Double mutant of Aspergillus oryzae for improved production of l‐dopa (3,4‐dihydroxyphenyl‐l‐alanine) from l‐tyrosine

Abstract

Aspergillus oryzae mutant strain UV-7 was further improved for the production of L-dopa from L-tyrosine using chemical mutation. Different putative mutant strains of the organism were tested for the production of L-dopa in triplicate shake-flask cultures. Among these putative mutants, the strain designated SI-12 gave a maximal production of L-dopa (444+/-14 mg of L-dopa/g of cells). The regulation of L-dopa from different carbon source solutions [initial substrate concentration (S(0))=30 g/l] by the mutant culture was investigated. At an initial pH (pH(0)) of 5.0 and a temperature (T) of 30 degrees C, 100% of sugars were utilized for product and cell mass formation, corresponding to final L-dopa product yield of 189+/-8 mg/g of substrate utilized and maximum volumetric and specific productivities of 145+/-5 mg/h per litre and 155+/-8 mg/h per g of cells respectively. There was up to 3-fold enhancement in product formation rate. This enhancement is, to our knowledge, the highest reported in the literature. To explain the kinetic mechanism of L-dopa formation and its thermal inactivation, the thermodynamic parameters were determined with the application of the Arrhenius model. Activation enthalpy and entropy for product formation, in the case of the mutant derivative, were 40 kJ/mol and 0.076 kJ.mol(-1).K(-1) for its production and 116 kJ/mol and 0.590 kJ.mol(-1).K(-1) for thermal inactivation respectively. The respective values for product formation and product de-activation were lower than the respective values for the parental culture. Therefore the mutant strain was thermodynamically more resistant to thermal denaturation during the product-formation process.

Fungal biotransformation of synthetic levodopa to stable dopamine in l-ascorbate-mediated aerobic-thermophilic biochemical process

“…Although, some reports in the literature have appeared which described the chemical conversion of l-tyrosine to levodopa that ultimately converted into dopamine and some other intermediates of the melanogenesis' cycle (Minelli et al 1979;Ali et al 2005;Tang et al 2017). However, work is still needed to produce dopamine from the substrate levodopa by microbiological techniques.…”

Production of 3,4-dihydroxy L-phenylalanine by a newly isolated Aspergillus niger and parameter significance analysis by Plackett-Burman design

“…Another alternative method is the L-dopa production from L-tyrosine with an immobilized tyrosinase. The enzyme inhibits below pH 3.5 and thus decreases L-dopa production [10]. The optimal production was obtained when glucose was used as a carbon source [11,12].…”

Biological sources of L-DOPA: An alternative approach

“…There were many biological soures reported for enantiometrically pure L-DOPA ( Table 1). Stemonitis herbicola 50 mg [25] Aspergillus oryzae ( mutant) 1.28 mg/ml [26] Aspergillus oryzae 1.28 mg/ml [27] Aspergillus oryzae UV7( double mutant) 1.28 mg ml [28] Aspergillus oryzae 1.86 mg/ml [29] Aspergillus oryzae UV-7 444 g cells [30] Aspergillus oryzae ME2 (Illite) 1.686 mg/ml [31] Aspergillus oryzae ME2 (Celite) 0.428 mg/ml [32] Aspergillus oryzae (Double mutant) 300 mg [33] Aspergillus oryzae IIB-6 1.34 mg/ml [34] Acremonium retilum 0.89 mg/ml [35] Aspergillus niger 0.365 mg/ml [36] Actinomycetes 28.6% [37] Yeast Yarrowia lipolytica NRRL-143 2.96 mg/ml [38] Egyptian halophilic black yeast 66 ug/ml [39] Bacteria Vibrio tyrosinaticus 4 mg/ml [40] Pseudomonas melanogenum 8 mg/ml [41] E. coli W(ATCC 11105) (p-hydroxyphenyl acetate 3-hydroxylase) 48 mM in reaction mixture [42] Bacillus sp. JPJ 0.497 mg/ml [7] Recombinant The production of L-DOPA from biological sources involves the oxidation of L-tyrosine by enzyme tyrosinase (E.C.1.14.18.1), which is copper containing enzyme widely distributed in plants, animals and microorganisms [13].…”

“…L-DOPA produced by the method was enantiometrically pure as well as it is cost effective. Similarly, biotransformation of L-DOPA from L-tyrosine was carried out using Acremonium reticulum by submerged fermentation process yields more amount of L-DOPA in the broth [24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Production of L-DOPA also reported from yeast species [38,39].…”