Project description:The Gram-positive soil bacterium Corynebacterium glutamicum is widely used in industrial fermentative processes for the production of amino acids. The world production of L-lysine has surpassed 2 million tons per year. Glucose is taken up into the C. glutamicum cell by the phosphotransferase system PTS which can be replaced and/or enhanced by a permease and a glucokinase. Heterologous expression of the gene for the high-affinity glucose permease from Streptomyces coelicolor and of the Bacillus subitilis glucokinase gene fully compensated for the absence of the PTS in ï??hpr strains and strains grew as fast with glucose as C. glutamicum wild type. Growth of PTS-positive strains with glucose was accelerated when the endogenous inositol permease IolT2 and the glucokinase from Bacillus subtilis were overproduced using plasmid pEKEx3-IolTBest. When the genome-reduced C. glutamicum strain GRLys1 carrying additional in-frame deletions of sugR and ldhA to derepress glycolytic and PTS genes and to circumvent formation of L-lactate as by-product was transformed with this plasmid, a 40% higher L-lysine titer and a 30% higher volumetric productivity as compared to GRLys1(pEKEx3) resulted. The non-proteinogenic amino acid pipecolic acid (L-PA), a precursor of immunosuppressants, peptide antibiotics or piperidine alkaloids, can be derived from L-lysine. To enable production of L-PA by the L-lysine producing strain, the L-Lysine dehydrogenase gene lysDH from Silicibacter pomeroyi and the endogenous pyrroline 5-carboxylate reductase gene proC were expressed as synthetic operon. This enabled C. glutamicum to L-PA with a yield of 0.49 ± 0.03 gg-1 and a volumetric productivity of 0.04 ± 0.00 gL-1h-1.To the best of our knowledge, this is the first fermentative process for the production of L-PA. Two conditions tested, 200 mM NaCl Vs 200 mM pipecolic supplemented in the culture medium, control experiments done with the addition of 200mM of NaCl. Four technical replicates.
Project description:The Gram-positive soil bacterium Corynebacterium glutamicum is widely used in industrial fermentative processes for the production of amino acids. The world production of L-lysine has surpassed 2 million tons per year. Glucose is taken up into the C. glutamicum cell by the phosphotransferase system PTS which can be replaced and/or enhanced by a permease and a glucokinase. Heterologous expression of the gene for the high-affinity glucose permease from Streptomyces coelicolor and of the Bacillus subitilis glucokinase gene fully compensated for the absence of the PTS in hpr strains and strains grew as fast with glucose as C. glutamicum wild type. Growth of PTS-positive strains with glucose was accelerated when the endogenous inositol permease IolT2 and the glucokinase from Bacillus subtilis were overproduced using plasmid pEKEx3-IolTBest. When the genome-reduced C. glutamicum strain GRLys1 carrying additional in-frame deletions of sugR and ldhA to derepress glycolytic and PTS genes and to circumvent formation of L-lactate as by-product was transformed with this plasmid, a 40% higher L-lysine titer and a 30% higher volumetric productivity as compared to GRLys1(pEKEx3) resulted. The non-proteinogenic amino acid pipecolic acid (L-PA), a precursor of immunosuppressants, peptide antibiotics or piperidine alkaloids, can be derived from L-lysine. To enable production of L-PA by the L-lysine producing strain, the L-Lysine dehydrogenase gene lysDH from Silicibacter pomeroyi and the endogenous pyrroline 5-carboxylate reductase gene proC were expressed as synthetic operon. This enabled C. glutamicum to L-PA with a yield of 0.49 ± 0.03 gg-1 and a volumetric productivity of 0.04 ± 0.00 gL-1h-1.To the best of our knowledge, this is the first fermentative process for the production of L-PA.
Project description:Strains: non-producing refernece strain pXMJ19 (CR099 pXMJ19; Goldbeck et al., 2021) and Pediocin-producer pxMJ19 ped (CR099 pXMJ19 Ptac pedACDCg, Goldbeck et al., 2021) Pediocin-producing and non-producing strains of Corynebacterium glutamicum were compared in a whole genome microarray analysis setup in order to identify potential strain optimization targets
Project description:In humans, inactivating mutations in MLL4, which encodes a histone H3-lysine 4-methyltrasferase, lead to Kabuki syndrome (KS). While dwarfism is a cardinal feature of KS, the underlying etiology remains unclear. Here we report that Mll4 is a critical regulator of the development of growth hormone-releasing hormone (GHRH)-producing neurons in the hypothalamus. The two distinct Mll4 mutant mouse models exhibited dwarfism, accompanied by impairment of developmental programs for GHRH-neurons. Our genome-wide studies revealed that, in the developing hypothalamus, Mll4 collaborates mainly with the transcription factor Nrf1 to trigger the expression of GHRH-neuronal genes. Interestingly, the deficiency of Mll4 resulted in a marked reduction of transcriptionally active histone marks in the embryonic hypothalamus, which was rescued by treatment with the histone deacetylase inhibitor AR-42. Further, AR-42 treatment restored GHRH-neuronal production in Mll4 mutant mice. Together, our results suggest that the dysregulation of MLL4-directed epigenetic control of GHRH-neuronal genes is a substantial contributing factor to dwarfism in human KS.
Project description:This experiment aimed to investigate whether cells that express the L-Lysine-producing enzyme lyr exhibit any mRNA changes when grown on precursor D-Lysine relative to L-Lysine. Total RNA obtained from lyr-expressing MDA-MB-231 cells after 3 days in culture with amino acid precursor D-Lysine, L-Lysine, or starved of both.
Project description:This experiment aimed to investigate whether cells that express the L-Lysine-producing enzyme lyr exhibit any mRNA changes when grown on precursor D-Lysine relative to L-Lysine.
Project description:To investigate gene expression differences of different tylosin high-producing strains, transcriptomes of three tylosin high-producing engineered strains (TLPH08-2, TLPH11 and TLPH17) and the vector control strain TLSET152 were analyzed by RNA-Seq. Different strains (TLSET152, TLPH08-2, TLPH11 and TLPH17) were harvested at 96 h of fermentationat and then RNA isolation, transcriptome sequencing and data analysis were conducted.