Project description:Soluble pyridine nucleotide transhydrogenase (EcSthA) derived from Escherichia coli was introduced into the L-malic acid producing strain MA009-5 of Pichia kudriavzevii to obtain strain MA009-10. It was found that MA009-10 was superior to MA009-5 in terms of L-malic acid titer, glucose consumption rate, and glucose/L-malic acid conversion rate. To elucidate the effect of EcSthA expression on L-malic acid synthesis, we analyzed the RNA-seq data of both strains.
Project description:Transcriptome and proteome were used to conjoint analysis the preservation mechanism of the citric acid combined with L-cysteine on post-harvested litchi fruit.
Project description:Purpose of study was to investigate whole genome expression changes of a strain with deletion of the two-component system TctD-TctE and determine genes dysregulate relative to the parental wildtype to gain insight into possible regulatory targets of TctD-TctE. TctD-TctE is a two-component system in Pseudomonas aeruginosa that responds to and regulates uptake of tricarboxylic acids such as citric acid. It accomplishes this through derepression of the porin encoding the gene opdH, thereby regulating influx of citrate metabolites from the surrounding environment. Deletion of the tctED operon (ΔtctED) resulted in a reduced growth phenotype when citric acid is present in media. In the ΔtctED strain the presence of citric acid was found to have an inhibitory effect on growth. When the alternative carbon source arginine was present, wildtype levels of growth could not be restored. Static cultures of ΔtctED had low cell density in the presence of citric acid but maintained the same levels of biofilm formation compared to conditions when no citric acid was present. This suggests a dysregulation of biofilm formation in the presence of citric acid. In the ΔtctED strain there was also greater accumulation of tobramycin within the biofilm compared to the PA14 wildtype strain. Additionally, analysis of whole-genome expression found that multiple metabolic genes were dysregulated in ΔtctED. Here it is concluded that TctD-TctE is involved in biofilm tolerance to tobramycin in the presence of citrate metabolites.
Project description:Plant-based foods contain bioactive compounds such as polyphenols that resist digestion and potentially benefit the host through interactions with their gut microbiome. Based on previous observations, we hypothesized thatprobiotic Lactobacillus plantarum interact with cranberry polyphenols and dietary oligosaccharides to synergistically impact its physiology. In this study, L. plantarum ATCC BAA-793 was grown on dietary oligosaccharides including cranberry xyloglucans, fructooligosaccharides, and human milk oligosaccharidesin conjunction with proanthocyanidins (PACs) extracted from cranberry. As a result, L. plantarum exhibits a differential physiological response to cranberry PACs dependent on the carbohydrate source and polyphenol fraction introduced. Of two extracts evaluated, the PAC1 fraction increased growth regardless of oligosaccharide whereas PAC2 positively modulates growth during xyloglucan metabolism. Interestingly, PAC1 enables ATCC BAA-793 to utilize fructooligosaccharides efficiently as it is unable to ferment this substrate ordinarily. Relative to glucose, oligosaccharide metabolism increases the ratio of secreted acetic acid to lactic acid. The PAC2 fraction differentially increases this ratio during cranberry xyloglucan fermentation compared with PAC1. RNA-seq transcriptomics link expression of putative polyphenol degradation genes, polyphenol degradation profiles, and physiological phenotypes.
Project description:Polyethylene glycol is the gold standard of bowel preparation for colonoscopy. The most important disadvantage is high volume of this preparation. Sulphate based solution (SBS), low volume PEG + ascorbic acid and solution of magnesium citric acid and sodium picosulfate could be suitable substitution of polyethylene glycol.
Project description:LaeA, a putative methyltransferase, is a global regulator for metabolic and development process in filamentous fungi. We characterized the laeA homologous genes in the white koji fungus, Aspergillus luchuensis mut. kawachii (A. kawachii) to examine their role in citric acid production. The ΔlaeA strain showed a significant reduction in the citric acid productivity. The cap-analysis gene expression (CAGE) revealed the laeA is required for the gene expression of a putative citrate exporter encoding cexA, which has a critical role for the citric acid production. The deficient citric acid productivity of the ΔlaeA strain was remedied by overexpression of cexA to a comparative level to that of the cexA overexpressing ΔcexA strain. In addition, chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) analysis indicated that LaeA regulates gene expression of the citrate exporter encoding cexA gene via histone H3K4 and histone H3K9 methylation levels. These results indicate that LaeA is involved in the citric acid production through epigenetic regulation of cexA in A. kawachii.
