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SERS-based Microdroplet Platform for High-throughput Screening of Strains for the Efficient Biosynthesis of D-phenyllactic Acid

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Date 2024 Oct 7
PMID 39372433
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Abstract

D-Phenyllactic acid (D-PLA) is a potent antimicrobial typically synthesized through chemical methods. However, due to the complexity and large pollution of these reactions, a simpler and more eco-friendly approach was needed. In this study, a strain for D-PLA biosynthesis was constructed, but the efficiency was restricted by the activity of D-lactate dehydrogenase (DLDH). To address this issue, a DLDH mutant library was constructed and the Surface-Enhanced Raman Spectroscopy (SERS) was employed for the precise quantification of D-PLA at the single-cell level. The TB24 mutant exhibited a significant improvement in D-PLA productivity and a 23.03-fold increase in enzymatic activity, which was attributed to the enhanced hydrogen bonding and increased hydrophobicity within the substrate-binding pocket. By implementing multi-level optimization strategies, including the co-expression of glycerol dehydrogenase (GlyDH) with DLDH, chassis cell replacement, and RBS engineering, a significant increase in D-PLA yields was achieved, reaching 128.4 g/L. This study underscores the effectiveness of SERS-based microdroplet high-throughput screening (HTS) in identifying superior mutant enzymes and offers a strategy for large-scale D-PLA biotransformation.

References
1.
Meng X, Zhang M, Liu L, Du J, Li N, Zou W . Rapid and robust analysis of aristolochic acid I in Chinese medicinal herbal preparations by surface-enhanced Raman spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc. 2022; 285:121880. DOI: 10.1016/j.saa.2022.121880. View

2.
Kroll A, Ranjan S, Engqvist M, Lercher M . A general model to predict small molecule substrates of enzymes based on machine and deep learning. Nat Commun. 2023; 14(1):2787. PMC: 10185530. DOI: 10.1038/s41467-023-38347-2. View

3.
Zhu Y, Wang Y, Xu J, Chen J, Wang L, Qi B . Enantioselective Biosynthesis of l-Phenyllactic Acid by Whole Cells of Recombinant Escherichia coli. Molecules. 2017; 22(11). PMC: 6150373. DOI: 10.3390/molecules22111966. View

4.
Cheng Y, Park T, Seong H, Kim T, Han N . Biological characterization of D-lactate dehydrogenase responsible for high-yield production of D-phenyllactic acid in Sporolactobacillus inulinus. Microb Biotechnol. 2022; 15(11):2717-2729. PMC: 9618312. DOI: 10.1111/1751-7915.14125. View

5.
Liu F, Sun Z, Wang F, Liu Y, Zhu Y, Du L . Inhibition of biofilm formation and exopolysaccharide synthesis of Enterococcus faecalis by phenyllactic acid. Food Microbiol. 2019; 86:103344. DOI: 10.1016/j.fm.2019.103344. View