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1.
Int J Mol Sci ; 24(18)2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37762288

RESUMEN

A high temperature-adapted bacteriophage, vB_PtoS_NIIg3.2 (NIIg3.2), was isolated in Lithuania from compost heaps using Parageobacillus toebii strain NIIg-3 as a host for phage propagation. Furthermore, NIIg3.2 was active against four strains of Geobacillus thermodenitrificans, and it infected the host cells from 50 to 80 °C. Transmission electron microscopy analysis revealed siphovirus morphology characterized by an isometric head (~59 nm in diameter) and a noncontractile tail (~226 nm in length). The double-stranded DNA genome of NIIg3.2 (38,970 bp) contained 71 probable protein-encoding genes and no genes for tRNA. In total, 29 NIIg3.2 ORFs were given a putative functional annotation, including those coding for the proteins responsible for DNA packaging, virion structure/morphogenesis, phage-host interactions, lysis/lysogeny, replication/regulation, and nucleotide metabolism. Based on comparative phylogenetic and bioinformatic analysis, NIIg3.2 cannot be assigned to any genus currently recognized by ICTV and potentially represents a new one within siphoviruses. The results of this study not only extend our knowledge about poorly explored thermophilic bacteriophages but also provide new insights for further investigation and understanding the evolution of Bacilllus-group bacteria-infecting viruses.


Asunto(s)
Bacteriófagos , Bacteriófagos/genética , Filogenia , Lisogenia , Técnicas de Tipificación Bacteriana , Muerte Celular
2.
Viruses ; 15(8)2023 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-37632033

RESUMEN

We report a detailed characterization of five thermophilic bacteriophages (phages) that were isolated from compost heaps in Vilnius, Lithuania using Geobacillus thermodenitrificans strains as the hosts for phage propagation. The efficiency of plating experiments revealed that phages formed plaques from 45 to 80 °C. Furthermore, most of the phages formed plaques surrounded by halo zones, indicating the presence of phage-encoded bacterial exopolysaccharide (EPS)-degrading depolymerases. Transmission Electron Microscopy (TEM) analysis revealed that all phages were siphoviruses characterized by an isometric head (from ~63 nm to ~67 nm in diameter) and a non-contractile flexible tail (from ~137 nm to ~150 nm in length). The genome sequencing resulted in genomes ranging from 38,161 to 39,016 bp. Comparative genomic and phylogenetic analysis revealed that all the isolated phages had no close relatives to date, and potentially represent three new genera within siphoviruses. The results of this study not only improve our knowledge about poorly explored thermophilic bacteriophages but also give new insights for further investigation of thermophilic and/or thermostable enzymes of bacterial viruses.


Asunto(s)
Bacteriófagos , Compostaje , Geobacillus , Filogenia , Técnicas de Tipificación Bacteriana , Bacteriófagos/genética , Geobacillus/genética
3.
Microorganisms ; 10(2)2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-35208903

RESUMEN

Extraintestinal pathogenic Escherichia coli (ExPEC) isolates are a main cause of bloodstream infections. The aim of this study was to characterize 256 ß-lactam-resistant, bacteremia-causing E. coli isolates collected from 12 healthcare institutions in Lithuania in 2014 and 2018. All isolates were identified as E. coli via MALDI-TOF MS and VITEK ®2. In addition, the isolates were analyzed for the presence of 29 resistance genes and 13 virulence genes, divided into phylogenetic groups (A, B1, B2, C, D, E, and F), and characterized using rep-PCR genotyping methods (BOX-PCR and (GTG)5-PCR). Analyzing the results of this study showed tetA-strB-sul2-TEM-NDM-strA-fosA-AIM-sul3-aadA-CTX-M-9 to be the most common resistance gene combination (67.2% of all isolates). Additionally, the most common virulence genes established were fimH (98.4% of all isolates), fyuA (91.8%), and traT (81.3%) and the most common gene combination was fuyA-fimH-iroN (58.6% of all isolates). Next, the isolates were separated into four phylogenetic groups: A, B1, B2, and F, where group A isolates were detected at a significantly higher frequency (79.3% of all isolates). Finally, a total of 235 genotyping profiles were established using rep-PCR methods, and all profiles were separated into fourteen genotypic clusters, with each cluster containing profiles with a variety of virulence and resistance genes not restricted to any specific cluster. The results of this study elucidate E. coli antimicrobial resistance patterns by highlighting the variability and diversity of resistance and virulence genes and providing phylogenetic classification, genetic profiling, and clustering data. These results may improve clinical control of multidrug-resistant infections in healthcare institutions and contribute to the prevention of potential outbreaks.

