Azospirillum: A genus of gram-negative aerobic bacteria that occurs free-living in the soil or associated with the roots of cereal crops or grasses (POACEAE).Azospirillum brasilense: A species of motile, free-living, gram-negative bacteria that occur in the soil. They are aerobic or microaerophilic and are sometimes capable of nitrogen fixation.Nitrogen Fixation: The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.Azospirillum lipoferum: A species of gram-negative to gram-variable, nitrogen-fixing bacteria. They are free-living in SOIL or found in association with PLANT ROOTS. It is the type species of the genus AZOSPIRILLUM.Gram-Negative Aerobic Bacteria: A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.Nitrogenase: An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC 1.18.6.1.Glutamate Synthase: An enzyme that catalyzes the formation of 2 molecules of glutamate from glutamine plus alpha-ketoglutarate in the presence of NADPH. EC 1.4.1.13.Flocculation: The aggregation of suspended solids into larger clumps.Agricultural Inoculants: Beneficial microorganisms (bacteria or fungi) encapsulated in carrier material and applied to the environment for remediation and enhancement of agricultural productivity.PII Nitrogen Regulatory Proteins: A family of signal transducing adaptor proteins that control the METABOLISM of NITROGEN. They are primarily found in prokaryotes.Dinitrogenase Reductase: A non-heme iron-sulfur protein isolated from Clostridium pasteurianum and other bacteria. It is a component of NITROGENASE along with molybdoferredoxin and is active in nitrogen fixation.Spirillum: A genus of gram-negative, curved and spiral-shaped bacteria found in stagnant, freshwater environments. These organisms are motile by bipolar tufts of flagella having a long wavelength and about one helical turn. Some species of Spirillum cause a form of RAT-BITE FEVER.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Fuel Oils: Complex petroleum hydrocarbons consisting mainly of residues from crude oil distillation. These liquid products include heating oils, stove oils, and furnace oils and are burned to generate energy.Hydroxybutyrates: Salts and esters of hydroxybutyric acid.Soil Microbiology: The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.Rhodospirillaceae: A family of phototrophic bacteria, in the order Rhodospirillales, isolated from stagnant water and mud.Polyesters: Polymers of organic acids and alcohols, with ester linkages--usually polyethylene terephthalate; can be cured into hard plastic, films or tapes, or fibers which can be woven into fabrics, meshes or velours.Genes, Bacterial: The functional hereditary units of BACTERIA.Triticum: A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.Phloroglucinol: A trinitrobenzene derivative with antispasmodic properties that is used primarily as a laboratory reagent.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.AcetyleneAmmonia: A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Atriplex: A plant genus in the CHENOPODIACEAE family.Herbaspirillum: A genus of gram-negative bacteria in the family OXALOBACTERACEAE, comprised of vibrioid or sometimes helical cells. They are chemoorganotrophic nitrogen fixers and are found free-living in the soil or in association with the roots of members of the GRAMINEAE. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Bacterial Proteins: Proteins found in any species of bacterium.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Pennisetum: A plant genus of the family POACEAE. The seed is one of the millets used in EDIBLE GRAIN. It contains vitexin. The common name of buffelgrass is also used for CENCHRUS.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Xanthomonas axonopodis: A species of gram-negative bacteria in the genus XANTHOMONAS, which causes citrus cankers and black rot in plants.Gram-Negative Bacteria: Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.Click Chemistry: Organic chemistry methodology that mimics the modular nature of various biosynthetic processes. It uses highly reliable and selective reactions designed to "click" i.e., rapidly join small modular units together in high yield, without offensive byproducts. In combination with COMBINATORIAL CHEMISTRY TECHNIQUES, it is used for the synthesis of new compounds and combinatorial libraries.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)PeptidoglycanMuramic Acids: Compounds consisting of glucosamine and lactate joined by an ether linkage. They occur naturally as N-acetyl derivatives in peptidoglycan, the characteristic polysaccharide composing bacterial cell walls. (From Dorland, 28th ed)Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Uridine Diphosphate N-Acetylmuramic Acid: A nucleoside diphosphate sugar which is formed from UDP-N-acetylglucosamine and phosphoenolpyruvate. It serves as the building block upon which peptidoglycan is formed.Aminoacyltransferases: Enzymes that catalyze the transfer of an aminoacyl group from donor to acceptor resulting in the formation of an ester or amide linkage. EC 2.3.2.Azetidinecarboxylic Acid: A proline analog that acts as a stoichiometric replacement of proline. It causes the production of abnormal proteins with impaired biological activity.Francisella: The lone genus of bacteria in the family Francisellaceae, frequently found in natural waters. It can be parasitic in humans, other MAMMALS; BIRDS; and ARTHROPODS.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Ribulose-Bisphosphate Carboxylase: A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.Ribulosephosphates: Ribulose substituted by one or more phosphoric acid moieties.Adaptor Protein Complex sigma Subunits: A family of small adaptin protein complex subunits of approximately 19 KDa in size.Electronic Mail: Messages between computer users via COMPUTER COMMUNICATION NETWORKS. This feature duplicates most of the features of paper mail, such as forwarding, multiple copies, and attachments of images and other file types, but with a speed advantage. The term also refers to an individual message sent in this way.Nitrate Reductase: An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Nitrate Reductases: Oxidoreductases that are specific for the reduction of NITRATES.