title: Metabolomics profiling of extracellular metabolites in recombinant Chinese Hamster Ovary fed-batch culture.
abstract: A metabolomics-based approach was used to time profile extracellular metabolites in duplicate fed-batch bioreactor cultures of recombinant Chinese Hamster Ovary (CHO) cells producing monoclonal IgG antibody. Culture medium was collected and analysed using a high-performance liquid chromatography (HPLC) system in tandem with an LTQ-Orbitrap mass spectrometer. An in-house software was developed to pre-process the LC/MS data in terms of filtering and peak detection. This was followed by principal component analysis (PCA) to assess variance amongst the samples, and hierarchical clustering to categorize mass peaks by their time profiles. Finally, LC/MS2 experiments using the LTQ-Orbitrap (where standard was available) and SYNAPT HDMS (where standard was unavailable) were performed to confirm the identities of the metabolites. Two groups of identified metabolites were of particular interest; the first consisted of metabolites that began to accumulate when the culture entered stationary phase. The majority of them were amino acid derivatives and they were likely to be derived from the amino acids in the feed media. Examples included acetylphenylalanine and dimethylarginine which are known to be detrimental to cell growth. The second group of metabolites showed a downward trend as the culture progressed. Two of them were medium components--tryptophan and choline, and these became depleted midway into the culture despite the addition of feed media. The findings demonstrated the potential of utilizing metabolomics to guide medium design for fed-batch culture to potentially improve cell growth and product titer.
authors.affiliation: Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, Centros #06-01, Singapore 138668. william_chong@bti.a-star.edu.sg
authors.forename: William P K
authors.initials: WP
authors.lastname: Chong
authors.forename: Lin Tang
authors.initials: LT
authors.lastname: Goh
authors.forename: Satty G
authors.initials: SG
authors.lastname: Reddy
authors.forename: Faraaz N K
authors.initials: FN
authors.lastname: Yusufi
authors.forename: Dong Yup
authors.initials: DY
authors.lastname: Lee
authors.forename: Niki S C
authors.initials: NS
authors.lastname: Wong
authors.forename: Chew Kiat
authors.initials: CK
authors.lastname: Heng
authors.forename: Miranda G S
authors.initials: MG
authors.lastname: Yap
authors.forename: Ying Swan
authors.initials: YS
authors.lastname: Ho
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D019149:Bioreactors; D016466:CHO Cells / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D016000:Cluster Analysis; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media; D004151:Dipeptides / Q000737:chemistry / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D025341:Principal Component Analysis; D011994:Recombinant Proteins / Q000378:metabolism; D012984:Software
chemical_list: D000596:Amino Acids; D000911:Antibodies, Monoclonal; D003470:Culture Media; D004151:Dipeptides; D007074:Immunoglobulin G; D011994:Recombinant Proteins; C020621:gamma-glutamylphenylalanine