This group has previously highlighted the prevalence of Csp genes from cold Himalayan environments. However, this study has explored the uncultured diazotrophs from metagenomes of western Indian Himalayas. The metagenomic nifH gene clone library was constructed from the Temperate, Subtropical and Tarai soils of Western Himalaya, India followed by polymerase chain reaction (PCR) amplification. A...

The diversity within the genus Aphanizomenon (Nostocales, Cyanobacteria) is still controversial and more studies are needed to clarify its heterogeneity. Aphanizomenon strains isolated from the eutrophic shallow Vela Lake (Centralwestern Portugal) during bloom formation in summer months from 2001 to 2007 were characterized combining phenotypic and molecular approaches. The molecular affiliation...

The molybdenum nitrogenase, present in a diverse group of bacteria and archea, is the major contributor to biological nitrogen fixation. The nitrogenase active site contains an iron-molybdenum cofactor (FeMo-co) composed of 7Fe, 9S, 1Mo, one unidentified light atom, and homocitrate. The nifQ gene was known to be involved in the incorporation of molybdenum into nitrogenase. Here we show direct b...

MOTIVATION Studies of the biochemical functions and activities of uncultivated microorganisms in the environment require analysis of DNA sequences for phylogenetic characterization and for the development of sequence-based assays for the detection of microorganisms. The numbers of sequences for genes that are indicators of environmentally important functions such as nitrogen (N2) fixation have ...

Many soil bacteria contain 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which degrades ACC, a precursor of the phytohormone ethylene. In order to examine the regulation of the acdS gene encoding ACC deaminase in Mesorhizobium loti MAFF303099 during symbiosis with the host legume Lotus japonicus, we introduced the beta-glucuronidase (GUS) gene into acdS so that GUS was expressed under ...

Chickpea has been considered as a restrictive host for nodulation by rhizobia. However, recent studies have reported that several Mesorhizobium species may effectively nodulate chickpea. With the purpose of investigating the evolutionary relationships between these different species with the ability of nodulating the same host, we analysed 21 Portuguese chickpea rhizobial isolates. Symbiosis ge...

In order to contribute to knowledge about structure of marine diazotrophic communities in the sediments of South China Sea, the molecular diversity of the nifH gene, which encodes the Fe protein of the nitrogenase complex, was assessed by polymerase chain reaction (PCR) amplification using PolF/R primers, followed by cloning and sequencing. Sequences of nifH genes were amplified from environmen...

The structural gene (nifH1) encoding the nitrogenase iron protein of Clostridium pasteurianum has been cloned and sequenced. It is located on a 4-kilobase EcoRI fragment (cloned into pBR325) that also contains a portion of nifD and another nifH-like sequence (nifH2). C. pasteurianum nifH1 encodes a polypeptide (273 amino acids) identical to that of the isolated iron protein, indicating that the...

Sponges that harbor microalgal or, cyanobacterial symbionts may benefit from photosynthetically derived carbohydrates, which are rich in carbon but devoid of nitrogen, and may therefore encounter nitrogen limitation. Diazotrophic communities associated with two Caribbean sponges, Ircinia strobilina and Mycale laxissima were studied in a time series during which three individuals of each sponge ...

Plants engineer the rhizosphere to their advantage by secreting various nutrients and secondary metabolites. Coupling transcriptomic and metabolomic analyses of the pea (Pisum sativum) rhizosphere, a suite of bioreporters has been developed in Rhizobium leguminosarum bv viciae strain 3841, and these detect metabolites secreted by roots in space and time. Fourteen bacterial lux fusion bioreporte...