4.
Life (Basel) ; 11(2)2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33669401

RESUMEN

Bacterial resistance to antimicrobial agents plays an important role in the treatment of bacterial infections in healthcare institutions. The spread of multidrug-resistant bacteria can occur during inter- and intra-hospital transmissions among patients and hospital personnel. For this reason, more studies must be conducted to understand how resistance occurs in bacteria and how it moves between hospitals by comparing data from different years and looking out for any patterns that might emerge. Multidrug-resistant (MDR) Acinetobacter spp. was studied at 14 healthcare institutions in Lithuania during 2014, 2016, and 2018 using samples from human bloodstream infections. In total, 194 isolates were collected and identified using MALDI-TOF and VITEK2 analyzers as Acinetobacter baumannii group bacteria. After that, the isolates were analyzed for the presence of different resistance genes (20 genes were analyzed) and characterized by using the Rep-PCR and MLVA (multiple-locus variable-number tandem repeat analysis) genotyping methods. The results of the study showed the relatedness of the different Acinetobacter spp. isolates and a possible circulation of resistance genes or profiles during the different years of the study. This study provides essential information, such as variability and diversity of resistance genes, genetic profiling, and clustering of isolates, to better understand the antimicrobial resistance patterns of Acinetobacter spp. These results can be used to strengthen the control of multidrug-resistant infections in healthcare institutions and to prevent potential outbreaks of this pathogen in the future.

5.
Microb Ecol ; 81(1): 110-121, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32638044

RESUMEN

Caves are considered to be extreme and challenging environments. It is believed that the ability of microorganisms to produce secondary metabolites enhances their survivability and adaptiveness in the energy-starved cave environment. Unfortunately, information on the genetic potential for the production of secondary metabolites, such as polyketides and nonribosomal peptides, is limited. In the present study, we aimed to identify and characterize genes responsible for the production of secondary metabolites in the microbial community of one of the deepest caves in the world, Krubera-Voronja Cave (43.4184 N 40.3083 E, Western Caucasus). The analysed sample materials included sediments, drinkable water from underground camps, soil and clay from the cave walls, speleothems and coloured spots from the cave walls. The type II polyketide synthases (PKSs) ketosynthases α and ß and the adenylation domains of nonribosomal peptide synthetases (NRPSs) were investigated using a metagenomic approach. Taxonomic diversity analysis showed that most PKS sequences could be attributed to Actinobacteria followed by unclassified bacteria and Acidobacteria, while the NRPS sequences were more taxonomically diverse and could be assigned to Proteobacteria, Actinobacteria, Cyanobacteria, Firmicutes, Chloroflexi, etc. Only three putative metabolites could be predicted: an angucycline group polyketide, a massetolide A-like cyclic lipopeptide and a surfactin-like lipopeptide. The absolute majority of PKS and NRPS sequences showed low similarity with the sequences of the reference biosynthetic pathways, suggesting that these sequences could be involved in the production of novel secondary metabolites.


