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https://ptsldigital.ukm.my/jspui/handle/123456789/515366| Title: | Systems biology approach for the analysis of metabolites and metabolic fluxes of Lactococcus lactis subsp. cremoris MG1363 in response to different growth conditions |
| Authors: | Kamalrul Azlan bin Azizan (P57329) |
| Supervisor: | Syarul Nataqain Baharum, Dr. |
| Keywords: | Systems biology approach Metabolites and metabolic fluxes Lactococcus lactis subsp. cremoris MG1363 Growth conditions Lactococcus lactis |
| Issue Date: | 17-Sep-2014 |
| Description: | While the great potential for Lactococcus lactis has been highlighted, knowledge on the metabolites and flux in response to various environmental stresses of the industrially important L. lactis subsp. cremoris is still lacking. The information on its metabolites which are directly linked to the flux distribution is of fundamental importance of the characterization of its phenotype. In order to gain an improved understanding of its phenotype, 13C-labelling experiments and gas chromatography mass spectrometry (GC-MS) were employed to evaluate the metabolites and calculate the intracellular fluxes. Analysis of volatiles by GC-MS using methyl chloroformate (MCF) derivatization and the N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) derivatization showed forty-seven metabolites (p<0.05) were detected including alcohols, aldehydes, ketones and organic acids of amino acids, carboxylic acids and fatty acids when L. lactis was grown at 30°C with (AG) and without agitation (30) and at 37°C without agitation (37). More importantly, the shift towards mixed-acid fermentation to produce lactate, acetate and ethanol was observed when L. lactis was grown at 30°C with agitation and at 37°C without agitation. 13C-labelling experiments of L. lactis revealed that the flux for glycolysis increased (>60%) when grown at 30°C and 37°C without agitation but decreased (<50%) when grown at 30°C with agitation. In addition, the glyoxylate shunt became active when L. lactis was grown at 37°C without agitation. Systematic analysis of the proteinogenic and extracellular amino acids indicated aspartate and serine gave impact to the metabolic changes of the branch point between fructose-6-phosphate (F6P) and triose phosphate. Meanwhile the increased flux through anaplerotic reactions and glyoxylate shunt were resulted from the high levels of 13°C enrichment in glutamate, proline, leucine and threonine. The study highlighted the role of amino acids and its contribution towards the changes in metabolic flux in response to the environmental conditions.,Ph.D |
| Pages: | 228 |
| Call Number: | QR82.S78.K345 2014 |
| Publisher: | UKM, Bangi |
| Appears in Collections: | Institute of Systems Biology / Institut Biologi Sistem (INBIOSIS) |
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|---|---|---|---|---|
| ukmvital_74390+Source01+Source010.PDF Restricted Access | 5.43 MB | Adobe PDF |  View/Open |
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