Biosynthesis of indole-3-acetic acid (IAA) via the indole-3-pyruvic acid pathway involves three kinds of enzymes; aminotransferase encoded by aspC, indole-3-pyruvic acid decarboxylase encoded by ipdC, and indole-3-acetic acid dehydrogenase encoded by iad1. The ipdC from Enterobacter cloacae ATCC 13047, aspC from Escherichia coli, and iad1 from Ustilago maydis were cloned and expressed under the...

Intracellular precursor supply is a critical factor for amino acid productivity. In the present study, ppsA and tktA genes were overexpressed in genetically engineered Escherichia coli to enhance the availability of two precursor substrates, phosphoenolpyruvate and erythrose-4-phosphate. The engineered strain, TRTH0709 carrying pSV709, produced 35.9 g/L tryptophan from glucose after 40 h in fed...

Previously, we demonstrated that the endogenous glutamate receptor antagonist kynurenic acid dose-dependently and significantly affected rat heart mitochondria. Now we have investigated the effects of L-tryptophan, L-kynurenine, 3-hydroxykynurenine and kynurenic, anthranilic, 3-hydroxyanthranilic, xanthurenic and quinolinic acids on respiratory parameters (ie, state 2, state 3), respiratory con...

The various calorimetric methods now employed for the estimation of tryptophan are not specific for tryptophan but give colored products with many compounds containing the indole nucleus, including indole itself. In order to facilitate studies of the enzymatic synthesis of tryptophan from indole and serine by extracts of Neurospora (l), a search for a rapid, quantitative method for the estimati...

The l-tryptophan degradation product indole is a purported extracellular signaling molecule that influences biofilm formation in various bacteria. Here we analyzed the mechanisms of indole production in Fusobacterium nucleatum and the effects of tryptophan and indole on F. nucleatum planktonic and biofilm cells. The amino acid sequence deduced from the fn1943 gene in F. nucleatum ATCC 25586 was...

Epidemic eosinophilia-myalgia syndrome (EMS) associated with excess L-tryptophan (Trp) consumption in humans has been declared a major public health problem. The EMS problem has not been observed in pigs, nor has comprehensive pathology associated with EMS in humans been described. Experiments were therefore conducted to evaluate the pathology and effects of excess dietary L-Trp for finishing (...