotypic and phylogenetic characteristics, a novel species, Bacteroides caecigallinarum sp. nov., is proposed (type strain C13EG111T = LIPI12-4-Ck773T = JSAT12-4-Ck773T = InaCC B455T = NBRC 110959T).
Asunto(s)
Bacteroides/clasificación , Ciego/microbiología , Pollos/microbiología , Filogenia , Animales , Técnicas de Tipificación Bacteriana , Bacteroides/genética , Bacteroides/aislamiento & purificación , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Microbioma Gastrointestinal , Indonesia , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/químicaRESUMEN
Using a polyphasic taxonomic approach, we investigated three bacterial strains - IWT30T, IWT8 and IWT75 - isolated from total mixed ration silage prepared in Hachimantai, Iwate, Japan. The isolates comprised Gram-stain positive, non-motile, non-spore-forming, catalase-negative, rod-shaped bacteria. Good growth occurred at 15-45 °C and at pH 4.0-7.5. Their major cellular fatty acids were C18:1ω9c and C19:1 cyclo 9,10.The G+C content of genomic DNA of strain IWT30T was 44.6 mol%. Comparative 16S rRNA gene sequence analysis showed that these novel strains belonged to the genus Lactobacillus. These strains shared 100 % 16S rRNA gene sequence similarity and were most closely related to the type strains of Lactobacillus silagei, Lactobacillus odoratitofui, Lactobacillus similis, Lactobacillus collinoides, Lactobacillus paracollinoides and Lactobacillus kimchicus, with sequence similarity values of 99.5, 98.8, 98.7, 97.8, 97.8 and 96.8 %, respectively. The level of DNA-DNA relatedness between these strains and their closest phylogenetic neighbours was less than 30 %. On the basis of additional phylogenetic analysis of pheS and rpoA gene sequences and phenotypic and chemotaxonomic characteristics, we conclude that these three strains represent a novel species of the genus Lactobacillus, for which we propose the name Lactobacillus mixtipabuli sp. nov. The type strain is IWT30T ( = JCM 19805T = DSM 28580T).
Asunto(s)
Lactobacillus/clasificación , Filogenia , Ensilaje/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Fermentación , Genes Bacterianos , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Lactobacillus is the largest genus within the lactic acid bacteria (LAB), with almost 180 species currently identified. Motility has been reported for at least 13 Lactobacillus species, all belonging to the Lactobacillus salivarius clade. Motility in lactobacilli is poorly characterized. It probably confers competitive advantages, such as superior nutrient acquisition and niche colonization, but it could also play an important role in innate immune system activation through flagellinToll-like receptor 5 (TLR5) interaction. We now report strong evidence of motility in a species outside the L. salivarius clade, Lactobacillus curvatus (strain NRIC0822). The motility of L. curvatus NRIC 0822 was revealed by phase-contrast microscopy and soft-agar motility assays. Strain NRIC 0822 was motile at temperatures between 15 °C and 37 °C, with a range of different carbohydrates, and under varying atmospheric conditions. We sequenced the L. curvatus NRIC 0822 genome, which revealed that the motility genes are organized in a single operon and that the products are very similar (>98.5% amino acid similarity over >11,000 amino acids) to those encoded by the motility operon of Lactobacillus acidipiscis KCTC 13900 (shown for the first time to be motile also). Moreover, the presence of a large number of mobile genetic elements within and flanking the motility operon of L. curvatus suggests recent horizontal transfer between members of two distinct Lactobacillus clades: L. acidipiscis in the L. salivarius clade and L. curvatus inthe L. sakei clade. This study provides novel phenotypic, genetic, and phylogenetic insights into flagellum-mediated motility in lactobacilli.
