Microbial Phenylalanine Ammonia Lyase: Recent Advances and Emerging Applications

As a versatile biocatalyst in the lyase family, phenylalanine ammonia lyase (PAL, EC 4.3.1.24) appears naturally in diverse organisms including higher plants, numerous fungi, yeasts, <i>Streptomyces</i> species, and some Cyanobacteria. Naturally, catalyzed by PAL, l-phenylalanine (l-Phe) undergoes stereospecific deamination, yielding trans-cinnamic acid (t-CA) and ammonia. PAL has made major strides in a number of clinical, industrial, and biotechnological applications over last few decades. Since its initial characterization in <i>Hordeum vulgare</i>, PAL's involvement in the phenylpropanoid pathway has been the subject of extensive investigation both in plants and in microorganism. However, there are few articles focusing on the overall summary of microbial PAL. This mini-review systematically examines current breakthroughs in microbial PAL technology, encompassing both production optimization strategies and novel application frontiers. By summarizing cutting-edge research and industrial practices, this work aims to catalyze the next wave of PAL-based innovations, positioning microbial PAL as a transformative force in 21st-century biotechnology.