Advances in metabolic engineering for the production of aromatic chemicals / 生物工程学报

Metabolic engineering has been developed for nearly 30 years since the early 1990s, and it has given a great impetus to microbial strain breeding and improvement. Aromatic chemicals are a variety of important chemicals that can be produced by microbial fermentation and are widely used in the pharmaceutical, food, feed, and material industry. Microbial cells can be engineered to accumulate a variety of useful aromatic chemicals in a targeted manner through rational engineering of the biosynthetic pathways of shikimate and the derived aromatic amino acids. This review summarizes the metabolic engineering strategies and biosynthetic pathways for the production of aromatic chemicals developed in the past 30 years, with the aim to provide a valuable reference and promote the research in this field.

Synthetic biology for the synthesis of aromatic natural products: a review / 生物工程学报

Plant-derived aromatic natural products have important medicinal value and can be made into pharmaceutical and healthcare products with antibacterial, anti-inflammatory, analgesic, anti-oxidative, insecticidal and anthelmintic, expectorant and cough suppressant, tranquilizer and antitumor effects. However, the low content of aromatic natural products in plants and the difficulty and high costs in extraction and purification hampered its large-scale production and application. Recent advances in synthetic biology and metabolic engineering have enabled the tailor-made production of aromatic natural products using engineered microbial cell factories. This review summarizes the categories, the synthetic pathways, the key enzymes and the synthetic biology strategies for production of aromatic natural products, and discusses the challenges and opportunities in this area.

Characterization of 5-Enolpyruvylshikimate-3- phosphate Synthase from Sclerotinia sclerotiorum / 中国生物化学与分子生物学报

The 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase activity of Sclerotinia sclerotiorum is one of the multifunctional enzyme AROM activities, which catalyzes a reversible conversion of shikimate 3-phosphate (S3P) and phosphoenolpyruvate (PEP) to EPSP and inorganic phosphate, and is inhibited by the herbicide glyphosate (N-phosphonomethyl glycine). AROM protein has been purified from Sclerotinia sclerotiorum and the EPSP synthase has been analyzed. The results indicated that the optimal pH and temperature of EPSP synthase were 7.2 and 30℃ respectively. The activation energy of the heat-deactivated reaction of the enzyme was found to be 69.62 kJ/mol. Both of the substrates, S3P and PEP, were showed to inhibit the reaction rate when their concentrations exceeded 1 mmol/L and 2 mmol/L respectively. The Km of 140.98 μmol/L for PEP and 139.58 μmol/L for S3P were obtained by Dalziel equation which was a steadystate kinetic equation of the enzymatic reaction with the double substrates. The kinetic pattern of the enzyme was consistent with a sequential mechanism. Inhibition of the EPSP synthase reaction by glyphosate was competitive with respect to PEP, with the Ki 0. 32 μmol/L, and noncompetitive with regard to S3P. Activation by [ K+ ] was observed in the forward reaction. The Km (PEP) was lowered by increasing [ K+ ], while the Km (S3P) changed irregularly and the Ki (PEP) was enhanced.