Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Escherichia coli (E. coli) amine oxidase (ECAO) encoded by tynA gene has been one of the model enzymes to study the mechanism of oxidative deamination of amines to the corresponding aldehydes by amine oxidases. The biological roles of ECAO have been less addressed. Therefore we have constructed a gene deletion Escherichia coli K-12 strain, E. coli tynA-, and used the microarray technique to address its function by comparing the total RNA gene expression to the one of the wt. Our results suggest that tynA is a reserve gene for stringent environmental conditions and its gene product ECAO a growth advantage compared to other bacteria due to H2O2 production.
Project description:Despite the characterization of many aetiologic genetic changes. The specific causative factors in the development of sporadic colorectal cancer remain unclear. This study was performed to detect the possible role of Enteropathogenic Escherichia coli (EPEC) in developing colorectal carcinoma.
Project description:Specific growth rate dependent gene expression changes of Escherichia coli K12 MG1655 were determined by microarray and real time PCR analyses. The bacteria were cultivated on glucose limited minimal medium using the accelerostat method (A-stat), where starting from steady state conditions in a chemostat culture, dilution rate is constantly increased. At specific growth rate (μ) 0.47 h-1, E. coli had focused its metabolism to glucose utilization by down-regulation of alternative substrate transporters expression compared to μ = 0.3 h-1. It was found that acetic acid accumulation began at μ = 0.34 ± 0.01 h-1 and two acetate synthesis pathways (phosphotransacetylase-acetate kinase (pta-ackA) and pyruvate oxidase (poxB)) contributed to the synthesis at the beginning of overflow metabolism, i.e. onset of acetate excretion. On the other hand, poxB, pta and ackA expression patterns suggest that pyruvate oxidase may be the only enzyme synthesizing acetate at μ = 0.47 h-1. Down-regulation of acs-yjcH-actP operon, the resulting loss of glucose and acetate co-utilization between specific growth rates 0.3 h-1 – 0.42 h-1 and acetic acid accumulation from μ = 0.34 ± 0.01 h-1 allows one to surmise that the acetate utilization operon expression might play an important role in overflow metabolism.
Project description:Purpose: We use the gene expression data to estimate the effects of tetracycline on gene expression and average ribosome density. Methods: The mRNAs were extracted with TRIzol reagent. The mRNAs were fragmented into 280 bp and the sequencing process was conducted on HiSeq 2500 platform. We use cutadapt, bowtie2, Plastid and DEseq2 software to analyze the expression levels of genes in two Escherichia coli strains. Results: The gene expression in EF4 knockout Escherichia coli strain was similar with BW25113 strain under normal condition. Under tetracycline treatment, many genes' expression were differentially regulated. Interestingly, we found that the gene expression of ribosomal proteins was up-regulated in WT strain comparing with EF4 knockout E. coli strain. Conclusions: Our results suggest that EF4 affects the average ribosome density and global gene expression in two Escherichia coli strain under tetracycline treatment.
