scholarly journals Sulfur Amino Acid Metabolism in Pregnancy: The Impact of Methionine in the Maternal Diet

2006 ◽  
Vol 136 (6) ◽  
pp. 1701S-1705S ◽  
Author(s):  
William D. Rees ◽  
Fiona A. Wilson ◽  
Christopher A. Maloney
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Maternal Diet ◽  
Sulfur Amino Acid ◽  
The Impact ◽  
In Pregnancy

Disorders of Sulfur Amino Acid Metabolism

2000 ◽  
pp. 224-231 ◽  
Author(s):  
Generoso Andria ◽  
Brian Fowler ◽  
Gianfranco Sebastio
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Sulfur Amino Acid

scholarly journals Methionine to cystine ratio in the total sulfur amino acid requirements and sulfur amino acid metabolism using labelled amino acid approach for broilers

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Letícia G. Pacheco ◽  
Nilva K. Sakomura ◽  
Rafael M. Suzuki ◽  
Juliano C. P. Dorigam ◽  
Gabriel S. Viana ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Sulfur Amino Acid ◽  
Total Sulfur ◽  
Amino Acid Requirements

scholarly journals Impact of Classical Strain Improvement of Penicillium rubens on Amino Acid Metabolism during β-Lactam Production

2019 ◽  
Vol 86 (3) ◽  
Author(s):  
Min Wu ◽  
Ciprian G. Crismaru ◽  
Oleksandr Salo ◽  
Roel A. L. Bovenberg ◽  
Arnold J. M. Driessen
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Strain Improvement ◽  
Tryptophan Synthase ◽  
Cysteine Biosynthesis ◽  
Penicillin Production ◽  
Content Type ◽  
Classical Strain ◽  
The Impact

ABSTRACT To produce high levels of β-lactams, the filamentous fungus Penicillium rubens (previously named Penicillium chrysogenum) has been subjected to an extensive classical strain improvement (CSI) program during the last few decades. This has led to the accumulation of many mutations that were spread over the genome. Detailed analysis reveals that several mutations targeted genes that encode enzymes involved in amino acid metabolism, in particular biosynthesis of l-cysteine, one of the amino acids used for β-lactam production. To examine the impact of the mutations on enzyme function, the respective genes with and without the mutations were cloned and expressed in Escherichia coli, purified, and enzymatically analyzed. Mutations severely impaired the activities of a threonine and serine deaminase, and this inactivates metabolic pathways that compete for l-cysteine biosynthesis. Tryptophan synthase, which converts l-serine into l-tryptophan, was inactivated by a mutation, whereas a mutation in 5-aminolevulinate synthase, which utilizes glycine, was without an effect. Importantly, CSI caused increased expression levels of a set of genes directly involved in cysteine biosynthesis. These results suggest that CSI has resulted in improved cysteine biosynthesis by the inactivation of the enzymatic conversions that directly compete for resources with the cysteine biosynthetic pathway, consistent with the notion that cysteine is a key component during penicillin production. IMPORTANCE Penicillium rubens is an important industrial producer of β-lactam antibiotics. High levels of penicillin production were enforced through extensive mutagenesis during a classical strain improvement (CSI) program over 70 years. Several mutations targeted amino acid metabolism and resulted in enhanced l-cysteine biosynthesis. This work provides a molecular explanation for the interrelation between secondary metabolite production and amino acid metabolism and how classical strain improvement has resulted in improved production strains.

scholarly journals Nutritional and Functional Importance of Intestinal Sulfur Amino Acid Metabolism

2005 ◽  
Vol 135 (7) ◽  
pp. 1609-1612 ◽  
Author(s):  
Anna K. Shoveller ◽  
Barbara Stoll ◽  
Ronald O. Ball ◽  
Douglas G. Burrin
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Sulfur Amino Acid ◽  
Functional Importance
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