Acute Disease ; Female ; Humans ; Infant ; Infant, Newborn ; Propionates ; blood ; Pyruvate Carboxylase Deficiency Disease

OBJECTIVE: To analyze the clinical features and genetic basis for a child with pyruvate carboxylase deficiency type A (PCD-A). METHODS: Clinical data of the child was retrospectively analyzed. The child and his parents were subjected to trio-whole exome sequencing, and candidate variants were verified by bioinformatics analysis. RESULTS: The child was admitted due to fever with vomiting and disturbance of consciousness. His clinical manifestations included severe decompensated acidosis, hypotension and intractable shock. Cranial MRI showed abnormal signal in the brain, and chest X-ray revealed acute pulmonary edema. DNA sequencing revealed that he has harbored compound heterozygous variants of the PC gene, namely c.182T>C (p.I61T) and c.2581G>A (p.V861M), which were respectively inherited from his father and mother. Neither variant was retrievable in the ClinVar and HGMD databases. Through prediction of protein structure, both variants may affect the functional stability of the protein product. CONCLUSION The compound heterozygous variants of the PC gene probably underlay the PCD-A in this child. Combined with the clinical features, the child was ultimately diagnosed as PCD-A. Above finding has enriched the spectrum of PC gene variation underlying PCD-A.
Child ; Family ; Humans ; Male ; Mutation ; Pyruvate Carboxylase Deficiency Disease ; Retrospective Studies ; Exome Sequencing

Escherichia coli BA002, in which the ldhA and pflB genes are deleted, cannot utilize glucose anaerobically due to the inability to regenerate NAD+. To restore glucose utilization, overexpression of nicotinic acid phosphoribosyltransferase (NAPRTase) encoded by the pncB gene, a rate-limiting enzyme of NAD(H) synthesis pathway, resulted in a significant increase in cell mass and succinate production under anaerobic conditions. However, a high concentration of pyruvate was accumulated. Thus, co-expression of NAPRTase and the heterologous pyruvate carboxylase (PYC) of Lactococcus lactis subsp. cremoris NZ9000 in recombinant E. coli BA016 was investigated. Results in 3 L fermentor showed that OD600 is 4.64 and BA016 consumed 35.00 g/L glucose and produced 25.09 g/L succinate after 112 h under anaerobic conditions. Overexpression of pncB and pyc in BA016, the accumulation of pyruvic acid was further decreased, and the formation of succinic acid was further increased.
Anaerobiosis ; Escherichia coli ; enzymology ; genetics ; metabolism ; Fermentation ; Genetic Engineering ; Glucose ; metabolism ; Industrial Microbiology ; Lactococcus lactis ; enzymology ; NAD ; metabolism ; Pentosyltransferases ; biosynthesis ; genetics ; Pyruvate Carboxylase ; biosynthesis ; genetics ; Succinic Acid ; metabolism

Escherichia coli strain DC1515, deficient in glucose phosphotransferase (ptsG), lactate dehydrogenase (ldhA) and pyruvate:formate lyase (pflA), is a promising candidate for the fermentative production of succinate. To further improve the succinate producing capability of DC1515, we constructed plasmid pTrchisA-pyc with heterogenous pyruvate carboxylase (pyc) from Bacillus subtilis 168 under the Trc promoter and introduced it into DC1515. We used lactose as a substitute of IPTG to induce pyc. We optimized the culture conditions such as the lactose addition time, the lactose concentration and the culture temperature after induction for succinate production. We also explored the effect of lactose supplement during the fermentation. The results showed that pyc can be expressed under lactose induction in the fermentative medium with 15 g/L glucose due to the deficient of ptsG in DC1515. Under optimized conditions, the final succinate concentration reached to 15.17 g/L, which was 1.78-fold higher than that of control strain. If complementing lactose twice to the concentration of 1 g/L during the fermentation, the final succinate concentration could further reach to 17.54 g/L. This work might provide valuable information for gene expression in E. coli strains using lactose as inducer for succinate production in a glucose-medium. Due to the reduced cost, E. coli is becoming a more promising strain for succinate production through fermentation.
Bacillus subtilis ; enzymology ; Culture Media ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Lactose ; pharmacology ; Promoter Regions, Genetic ; Pyruvate Carboxylase ; biosynthesis ; genetics ; Succinic Acid ; metabolism

