De novo tryptophanase-based indole production by metabolically engineered Corynebacterium glutamicum.

Indole has an increasing interest in the flavor and fragrance industry. It is used in dairy products, tea drinks, and fine fragrances due to its distinct floral odor typical of jasmine blossoms. The current production of indole based on isolation from coal tar is non-sustainable and its isolation from plants is often unprofitable due to low yields.

Engineered as the Platform for the Production of Aromatic Aldehydes.

Aromatic aldehydes, including 4-hydroxybenzaldehyde (4-HB aldehyde), protocatechuic (PC) aldehyde, and vanillin, are used as important flavors, fragrances, and pharmaceutical precursors and have several biological and therapeutic effects. Production of aromatic aldehydes in microbial hosts poses a challenge due to its rapid and endogenous reduction to alcohols. To address this hurdle, prospecting of the genome of yielded 27 candidate proteins that were used in comprehensive screening with a 4-hydroxybenzyl (4-HB) alcohol-producing strain.

l-Serine Biosensor-Controlled Fermentative Production of l-Tryptophan Derivatives by .

l-Tryptophan derivatives, such as hydroxylated or halogenated l-tryptophans, are used in therapeutic peptides and agrochemicals and as precursors of bioactive compounds, such as serotonin. l-Tryptophan biosynthesis depends on another proteinogenic amino acid, l-serine, which is condensed with indole-3-glycerophosphate by tryptophan synthase. This enzyme is composed of the α-subunit TrpA, which catalyzes the retro-aldol cleavage of indole-3-glycerol phosphate, yielding glyceraldehyde-3-phosphate and indole, and the β-subunit TrpB that catalyzes the β-substitution reaction between indole and l-serine to water and l-tryptophan.

Fermentative Indole Production via Bacterial Tryptophan Synthase Alpha Subunit and Plant Indole-3-Glycerol Phosphate Lyase Enzymes.

Indole is produced in nature by diverse organisms and exhibits a characteristic odor described as animal, fecal, and floral. In addition, it contributes to the flavor in foods, and it is applied in the fragrance and flavor industry. In nature, indole is synthesized either from tryptophan by bacterial tryptophanases (TNAs) or from indole-3-glycerol phosphate (IGP) by plant indole-3-glycerol phosphate lyases (IGLs).

Production of indole by Corynebacterium glutamicum microbial cell factories for flavor and fragrance applications.

Background: The nitrogen containing aromatic compound indole is known for its floral odor typical of jasmine blossoms. Due to its characteristic scent, it is frequently used in dairy products, tea drinks and fine fragrances. The demand for natural indole by the flavor and fragrance industry is high, yet, its abundance in essential oils isolated from plants such as jasmine and narcissus is low.

Fermentative -Methylanthranilate Production by Engineered .

The -functionalized amino acid -methylanthranilate is an important precursor for bioactive compounds such as anticancer acridone alkaloids, the antinociceptive alkaloid -isopropyl -methylanthranilate, the flavor compound -methyl--methylanthranilate, and as a building block for peptide-based drugs. Current chemical and biocatalytic synthetic routes to -alkylated amino acids are often unprofitable and restricted to low yields or high costs through cofactor regeneration systems. Amino acid fermentation processes using the Gram-positive bacterium are operated industrially at the million tons per annum scale.

Rational engineering of the shikimate and related pathways in Corynebacterium glutamicum for 4-hydroxybenzoate production.

4-Hydroxybenzoate (4HBA) is a valuable platform intermediate for the production of commodity and fine chemicals, including protocatechuate, cis,cis-muconic acid, adipic acid, terephthalic acid, phenol, vanillin, and 4-hydroxybenzyl alcohol glycoside (gastrodin). Here we describe rational engineering of the shikimate and related pathways in Corynebacterium glutamicum ATCC13032 for over-producing 4HBA. As an approach to increase the carbon flux to 4HBA, we first introduced a mutated chorismate-pyruvate lyase (CPL) and feedback-resistant 3-deoxy-d-arabinoheptulosonate-7-phosphate synthases encoded by ubiC and aroF/aroG, respectively, from Escherichia coli along with blockage of carbon flux to the biosynthetic pathways for aromatic amino acids and the catabolic pathway for 4HBA by deletion of the genes trpE (encoding anthranilate synthase I), csm (chorismate mutase), and pobA (4HBA hydroxylase).