Search results for "bacteri"

Influence of fermented food consumption on oral microbiota and taste perception

2022

Inactivation of PadR, the repressor of the phenolic acid stress response, by molecular interaction with Usp1, a universal stress protein from Lactoba…

2009

ABSTRACT The phenolic acid decarboxylase gene padA is involved in the phenolic acid stress response (PASR) in gram-positive bacteria. In Lactobacillus plantarum , the padR gene encodes the negative transcriptional regulator of padA and is cotranscribed with a downstream gene, usp1 , which encodes a putative universal stress protein (USP), Usp1, of unknown function. The usp1 gene is overexpressed during the PASR. However, the role and the mechanism of action of the USPs are unknown in gram-positive bacteria. Therefore, to gain insights into the role of USPs in the PASR; (i) a usp1 deletion mutant was constructed; (ii) the two genes padR and usp1 were coexpressed with padA under its own promo…

Biotechnological applications of the sepiolite interactions with bacteria: Bacterial transformation and DNA extraction

2020

International audience; Among the various clay minerals, sepiolite, which is a natural nanofibrous silicate that exhibit a poor cell toxicity, is a potential promising nanocarrier for the non-viral and stable transfer of plasmid DNA into bacteria, mammalian and human cells. We first show here that sepiolite binds to bacteria, which can be useful in decontamination protocols. In a previous research we have shown that is possible to modulate the efficiency of the absorption of different types of DNA molecules onto sepiolite, and that the DNA previously adsorbed could be recovered preserving the DNA structure and biological activity. Taking advantage of both, the sepiolite/bacteria and sepioli…

Current and New Insights on Molecular Methods to Identify Microbial Growth in Fruit Juices

2018

International audience; Identification of microorganisms in fruit juices plays an important role as it determines the viability of this food product from a commercial point of view. Several microorganisms use fruit as a substrate, thus causing spoilage and generating off‐flavors and odors. In addition, under favorable conditions, toxigenic fungi can produce mycotoxins in fruit juices. Conventional detection and enumeration of microorganisms using traditional plating assays are accurate and can detect low microbial contamination levels. However, in most cases they require long detection times. In recent years, the food industry has shown increased interest in developing new methods with incr…

Volatile Organic Compounds of Malignant Breast Cancer Wounds: Identification and Odors.

2018

International audience; Introduction. During the metabolic processes of malignant wounds, bacteria produce a large amount of volatile organic compounds (VOCs) that are responsible for malodors and may have a major impact on the patient's quality of life with a risk of isolation. Objective. A translational study was conducted on 32 malignant breast wounds by combining the identification of bacterial strains present on wounds, the identification of VOCs produced by these bacterial strains, and sensory evaluation to assess odor intensity and quality of odorous bacteria. Materials and Methods. Thirty-two patients with malignant breast cancer wounds > 10 cm(2) at various stages of the disease (c…

Screening of Lactococcus lactis starters with Absorbance Reduction Activity Method (ARAm)

2022

Lactococcus lactis is one of the most used species in the dairy industry. This species has the ability to reduce to very negative values the redox potential (Eh) of food matrices, making it one of the most reducing Lactic Acid Bacteria (LAB) [1]. This reducing activity influences oxidation-reduction reactions involved in the organoleptic quality of the product and prevents the undesired microorganisms development [2–4]. The main mechanism involved are exofacial thiol groups, NoxE NADH Oxidase and the Electron Transport Chain mechanism [5-7]. For Eh measurement, the commonly used method consists of a redox probe placed in a liquid medium or food matrix [8]. With this probe, Cachon et al. (20…

Fermentation Products of Commensal Bacteria Alter Enterocyte Lipid Metabolism

2020

eferred to byJia Wen, John F. RawlsFeeling the Burn: Intestinal Epithelial Cells Modify Their Lipid Metabolism in Response to Bacterial Fermentation ProductsCell Host & Microbe, Volume 27, Issue 3, 11 March 2020, Pages 314-316; International audience; Despite the recognized capacity of the gut microbiota to regulate intestinal lipid metabolism, the role of specific commensal species remains undefined. Here, we aimed to understand the bacterial effectors and molecular mechanisms by which Lactobacillus paracasei and Escherichia coli regulate lipid metabolism in enterocytes. We show that L-lactate produced by L. paracasei inhibits chylomicron secretion from enterocytes and promotes lipid stora…

A new method for the direct quantification of lipopolysaccharide by High Performance Liquid Chromatography coupled with Mass Spectrometry in non-infe…

2017

IF 13.246; International audience

Acute Postcataract Surgery Endophthalmitis Due to Streptococcus Species Differs From Endophthalmitis Due to Staphylococcus Species at Presentation

2009

Purpose: : To correlate the presenting clinical ophthalmic features with the bacterial identification in 100 patients with acute post catarcat endophthalmitis enrolled in the FRench Instutionnal ENdophthalmitis Study (FRIENDS).Methods: : Demographic data, past medical history and initial eye examination were recorded in a standardized form in 100 patients with acute endophthalmitis after cataract extraction (< 6 weeks) in a prospective multicenter study. Relationship between microbiological identification (using conventional cultures and panbacterial PCR) and clinical factors at baseline was studied using univariate (ANOVA).Results: : 100 patients were hospitalized for endophthalmitis treat…

Biogeographical patterns of soil bacterial communities.

2009

International audience; This study provides the first maps of variations in bacterial community structure on a broad scale based on genotyping of DNA extracts from 593 soils from four different regions of France (North, Brittany, South-East and Landes). Soils were obtained from the soil library of RMQS (Réseau de Mesures de la Qualité des Sols = French soil quality monitoring network). The relevance of a biogeographic approach for studying bacterial communities was demonstrated by the great variability in community structure and specific geographical patterns within and between the four regions. The data indicated that the distribution of bacterial community composition might be more relate…