Malic acid is widely used in food, and chemical industries. Through overexpressing pyruvate carboxylase and malate dehydrogenase in pdc1-deficient Saccharomyces cerevisiae, malic acid was successfully produced through the reductive TCA pathway. No malic acid was detected in wild type Saccharomyces cerevisiae, however, 45 mmol/L malic acid was produced in engineered strain, and the concentration of byproduct ethanol also reduced by 18%. The production of malic acid enhanced 6% by increasing the concentration of Ca2+. In addition, the final concentration reached 52.5 mmol/L malic acid by addition of biotin. The increasing is almost 16% higher than that of the original strain.
Citric Acid Cycle ; Fermentation ; Industrial Microbiology ; methods ; Malate Dehydrogenase ; genetics ; metabolism ; Malates ; metabolism ; Metabolic Engineering ; methods ; Metabolic Networks and Pathways ; Oxidation-Reduction ; Pyruvate Carboxylase ; genetics ; metabolism ; Saccharomyces cerevisiae ; genetics ; metabolism ; Signal Transduction

PURPOSE: Seizure associated with fever may indicate the presence of underlying inherited metabolic diseases. The present study was performed to investigate the presence of underlying metabolic diseases in patients with complex febrile seizures, using analyses of urine organic acids. METHODS: We retrospectively analyzed and compared the results of urine organic acid analysis with routine laboratory findings in 278 patients referred for complex febrile seizure. RESULTS: Of 278 patients, 132 had no abnormal laboratory findings, and 146 patients had at least one of the following abnormal laboratory findings: acidosis (n=58), hyperammonemia (n=55), hypoglycemia (n=21), ketosis (n=12). Twenty-six (19.7%) of the 132 patients with no abnormal findings and 104 (71.2%) of the 146 patients with statistically significant abnormalities showed abnormalities on the organic acid analysis (P<0.05). Mitochondrial respiratory chain disorders (n=23) were the most common diseases found in the normal routine laboratory group, followed by PDH deficiency (n=2 ) and ketolytic defect (n=1). In the abnormal routine laboratory group, mitochondrial respiratory chain disorder (n=29) was the most common disease, followed by ketolytic defects (n=27), PDH deficiency (n=9), glutaric aciduria type II (n=9), 3-methylglutaconic aciduria type III (n=6), biotinidase deficiency (n=5), propionic acidemia (n=4), methylmalonic acidemia (n=2), 3-hydroxyisobutyric aciduria (n=2), orotic aciduria (n=2), fatty acid oxidation disorders (n=2), 2-methylbranched chain acyl CoA dehydrogenase deficiency (n=2), 3-methylglutaconic aciduria type I (n=1), maple syrup urine disease (n=1), isovaleric acidemia (n=1), HMG-CoA lyase deficiency (n=1), L-2-hydroxyglutaric aciduria (n=1), and pyruvate carboxylase deficiency (n=1). CONCLUSION: These findings suggest that urine organic acid analysis should be performed in all patients with complex febrile seizure and other risk factors for early detection of inherited metabolic diseases.
Acetyl-CoA C-Acetyltransferase ; Acidosis ; Acyl-CoA Dehydrogenase ; Amino Acid Metabolism, Inborn Errors ; Biotinidase Deficiency ; Brain Diseases, Metabolic, Inborn ; Electron Transport ; Fever ; Humans ; Hydroxybutyrates ; Hyperammonemia ; Hypoglycemia ; Isovaleryl-CoA Dehydrogenase ; Ketosis ; Maple Syrup Urine Disease ; Metabolic Diseases ; Multiple Acyl Coenzyme A Dehydrogenase Deficiency ; Propionic Acidemia ; Pyruvate Carboxylase Deficiency Disease ; Pyruvate Dehydrogenase Complex Deficiency Disease ; Retrospective Studies ; Risk Factors ; Seizures ; Seizures, Febrile