Asunto(s)
Bacterias/genética , Cuevas/microbiología , Sedimentos Geológicos/microbiología , Péptido Sintasas/genética , Sintasas Poliquetidas/genética , Metabolismo Secundario/genética , Acidobacteria/genética , Actinobacteria/genética , Bacterias/clasificación , Bacterias/metabolismo , Chloroflexi/genética , Firmicutes/genética , Georgia (República) , Metagenoma/genética , Microbiota/genética , Proteobacteria/genética , ARN Ribosómico 16S/genética , Microbiología del Suelo
6.
Front Microbiol ; 11: 612483, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33505378

RESUMEN

The genome sequencing and mining of microorganisms from unexplored and extreme environments has become important in the process of identifying novel biosynthetic pathways. In the present study, the biosynthetic potential of Paenibacillus sp. strains 23TSA30-6 and 28ISP30-2 was investigated. Both strains were isolated from the deep oligotrophic Krubera-Voronja Cave and were found to be highly active against both Gram-positive and Gram-negative bacteria. Genome mining revealed a high number of biosynthetic gene clusters in the cave strains: 21 for strain 23TSA30-6 and 19 for strain 28ISP30-2. Single clusters encoding the biosynthesis of phosphonate, terpene, and siderophore, as well as a single trans-AT polyketide synthase/non-ribosomal peptide synthetase, were identified in both genomes. The most numerous clusters were assigned to the biosynthetic pathways of non-ribosomal peptides and ribosomally synthesized and post-translationally modified peptides. Although four non-ribosomal peptide synthetase gene clusters were predicted to be involved in the biosynthesis of known compounds (fusaricidin, polymyxin B, colistin A, and tridecaptin) of the genus Paenibacillus, discrepancies in the structural organization of the clusters, as well as in the substrate specificity of some adenylation domains, were detected between the reference pathways and the clusters in our study. Among the clusters involved in the biosynthesis of ribosomally synthesized peptides, only one was predicted to be involved in the biosynthesis of a known compound: paenicidin B. Most biosynthetic gene clusters in the genomes of the cave strains showed a low similarity with the reference pathways and were predicted to represent novel biosynthetic pathways. In addition, the cave strains differed in their potential to encode the biosynthesis of a few unique, previously unknown compounds (class II lanthipeptides and three non-ribosomal peptides). The phenotypic characterization of proteinaceous and volatile compounds produced by strains 23TSA30-6 and 28ISP30-2 was also performed, and the results were compared with those of genome mining.

7.
Genomics ; 112(3): 2271-2281, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31884159

RESUMEN

Collagens and collagen-like proteins are found in a wide range of organisms. The common feature of these proteins is a triple helix fold, requiring a characteristic pattern of amino acid sequences, composed of Gly-X-Y tripeptide repeats. Collagen-like proteins from bacteria are heterogeneous in terms of length and amino acid composition of their collagenous sequences. However, different bacteria live in different environments, some at extreme temperatures and conditions. This study explores the occurrence of collagen-like sequences in the genomes of different extreme condition-adapted bacteria, and investigates features that could be linked to conditions where they thrive. Our results show that proteins containing collagen-like sequences are encoded by genomes of various extremophiles. Some of these proteins contain conservative domains, characteristic of cell or endospore surface proteins, while most other proteins are unknown. The characteristics of collagenous sequences may depend on both, the phylogenetic relationship and the living conditions of the bacteria.


Asunto(s)
Proteínas Bacterianas/química , Colágeno/química , Secuencia de Aminoácidos , Aminoácidos/análisis , Proteínas Bacterianas/genética , Colágeno/genética , Secuencia Conservada , Extremófilos/genética , Firmicutes/genética , Genoma Bacteriano , Dominios Proteicos
8.
Front Microbiol ; 10: 2149, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31572349

