Isolation of Rhizobium meliloti nod gene inducers from alfalfa rhizosphere soil
Article Abstract:
The induction of nodulation (nod) gene transcription in Rhizobium meliloti by methanolic extracts of alfalfa rhizpspere soil is discussed. High-performance liquid chromatography separated six peaks of nod-inducing activity from rhizosphere soil extract. The compound that activates the nod proteins was identified by nuclear magnetic resonance, mass spectrometry and UV-visible spectra. Findings indicate either that the unexpectedly stable presence of glycosides in soil or the release of large amounts of glycoside by roots as the cause of the presenceof glycoside in rhizosphere soil.
Publication Name: Applied and Environmental Microbiology
Subject: Biological sciences
ISSN: 0099-2240
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
Recombinant Rhizobium meliloti strains with extra biotin synthesis capability
Article Abstract:
Rhizobium meliloti with the Escherichia coli biotin synthesis gene overproduce biotin in biotin-limited rhizospheres. Biotin overproduction is related to a higher growth rate and a 99% decrease in viability in the R. meliloti strains. The failure of the R. meliloti to decrease biotin production in the presence of high biotin levels implies that they poorly regulate the E.coli biotin synthesis gene expression. However, a separate stabilizing factor from the E. coli DNA decreases cell death in the R. meliloti strains.
Publication Name: Applied and Environmental Microbiology
Subject: Biological sciences
ISSN: 0099-2240
Year: 1996
User Contributions:
Comment about this article or add new information about this topic:
Occurrence of flavonoids and nucleosides in agricultural soils
Article Abstract:
Flavonoids and nucleosides were identified in soils by a soil extraction procedure. The method is said to be ecologically relevant because it identifies metabolically important substances necessary for microbial growth and development. Two flavonoids were extracted from soil samples from alfalfa plots while nucleosides were identified in all soil samples analyzed. The method provides molecular ecologists with a new technique in the evaluation of microbial activities and metabolism.
Publication Name: Applied and Environmental Microbiology
Subject: Biological sciences
ISSN: 0099-2240
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Chemotaxis of Rhizobium meliloti towards nodulation gene-inducing compounds from alfalfa roots. Starvation-induced changes in motility, chemotaxis, and flagellation of Rhizobium meliloti
- Abstracts: Regulation of the feruloyl esterase (faeA) gene from Aspergillus niger. Localization of glucose oxidase and catalase activities in Aspergillus niger
- Abstracts: Four unnamed species of nonsymbiotic rhizobia isolated from the rhizosphere of Lotus corniculatus. Diversity among rhizobia effective with Robinia pseudoacacia L
- Abstracts: Identification of four phage resistance plasmids from Lactococcus lactis subsp. cremoris HO2. Controlled integration into the Lactococcus chromosome of the pCI829-encoded abortive infection gene from Lactococcus lactis subsp. lactis UC811
- Abstracts: Variation of microcystins, cyanobacterial hepatotoxins, in Anabaena spp. as a function of growth stimuli. Dissolved nitrogen uptake by a cyanobacterial bloom (Anabaena flos-aquae) ina subartic lake