Project description:Statins reduce cardiovascular disease risk by lowering plasma low density lipoprotein (LDL)-cholesterol. To identify novel pathways that modulate statin response, we assessed the influence of simvastatin exposure on expression quantitative trait locus (eQTL) associations across the genome in 480 lymphoblastoid cell lines (LCLs). Cell lines were derived blood samples collected ant entry visit from participants in the Cholesterol and Pharmacogenomics (CAP) trial, who underwent a 6 week 40mg/day simvastatin trial. We identified 4590 cis-eQTLS that were independent of treatment status (FDR=1%) and six cis-eQTLS for which there was evidence of an interaction with treatment (FDR=20%). Genotypes and Phenotypes derived from these indivudals are available through dbGaP (Accession Number). eQTL results are available at: http://eqtl.uchicago.edu/cgi=bin/gbrowse/eqtl/ Dataset consists of 960 expression beadarrays (Illumina HumanRef-8v3) representing paired samples derived from 24-hour exposures of 480 lymphoblastoid cell lines (LCLs) to 2 micromolar simvastatin acid or control buffer.
Project description:To understand the population genetics of structural variants (SVs), and their effects on phenotypes, we developed an approach to mapping SVs, particularly transpositions, segregating in a sequenced population, and which avoids calling SVs directly. The evidence for a potential SV at a locus is indicated by variation in the counts of short-reads that map anomalously to the locus. These SV traits are treated as quantitative traits and mapped genetically, analogously to a gene expression study. Association between an SV trait at one locus and genotypes at a distant locus indicate the origin and target of a transposition. Using ultra-low-coverage (0.3x) population sequence data from 488 recombinant inbred Arabidopsis genomes, we identified 6,502 segregating SVs. Remarkably, 25% of these were transpositions. Whilst many SVs cannot be delineated precisely, PCR validated 83% of 44 predicted transposition breakpoints. We show that specific SVs may be causative for quantitative trait loci for germination, fungal disease resistance and other phenotypes. Further we show that the phenotypic heritability attributable to sequence anomalies differs from, and in the case of time to germination and bolting, exceeds that due to standard genetic variation. Gene expression within SVs is also more likely to be silenced or dysregulated, as inferred from RNA-seq data collected from a subset of just over 200 of the MAGIC lines. This approach is generally applicable to large populations sequenced at low-coverage, and complements the prevalent strategy of SV discovery in fewer individuals sequenced at high coverage.
Project description:The simultaneous gene fungal-fruit expression at appressoria, quiescence and necrotrophic stages in C. gloeosporioides-tomato fruit interaction were characterized by Illumina NGS. Fungal appressoria stage on green fruit showed stage-specific transcription and was accompanied by massive fruit transcriptional defense response. The quiescent fungal transcriptome showed activation of chromatin remodeling genes while the fruit response continued a highly integrated and massive up-regulation of defense genes. The necrotrophic stage showed a dramatic shift in up-regulation of C. gloeosporioides pathogenicity factors and a susceptive fruit response that shows activation of the salicylic acid pathway culminating in cell death and anthracnose disease. Simultaneous fungal-fruit transcriptome analysis deepens our perception of the unfolding fungal-fruit arms and defenses race.
Project description:Several different mechanisms have been proposed to explain the possible role of cranberries, cranberry juice, and cranberry extracts in inhibiting bacterial growth. In this report, we showed that Escherichia coli showed slower growth rate in response to the presence of cranberry juice in the growth media. By compareing the global transcript profiles, significant modulation of several genes of E. coli grown in LB broth with 10% cranberry juice were identified and provided identification of the potential mechanisms involved in the inhibitory effects of cranberry juice. The results presented clearly demonstrate that the inhibitory effect on bacterial growth observed in the presence of cranberry juice/extracts is primarily a result of the iron chelation capacity of PACs and direct disruption of metabolic enzymes. The results are discussed with a focus on the genes associated with iron chelation capability. Keywords: growth inhibition of cranberry juice