RESUMEN

Identification of novel bioactive compounds represents an important field in modern biomedical research. Microorganisms of the underexplored environments, such as deserts, hot springs, oceans, and caves are highly promising candidates for screening such metabolites. Screening for biosynthetic genes is the most effective strategy to characterize bioactivity in a certain environment. However, knowledge is either scant or non-existent about the expression of the biosynthetic genes encoding for various bioactive compounds in the microorganisms from the caves. The aim of the current study was to screen for the genes of polyketide synthases and non-ribosomal peptide synthetases in Krubera-Voronja Cave (43.4184 N 40.3083 E, Western Caucasus) bacterial isolates as well as to evaluate the expression of these genes under laboratory conditions. In total, 91 bacterial strains isolated from the cave were screened for the presence of polyketide synthase and non-ribosomal peptide synthetase genes. Phenotypically inactive strains were the main focus (the test group) of our study, while the strains with the identified antibacterial activity served as the control group. Our PCR-based screening clearly showed that the majority of the strains harbored at least one biosynthetic gene. Prediction of the putative products allowed us to identify bioactive compounds with antibacterial, anticancer, antifungal, anti-inflammatory, antimycoplasmic, antiviral, insecticidal, and thrombolytic activity. For most polyketide synthases and non-ribosomal peptide synthetases, putative products could not be predicted; they are unknown. Qualitative transcriptional analysis did not show substantial differences between the test group and the control group of the strains. One to four biosynthetic genes were constitutively expressed in all the tested strains, irrespective of the group. Quantitative transcriptional analysis of the constitutively expressed biosynthetic genes demonstrated that the expression of a particular gene could be affected by both the amount of the nutrients in the culture medium and the growth phase.

9.
Eur J Clin Microbiol Infect Dis ; 38(10): 1953-1959, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31327067

RESUMEN

Clostridioides difficile has become the leading nosocomial Gram-positive pathogen in the developed countries. In Lithuania, the national surveillance program for C. difficile started in 2017. Enzyme immunoassay, the real-time PCR system, and culture are used for laboratory confirmation of C. difficile infection in Lithuanian clinical laboratories. No reference laboratory for C. difficile is present in Lithuania. Fifty-eight isolates of C. difficile were collected in 2016 and 2017 in two hospitals using real-time PCR and culture methods. Agarose gel-based PCR ribotyping, multilocus variable number tandem repeats analysis (MLVA), and multilocus sequence typing (MLST) were used for the genotypic characterization of 28 isolates. PCR ribotyping and MLST showed that 78.6% of the tested toxigenic isolates belong to the ribotype RT027/ST1. Using MLVA, 95.5% of RT027 isolates were genetically related. MLVA revealed three clonal complexes in RT027. Six non-RT027 isolates showed four different electrophoretic profiles in PCR ribotyping and were assigned to the MLST sequence types ST2, ST13, ST54, and ST63. The highest discriminatory power showed the genotyping by MLVA. In total, 20 MLVA profiles were identified. This genotyping technique allowed to identify four groups of RT027/ST1 isolates that were indistinguishable by PCR ribotyping and MLST. Our study is the first genotypic characterization of C. difficile isolates in Lithuania. We observed a high prevalence of presumptive RT027 that suggests unfavorable epidemiological situation in Lithuania. Our results stress for implementation of genotyping of C. difficile isolates in Lithuanian surveillance.


Asunto(s)
Clostridioides difficile/clasificación , Clostridioides difficile/genética , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Genotipo , Ribotipificación , Técnicas Bacteriológicas , Clostridioides difficile/aislamiento & purificación , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Hospitales , Humanos , Lituania/epidemiología , Repeticiones de Minisatélite , Técnicas de Diagnóstico Molecular , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Proyectos Piloto , Prevalencia
10.
Microb Drug Resist ; 25(3): 326-335, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30339100