Asunto(s)
Genoma Bacteriano , Lactobacillus/citología , Lactobacillus/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Flagelina/genética , Flagelina/metabolismo , Regulación Bacteriana de la Expresión Génica , Genómica , Lactobacillus/clasificación , Lactobacillus/metabolismo , Operón , FilogeniaRESUMEN
Two strains of lactic acid bacteria, Nu27(T) and Nu29, were isolated from Nukadoko, rice bran paste for Japanese pickles. The isolates were Gram-stain-positive, rod-shaped, catalase-negative, non-motile and facultatively anaerobic lactic acid bacteria. The isolates showed identical 16S rRNA gene sequences. The closest relatives to strain Nu27(T) based on 16S rRNA gene sequence similarities were Lactobacillus versmoldensis KU-3(T) (98.9% 16S rRNA gene sequence similarity), Lactobacillus nodensis iz4b(T) (96.3%) and Lactobacillus tucceti CECT 5290(T) (97.2%). DNA-DNA relatedness values revealed genotype separation of the two isolates from the above three species. Based on the physiological, biochemical and genotypic characteristics provided, the isolates represent a novel species of the genus Lactobacillus, for which name is Lactobacillus furfuricola proposed. The type strain is Nu 27(T) (â=âJCM 18764(T)â=âNRIC 0900(T)â=âDSM 27174(T)).
Asunto(s)
Microbiología de Alimentos , Lactobacillus/clasificación , Oryza/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Fermentación , Genes Bacterianos , Japón , Ácido Láctico/metabolismo , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Here, we report the draft genome sequence of a motile lactic acid bacterium, Lactobacillus sucicola JCM 15457(T), isolated from oak sap. Motility-related genes and their organization in the annotated genome were broadly similar to those in the sequenced genomes of related lactobacilli.
RESUMEN
Three lactic acid bacteria were isolated from faeces of a jackal (Canis mesomelas) and raccoons (Procyron lotor). The isolates formed a subcluster in the Lactobacillus salivarius phylogenetic group, closely related to Lactobacillus animalis, Lactobacillus apodemi and Lactobacillus murinus, by phylogenetic analysis based on 16S rRNA and recA gene sequences. Levels of DNA-DNA relatedness revealed that the isolates belonged to the same taxon and were genetically separated from their phylogenetic relatives. The three strains were non-motile, obligately homofermentative and produced l-lactic acid as the main end-product from d-glucose. The strains metabolized raffinose. The major cellular fatty acids in the three strains were C16â:â0, C18â:â1ω9c and C19â:â1 cyclo 9,10. Based on the data provided, it is concluded that the three strains represent a novel species of the genus Lactobacillus, for which the name Lactobacillus faecis sp. nov. is proposed. The type strain is AFL13-2(T) (â=âJCM 17300(T)â=âDSM 23956(T)).
Asunto(s)
Heces/microbiología , Lactobacillus/clasificación , Filogenia , Animales , Canidae/microbiología , ADN Bacteriano/genética , Ácidos Grasos/química , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Mapaches/microbiología , Análisis de Secuencia de ADN , SudáfricaRESUMEN
A Gram-reaction-positive, facultatively anaerobic, non-spore-forming and catalase-negative rod-shaped bacterial strain, designated IWT126(T), was isolated from orchardgrass (Dactylis glomerata L.) silage preserved in Hachimantai, Iwate, Japan. The isolate showed growth at 15-45 °C, pH 3.5-7.5 and with 4.0â% (w/v) NaCl. The cell wall peptidoglycan did not contain meso-diaminopimelic acid, and the DNA G+C content was 45.6 mol%. The major cellular fatty acids were C16â:â0 and C19â:â1 cyclo 9,10. Based on 16S rRNA gene sequence similarity, strain IWT126(T) was classified as a member of the genus Lactobacillus and was most closely related to Lactobacillus odoratitofui YIT 11304(T) (98.7â%), Lactobacillus similis JCM 2765(T) (98.5â%), Lactobacillus collinoides JCM 1123(T) (97.6â%), Lactobacillus paracollinoides DSM 15502(T) (97.6â%) and Lactobacillus kimchicus DCY51(T) (96.9â%). Based on sequence analysis of the phenylalanyl-tRNA synthase α-subunit (pheS) gene, strain IWT126(T) was well separated from its phylogenetic neighbours in the genus Lactobacillus. Based on physiological, biochemical and genotypic results, as well as low DNA-DNA relatedness to recognized phylogenetic relatives in the genus Lactobacillus, classification of strain IWT126(T) as a representive of a novel species named Lactobacillus silagei sp. nov. is proposed. The type strain is IWT126(T) (â=âJCM 19001(T)â=âDSM 27022(T)).
