| 2,4,5-trichlorophenol degradation using a novel tio2-coated biofilm carrier: roles of adsorption, photocatalysis, and biodegradation. | intimate coupling of photocatalysis and biodegradation (icpb) offers potential for degrading biorecalcitrant and toxic organic compounds. this study reports on a novel sponge-type, tio(2)-coated biofilm carrier that showed significant adherence of tio(2) and ability to accumulate biomass in its interior. this carrier was tested for icpb in a continuous-flow photocatalytic circulating-bed biofilm reactor (pcbbr) to mineralize 2,4,5-trichlorophenol (tcp), which is biorecalcitrant. four mechanisms ... | 2011 | 21861477 |
| Unique structural features and sequence motifs of proline utilization A (PutA). | Proline utilization A proteins (PutAs) are bifunctional enzymes that catalyze the oxidation of proline to glutamate using spatially separated proline dehydrogenase and pyrroline-5-carboxylate dehydrogenase active sites. Here we use the crystal structure of the minimalist PutA from Bradyrhizobium japonicum (BjPutA) along with sequence analysis to identify unique structural features of PutAs. This analysis shows that PutAs have secondary structural elements and domains not found in the related mon ... | 2012 | 22201760 |
| Efficient electricity generation from sewage sludge usingbiocathode microbial fuel cell. | Microbial fuel cells (MFCs) with abiotic cathodes require expensive catalyst (such as Pt) or catholyte (such as hexacynoferrate) to facilitate oxidation reactions. This study incorporated biocathodes into a three-chamber MFC to yield electricity from sewage sludge at maximum power output of 13.2±1.7W/m(3) during polarization, much higher than those previously reported. After 15d operation, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of cell reached 40.8±9.0% and ... | 2012 | 22078254 |
| Diversity of 16S rRNA genes from bacteria of sugarcane rhizosphere soil. | Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire ba ... | 2011 | 22042267 |
| [phenotypic and genotypic characterization of twelve rhizobial isolates from different regions of venezuela]. | rhizobial taxonomy and systematics have progressed substantially, nevertheless, few studies have been developed on venezuelan species. this study evaluated the phenotypic and genetic variation between 12 venezuelan indigenous rhizobial isolates and 10 international referential strains, by phenotypical traits and dna molecular markers. in this regard, a pcr-rflp of the 16s rdna gene, the presence of large plasmids, metabolic assays in solid media, salinity resistance, ph and temperature growth co ... | 2011 | 22017109 |
| Biodegradation of melamine and its hydroxy derivatives by a bacterial consortium containing a novel Nocardioides species. | Melamine has recently been recognized as a food contaminant with adverse human health effects. Melamine contamination in some crops arises from soil and water pollution from various causes. To remove melamine from the polluted environment, a novel bacterium, Nocardioides sp. strain ATD6, capable of degrading melamine was enriched and isolated from a paddy soil sample. The enrichment culture was performed by the soil-charcoal perfusion method in the presence of triazine-degrading bacteria previou ... | 2011 | 22105542 |
| nitrate-dependent n₂o emission from intact soybean nodules via denitrification by bradyrhizobium japonicum bacteroids. | in the presence of nitrate, n₂o emission increased markedly from soybean roots inoculated with nosz mutant of bradyrhizobium japonicum, but not from soybean roots inoculated with a napa nosz double mutant, indicating that b. japonicum bacteroids in soybean nodules are able to convert the exogenously supplied nitrate into n₂o via a denitrification pathway. | 2011 | 22003029 |
| microvirga lupini sp. nov., microvirga lotononidis sp. nov., and microvirga zambiensis sp. nov. are alphaproteobacterial root nodule bacteria that specifically nodulate and fix nitrogen with geographically and taxonomically separate legume hosts. | strains of gram-negative, rod-shaped, non-spore-forming bacteria were isolated from nitrogen-fixing nodules of the native legumes listia angolensis (from zambia) and lupinus texensis (from texas, usa). phylogenetic analysis of the 16s rrna gene showed that the novel strains belong to the genus microvirga, with 96.1 % or greater sequence similarity with type strains of this genus. the closest relative of the representative strains lut6t and wsm3557t was m. flocculans tfbt, with 97.6-98.0 % simila ... | 2011 | 22199210 |
| a unique bicyclic monosaccharide from the bradyrhizobium lipopolysaccharide and its role in the molecular interaction with plants. | sugar coat: the nitrogen-fixing soil bacterium bradyrhizobium sp. btai1 is coated with a unique lipopolysaccharide that does not induce innate immune responses in its host plant aeschynomene indica or in different plant families. the chemical nature of the monosaccharide forming the polymer is unprecedented in nature, which helps to avoid "harmful" recognition by its symbiotic host. | 2011 | 22058060 |
| long-term field fertilization alters the diversity of autotrophic bacteria based on the ribulose-1,5-biphosphate carboxylase/oxygenase (rubisco) large-subunit genes in paddy soil. | carbon dioxide (co(2)) assimilation by autotrophic bacteria is an important process in the soil carbon cycle with major environmental implications. the long-term impact of fertilizer on co(2) assimilation in the bacterial community of paddy soils remains poorly understood. to narrow this knowledge gap, the composition and abundance of co(2)-assimilating bacteria were investigated using terminal restriction fragment length polymorphism and quantitative pcr of the cbbl gene [that encodes ribulose- ... | 2011 | 22159889 |
