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131 result(s) for "Paulin, Lars"
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Relationships of gut microbiota, short-chain fatty acids, inflammation, and the gut barrier in Parkinson’s disease
Background Previous studies have reported that gut microbiota, permeability, short-chain fatty acids (SCFAs), and inflammation are altered in Parkinson’s disease (PD), but how these factors are linked and how they contribute to disease processes and symptoms remains uncertain. This study sought to compare and identify associations among these factors in PD patients and controls to elucidate their interrelations and links to clinical manifestations of PD. Methods Stool and plasma samples and clinical data were collected from 55 PD patients and 56 controls. Levels of stool SCFAs and stool and plasma inflammatory and permeability markers were compared between patients and controls and related to one another and to the gut microbiota. Results Calprotectin was increased and SCFAs decreased in stool in PD in a sex-dependent manner. Inflammatory markers in plasma and stool were neither intercorrelated nor strongly associated with SCFA levels. Age at PD onset was positively correlated with SCFAs and negatively correlated with CXCL8 and IL-1β in stool. Fecal zonulin correlated positively with fecal NGAL and negatively with PD motor and non-motor symptoms. Microbiota diversity and composition were linked to levels of SCFAs, inflammatory factors, and zonulin in stool. Certain relationships differed between patients and controls and by sex. Conclusions Intestinal inflammatory responses and reductions in fecal SCFAs occur in PD, are related to the microbiota and to disease onset, and are not reflected in plasma inflammatory profiles. Some of these relationships are distinct in PD and are sex-dependent. This study revealed potential alterations in microbiota-host interactions and links between earlier PD onset and intestinal inflammatory responses and reduced SCFA levels, highlighting candidate molecules and pathways which may contribute to PD pathogenesis and clinical presentation and which warrant further investigation.
Bacterial diversity at different stages of the composting process
Background Composting is an aerobic microbiological process that is facilitated by bacteria and fungi. Composting is also a method to produce fertilizer or soil conditioner. Tightened EU legislation now requires treatment of the continuously growing quantities of organic municipal waste before final disposal. However, some full-scale composting plants experience difficulties with the efficiency of biowaste degradation and with the emission of noxious odours. In this study we examine the bacterial species richness and community structure of an optimally working pilot-scale compost plant, as well as a full-scale composting plant experiencing typical problems. Bacterial species composition was determined by isolating total DNA followed by amplifying and sequencing the gene encoding the 16S ribosomal RNA. Results Over 1500 almost full-length 16S rRNA gene sequences were analysed and of these, over 500 were present only as singletons. Most of the sequences observed in either one or both of the composting processes studied here were similar to the bacterial species reported earlier in composts, including bacteria from the phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and Deinococcus-Thermus. In addition, a number of previously undetected bacterial phylotypes were observed. Statistical calculations estimated a total bacterial diversity of over 2000 different phylotypes in the studied composts. Conclusions Interestingly, locally enriched or evolved bacterial variants of familiar compost species were observed in both composts. A detailed comparison of the bacterial diversity revealed a large difference in composts at the species and strain level from the different composting plants. However, at the genus level, the difference was much smaller and illustrated a delay of the composting process in the full-scale, sub-optimally performing plants.
Cloning of the wheat Yr15 resistance gene sheds light on the plant tandem kinase-pseudokinase family
Yellow rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is a devastating fungal disease threatening much of global wheat production. Race-specific resistance ( R )-genes are used to control rust diseases, but the rapid emergence of virulent Pst races has prompted the search for a more durable resistance. Here, we report the cloning of Yr15 , a broad-spectrum R -gene derived from wild emmer wheat, which encodes a putative kinase-pseudokinase protein, designated as wheat tandem kinase 1, comprising a unique R -gene structure in wheat. The existence of a similar gene architecture in 92 putative proteins across the plant kingdom, including the barley RPG1 and a candidate for Ug8 , suggests that they are members of a distinct family of plant proteins, termed here tandem kinase-pseudokinases (TKPs). The presence of kinase-pseudokinase structure in both plant TKPs and the animal Janus kinases sheds light on the molecular evolution of immune responses across these two kingdoms. Yellow rust fungus severely limits global wheat production and breeding of durable resistance is challenging. Here Klymiuk et al. isolate the broad-spectrum Yr15 resistance gene from wild emmer wheat and show that it is a member of a distinct tandem kinase-pseudokinase family of plant proteins.