RESUMEN

Spread of multidrug-resistant pathogenic bacteria became one of the greatest threats in healthcare worldwide. It is generally accepted that both inter- and intrahospital transmissions of these bacteria contribute significantly to this problem. The purpose of the current study was the evaluation of the inter- and intrahospital spread of multidrug resistant Gram-negative pathogenic bacteria in Lithuania. Clinical isolates of Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were subjected for the screening for extended spectrum ß-lactamase, carbapenemase, as well as plasmid-mediated AmpC ß-lactamase genes. BOX-PCR genotyping was used for the genotyping of these isolates. Our results show that all four pathogens are involved in the intra- and/or interhospital dissemination between the Lithuanian healthcare institutions. The level of transmissions differed between pathogens, and the worst situation was detected for Acinetobacter sp. followed by E. coli. In almost all cases, transmissible strains had at least one gene conferring ß-lactam resistance, thereby contributing to the dissemination of the resistance determinants in and between Lithuanian hospitals. Our study clearly demonstrated that immediate actions, more effective strategy, and surveillance are needed to confine and prevent further spread of multidrug resistant Gram-negative pathogenic bacteria in Lithuanian healthcare institutions.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Bacterias Gramnegativas/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/transmisión , Proteínas Bacterianas/genética , Técnicas de Genotipaje/métodos , Bacterias Gramnegativas/genética , Hospitales , Humanos , Lituania , Resistencia betalactámica/genética , beta-Lactamasas/genética
11.
Braz. j. microbiol ; 48(1): 7-8, Jan.-Mar. 2017. tab
Artículo en Inglés | LILACS | ID: biblio-839336

RESUMEN

Abstract Geobacillus thermodenitrificans DSM 101594 was isolated as a producer of extracellular thermostable pectic polysaccharide degrading enzymes. The completely sequenced genome was 3.6 Mb in length with GC content of 48.86%. A number of genes encoding enzymatic active against the high molecular weight polysaccharides of potential biotechnological importance were identified in the genome.


Asunto(s)
Genoma Bacteriano , Genómica , Geobacillus/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Pectinas/metabolismo , Biología Computacional/métodos , Genómica/métodos , Geobacillus/metabolismo , Anotación de Secuencia Molecular
12.
Biochem Pharmacol ; 134: 18-34, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-27867014

RESUMEN

This review highlights cave habitats, cave microbiomes and their potential for drug discovery. Such studies face many challenges, including access to remote and pristine caves, and sample collection and transport. Inappropriate physical and chemical growth conditions in the laboratory for the isolation and cultivation of cave microorganisms pose many complications including length of cultivation; some cave microorganisms can take weeks and even months to grow. Additionally, DNA extraction from cave environmental samples may be difficult due to the high concentration of various minerals that are natural DNA blocking agents. Once cave microorganisms are grown in the lab, other problems often arise, such as maintenance of pure culture, consistency of antimicrobial activity and fermentation conditions for antimicrobial production. In this review, we suggest that, although based on what has been done in the field, there is potential in using cave microorganisms to produce antimicrobial agents, one needs to be highly committed and prepared.


Asunto(s)
Fenómenos Fisiológicos Bacterianos/efectos de los fármacos , Productos Biológicos/aislamiento & purificación , Cuevas/microbiología , Descubrimiento de Drogas/métodos , Microbiota , Animales , Fenómenos Fisiológicos Bacterianos/genética , Productos Biológicos/farmacología , Descubrimiento de Drogas/tendencias , Humanos , Microbiota/genética
13.
Braz J Microbiol ; 48(1): 7-8, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27818089

RESUMEN

Geobacillus thermodenitrificans DSM 101594 was isolated as a producer of extracellular thermostable pectic polysaccharide degrading enzymes. The completely sequenced genome was 3.6Mb in length with GC content of 48.86%. A number of genes encoding enzymatic active against the high molecular weight polysaccharides of potential biotechnological importance were identified in the genome.


