Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Clin Med ; 12(22)2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38002651

RESUMO

Osteoarthritis (OA) ranks among the most prevalent inflammatory diseases affecting the musculoskeletal system and is a leading cause of disability globally, impacting approximately 250 million individuals. This study aimed to assess the relationship between the severity of knee osteoarthritis (KOA) and body composition in postmenopausal women using bioimpedance analysis (BIA). The study included 58 postmenopausal females who were candidates for total knee arthroplasty. The control group consisted of 25 postmenopausal individuals with no degenerative knee joint changes. The anthropometric analysis encompassed the body mass index (BMI), mid-arm and mid-thigh circumferences (MAC and MTC), and triceps skinfold thickness (TSF). Functional performance was evaluated using the 30 s sit-to-stand test. During the BIA test, electrical parameters such as membrane potential, electrical resistance, capacitive reactance, impedance, and phase angle were measured. Additionally, body composition parameters, including Total Body Water (TBW), Extracellular Water (ECW), Intracellular Water (ICW), Body Cellular Mass (BCM), Extracellular Mass (ECM), Fat-Free Mass (FFM), and Fat Mass (FM), were examined. The study did not find any statistically significant differences in the electrical parameters between the control (0-1 grade on the K-L scale) and study groups (3-4 grade on the K-L scale). However, statistically significant differences were observed in BMI, fat mass (FM), arm circumference, triceps skinfold thickness, and sit-to-stand test results between the analyzed groups. In conclusion, the association between overweight and obesity with KOA in postmenopausal women appears to be primarily related to the level of adipose tissue and its metabolic activity.

2.
Artigo em Inglês | MEDLINE | ID: mdl-35329164

RESUMO

Root-feeding Amphimallon solstitiale larvae and certain other scarab beetles are the main soil-dwelling pests found in Europe, while entomopathogenic nematodes (EPN) have been used as a biocontrol agent against these species. Our study provides the first detailed characterization of the bacterial community of the midgut in wild A. solstitiale larvae, based on the nanopore sequencing of the 16S rRNA gene. In the whole dataset, we detected 2586 different genera and 11,641 species, with only 83 diverse bacterial genera shared by all studied individuals, which may represent members of the core midgut microbiota of A. solstitiale larvae. Subsequently, we compared the midgut microbiota of EPN-resistant and T0 (prior to EPN exposure) individuals, hypothesizing that resistance to this parasitic infection may be linked to the altered gut community. Compared to the control, the resistant insect microbiota demonstrated lower Shannon and Evenness indices and significant differences in the community structure. Our studies confirmed that the gut microbiota alternation is associated with resistant insects; however, there are many processes involved that can affect the bacterial community. Further research on the role of gut microbiota in insect-parasitic nematode interaction may ultimately lead to the improvement of biological control strategies in insect pest management.


Assuntos
Besouros , Microbiota , Sequenciamento por Nanoporos , Nematoides , Animais , Bactérias/genética , Insetos/genética , Larva/parasitologia , Nematoides/genética , RNA Ribossômico 16S/genética
3.
Int J Mol Sci ; 22(21)2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34769435

RESUMO

Entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) are a group of organisms capable of infecting larvae of insects living in soil, including representatives of the family Scarabaeidae. Their insecticidal activity is related to the presence of symbiotic bacteria Xenorhabdus spp. or Photorhabdus spp. in the alimentary tract, which are released into the insect body, leading to its death caused by bacterial toxins and septicemia. Although the antibacterial activities of symbionts of entomopathogenic nematodes have been well described, there is insufficient knowledge of the interactions between these bacteria and microorganisms that naturally inhabit the alimentary tract of insects infested by nematodes. In this study, 900 bacterial strains isolated from midgut samples of Amphimallon solstitiale larvae were tested for their antagonistic activity against the selected five Xenorhabdus and Photorhabdus species. Cross-streak tests showed significant antibacterial activity of 20 isolates. These bacteria were identified as Bacillus [Brevibacterium] frigoritolerans, Bacillus toyonensis, Bacillus wiedmannii, Chryseobacterium lathyri, Chryseobacterium sp., Citrobacter murliniae, Enterococcus malodoratus, Paenibacillus sp., Serratia marcescens and Serratia sp. Since some representatives of the intestinal microbiota of A. solstitiale are able to inhibit the growth of Xenorhabdus and Photorhrhabdus bacteria in vitro, it can be assumed that this type of bacterial interaction may occur at certain stages of insect infection by Steinernema or Heterorhabditis nematodes.


