Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lactate growth of Geobacter sulfurreducens PCA was enhanced by laboratory adaptive evolution. The enhanced growth was considered to be attributed to increased expression of sucCD genes for succinyl-CoA synthetase. To further investigate the function of the succinyl-CoA synthetase, the sucCD genes were deleted from G. sulfurreducens The mutant showed defective growth on lactate, but not on acetate. Introduction of the sucCD genes into the mutant restored the full potential to grow on lactate. These verify the importance of the succinyl-CoA synthetase in lactate growth. Genome analysis of Geobacter species identified candidate genes, GSU1623, GSU1624, and GSU1620, for lactate dehydrogenase. Deletion mutants of the identified genes for D-lactate dehydrogenase (GSU1623/1624) or L-lactate dehydrogenase (GSU1620) could not grow on D-lactate or L-lactate, but could grow on acetate and L- or D-lactate, respectively. Introduction of the respective genes into the mutants allowed growth on the corresponding lactate stereoisomer. These suggest that the identified genes were essential for D- or L-lactate utilization. The lacZ-reporter assay demonstrated that the putative promoter regions were more active during growth on lactate than acetate, indicating that the genes for the lactate dehydrogenases were expressed more during growth on lactate than acetate. The gene deletion phenotypes and the expression profiles indicate metabolic switches between lactate and acetate. This study advances the understanding of anaerobic lactate utilization in G. sulfurreducens Importance Lactate is microbial fermentation product as well as source of carbon and electron for microorganisms in the environment. Furthermore, lactate is a common amendment for stimulation of microbial growth in environmental biotechnology applications. However, anaerobic metabolism of lactate has been poorly studied for environmentally relevant microorganisms. Geobacter species are found in various environments and environmental biotechnology applications. By employing genomic and genetic approaches succinyl-CoA synthetase and lactate dehydrogenase were identified as key enzymes in anaerobic metabolism of lactate in Geobacter sulfurreducens, a representative of Geobacter species. Differential gene expression during growth on lactate and acetate was observed, demonstrating that G. sulfurreducens could metabolically switch to adapt to available substrates in the environment. The findings provide new insights into basic physiology in lactate metabolism as well as cellular response to growth conditions in the environment, and can be informative for the lactate application in environmental biotechnology.
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PMID:Key enzymes for anaerobic lactate metabolism in Geobacter sulfurreducens. 3315 92