Asunto(s)
Genoma Bacteriano , Genómica , Geobacillus/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Biología Computacional/métodos , Genómica/métodos , Geobacillus/metabolismo , Anotación de Secuencia Molecular , Pectinas/metabolismo
14.
Int J Biol Macromol ; 89: 669-76, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27181578

RESUMEN

There is a growing interest in supporting human health by using prebiotics, such as oligosaccharides, and beneficial bacteria, also called probiotics. Combining these two components we can develop synbiotics. In order to create successful combination of synbiotic it is very important to evaluate the influence of prebiotic oligosaccharides to probiotic bacteria and their behavior, such as growth and secretion of health related biomolecules, including bacteriocins. In this study seven type strains of probiotic bacteria (five Lactobacillus sp. and two Lactococcus sp.) and two Lactobacillus sp. strains, isolated from probiotic yoghurt, were cultivated with various commercially available and extracted oligosaccharides (OS). The aim of this study was to evaluate the influence of these OS on type and isolated bacterial strains growth and antibacterial activity. Obtained results suggest that combination of certain OS with probiotic strains may considerably improve their growth and/or antibacterial activity. We also determined the antibacterial activity spectrum of investigated strains with combination of OS against common food borne pathogens. Results of this work show that prebiotic OS can be useful for modulating probiotic bacteria growth, antibacterial activity and even specificity of this activity.


Asunto(s)
Bacteriocinas/química , Lactobacillus/química , Oligosacáridos/química , Probióticos , Bacteriocinas/biosíntesis , Bacteriocinas/farmacología , Fermentación , Microbiología de Alimentos , Humanos , Lactobacillus/metabolismo , Oligosacáridos/biosíntesis , Oligosacáridos/farmacología , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/patogenicidad , Yogur/microbiología
15.
J Microbiol Biotechnol ; 25(7): 1070-83, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25791847

RESUMEN

A gene (GT-SM3B) encoding a thermostable secreted oligoendopeptidase (GT-SM3B) was cloned from the thermophile Geobacillus thermoleovorans DSM 15325. GT-SM3B is 1,857 bp in length and encodes a single-domain protein of 618 amino acids with a 23-residue signal peptide having a calculated mass of 67.7 kDa after signal cleavage. The deduced amino acid sequence of GT-SM3B contains a conservative zinc metallopeptidase motif (His(400)-Glu(401)-X-XHis (404)). The described oligopeptidase belongs to the M3B subfamily of metallopeptidases and displays the highest amino acid sequence identity (40.3%) to the oligopeptidase PepFBa from mesophilic Bacillus amyloliquefaciens 23-7A among the characterized oligopeptidases. Secretory production of GT-SM3B was used, exploiting successful oligopeptidase signal peptide recognition by Escherichia coli BL21 (DE3). The recombinant enzyme was purified from the culture fluid. Homodimerization of GT-SM3B was determined by SDS-PAGE. Both the homodimer and monomer were catalytically active within a pH range of 5.0-8.0, at pH 7.3 and 40°C, showing the Km, Vmax, and kcat values for carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala-OH peptidolysis to be 2.17 ± 0.04 × 10(-6) M, 2.65 ± 0.03 × 10(-3) micrometer/min, and 5.99 ± 0.07 s(-1), respectively. Peptidase remained stable at a broad pH range of 5.0-8.0. GT-SM3B was thermoactive, demonstrating 84% and 64% of maximum activity at 50°C and 60°C, respectively. The recombinant oligopeptidase is one of the most thermostable M3B peptidase, retaining 71% residual activity after incubation at 60°C for 1 h. GT-SM3B was shown to hydrolyze a collagenous peptide mixture derived from various types of collagen, but less preferentially than synthetic hexapeptide. This study is the first report on an extracellular thermostable metallo-oligopeptidase.


