Bioproduction of Natural Phenethyl Acetate, Phenylacetic Acid, Ethyl Phenylacetate, and Phenethyl Phenylacetate from Renewable Feedstock

Abstract

Natural phenethyl acetate (PEA), phenylacetic acid (PAA), ethyl phenylacetate (Et‐PA), and phenethyl phenylacetate (PE‐PA) are highly desirable aroma chemicals, but with limited availability and high price. Here, green, sustainable, and efficient bioproduction of these chemicals as natural products from renewable feedstocks was developed. PEA and PAA were synthesized from l‐phenylalanine (l‐Phe) via novel six‐ and five‐enzyme cascades, respectively. Whole‐cell‐based cascade biotransformation of 100 mm l‐Phe in a two‐phase system (aqueous/organic: 1 : 0.5 v/v) containing ethyl oleate or biodiesel as green solvent gave 13.6 g L−1 PEA (83.1 % conv.) and 11.6 g L−1 PAA (87.1 % conv.), respectively. Coupled fermentation and biotransformation approach produced 10.4 g L−1 PEA and 9.2 g L−1 PAA from glucose or glycerol, respectively. The biosynthesized PAA was converted to natural Et‐PA and PE‐PA by esterification using lipases with ethanol or 2‐phenylethanol derived from sugar, affording 2.7 g L−1 Et‐PA (83.1 % conv.) and 4.6 g L−1 PE‐PA (96.3 % conv.), respectively.

High-Yield Synthesis of Enantiopure 1,2-Amino Alcohols from l-Phenylalanine via Linear and Divergent Enzymatic Cascades

“…The reaction formally consumes only dioxygen as a simple and innocuous reagent and produces stoichiometric hydrogen carbonate as the sole byproduct, while water and ammonia molecules are formally exchanged along the process. These results also pave the way for the future metabolic engineering of E. coli whole-cell systems in which all the required enzymes for a certain cascade are coexpressed, thereby potentially improving the efficiency of the biochemical process. , …”

“…These results also pave the way for the future metabolic engineering of E. coli whole-cell systems in which all the required enzymes for a certain cascade are coexpressed, thereby potentially improving the efficiency of the biochemical process. 24,102 4. EXPERIMENTAL PART 4.1.…”

Herstellung von biobasiertem Ethylbenzol durch Kaskaden‐Biokatalyse mit einer speziell entwickelten Photodecarboxylase

“…Um die Herstellung von 4 aus biobasierten Rohstoffen wie Glycerin zu demonstrieren, haben wir einen gekoppelten Fermentations‐ und Biotransformationsprozess angewandt [8b,c] . Der zuvor entwickelte E. coli ‐Stamm NST74‐Phe, der fünf Schlüsselenzyme des Shikimatwegs überexprimiert, wurde für die fermentative Herstellung von 1 aus Glycerin eingesetzt.…”

Styrene Oxide Isomerase‐Catalyzed Meinwald Rearrangement in Cascade Biotransformations: Synthesis of Chiral and/or Natural Chemicals

“…The biosynthesized 16 a was also esterified with ethanol or bioderived 17 a using lipases, producing natural esters 25 or 26 (Scheme 6a). [42] A decarboxylation-epoxidation-isomerization-reduction enzymatic cascade was developed to convert bio-derived p-CA to natural tyrosol 17 b at a concentration of 2.07 g/L. Additionally, tyrosine ammonia lyase (TAL) was introduced to produce p-CA from L-tyrosine metabolism, thus allowing the recombinant E. coli strain to utilize glycerol and glucose as substrates (Scheme 6b).…”

“…Another multi‐enzymatic cascade sequence PAL‐PAD‐SMO‐SOI‐ Ec ALDH was used to convert bio‐derived L‐Phe to phenylacetic acid 16 a in up to 11.6 g/L. The biosynthesized 16 a was also esterified with ethanol or bioderived 17 a using lipases, producing natural esters 25 or 26 (Scheme 6a) [42] …”