title: Metabolic profiling of Lactococcus lactis under different culture conditions.
abstract: Gas chromatography mass spectrometry (GC-MS) and headspace gas chromatography mass spectrometry (HS/GC-MS) were used to study metabolites produced by Lactococcus lactis subsp. cremoris MG1363 grown at a temperature of 30 °C with and without agitation at 150 rpm, and at 37 °C without agitation. It was observed that L. lactis produced more organic acids under agitation. Primary alcohols, aldehydes, ketones and polyols were identified as the corresponding trimethylsilyl (TMS) derivatives, whereas amino acids and organic acids, including fatty acids, were detected through methyl chloroformate derivatization. HS analysis indicated that branched-chain methyl aldehydes, including 2-methylbutanal, 3-methylbutanal, and 2-methylpropanal are degdradation products of isoleucine, leucine or valine. Multivariate analysis (MVA) using partial least squares discriminant analysis (PLS-DA) revealed the major differences between treatments were due to changes of amino acids and fermentation products.
authors: Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors: Kamalrul Azlan
authors: KA
authors: Azizan
authors: Syarul Nataqain
authors: SN
authors: Baharum
authors: Normah
authors: N
authors: Mohd Noor
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D016000:Cluster Analysis; D003470:Culture Media / Q000494:pharmacology*; D016002:Discriminant Analysis; D005285:Fermentation / Q000187:drug effects; D005561:Formates / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D019344:Lactic Acid / Q000378:metabolism; D013294:Lactococcus lactis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D016018:Least-Squares Analysis; D055442:Metabolome / Q000187:drug effects*; D055432:Metabolomics / Q000379:methods*; D025341:Principal Component Analysis; D013696:Temperature; D014297:Trimethylsilyl Compounds / Q000737:chemistry
chemical_list: D000596:Amino Acids; D003470:Culture Media; D005561:Formates; D014297:Trimethylsilyl Compounds; C030544:formic acid; D019344:Lactic Acid