Project description:To investigate the transcriptional profile of GVE2 genes, the viral genes were identified by DNA microarray with Cy5- or Cy3-dUTP-labeled cDNAs prepared from uninfected and GVE2-infected Geobacillus sp. E263 at 4 h p.i.. After hybridization with the Cy3-dUTP-labeled cDNAs from GVE2-infected Geobacillus sp. E263 at 4 h p.i., Cy5-dUTP-labeled cDNAs from uninfected Geobacillus sp. E263 as well as Cy3- dUTP-labeled yeast cDNAs and Hex DNA, many spots produced positive signals significantly above the background, while no signal appeared for the Cy5-dUTP-labeled cDNAs from uninfected Geobacillus sp. E263., indicating that the positive signals represented the GVE2 gene transcripts detectable by DNA microarray. The DNA fragments, detected to be positive in the reverse transcripts at 4 h p.i., contained 74.2% of the presumptive GVE2 ORFs. Keywords: Transcriptional profile of thermophilic bacteriophage at 4 h p.i.
Project description:To investigate the transcriptional profile of GVE2 genes, the viral genes were identified by DNA microarray with Cy5- or Cy3-dUTP-labeled cDNAs prepared from uninfected and GVE2-infected Geobacillus sp. E263 at 4 h p.i.. After hybridization with the Cy3-dUTP-labeled cDNAs from GVE2-infected Geobacillus sp. E263 at 4 h p.i., Cy5-dUTP-labeled cDNAs from uninfected Geobacillus sp. E263 as well as Cy3- dUTP-labeled yeast cDNAs and Hex DNA, many spots produced positive signals significantly above the background, while no signal appeared for the Cy5-dUTP-labeled cDNAs from uninfected Geobacillus sp. E263., indicating that the positive signals represented the GVE2 gene transcripts detectable by DNA microarray. The DNA fragments, detected to be positive in the reverse transcripts at 4 h p.i., contained 74.2% of the presumptive GVE2 ORFs. Keywords: Transcriptional profile of thermophilic bacteriophage at 4 h p.i. A DNA microarray containing 82 DNA fragments of the viral genome was constructed following a PCR-based microarray method. Briefly, specific primer sets were designed to amplify approximately 500-bp fragment each using viral genome as template. All PCR products showing a single band of the appropriate size by gel electrophoresis were purified, and reconstituted in TE buffer at a final concentration of about 500 μg/ml for spotting in triplicates onto the silylated-glass slides (CEL Associates, Inc. USA) using a microarrayer (Smart Arrayer 48, CapitalBio). Eight DNA fragments from yeast genome and a randomly synthesized DNA fragment (Hex) were included as exogenous positive controls to normalize the microarry date. Distilled water was used as negative controls. Total RNAs were isolated from the uninfected and phage-infected Geobacillus sp. E263 cells at 4 h postinfection. The cDNAs from uninfected Geobacillus sp. E263 were labeled with Cy5 and the cDNAs from phage-infected Geobacillus sp. E263 labeled with Cy3. At the same time, the cDNAs from yeast and the Hex DNA were labeled with Cy3. The Cy5- or Cy3-dUTP-labeled cDNAs were resuspended in hybridization solution and hybridized with the microarrays for 16 to 18 h at 42°C. Then the microarrays were rinsed several times following the standard method. Following the washing steps, the microarrays were dried by low-speed centrifugation (500 g for 5 min), and immediately scanned using a GenePix 4000B array scanner (Axon Instruments, Inc.). Images obtained from scanning were analyzed by GenePix Pro 4.0 array analysis software (Axon Instruments, Inc.)
Project description:D-lactic acid is a three-carbon organic acid with a chiral structure and can improve the thermostability of polylactic acid. Microorganisms such as the methylotrophic yeast Pichia pastoris, which lack the natural ability to produce or accumulate high amounts of D-lactic acid, have been engineered to produce it in high titers. However, tolerance to D-lactic acid remains a challenge. In this study, we demonstrate that cell flocculation improves tolerance to D-lactic acid and leads to increased D-lactic acid production in Pichia pastoris. By incorporating a flocculation gene from Saccharomyces cerevisiae (ScFLO1) into P. pastoris KM71, we created a strain (KM71-ScFlo1) that demonstrated up to a 1.6-fold improvement in specific growth rate at high D-lactic acid concentrations. Furthermore, integrating a D-lactate dehydrogenase gene from Leuconostoc pseudomesenteroides (LpDLDH) into KM71-ScFlo1 resulted in an engineered strain (KM71-ScFlo1-LpDLDH) that can produce D-lactic acid at a titer of 5.12 0.35 g/L in 48 hours , a 2.6-fold improvement over the control strain lacking ScFLO1 expression. Transcriptomics analysis of this strain provided insights into the mechanism of increased tolerance to D-lactic acid including the upregulations of genes involved in lactate transport and iron metabolism. Overall, our work represents an advancement in the efficient microbial production of D-lactic acid by manipulating yeast flocculation.
