Fifteen mutants of Sinorhizobium (Rhizobium ) meliloti unable to utilize acetate as a sale carbon source (Ace-) were characterized in this study. Merodiploid complementation tests showed that nine of these mutations were in loci distinct from previously described gluconeogenic loci. The chromosomal locations of the mutations were determined, and complementing clones were isolated from the cosmid library of S. meliloti genomic DNA. The mutants were placed into four groups (I--IV) based on genetic linkage in phage co-transduction. None of the mutations were in glyoxylate shunt enzyme-encoding genes. Nucleotide sequence analysis of ace mutants from Groups III and IV showed mutations in genes encoding acetyl-CoA synthetase ( acsB) and anaerobic coproporphyrinogen III oxidase (hemN ) respectively. Cell extracts of the hemN mutant exhibited double the isocitrate lyase levels of the wild type. The acsB mutant lacked acetyl-CoA synthetase activity and had an interesting growth phenotype; it was able to grow on low concentrations of acetate only. (Abstract shortened by UMI.)
Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.29926 |
Date | January 1999 |
Creators | Thaha, Fathuma Zuleikha. |
Contributors | Charles, Trevor C. (advisor) |
Publisher | McGill University |
Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
Language | English |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Format | application/pdf |
Coverage | Master of Science (Department of Natural Resource Sciences.) |
Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
Relation | alephsysno: 001738013, proquestno: MQ55093, Theses scanned by UMI/ProQuest. |
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