Abstract

L-DOPA, a precursor of dopamine, is the drug of choice for Parkinson’s disease, which persists due to decreased levels of dopamine in the brain. Present study emphasis the microbial production of L-DOPA rather than the biotransformation of L-DOPA by L-tyrosine. The production of L-DOPA by bacterial isolates had gained more acceptance due to its more straightforward extraction and downstream processes. Pseudomonas fluorescens was used to produce the L-DOPA in a bioreactor system under submerged condition. The design of experiment-based Taguchi orthogonal array method was adopted for the optimization of production. L-9 orthogonal array using the analysis of mean approach was used to study the effect of different factors viz NaCl, lactose, tryptone, and inducer on the microbial production of L-DOPA. The method mentioned above is less time consuming and does not require any harsh chemicals, proving it to be an eco-friendly process. After optimizing selected factors, i.e., NaCl (1.2 g/l), lactose (1.5 g/l), tryptone (4 g/l), and inducer (0.1 g/l), 16.9 % of enhancement in L-DOPA production with 66.6% of process cost saving was observed. The production of L-DOPA was increased from 3.426 ± 0.08 g/l to 4.123 ± 0.05 g/l after optimization. Subsequently, unstructured kinetic models were adopted to simulate the fermentation kinetics and understand the metabolic process. Fisher’ F test and determination coefficients (R²) confirmed that the Velhurst–Pearl logistic equation, Luedeking–Piret equation, and modified Luedeking–Piret equation was best fitted with the biomass production, product formation, and substrate utilization, respectively.

摘要

L -DOPA 是多巴胺的前体，是帕金森病的首选药物，由于大脑中多巴胺水平的降低而持续存在。目前的研究强调L -DOPA的微生物生产，而不是L-酪氨酸对 L-DOPA的生物转化。通过细菌分离物生产L- DOPA 由于其更直接的提取和下游工艺而获得了更多的认可。荧光假单胞菌用于生产L-淹没条件下生物反应器系统中的多巴。采用基于实验的田口正交阵列法进行生产优化。L-9正交阵列采用均值分析法研究了NaCl、乳糖、胰蛋白胨和诱导剂等不同因素对微生物产生L- DOPA的影响。上述方法耗时较少，不需要任何刺激性化学品，证明它是一种环保工艺。在优化选定的因素后，即 NaCl (1.2 g/l)、乳糖 (1.5 g/l)、胰蛋白胨 (4 g/l) 和诱导剂 (0.1 g/l)，L- DOPA 产量提高了 16.9%观察到 66.6% 的过程成本节省。L的生产-优化后多巴从 3.426 ± 0.08 g/l 增加到 4.123 ± 0.05 g/l。随后，采用非结构化动力学模型来模拟发酵动力学并了解代谢过程。Fisher' F检验和确定系数 ( R ² ) 证实 Velhurst-Pearl 逻辑方程、Luedeking-Piret 方程和修正的 Luedeking-Piret 方程分别与生物质生产、产物形成和底物利用的拟合效果最佳。