| Evolutionary instability of symbiotic function in Bradyrhizobium japonicum. | Bacterial mutualists are often acquired from the environment by eukaryotic hosts. However, both theory and empirical work suggest that this bacterial lifestyle is evolutionarily unstable. Bacterial evolution outside of the host is predicted to favor traits that promote an independent lifestyle in the environment at a cost to symbiotic function. Consistent with these predictions, environmentally-acquired bacterial mutualists often lose symbiotic function over evolutionary time. Here, we investiga ... | 2011 | 22073160 |
| A Role for Bradyrhizobium japonicum ECF16 Sigma Factor EcfS in the Formation of a Functional Symbiosis with Soybean. | Alternative sigma (s) factors, proteins that recruit RNA polymerase core enzyme to target promoters, are one mechanism by which bacteria transcriptionally regulate groups of genes in response to environmental stimuli. A class of s(70) proteins, termed extracytoplasmic function (ECF) s factors, are involved in cellular processes such as bacterial stress responses and virulence. Here, we describe an ECF16 s factor, EcfS (Blr4928) from the gram-negative soil bacterium Bradyrhizobium japonicum USDA1 ... | 2012 | 21879796 |
| comparison of the 'ca. liberibacter asiaticus' genome adapted for an intracellular lifestyle with other members of the rhizobiales. | an intracellular plant pathogen 'candidatus liberibacter asiaticus,' a member of the rhizobiales, is related to sinorhizobium meliloti, bradyrhizobium japonicum, nitrogen fixing endosymbionts, agrobacterium tumefaciens, a plant pathogen, and bartonella henselae, an intracellular mammalian pathogen. whole chromosome comparisons identified at least 50 clusters of conserved orthologous genes found on the chromosomes of all five metabolically diverse species. the intracellular pathogens 'ca. liberib ... | 2011 | 21876745 |
| genotypic characterization of phage-typed indigenous soybean bradyrhizobia and their host range symbiotic effectiveness. | analysis of genetic diversity among indigenous rhizobia and its symbiotic effectiveness with soybean cultivar is important for development of knowledge about rhizobial ecology. in india, little is known about the genetic resources and diversity of rhizobia nodulating soybean. indigenous bradyrhizobia isolated from root nodules of soybean plants, collected from traditional cultivating regions of two states (madhya pradesh and uttar pradesh) of india, were screened for bacteriophage sensitivity to ... | 2011 | 21984348 |
| photosynthetic bradyrhizobium sp. strain ors285 synthesizes 2-o-methylfucosylated lipochitooligosaccharides for nod gene? dependent interaction with aeschynomene plants. | bradyrhizobium sp. strain ors285 is a photosynthetic bacterium that forms nitrogen-fixing nodules on the roots and stems of tropical aquatic legumes of the aeschynomene genus. the symbiotic interaction of bradyrhizobium sp. strain ors285 with certain aeschynomene spp. depends on the presence of nodulation (nod) genes whereas the interaction with other species is nod gene independent. to study the nod gene-dependent molecular dialogue between bradyrhizobium sp. strain ors285 and aeschynomene spp. ... | 2011 | 21864045 |
| the nitric oxide response in plant-associated endosymbiotic bacteria. | nitric oxide (no) is a gaseous signalling molecule which becomes very toxic due to its ability to react with multiple cellular targets in biological systems. bacterial cells protect against no through the expression of enzymes that detoxify this molecule by oxidizing it to nitrate or reducing it to nitrous oxide or ammonia. these enzymes are haemoglobins, c-type nitric oxide reductase, flavorubredoxins and the cytochrome c respiratory nitrite reductase. expression of the genes encoding these enz ... | 2011 | 22103544 |
| bacterial outer membrane channel for divalent metal ion acquisition. | the prevailing model of bacterial membrane function predicts that the outer membrane is permeable to most small solutes because of pores with limited selectivity based primarily on size. here, we identified mnop in the gram-negative bacterium bradyrhizobium japonicum as a gene coregulated with the inner membrane mn(2+) transporter gene mnth. mnop is an outer membrane protein expressed specifically under manganese limitation. mnop acts as a channel to facilitate the tranlocation of mn(2+), but no ... | 2011 | 21880957 |
| mercury-resistant rhizobial bacteria isolated from nodules of leguminous plants growing in high hg-contaminated soils. | a survey of symbiotic bacteria from legumes grown in high mercury-contaminated soils (almadén, spain) was performed to produce a collection of rhizobia which could be well adapted to the environmental conditions of this region and be used for restoration practices. nineteen hg-tolerant rhizobia were isolated from nodules of 11 legume species (of the genera medicago, trifolium, vicia, lupinus, phaseolus, and retama) and characterized. based on their growth on hg-supplemented media, the isolates w ... | 2012 | 22246528 |
| [genetic diversity and phylogeny of bradyrhizobia associated with desmodium spp]. | genetic diversity and phylogeny of bradyrhizobial strains associated with desmodium spp. in subtropic and temperate regions of china were analyzed. | 2011 | 22233051 |