Environmental biodiversity, human microbiota, and allergy are interrelated
Rapidly declining biodiversity may be a contributing factor to another global megatrend—the rapidly increasing prevalence of allergies and other chronic inflammatory diseases among urban populations worldwide. According to the \"biodiversity hypothesis,\" reduced contact of people with natural environmental features and biodiversity may adversely affect the human commensal microbiota and its immunomodulatory capacity. Analyzing atopic sensitization (i.e., allergic disposition) in a random sample of adolescents living in a heterogeneous region of 100 x 150 km, we show that environmental biodiversity in the surroundings of the study subjects’ homes influenced the composition of the bacterial classes on their skin. Compared with healthy individuals, atopic individuals had lower environmental biodiversity in the surroundings of their homes and significantly lower generic diversity of gammaproteobacteria on their skin. The functional role of the Gram-negative gammaproteobacteria is supported by in vitro measurements of expression of IL-10, a key anti-inflammatory cytokine in immunologic tolerance, in peripheral blood mononuclear cells. In healthy, but not in atopic, individuals, IL-10 expression was positively correlated with the abundance of the gammaproteobacterial genus Acinetobacter on the skin. These results raise fundamental questions about the consequences of biodiversity loss for both allergic conditions and public health in general.
Transcriptomic time-series analysis of cold- and heat-shock response in psychrotrophic lactic acid bacteria
Background Psychrotrophic lactic acid bacteria (LAB) species are the dominant species in the microbiota of cold-stored modified-atmosphere-packaged food products and are the main cause of food spoilage. Despite the importance of psychrotrophic LAB, their response to cold or heat has not been studied. Here, we studied the transcriptome-level cold- and heat-shock response of spoilage lactic acid bacteria with time-series RNA-seq for Le. gelidum, Lc. piscium , and P. oligofermentans at 0 °C, 4 °C, 14 °C, 25 °C, and 28 °C. Results We observed that the cold-shock protein A ( cspA ) gene was the main cold-shock protein gene in all three species. Our results indicated that DEAD-box RNA helicase genes ( cshA , cshB ) also play a critical role in cold-shock response in psychrotrophic LAB. In addition, several RNase genes were involved in cold-shock response in Lc. piscium and P. oligofermentans. Moreover, gene network inference analysis provided candidate genes involved in cold-shock response. Ribosomal proteins, tRNA modification, rRNA modification, and ABC and efflux MFS transporter genes clustered with cold-shock response genes in all three species, indicating that these genes could be part of the cold-shock response machinery. Heat-shock treatment caused upregulation of Clp protease and chaperone genes in all three species. We identified transcription binding site motifs for heat-shock response genes in Le. gelidum and Lc. piscium. Finally, we showed that food spoilage-related genes were upregulated at cold temperatures. Conclusions The results of this study provide new insights on the cold- and heat-shock response of psychrotrophic LAB. In addition, candidate genes involved in cold- and heat-shock response predicted using gene network inference analysis could be used as targets for future studies.
