It is generally believed that probiotic bacteria need to survive gastrointestinal transit to exert a health-promoting effect. In this study, a genuine luxS mutant and a luxS mutant containing unknown suppressor mutations of the probiotic strain Lactobacillus rhamnosus GG were compared to the wild type for survival and persistence in the murine gastrointestinal tract. The LuxS enzyme, catalyzing the production of the autoinducer-2 signaling molecule, also forms an integral part of the activated methyl cycle and the metabolism of methionine and cysteine. The genuine luxS mutant CMPG5412 showed drastically reduced persistence in mice, which was related to less survival in simulated gastric juice, indicating that LuxS metabolism is crucial for the gastric stress resistance of L. rhamnosus GG. The suppressor mutations in the other luxS mutant, CMPG5413, appear to compensate for the metabolic defects of the luxS mutation and to restore the resistance to gastric juice but cause a defect in adherence, biofilm formation, and exopolysaccharide production. The shorter residence time of this suppressor mutant in the murine gastrointestinal tract indicates a role for biofilm formation and exopolysaccharides in the persistence capacity of L. rhamnosus GG.
- American Society for Microbiology
- Impact of luxs and suppressor mutations on the gastrointestinal ...
Impact of luxs and suppressor mutations on the gastrointestinal transit of lactobacillus rhamnosus GG
Courtesy of American Society for Microbiology
Kuriverter IK-110 application in industrial water preparation for a boiler system
Download our case study about successful treatment with Kuriverter IK 110 for effective elimination of biofilms on RO membranes. Learn how we saved 28% in total operation costs using Kuriverter IK 110 in industrial water preparation for boiler system. Download CS126 here: https://www.kurita.eu/en/case-studies
Biofiltration optimization: phosphorus supplementation effects on disinfection byproduct formation ...
This study investigates the effects of phosphorus supplementation on the formation potential of total trihalomethanes (TTHMfp) and five species of haloacetic acids (HAA5fp) during exposure to clearwell disinfection contact times. In addition, the study investigates the effects of phosphorus supplementation on the dissolved oxygen, organic carbon and nitrogen removal along with biofilm coverage of the filter media and biomass viability of the attached biofilm. The uptake of total phosphorus in the P enhanced...
4 reasons chlorine dioxide should be your preferred sanitiser
To the lay-person, a commercial kitchen is just a floor and some equipment that needs a good clean regularly. They don’t understand the dangers of bacterial contamination and how easy it is for food to be affected. Most commercial kitchens will use bleach, or a similar sanitiser, to keep their space safe. Today, we will share with you the top five reasons you should be using chlorine dioxide instead. Chlorine dioxide is more effective. When we say that chlorine dioxide is more effective, we are referring...
The role of Arthrobacter viscosus in the removal of Pb(II) from aqueous solutions
The aim of this paper was to establish the optimum parameters for the biosorption of Pb(II) by dead and living Arthrobacter viscosus biomass from aqueous solution. It was found that at an initial pH of 4 and 26 °C, the dead biomass was able to remove 97% of 100 mg/L Pb(II), while the living biomass removed 96% of 100 mg/L Pb(II) at an initial pH of 6 and 28 ± 2 °C. The results were modeled using various kinetic and isotherm models so as to find out the mechanism of Pb(II) removal by A. viscosus. The modeling...
Pentachlorophenol degradation by Pseudomonas fluorescens
Fluorescent Pseudomonads strains were considered as plant growth promoting bacteria. They exhibited antagonistic activities against phytopathogens and showed bio-fertilizing properties. The strain Pseudomonas fluorescens PsWw128, isolated from wastewater, can use the pentachlorophenol (PCP) as the sole source of carbon and energy. High-performance liquid chromatography (HPLC) and spectrophotometric methods were used to follow the PCP degradation and biomass PsWw128 formation. However, the removal efficiency of...