Project description:We isolated an efficient doxycycline degrading strain Chryseobacterium sp. WX1. To investigate gene expression patterns during doxycyclinedegradation by strain WX1, we conducted a comparative transcriptomic analysis using cultures of strain WX1 with and without doxycycline addition. The RNA-Seq data revealed that 90.44-96.56% of the reads mapped to the genome of Chryseobacterium sp. WX1 across all samples. Differentially expressed genes (DEGs) analysis (|log2FC| >2; p < 0.01) showed that 693 genes were significantly up-regulated and 592 genes were significantly down-regulated.
Project description:We isolated an efficient tetracycline degrading strain Sphingobacterium sp. WM1. To investigate gene expression patterns during tetracycline degradation by strain WM1, we conducted a comparative transcriptomic analysis using cultures of strain WM1 with and without tetracycline addition. The RNA-Seq data revealed that 90.44-96.56% of the reads mapped to the genome of Sphingobacterium sp. WM1 across all samples. Differentially expressed genes (DEGs) analysis (|log2FC| >2; p < 0.01) showed that 693 genes were significantly up-regulated and 592 genes were significantly down-regulated.
Project description:To understand the the effect of poly(lactic-co-glycolic acid) nanoparticles (NPs) encapsulating a fluorine contrast agent on hematopoietic stem cells (CD34+ fraction of umbilical cord blood mononuclear cells), we have employed whole genome microarray expr
Project description:This study examines genome-wide expression of the phenanthrene-degrading Sphingomonas sp. LH128 as a response to short-term starvation stress. For this purpose, the strain was subjected to complete nutrient starvation for 4h after growth on a rich medium. Survival was monitored by plating and transcriptomic response was determined by whole-genome microarray analysis. The data showed no major differences were obsrved in gene expression and the viability of the cells were not affected during short-term incubation time Transcriptomic response of phenanthrene degrading Sphingomonas sp. LH128 starved for 4h in isotonic solution of 0.01 mM MgS04 was studied using genome-wide gene expression analysis. For this purpose, the strain was pregrown in minimal medium to an OD600 of 0.5, washed twice with 0.01 mM MgS04 and resuspended in the same solution to an OD of 0.5. RNA was extracted both from starved cells and from the initial culture (non-starved cells) and cDNA was synthesized and labeled with Cy3. Transcriptomic response of three replicates were analyzed and compared with the initial inoculum
Project description:This study examines the transcriptomic response of biofilms of the PAH-degrading Sphingomonas sp. LH128 on solute stress when actively degrading and growing on the PAH compound. To address the effect of solute stress on bacterial physiology and transcriptomic response, NaCl was used as osmolyte. Both acute and chronic solute stress was invoked to assess differences in short-term and long-term responses. Transcriptomic response of phenanthrene degrading Sphingomonas sp. LH128 biofilms as a response to short-term and long-term solute (NaCl) stress was studied using genome-wide gene expression analysis. For this purpose, the strain was grown in customized continuous glass flow chambers that contain solid phenanthrene as a sole carbon source and that allow easy recovery of biofilm cells for transcriptomic and physiological analysis. A NaCl stress of 450 mM was imposed on LH128 biofilms growing on phenanthrene crystals coated on glass slides either for 4 hours (acute stress) or for 3 days (chronic stress). RNA was extracted from the biofilm and cDNA was synthesized and labeled with Cy3. Transcriptomic response in the stressed biofilms of three replicates per conditions were analyzed and compared with non-stressed
Project description:In this study, we identified the O-glycosylation sites in recombinant Clostridium botulinum flagellin (CbFla) and Geobacillus kaustophilus flagellins, GkFlaA1 and GkFlaA2, expressed from the E. coli strains, EV136 and EV240 (K1:K12 strains engineered by Prof. Eric Vimr’s group to accumulate CMP-sialic acid in the cytosol), EV36 (wildtype K1:K12 strain), and BL21(DE3) (laboratory strain used for protein expression using T7 RNA polymerase). The recombinant flagellins were expressed with or without co-expression of motility associated factor (Maf) (flagellin nonulosonic acid glycosyltransferase) in these strains, purified and subjected to MS/MS analysis at Taplin Biological Mass Spectrometry facility.