Project description:The demand for alternative sources of food proteins is increasing due to the limitations and challenges associated with conventional food production. Advances in biotechnology have enabled the production of proteins using microorganisms, thus prompting the exploration of attractive microbial hosts capable of producing functional proteins in high titers. Corynebacterium glutamicum is widely used in industry for the production of amino acids and has many advantages as a host organism for recombinant protein production. However, its performance in this area is limited by low yields of target proteins and high levels of native protein secretion. Despite representing a challenge for heterologous protein production, the C. glutamicum secretome has not been fully characterized. In this study, state-of-the-art mass spectrometry-based proteomics was used to identify and analyze the proteins secreted by C. glutamicum. Both the wild-type strain and a strain that produced and secreted a recombinant ß-lactoglobulin protein were analyzed. A total of 427 proteins were identified in the culture supernatants, with 148 predicted to possess a secretion signal peptide. The top 12 most abundant proteins accounted for almost 80% of the secretome. These are uncharacterized proteins of unknown function, resuscitation promoting factors, protein PS1, Porin B, ABC-type transporter protein and hypothetical membrane protein. The data from this study can provide valuable insight for researchers looking to improve protein secretion and optimize C. glutamicum as a host for secretory protein production.
Project description:The response to iron limitation of the Gram-positive soil bacterium Corynebacterium glutamicum was analyzed with respect to proteome during growth in glucose minimal medium. C. glutamicum cells were grown at regular (36 µM) and low (1 µM) iron concentrations and harvested in the late exponential growth phase. Between 1056 and 1357 proteins were detected (1% false discovery rate, FDR) in the measurements of three biological replicates including technical replicates each for low and high iron conditions with a proteomic shotgun analysis using nanoLC-MS/MS, covering in total 1555 proteins. By SWATH-MS measurements, relative levels of 1123 proteins could be quantified. Thereof, 66 proteins exhibited at least two-fold altered ratios with a p-value ≤0.05 in iron-deprived cells compared to the cells cultivated with 36 μM iron. 38 proteins showed a ≥2-fold higher level under iron limitation, 16 of which were members of the DtxR regulon. The levels of 28 proteins were at least 2-fold lower under iron limitation, 10 of which were members of the RipA regulon.
Project description:Differential gene expression analysis of C. glutamicum ATCC 13032 in presence of 2.5 mM indole compared to control conditions without indole. C. glutamicum ATCC 13032 cells were cultivated in CGXII minimal medium with 40 g per litre glucose in presence of 2.5 mM indole and harvested during exponential phase (o.d.600 4).