Switzerland: Metabolic regulation in Lactobacillus paracasei FAM18149

Transcriptional Regulation of Cysteine and Methionine Metabolism in Lactobacillus paracasei FAM18149

Daniel Wüthrich, Claudia Wenzel, Tharmatha Bavan, Rémy Bruggmann, Hélène Berthoud and Stefan Irmler | Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland; Agroscope, Bern, Switzerland | 2018 | Frontiers in Microbiology; 9:1261  doi: 10.3389/fmicb.2018.01261

Lactobacillus bacteria is used for food fermentation, particularly in raw milk cheeses, to improve ripening and flavour development by amino acid metabolism. Bacteria synthesize the sulfur-containing amino acids, cysteine and methionine, to produce volatile sulfur compounds that enhance the flavour compounds in cheeses. It is currently unknown if expression of these genes occurs in Lactobacillus bacteria in a cheese environment. In this study, whole genome sequencing and a RT-qPCR, performed on the MIC Real-Time Cycler, was used to understand the metabolic pathway of cysteine and methionine in a cheese environment. Twenty-three genes were identified to be involved in cysteine to methionine and vice versa conversion at a transcriptional level. Gene expression located downstream of T-boxes were affected by the absence of cysteine or methionine.