Asunto(s)
Dactylis/microbiología , Lactobacillus/clasificación , Filogenia , Ensilaje/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Peptidoglicano/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Two bacterial strains, designated IWT246(T) and IWT248, were isolated from orchardgrass (Dactylis glomerata L.) silage from Iwate prefecture, Japan, and examined for a taxonomic study. Both organisms were rod-shaped, Gram-stain-positive, catalase-negative, facultatively anaerobic and homofermentative. The cell wall did not contain meso-diaminopimelic acid and the major fatty acids were C18â:â1ω9c and C19 cyclo 9,10/:1. Comparative analyses of 16S rRNA, pheS and rpoA gene sequences revealed that these strains were novel and belonged to the genus Lactobacillus. Based on 16S rRNA gene sequence similarity, the isolates were most closely related to the type strains of the following members of the genus Lactobacillus: Lactobacillus coryniformis subsp. coryniformis (96.7â% similarity), L. coryniformis subsp. torquens (96.6â%), L. bifermentans (95.5â%) and L. rennini (94.1â%). However, the 16S rRNA gene sequences of both IWT246(T) and IWT248 were 99.7â% similar to that of 'Lactobacillus backi' JCM 18665; this name has not been validly published. Genotypic, phenotypic and chemotaxonomic analyses confirmed that these novel strains occupy a unique taxonomic position. DNA-DNA hybridization experiments demonstrated genotypic separation of the novel isolates from related Lactobacillus species. The name Lactobacillus iwatensis sp. nov. is proposed for the novel isolates, with strain IWT246(T) (â=âJCM 18838(T)â=âDSM 26942(T)) as the type strain. Our results also suggest that 'L. backi' does represent a novel Lactobacillus species. The cells did not contain meso-diaminopimelic acid in their cell-wall peptidoglycan and the major fatty acids were C16â:â0, C19 cyclo 9,10/:1 and summed feature 10 (one or more of C18â:â1ω11c, C18â:â1ω9t, C18â:â1ω6t and unknown ECL 17.834). We therefore propose the corrected name Lactobacillus backii sp. nov., with the type strain JCM 18665(T) (â=âLMG 23555(T)â=âDSM 18080(T)â=âL1062(T)).
Asunto(s)
Dactylis/microbiología , Lactobacillus/clasificación , Filogenia , Ensilaje/microbiología , Técnicas de Tipificación Bacteriana , Pared Celular/química , ADN Bacteriano/genética , Ácidos Grasos/análisis , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Peptidoglicano/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
The taxonomic position of three Lactobacillus-like micro-organisms (strains SG293(T), SG296 and SG310) isolated from fermented rice grain (Oryza sativa L. subsp. japonica) in Japan was investigated. These heterofermentative lactic acid bacteria were Gram-stain-positive, rod-shaped, facultatively anaerobic, non-motile, non-spore-forming and did not show catalase activity. 16S rRNA gene sequence analysis of strain SG293(T) revealed that the type strains of Lactobacillus malefermentans (98.3 %), Lactobacillus odoratitofui (96.2 %), Lactobacillus similis (96.1 %), Lactobacillus kimchicus (96.1 %), Lactobacillus paracollinoides (95.9 %) and Lactobacillus collinoides (95.7 %) were the closest neighbours. Additional phylogenetic analysis on the basis of pheS and rpoA gene sequences, as well as biochemical and physiological characteristics, indicated that these three strains were members of the genus Lactobacillus and that the novel isolates had a unique taxonomic position. The predominant cellular fatty acids were C18 : 1ω9c and C19 : 1 cyclo 9,10. Because low DNA-DNA hybridization values among the isolates and Lactobacillus malefermentans JCM 12497(T) were observed, it is proposed that these unidentified isolates be classified as a novel species of the genus Lactobacillus, Lactobacillus oryzae sp. nov. The type strain is SG293(T) (= JCM 18671(T) = DSM 26518(T)).