Assuntos
Besouros/microbiologia , Microbioma Gastrointestinal , Photorhabdus/isolamento & purificação , Xenorhabdus/isolamento & purificação , Animais , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Toxinas Bacterianas , Larva , Simbiose
4.
J Nematol ; 532021.
Artigo em Inglês | MEDLINE | ID: mdl-34079955

RESUMO

A new species of entomopathogenic nematodes, Steinernema sandneri n. sp., was recovered by baiting from Poland. Its morphological traits indicate that the new species is a member of the feltiae-kraussei group. A body length of 843 (708-965) µm, a more anterior position of excretory pore (56 µm), and the lower D% value (40 vs > 46) discriminate this species from most of the other group members. The first-generation males of S. sandneri n. sp. can be distinguished from the other clade members by a 60 µm long spicule, a relatively long gubernaculum (GS% = 79), and the position of the excretory pore (80 µm). Phylogenetic analysis of the ITS rDNA, D2D3 of 28 S rDNA, and cox1 sequences confirmed that S. sandneri n. sp. is a new species of the feltiae-kraussei group, closely related to S. kraussei and S. silvaticum.

5.
Pathogens ; 10(4)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33806200

RESUMO

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.

6.
Molecules ; 25(23)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33255915

RESUMO

Increasing knowledge of the role of the intestinal microbiome in human health and well-being has resulted in increased interest in prebiotics, mainly oligosaccharides of various origins. To date, there are no reports in the literature on the prebiotic properties of oligosaccharides produced by the hydrolysis of pure fungal α-(1→3)-glucan. The aim of this study was to prepare α-(1→3)-glucooligosaccharides (α-(1→3)-GOS) and to perform initial evaluation of their prebiotic potential. The oligosaccharides were obtained by acid hydrolysis of α-(1→3)-glucan isolated from the fruiting bodies of Laetiporus sulphureus and then, characterized by HPLC. Fermentation of α-(1→3)-GOS and reference prebiotics was compared in in vitro pure cultures of Lactobacillus, Bifidobacterium, and enteric bacterial strains. A mixture of α-(1→3)-GOS, notably with a degree of polymerization of 2 to 9, was obtained. The hydrolysate was utilized for growth by most of the Lactobacillus strains tested and showed a strong bifidogenic effect, but did not promote the growth of Escherichia coli and Enterococcus faecalis. α-(1→3)-GOS proved to be effective in the selective stimulation of beneficial bacteria and can be further tested to determine their prebiotic functionality.


Assuntos
Polissacarídeos Fúngicos/química , Glucanos/química , Oligossacarídeos/química , Polyporales/química , Prebióticos , Cromatografia Líquida de Alta Pressão , Humanos , Hidrólise
7.
Int J Mol Sci ; 21(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963214

RESUMO

The mechanisms of action of the complex including entomopathogenic nematodes of the genera Steinernema and Heterorhabditis and their mutualistic partners, i.e., bacteria Xenorhabdus and Photorhabdus, have been well explained, and the nematodes have been commercialized as biological control agents against many soil insect pests. However, little is known regarding the nature of the relationships between these bacteria and the gut microbiota of infected insects. In the present study, 900 bacterial isolates that were obtained from the midgut samples of Melolontha melolontha larvae were screened for their antagonistic activity against the selected species of the genera Xenorhabdus and Photorhabdus. Twelve strains exhibited significant antibacterial activity in the applied tests. They were identified based on 16S rRNA and rpoB, rpoD, or recA gene sequences as Pseudomonas chlororaphis, Citrobacter murliniae, Acinetobacter calcoaceticus, Chryseobacterium lathyri, Chryseobacterium sp., Serratia liquefaciens, and Serratia sp. The culture filtrate of the isolate P. chlororaphis MMC3 L3 04 exerted the strongest inhibitory effect on the tested bacteria. The results of the preliminary study that are presented here, which focused on interactions between the insect gut microbiota and mutualistic bacteria of entomopathogenic nematodes, show that bacteria inhabiting the gut of insects might play a key role in insect resistance to entomopathogenic nematode pressure.


Assuntos
Larva/microbiologia , Photorhabdus/genética , Photorhabdus/isolamento & purificação , Xenorhabdus/genética , Xenorhabdus/isolamento & purificação , Acinetobacter calcoaceticus/genética , Acinetobacter calcoaceticus/isolamento & purificação , Animais , Chryseobacterium/genética , Chryseobacterium/isolamento & purificação , Citrobacter/genética , Citrobacter/isolamento & purificação , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/fisiologia , Pseudomonas chlororaphis/genética , Pseudomonas chlororaphis/isolamento & purificação , RNA Ribossômico 16S/genética , Serratia liquefaciens/genética , Serratia liquefaciens/isolamento & purificação , Simbiose/genética , Simbiose/fisiologia
8.
Arch Microbiol ; 200(9): 1307-1316, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29946739