Asunto(s)
Geobacillus/enzimología , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Clonación Molecular , ADN Bacteriano/química , ADN Bacteriano/genética , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Geobacillus/genética , Concentración de Iones de Hidrógeno , Cinética , Datos de Secuencia Molecular , Peso Molecular , Péptido Hidrolasas/química , Multimerización de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Temperatura
16.
Pol J Microbiol ; 63(1): 33-41, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25033660

RESUMEN

Success in creating a synbiotic depends on compatibility between the chosen components--prebiotic and probiotic. In this work the interactions between Lactobacillus sp. strains isolated from yogurts and type strains of Lactobacillus sp. and Lactococcus sp., and the dependence of their growth and antibacterial activity on three oligosaccharides (OS)--palatinose, inulin and alpha-cyclodextrin were investigated. All isolated lactobacilli produce antibacterial compounds, which possibly are the bacteriocins of Lactobacillus casei ATCC334 strain. Results of growth analysis with different OS revealed that part of lactobacilli isolated from yogurts can effectively ferment inulin and may be used for the development of synbiotics. Palatinose and Lactobacillus acidophilus could be used as symbiotics with effective antibacterial activity. One of the types of Lactococcus sp. strains can assimilate palatinose and alpha-cyclodextrin, so they both can be used as components of synbiotics with the investigated lactococci. Results of this analysis suggest that the investigated isolated and type strains of Lactobacillus sp. and Lactoccocus sp. can be useful as probiotics in the development of synbiotics. Together with prebiotics--palatinose, inulin and alpha-cyclodextrin, the synbiotics, which could regulate not only the growth of beneficial bacteria in the gastrointestinal tract, but also their antibacterial activity, can be created.


Asunto(s)
Inulina/metabolismo , Isomaltosa/análogos & derivados , Lactobacillus/fisiología , Probióticos , Simbióticos , alfa-Ciclodextrinas/metabolismo , Bacteriocinas/metabolismo , Bacteriocinas/farmacología , Isomaltosa/metabolismo , Yogur/microbiología
17.
Acta Crystallogr D Biol Crystallogr ; 69(Pt 3): 464-70, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23519421

RESUMEN

While small organic molecules generally crystallize forming tightly packed lattices with little solvent content, proteins form air-sensitive high-solvent-content crystals. Here, the crystallization and full structure analysis of a novel recombinant 10 kDa protein corresponding to the C-terminal domain of a putative U32 peptidase are reported. The orthorhombic crystal contained only 24.5% solvent and is therefore among the most tightly packed protein lattices ever reported.


Asunto(s)
Geobacillus/enzimología , Péptido Hidrolasas/química , Cristalización , Cristalografía por Rayos X , Peso Molecular , Fragmentos de Péptidos/química , Proteolisis , Selenometionina/metabolismo , Solventes
18.
Curr Microbiol ; 58(6): 547-53, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19205799

RESUMEN

In this work, the variability of spo0A gene in the genus Geobacillus and applicability of this gene for the taxonomy within this genus were evaluated. The protein Spo0A is the master regulator of the endospore-forming process in the all endospore-forming bacteria. Geobacillus genus-specific primers GEOSPO were designed based on the sequences of Geobacillus spo0A gene available through the public databases. Inter and intraspecific variability of Geobacillus spo0A gene was determined after sequencing of the GEOSPO-PCR products. Geobacillus spo0A sequence analysis showed that three species--Geobacillus thermodenitrificans, G. stearothermophilus, and G. jurassicus--could be easily identified. Similarity between the sequences of these species and the other species were in the range of 83.3%-92.0%. In contrast, intraspecific similarity of G. thermodenitrificans and G. stearothermophilus was high--above 99.0%. Similarity of spo0A sequences of G. subterraneus-G. uzenensis species cluster also matched this interval. Intercluster similarity between G. lituanicus-G. thermoleovorans-G. kaustophilus-G. vulcani and G. thermocatenulatus-G. gargensis-G. caldoxylosilyticus-G. toebii-G. thermoglucosidasius species clusters, as well as interspecific similarity within these two clusters was in the range of the intraspecific similarity determined for G. thermodenitrificans and G. stearothermophilus. It was also determined that spo0A cannot be used as the phylogenetic marker for the genus Geobacillus.


