Linked Life Data

15372312

Source:http://linkedlifedata.com/resource/pubmed/id/15372312

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-9-16
pubmed:abstractText
A metabolite analysis of the soil bacterium Sinorhizobium meliloti was established as a first step towards a better understanding of the symbiosis with its host plant Medicago truncatula. A crucial step was the development of fast harvesting and extraction methods for the bacterial metabolites because of rapid changes in their composition. S. meliloti 1021 cell cultures grown in minimal medium were harvested by centrifugation, filtration or immediate freezing in liquid nitrogen followed by a lyophilisation step. Bacteria were lysed mechanically in methanol and hydrophilic compounds were analysed after methoxymation and silylisation via GC-MS. The different compounds were identified by comparison with the NIST 98 database and available standards. From about 200 peaks in each chromatogram 65 compounds have been identified so far. A comparison of the different extraction methods giving the metabolite composition revealed clear changes in several amino acids and amino acid precursor pools. A principal component analysis (PCA) was able to distinguish S. meliloti cells grown on different carbon sources based on their metabolite profile. A comparison of the metabolite composition of a S. meliloti leucine auxotrophic mutant with the wild type revealed a marked accumulation of 2-isopropylmalate in the mutant. Interestingly, the accumulated metabolite is not the direct substrate of the mutated enzyme, 3-isopropylmalate dehydrogenase, but the substrate of isopropylmalate isomerase, which acts one step further upstream in the biosynthetic pathway of leucine. This finding further emphasises the importance of integrating metabolic data into post-genomic research.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1438-7948
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
219-30
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Comprehensive metabolite profiling of Sinorhizobium meliloti using gas chromatography-mass spectrometry.
pubmed:affiliation
Lehrstuhl für Genetik, Fakultät für Biologie, Universität Bielefeld, Postfach 100131, 33501, Bielefeld, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't