RESUMO

Three strains of symbiotic bacteria were isolated from an entomopathogenic nematode Steinernema poinari retrieved from soil in eastern Poland. Using 16S rDNA, recA, gltX, gyrB, and dnaN gene sequences for phylogenetic analysis, these strains were shown to belong to the species Xenorhabdus bovienii. The nucleotide identity between the studied S. poinari microsymbionts and other X. bovienii strains calculated for 16S rDNA and concatenated sequences of four protein-coding genes was 98.7-100% and 97.9-99.5%, respectively. The phenotypic properties of the isolates also supported their close phylogenetic relationship with X. bovienii. All three tested X. bovienii strains of different Steinernema clade origin supported the recovery of infective juveniles and subsequent development of the nematode population. However, the colonization degree of new infective juvenile generations was significantly affected by the bacterial host donor/recipient. The colonization degree of infective juveniles reared on bacterial symbionts deriving from a non-cognate clade of nematodes was extremely low, but proved the possible host-switching between non-related Steinernema species.


Assuntos
Rabditídios/microbiologia , Simbiose/fisiologia , Xenorhabdus/isolamento & purificação , Animais , Proteínas de Bactérias/genética , DNA Girase/genética , DNA Ribossômico/genética , DNA Polimerase Dirigida por DNA/genética , Filogenia , Polônia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Xenorhabdus/classificação , Xenorhabdus/genética
9.
Arch Microbiol ; 199(7): 979-989, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28382473

RESUMO

The relationships between six bacterial symbionts of the entomopathogenic nematodes Heterorhabditis bacteriophora and Heterorhabditis megidis from Poland to species and subspecies of the genus Photorhabdus were evaluated. This study was based on phylogenetic analysis of sequence data of five genes: 16S rRNA, gyrB, recA, gltX, and dnaN. The bacteria were also characterized phenotypically by biochemical and physiological tests. Our results have revealed that the Photorhabdus strains isolated from H. megidis belong to P. temperata, subsp. temperata and subsp. cinerea. Isolates from H. bacteriophora represent P. luminescens subs. kayaii and P. temperata subs. cinerea. This study for the first time provides evidence for H. bacteriophora and P. temperata subsp. cinerea symbiotic association. In addition, we tested whether the microsymbionts of the Polish H. bacteriophora and H. megidis isolates support the development of non-native nematode host population and colonization of their infective juveniles. It has been shown that the studied Photorhabdus strains can readily swap their nematode host, both at intra- and interspecies level. It supports the hypothesis of different symbiotic associations in the Heterorhabditis-Photorhabdus lineage.


Assuntos
Photorhabdus , Rhabditoidea/microbiologia , Animais , Proteínas de Bactérias/genética , DNA Girase/genética , DNA Bacteriano/genética , DNA Polimerase Dirigida por DNA/genética , Genes Essenciais/genética , Tipagem de Sequências Multilocus , Fenótipo , Photorhabdus/classificação , Photorhabdus/genética , Photorhabdus/isolamento & purificação , Filogenia , Polônia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Análise de Sequência de DNA , Simbiose
10.
Arch Microbiol ; 198(10): 995-1003, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27342112

RESUMO

Steinernema silvaticum is a common entomopathogenic nematode in soil of Europe; however, little is known about the bacteria living in symbiosis with this animal. In this study, we have isolated four bacterial strains from S. silvaticum and identified them as members of the species Xenorhabdus bovienii. This study was based on 16S rRNA and concatenated recA, dnaN, gltX, and gyrB gene sequence analysis. In addition, phenotypic traits have been considered, indicating that the tested strains are the most similar to those of X. bovienii. The phylogenetic relationships between the isolated strains and other strains of X. bovienii derived from various nematode hosts were analyzed and discussed. This is the first report confirming the symbiotic association of X. bovienii with S. silvaticum.


Assuntos
Rabditídios/metabolismo , Rabditídios/microbiologia , Solo/parasitologia , Simbiose/fisiologia , Xenorhabdus/metabolismo , Animais , Proteínas de Bactérias/genética , DNA Girase/genética , DNA Polimerase Dirigida por DNA/genética , Europa (Continente) , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Xenorhabdus/genética
11.
J Ind Microbiol Biotechnol ; 42(7): 985-96, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25896034