Asunto(s)
Bacillaceae/clasificación , Proteínas Bacterianas/genética , ADN Intergénico/genética , Filogenia , Bacillaceae/genética , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , ADN Ribosómico/genética , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
19.
Extremophiles ; 12(3): 415-29, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18305896

RESUMEN

The complete nucleotide sequence (62.8 kb) of pGS18, the largest sequenced plasmid to date from the species Geobacillus stearothermophilus, was determined. Computational analysis of sequence data revealed 65 putative open reading frames (ORFs); 38 were carried on one strand and 27 were carried on the other. These ORFs comprised 84.1% of the pGS18 sequence. Twenty-five ORFs (38.4%) were assigned to putative functions; four ORFs (6.2%) were annotated as pseudogenes. The amino acid sequences obtained from 29 ORFs (44.6%) had the highest similarity to hypothetical proteins of the other microorganisms, and seven (10.8%) had no significant similarity to any genes present in the current open databases. Plasmid replication region, strongly resembling that of the theta-type replicon, and genes encoding three different plasmid maintenance systems were identified, and a putative discontinuous transfer region was localized. In addition, we also found several mobile genetic elements and genes, responsible for DNA repair, distributed along the whole sequence of pGS18. The alignment of pGS18 with two other large indigenous plasmids of the genus Geobacillus highlighted the presence of well-conserved segments and has provided a framework that can be exploited to formulate hypotheses concerning the molecular evolution of these three plasmids.


Asunto(s)
Proteínas Bacterianas/genética , ADN Bacteriano/análisis , Geobacillus stearothermophilus/genética , Plásmidos , Secuencia de Bases , Reparación del ADN , Replicación del ADN , ADN Circular , Bases de Datos Genéticas , Evolución Molecular , Secuencias Repetitivas Esparcidas , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Alineación de Secuencia , Análisis de Secuencia de ADN , Análisis de Secuencia de Proteína
20.
Int J Syst Evol Microbiol ; 58(Pt 2): 505-9, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18218958

RESUMEN

Four bacterial strains, designated K9(T), K105, K1012A and K101, were isolated from soil in Lithuania. All these strains could use n-butanol as a sole carbon source. The strains grew in a medium containing 12-120 mM n-butanol. The strains were strictly aerobic, Gram-positive endospore-formers. The best growth was achieved at 25 degrees C and pH 7.0 in medium containing 1 % (w/v) NaCl. The strains showed identical profiles of 16S-23S rRNA internal transcribed spacer PCR and nearly identical 16S rRNA gene PCR-RFLP electrophoretic patterns and physiological characteristics, demonstrating their relationship at the species level. The cellular fatty acid profile of K9(T) consisted of significant amounts of the C(15) branched-chain fatty acids iso-C(15 : 0) (16.78 %) and anteiso-C(15 : 0) (45.80 %). The diagnostic cell-wall diamino acid was meso-diaminopimelic acid. The 16S rRNA gene sequence of K9(T) showed the highest similarity to the sequences of Bacillus simplex DSM 1321(T) and Bacillus muralis LMG 20238(T) (98.3 and 97.7 %, respectively). The DNA G+C content was 37.4 mol%. Studies of DNA-DNA relatedness, morphological, physiological and chemotaxonomic analyses and phylogenetic data based on 16S rRNA gene sequencing allowed strains K9(T), K105, K1012A and K101 to be described as members of a novel species of the genus Bacillus, for which the name Bacillus butanolivorans sp. nov. is proposed. The type strain is K9(T) (=DSM 18926(T) =LMG 23974(T)).


Asunto(s)
Bacillus/clasificación , Bacillus/aislamiento & purificación , Butanoles/metabolismo , Microbiología del Suelo , Bacillus/genética , Bacillus/fisiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/análisis , ADN Espaciador Ribosómico/análisis , Ácidos Grasos/análisis , Genes de ARNr , Microbiología Industrial/métodos , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie
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