). Using 13C- and 31P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B. japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homospermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation

of rhizobia to the surrounding microenvironment with its host plant cells. “
“Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a serious environmental pollutant on military land. This compound is the PD-166866 solubility dmso most widely used explosive and pollution has arisen primarily as the result of military training, see more along with munition manufacturing and disassembly processes. This toxic explosive

is recalcitrant to degradation in the environment and leaches rapidly into groundwater, where accumulation in aquifers is threatening drinking water supplies (Clausen, et al., 2004). While plants have only limited degradative activity towards RDX, microorganisms, including Rhodococcus rhodochrous 11Y, have been isolated from contaminated land. Despite the presence of microbial RDX-metabolising activity in contaminated soils, the persistence of RDX in leachate from contaminated soil indicates that this activity or biomass is insufficient, limiting its use to remediate polluted soils. Bacterial activity in the rhizosphere is of magnitudes greater than in the surrounding soil, and the roots of grass species on training ranges in the United States are known to penetrate deeply into

the soil, producing a compact root system and providing an ideal environment to support the capture of RDX by microorganisms in the rhizosphere. Here, we have investigated the ability of the root-colonising bacterium Pseudomonas fluorescens, engineered to express XplA, to degrade RDX in the rhizosphere. “
“Gene duplication and horizontal gene transfer (HGT) are two events that enable the generation of new genes. Rhodobacter sphaeroides (WS8 and 2.4.1 strains) has four Amino acid copies of the rpoN gene that are not functionally interchangeable. Until now, this is the only example of specialization of this sigma factor. In this work, we aimed to determine whether the multiple copies of this gene originated from HGT or through gene duplication. Our results suggest a multiplication origin of the different rpoN copies that occurred after the Rhodobacter clade separated. Functional tests indicate that the specialization of the rpoN genes is not restricted to R. sphaeroides. We propose that the rpoN copy involved in nitrogen fixation is the ancestral gene and that the other rpoN genes have acquired new specificities.

No related posts.