Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

Microbial Cell Factories

Research

Liisa Arike¹  Kaarel Adamberg¹  Petri-Jaan Lahtvee²  Kadri Aller²  Raivo Vilu²  Ranno Nahku² 

[1]Competence Center of Food and Fermentation Technologies, Akadeemia tee 15b, 12618, Tallinn, Estonia

[2]Tallinn University of Technology, Department of Food Processing, Ehitajate tee 5, 19086, Tallinn, Estonia

[3]Tallinn University of Technology, Department of Chemistry, Akadeemia tee 15, 12618, Tallinn, Estonia

[4]Competence Center of Food and Fermentation Technologies, Akadeemia tee 15b, 12618, Tallinn, Estonia

关键词: Specific Growth Rate;    Dilution Rate;    Chemically Define Medium;    Transcriptome Level;    Amino Acid Consumption;   

DOI  :  10.1186/1475-2859-10-12

 received in 2010-07-13, accepted in 2011-02-24,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundLactococcus lactis is recognised as a safe (GRAS) microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth.ResultsUsing glucose limited continuous cultivations, specific growth rate dependent metabolism of L. lactis including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of L. lactis became more efficient with rising specific growth rate in the range 0.10 - 0.60 h-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. L. lactis global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in L. lactis were presumably under allosteric control.ConclusionsThe current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of L. lactis which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product formation etc. Moreover, collected dataset is an excellent input for developing metabolic models.

【 授权许可】

Unknown   
© Lahtvee et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.