Bile microbiota in primary sclerosing cholangitis: Impact on disease progression and development of biliary dysplasia
The etiopathogenesis and risk for development of biliary neoplasia in primary sclerosing cholangitis (PSC) are largely unknown. Microbes or their metabolites have been suggested to play a role. To explore this potential microbial involvement, we evaluated the differences in biliary microbiota in PSC patients at an early disease stage without previous endoscopic retrograde cholangiography (ERC) examinations, advanced disease stage, and with biliary dysplasia or cholangiocarcinoma. Bile samples from the common bile duct were collected from 46 controls and 80 patients with PSC during ERC (37 with early disease, 32 with advanced disease, and 11 with biliary dysplasia). DNA isolation, amplification, and Illumina MiSeq sequencing were performed for the V1-V3 regions of the bacterial 16S rRNA gene. The most common phyla found were Bacteroidetes, Firmicutes, Proteobacteria, Fusobacteria, and Actinobacteria. The most common families were Prevotellaceae, Streptococcaceae, Veillonellaceae, Fusobacteriaceae, and Pasteurellaceae, and the most common genera were Prevotella, Streptococcus, Veillonella, Fusobacterium, and Haemophilus. The bacterial communities of non-PSC subjects and early stage PSC patients were similar. Alpha diversity was lower in patients with biliary dysplasia/cholangiocarcinoma than in other groups. An increase in Streptococcus abundance was positively correlated with the number of ERC examinations. Streptococcus abundance was also positively correlated with an increase in disease severity, even after controlling for the number of ERC examinations. Our findings suggest that the aetiology of PSC is not associated with changes in bile microbial communities, but the genus Streptococcus may play a pathogenic role in the progression of the disease.
Dietary supplementation with yeast hydrolysate in pregnancy influences colostrum yield and gut microbiota of sows and piglets after birth
Dietary supplementation with yeast derivatives (YD) contributes to the health and physiology of sows and piglets, but few studies have focused on how it influences gut health and performance of sows and piglets. The goal was therefore to examine whether YD, based on brewer's yeast hydrolysate added to pregnancy diet, would affect colostrum composition, yield (CY) and gut microbiota of sows and piglets. Sows were allocated to either a control diet (n = 19) or a control diet supplemented with 2g YD/kg (n = 18) during the pregnancy. Piglets suckling belonging to the control sows (n = 114) and supplemented sows (n = 108) were also included in the study. Gut microbiota populations of sows at farrowing and piglets at one and four weeks of age were assessed using 16S rRNA gene sequencing. Colostrum samples were examined for nutritional composition and immunoglobulin (Ig) content. All piglets were individually weighed at birth and 24 hours later in order to calculate CY, and later at four weeks to calculate average daily gain (ADG). Protein, lactose and dry matter content of colostrum did not significantly differ between the two groups, while sows fed YD had higher levels of fat in their colostrum (P < 0.05). Immunoglobulin A, IgM and IgG levels in colostrum did not differ between the two groups (P >0.05). Colostrum yield was lower in the control than that in YD group (3701g vs. 4581 g; P <0.05). Although the YD supplementation did not change fecal bacteria diversity in sow, more beneficial and fermentative bacteria (Roseburia, Paraprevotella, Eubacterium) were found in the YD fed group (P <0.01) while, some opportunistic pathogens, including Proteobacteria, especially the genera Desulfovibrio, Escherichia/Shigella and Helicobacter, were suppressed. Piglets at one week of age from sows fed YD had more beneficial microbial populations with significant diversity and fewer opportunistic pathogens. Additionally, we established a Pearson's correlations between CY, colostrum components, piglet birth weight and fecal microbiota. Therefore, YD added to the sow diet during pregnancy increases colostrum availability and its energy content for neonate piglets, also promoting beneficial maternal microbial sources for neonate.