RESUMO

New glycidyl methacrylate copolymers containing different numbers of epoxy groups were synthesized and used to develop effective procedures for inulinase immobilization. The beneficial characteristics of the carriers included a high degree of crosslinking, stability at ambient temperature, an appropriate surface, and the presence of reactive epoxy groups. Some factors affecting the efficiency of immobilization of crude inulinase, including the kind and amount of carrier, the number of epoxy groups, as well as buffer pH and buffer concentration were examined. The yield of immobilization of this enzyme on the investigated type of microspheres was higher than on the commercial carrier, Eupergit(®) C. After immobilization, the optimum temperature for inulinase activity shifted from 55 to 45 °C, whereas the optimum pH = 5 remained unchanged. The basic parameters of inulin hydrolysis were examined, and the possibility of applying the obtained biocatalyst in continuous conditions was tested. Inulin at a concentration of 0.5% (w/v) was almost completely hydrolyzed to fructose (in a yield of 98 %) at a flow rate of 0.1 mL/min. A tenfold increase in the speed of flow resulted in an increase in the yield of oligosaccharides (DP2-DP6) up to ~41% in the overall hydrolysate, as analysed by HPLC-RID and LC-ESI/MS. These results indicate that two forms of inulinase, an exo- and an endo-acting enzyme, were immobilized on our carrier. The enzyme showed good operational stability in a packed column over 28 days. There were no significant decreases in the efficiency of continuous hydrolysis during this time (about 17.4% in comparison to its initial value).


Assuntos
Enzimas Imobilizadas/química , Compostos de Epóxi/química , Proteínas Fúngicas/química , Glicosídeo Hidrolases/química , Metacrilatos/química , Ácidos Polimetacrílicos/química , Aspergillus niger/enzimologia , Biocatálise , Estabilidade Enzimática , Frutose/química , Concentração de Íons de Hidrogênio , Hidrólise , Inulina/química , Oligossacarídeos/química
12.
Prep Biochem Biotechnol ; 42(4): 335-47, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22708811

RESUMO

Mutanases are enzymes that catalyze hydrolysis of α-1,3-glucosidic bonds in various α-glucans. One of such glucans, mutan, which is synthesized by cariogenic streptococci, is a major virulence factor for induction of dental caries. This means that mutan-degrading enzymes have potential in caries prophylaxis. In this study, we report the purification, characterization, and partial amino acid sequence of extracellular mutanase produced by the MP-1 strain of Paenibacillus curdlanolyticus, bacterium isolated from soil. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme showed a single protein band of molecular mass 134 kD, while native gel filtration chromatography confirmed that the enzyme was a monomer of 142 kD. Mutanase showed a pH optimum in the range from pH 5.5 to 6.5 and a temperature optimum around 40-45°C. It was thermostable up to 45°C, and retained 50% activity after 1 hr at 50°C. The enzyme was fully stable at a pH range of 4 to 10. The enzyme activity was stimulated by the addition of Tween 20, Tween 80, and Ca²âº, but it was significantly inhibited by Hg²âº, Ag⁺, and Fe²âº, and also by p-chloromercuribenzoate, iodoacetamide, and ethylenediamine tetraacetic acid (EDTA). Mutanase preparation preferentially catalyzed the hydrolysis of various streptococcal mutans and fungal α-1,3-glucans. It also showed binding activity to insoluble α-1,3-glucans. The N-terminal amino acid sequence was NH2-Ala-Gly-Gly-Thr-Asn-Leu-Ala-Leu-Gly-Lys-Asn-Val-Thr-Ala-Ser-Gly-Gln. This sequence indicated an analogy of the enzyme to α-1,3-glucanases from other Paenibacillus and Bacillus species.


Assuntos
Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Paenibacillus/enzimologia , Sequência de Aminoácidos , Estabilidade Enzimática , Glicosídeo Hidrolases/isolamento & purificação , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Paenibacillus/química , Alinhamento de Sequência , Especificidade por Substrato , Temperatura
13.
Pol J Microbiol ; 60(1): 51-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21630574

RESUMO

A total of 24 yeast strains were tested for their capacity to produce ethanol, and of these, 8 were characterized by the best ethanol yields (73.11-8 1.78%). The most active mutant Saccharomyce s cerevisiae ER-A, resistant to ethanol stress, was characterized by high resistance to acidic (pH 1.0 and 2.0), oxidative (1 and 2% of H2O2), and high temperature (45 and 52 degrees C) stresses. During cultivation under all stress conditions, the mutants showed a considerably increased viability ranging widely from about 1.04 to 3.94-fold in comparison with the parent strain S. cerevisiae ER. At an initial sucrose concentration of 150 g/l in basal medium A containing yeast extract and mineral salts, at 300C and within 72 h, the most active strain, S. cerevisiae ER-A, reached an ethanol concentration of 80 g/1, ethanol productivity of 1.1 g/Il/h, and an ethanol yield (% of theoretical) of 99.13. Those values were significantly higher in comparison with parent strain (ethanol concentration 71 g/1 and productivity of 0,99 g/l/h). The present study seems to confirm the high effectiveness of selection of ethanol-resistant yeast strains by adaptation to high ethanol concentrations, for increased ethanol production.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Etanol/farmacologia , Fermentação , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA