Fermentation product with new equol-producing Lactobacillus paracasei as a probiotic candidate for prevention of skin and intestinal disorder (RNA-Seq)
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ABSTRACT: Fermentation product with new equol-producing Lactobacillus paracasei as a probiotic candidate for prevention of skin and intestinal disorder (RNA-Seq)
Project description:Equol is one of major isoflavones with an affinity to endoplasmic reticulum and has an estrogen-like biological activity. Equol-producing bacteria have been isolated and characterized, however fermentation has been performed in an anaerobic condition with soybean-based products as substrates. Pueraria lobata has been reported as a plant with a higher content of isoflavones, such as daidzein, daidzin, and puerarin.
Project description:A shotgun microarray-based approach was used to identify candidate genes encoding the FOS utilization pathway in L. paracasei 1195. Differential expression profiles between cells grown on FOS and glucose provided a basis for identifying genes specifically induced by FOS. In addition, transcriptional analysis of cells grown on FOS or FOS + glucose allowed us to investigate the effect of catabolite repression on the expression of the FOS-induced genes. Keywords: gene identification
Project description:A shotgun microarray-based approach was used to identify candidate genes encoding the FOS utilization pathway in L. paracasei 1195. Differential expression profiles between cells grown on FOS and glucose provided a basis for identifying genes specifically induced by FOS. In addition, transcriptional analysis of cells grown on FOS or FOS + glucose allowed us to investigate the effect of catabolite repression on the expression of the FOS-induced genes. For sugar induction experiment (FOS vs. glucose; FOS vs. fructose), L. paracasei were grown in modified MRS (mMRS) basal medium to a final OD625 nm of ca. 0.3, at which point all of the residual sugars in the medium were consumed (based on HPLC analysis of the supernatants). The culture was then divided into equal portions, where FOS or glucose was added to a 1% final concentration. Cells were collected for total RNA isolation after 30 min (OD625 nm ca. 0.3 â 0.4). For glucose repression experiment (FOS vs. FOS + glucose), cells were grown in mMRS supplemented with 2% FOS to an OD625 nm 0.6. The culture was split into equal portions, and glucose was added to one of the portions at a 2% final concentration. Both cultures were grown for another 60 min (OD625 nm ca. 1.0) before harvested for total RNA isolation. Both experiments were performed in independent replicates (two biological replicates per experiment) with incubation at 37 degree celsius in ambient atmosphere.
Project description:Purpose: To understand the bile salts resistance mechanisms in L. paracasei L9 Methods: Samples from L9 cultured with or without bile salts were sequenced on an Illumina Hiseq platform. Three independent biological replicates were produced including 6 samples in total. Results: Raw data were firstly processed through in-house perl scripts to generate clean data, and then clean date were mapped to the reference genome, getting about 8-10 million total mapped reads per sample.
Project description:Owing to their ability to secrete antimicrobials and benefit human health, lactic acid bacteria (LAB) cultures are an attractive nontoxic alternative to antibiotics for preserving food and combating pathogenic infections. Given that this strategy has several limitations, including strain-dependent antimicrobial effectiveness, reduced efficacy against multidrug-resistant strains, and difficulties in large-scale production without bacterial contamination, current research focuses on identifying and utilizing endolysins (enzymes that degrade bacterial cell walls) produced by novel or engineered LAB cultures to inhibit pathogen growth. The challenges faced by this approach (e.g., bactericidal activity lower than that of antibiotics, susceptibility to degradation by proteases, and high purification and quality control costs) can be overcome using engineered LAB-derived extracellular vesicles (LEVs) displaying pathogen-specific endolysins on their surface to directly recognize and eliminate target pathogens. Given that no LEV surface-displayed proteins (SDPs) have been characterized to date, this study identifies and characterizes a LEV SDP (LP-SDP3) from Lacticaseibacillus paracasei using proteomic analysis, heterologous expression of candidate SDPs, biochemical analysis, and SpyTag–SpyCatcher reactions. LP-SDP3 homologs are found in Escherichia coli and other LAB strains, exhibiting the same function in E. coli and Lactococcus lactis. Endolysin (PlyF307SQ-8C)-displaying LEVs derived from L. paracasei selectively kill Staphylococcus aureus, exhibiting an activity comparable with that of purified PlyF307SQ-8C. This study is the first to identify a universal extracellular vesicle SDP for E. coli and LAB strains, demonstrating its potential as a platform for developing endolysin–extracellular vesicle antibacterials without the need for labor-intensive and costly endolysin preparation.