BARCOSEL: a tool for selecting an optimal barcode set for high-throughput sequencing
Background Current high-throughput sequencing platforms provide capacity to sequence multiple samples in parallel. Different samples are labeled by attaching a short sample specific nucleotide sequence, barcode, to each DNA molecule prior pooling them into a mix containing a number of libraries to be sequenced simultaneously. After sequencing, the samples are binned by identifying the barcode sequence within each sequence read. In order to tolerate sequencing errors, barcodes should be sufficiently apart from each other in sequence space. An additional constraint due to both nucleotide usage and basecalling accuracy is that the proportion of different nucleotides should be in balance in each barcode position. The number of samples to be mixed in each sequencing run may vary and this introduces a problem how to select the best subset of available barcodes at sequencing core facility for each sequencing run. There are plenty of tools available for de novo barcode design, but they are not suitable for subset selection. Results We have developed a tool which can be used for three different tasks: 1) selecting an optimal barcode set from a larger set of candidates, 2) checking the compatibility of user-defined set of barcodes, e.g. whether two or more libraries with existing barcodes can be combined in a single sequencing pool, and 3) augmenting an existing set of barcodes. In our approach the selection process is formulated as a minimization problem. We define the cost function and a set of constraints and use integer programming to solve the resulting combinatorial problem. Based on the desired number of barcodes to be selected and the set of candidate sequences given by user, the necessary constraints are automatically generated and the optimal solution can be found. The method is implemented in C programming language and web interface is available at http://ekhidna2.biocenter.helsinki.fi/barcosel . Conclusions Increasing capacity of sequencing platforms raises the challenge of mixing barcodes. Our method allows the user to select a given number of barcodes among the larger existing barcode set so that both sequencing errors are tolerated and the nucleotide balance is optimized. The tool is easy to access via web browser.
Bacteria Contribute to Sediment Nutrient Release and Reflect Progressed Eutrophication-Driven Hypoxia in an Organic-Rich Continental Sea
In the sedimental organic matter of eutrophic continental seas, such as the largest dead zone in the world, the Baltic Sea, bacteria may directly participate in nutrient release by mineralizing organic matter or indirectly by altering the sediment's ability to retain nutrients. Here, we present a case study of a hypoxic sea, which receives riverine nutrient loading and in which microbe-mediated vicious cycles of nutrients prevail. We showed that bacterial communities changed along the horizontal loading and vertical mineralization gradients in the Gulf of Finland of the Baltic Sea, using multivariate statistics of terminal restriction fragments and sediment chemical, spatial and other properties of the sampling sites. The change was mainly explained by concentrations of organic carbon, nitrogen and phosphorus, which showed strong positive correlation with Flavobacteria, Sphingobacteria, Alphaproteobacteria and Gammaproteobacteria. These bacteria predominated in the most organic-rich coastal surface sediments overlain by oxic bottom water, whereas sulphate-reducing bacteria, particularly the genus Desulfobacula, prevailed in the reduced organic-rich surface sediments in the open sea. They correlated positively with organic nitrogen and phosphorus, as well as manganese oxides. These relationships suggest that the bacterial groups participated in the aerobic and anaerobic degradation of organic matter and contributed to nutrient cycling. The high abundance of sulphate reducers in the surficial sediment layers reflects the persistence of eutrophication-induced hypoxia causing ecosystem-level changes in the Baltic Sea. The sulphate reducers began to decrease below depths of 20 cm, where members of the family Anaerolineaceae (phylum Chloroflexi) increased, possibly taking part in terminal mineralization processes. Our study provides valuable information on how organic loading affects sediment bacterial community compositions, which consequently may maintain active nutrient recycling. This information is needed to improve our understanding on nutrient cycling in shallow seas where the dead zones are continuously spreading worldwide.
Independent evolution of betulin biosynthesis in Inonotus obliquus
Chaga mushroom ( Inonotus obliquus ) is a fungal species in the family Hymenochaetaceae (Basidiomycota) and the causative agent of white rot decay in Betula species. We assembled a high-quality 50.7 Mbp genome from PacBio sequencing and identified a lineage-specific whole genome duplication event approximately 1.3 million years ago, which has contributed to a major increase in biochemical diversity in the species through preferential retention of cytochrome P450 superfamily members. Secondary metabolism has further evolved through small-scale segmental duplications, such as tandem duplications within fungal biosynthetic gene clusters. Metabolomic fingerprinting confirmed increased complexity in terpene biosynthesis chemistry compared to related species that lacked the duplication event. This metabolic diversity may have arisen from co-evolution with the primary host species, which evolved high betulin content in its bark 4–8 million years ago.