Asunto(s)
Fermentación , Lactobacillus/clasificación , Oryza/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Microbiología de Alimentos , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Four strains of Gram-positive, non-spore-forming, rod-shaped, catalase-negative and non-motile lactic acid bacteria, LOOC260(T), LOOC253, LOOC273 and LOOC279, were isolated from timothy grass (Phleum pratense L.) silage produced in Hokkaido, a subarctic region of Japan. These isolates grew at 4-37 °C, indicating the psychrotolerant nature of these strains. Phylogenetic analysis on the basis of 16S rRNA and pheS gene sequences, as well as biochemical and physiological characteristics, indicated that these four strains were members of the genus Lactobacillus. 16S rRNA gene sequence analysis of strain LOOC260(T) demonstrated that the closest neighbours were the type strains of Lactobacillus suebicus (97.7 %), Lactobacillus oligofermentans (96.7 %) and Lactobacillus vaccinostercus (96.7 %). Strain LOOC260(T) showed low levels of DNA-DNA association with Lactobacillus suebicus JCM 9504(T) (14.7 ± 3.5 %), Lactobacillus oligofermentans JCM 16175(T) (15.1 ± 4.8 %) and Lactobacillus vaccinostercus JCM 1716(T) (10.7 ± 3.0 %). The cell wall contained meso-diaminopimelic acid and the major fatty acids were C18 : 1ω9c and C19 : 1 cyclo 9,10. On the basis of phenotypic, physiological and phylogenetic evidence, these isolates represent a novel species of the genus Lactobacillus, for which the name Lactobacillus hokkaidonensis sp. nov. is proposed. The type strain is LOOC260(T) ( = JCM 18461(T) = DSM 26202(T)).
Asunto(s)
Lactobacillus/clasificación , Phleum/microbiología , Filogenia , Ensilaje/microbiología , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Genes Bacterianos , Japón , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
A taxonomic study was conducted on two Gram-reaction-positive, catalase-negative, irregular short-rod-shaped or coccoid lactic acid bacteria, designated strains SG25(T) and SG23, that were isolated from grains of fermented Japanese rice (Oryza sativa L. subsp. japonica). A phylogenetic analysis based on 16S rRNA gene sequence data clearly showed that the strains belonged to the genus Weissella and were most closely related to Weissella soli LMG 20113(T) (with a sequence similarity of 96.9â% for each novel strain). The peptidoglycan of each strain contained the amino acids glutamic acid, lysine, serine and alanine in a molar ratio of 1.0â:â1.2â:â0.5â:â3.0, respectively. On the basis of the unusual phenotypic characteristics of the novel strains and the low levels of DNA-DNA relatedness recorded between each novel strain and Weissella soli JCM 12536(T), strains SG25(T) and SG23 represent a single novel species in the genus Weissella, for which the name Weissella oryzae sp. nov. is proposed. The type strain is SG25(T) (â=âJCM 18191(T) â=âDSM 25784(T)).
Asunto(s)
Oryza/microbiología , Filogenia , Weissella/clasificación , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Fermentación , Datos de Secuencia Molecular , Peptidoglicano/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Weissella/genética , Weissella/aislamiento & purificaciónRESUMEN
Lactobacillus kunkeei is an inhabitant of fructose-rich niches and is a potential member of the fructophilic lactic acid bacteria. In the present study, the phylogenetic and biochemical characteristics of the type strain and eight isolates of L. kunkeei, originating from wine, flowers and honey, were studied. The nine isolates, including the type strain, formed a well-defined phylogenetic subcluster based on the analysis of 16S rRNA gene sequences. The subcluster was not closely related to other subclusters in the Lactobacillus phylogenetic group. Biochemically, the eight new isolates showed typical fructophilic characteristics. The eight isolates grew poorly on glucose, but grew well on fructose. Good growth on glucose was only recorded in the presence of electron acceptors. The type strain of L. kunkeei differed from the other isolates only on the basis of poor growth on fructose. Although they belong to a group of obligately heterofermentative lactic acid bacteria, all nine isolates, including the type strain, produced almost equimolar amounts of lactic acid and acetic acid and very little ethanol from glucose. Eight of the isolates can thus be regarded as typical 'obligately' fructophilic lactic acid bacteria. Although the type strain of L. kunkeei was phenotypically slightly different from the other isolates, it possessed several important fructophilic characteristics. On the basis of the evidence gathered in this study, the type strain of L. kunkeei is recognized as a member of the 'obligately' fructophilic lactic acid bacteria.
Asunto(s)
Fructosa/metabolismo , Ácido Láctico/metabolismo , Lactobacillus/clasificación , Lactobacillus/metabolismo , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Flores/microbiología , Glucosa/metabolismo , Miel/microbiología , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vino/microbiologíaRESUMEN
Lysozyme (LZ), a bacteriolytic enzyme, is found in the egg white of many avian eggs and plays an important role in host defense; however, LZ activity in emu (Dromaius novaehollandiae) egg white is exceptionally undetectable. We cloned and characterized emu goose-type LZ (LZG) and chicken-type LZ (LZC) genes. RT-PCR analysis revealed very low LZG gene expression levels and absence of LZC gene expression in the emu oviduct. Sequencing of full-length LZG and LZC cDNAs indicated that their amino acid sequences show high similarities to ostrich LZG and LZC, respectively, with conserved catalytic residues for enzymatic activities. Whereas recombinant emu LZG prepared using Pichia pastoris exhibited similar enzyme activity as ostrich LZG, recombinant emu LZC exhibited significantly higher lytic activity than chicken LZC. We concluded that emus have functional genes for both LZG and LZC like many other avians, and the LZG gene is expressed in oviduct probably as in other ratite, however, its expression levels in egg white were low to be detected.
Asunto(s)
Dromaiidae/genética , Clara de Huevo/química , Muramidasa/metabolismo , Secuencia de Aminoácidos , Animales , Pollos/genética , Femenino , Gansos/genética , Muramidasa/genética , Oviductos/metabolismo , Filogenia , Pichia/genética , Proteínas Recombinantes , Alineación de Secuencia , Struthioniformes/genéticaRESUMEN
A novel actinobacterium, designated KMM 3890 was isolated from a bottom sediment sample collected from the Sakhalin shallow environment. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated strain KMM 3890 affiliation to the genus Citricoccus. In addition to its hemolytic activity, this strain exhibited inhibitory activity against Gram-positive bacteria. It was found that the marine isolate Citricoccus sp. KMM 3890 produced and excreted into the culture medium a large amount of the compound, which was isolated and structurally characterized as known cyclic siderophore nocardamine on the basis of combined spectral analyses. Nocardamine showed inhibitory effects to colony formation of T-47D, SK-Mel-5, SK-Mel-28 and PRMI-7951 tumor cell lines and a weak antimicrobial against Gram-positive bacteria and no revealed cytotoxic activity. This study can be considered as the first report on marine isolate of the genus Citricoccus producing nocardamine with antitumor activity.
Asunto(s)
Antineoplásicos/aislamiento & purificación , Antineoplásicos/metabolismo , Sedimentos Geológicos/microbiología , Micrococcaceae/aislamiento & purificación , Micrococcaceae/metabolismo , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/metabolismo , Antibiosis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Análisis por Conglomerados , Medios de Cultivo/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Humanos , Micrococcaceae/clasificación , Micrococcaceae/genética , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Análisis Espectral , Células MadreRESUMEN
Five strains (Ryu1-2(T), Gon2-9, Ryu4-3, Nog8-1 and Aza1-1) of lactic acid bacteria were isolated from flowers in mountainous areas in Japan, Oze National Park, Iizuna mountain and the Nikko area. The five isolates were found to share almost identical (99.6-100 % similar) 16S rRNA gene sequences and were therefore deemed to belong to the same species. These isolates exhibited low levels of 16S rRNA gene sequence similarity to known lactic acid bacteria; the closest recognized relatives to strain Ryu1-2(T) were the type strains of Lactobacillus hilgardii (92.8 % similarity), Lactobacillus kefiri (92.7 %), Lactobacillus composti (92.6 %) and Lactobacillus buchneri (92.4 %). Comparative analyses of rpoA and pheS gene sequences demonstrated that the novel isolates did not show significant relationships to other Lactobacillus species. The strains were Gram-stain-positive, catalase-negative and homofermentative. The isolates utilized a narrow range of carbohydrates as sources of carbon and energy, including glucose and fructose. On the basis of phenotypic characteristics and phylogenetic data, these isolates represent a novel species of the genus Lactobacillus, for which the name Lactobacillus floricola sp. nov. is proposed. The type strain is Ryu1-2(T) (â= NRIC 0774(T) â= JCM 16512(T) â= DSM 23037(T)).