College of Resources, Sichuan Agricultural University, 211 Huimin Rd, Chengdu 611130, China; Institute of Agro-products Processing Science and Technology, Sichuan Academy of Agricultural Sciences, 60 Shizishan Rd, Chengdu 610066, China.
College of Resources, Sichuan Agricultural University, 211 Huimin Rd, Chengdu 611130, China; Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 1, 00014, Finland.
Int J Food Microbiol. 2025 Jan 2;426:110923. doi: 10.1016/j.ijfoodmicro.2024.110923. Epub 2024 Sep 23.
Phenyllactic acid (PLA) is a broad-spectrum and efficient antimicrobial phenolic acid with potential applications in the food industry. Previous studies have demonstrated that fungi may be ideal producers of PLA. In this study, 15 fungi screened from Doubanjiang with the ability to produce PLA were first reported, including Wickerhamomyces anomalus, Candida etchellsii, Candida parasitosis, Pichia kudriavzevii, Pichia membranifaciens and Kodamaea ohmeri. Among them, K. ohmeri w5 had the highest PLA yield, producing up to 7160 mg/L PLA in shake flask fermentation with phenylalanine as substrate, which was more than ten times higher than the PLA produced by wild-type LAB under the similar conditions. In addition, K. ohmeri w5 was able to grow under extreme hypertonic conditions of 20 % NaCl (w/v) and 50 % glucose (w/v) as well as produce 57.12 ± 0.42 and 1609.22 ± 36.26 mg/L of PLA, respectively. Furthermore, the fermentation supernatant of K. ohmeri w5 demonstrated direct inhibitory effects against foodborne pathogenic microorganisms, Aspergillus flavus and Bacillus cereus. However, the inhibitory effect was weaker than that of the PLA standard at the same concentration. Further, 12,497,932 bp of w5 genome-wide information was obtained by sequencing and assembling. And its gene model was predicted based on transcriptomic evidence, which showed that a total of 7 genes related to PLA synthesis were identified in the w5 genome. Based on qRT-PCR, structure prediction, and molecular docking, a potentially key genetic resource from K. ohmeri w5 for PLA production was uncovered. The results will provide novel producers of PLA and its potential genetic resources.
苯乳酸（PLA）是一种广谱、高效的抗菌性酚酸，在食品工业中有很大的应用潜力。之前的研究表明，真菌可能是 PLA 的理想生产者。在本研究中，首次报道了从豆瓣中筛选出的 15 种具有产 PLA 能力的真菌，包括异常威克汉姆酵母、产朊假丝酵母、寄生假丝酵母、毕赤酵母、膜毕赤酵母和奥默毕赤酵母。其中，奥默毕赤酵母 w5 的 PLA 产量最高，在摇瓶发酵中以苯丙氨酸为底物，可产高达 7160mg/L 的 PLA，是相似条件下野生型 LAB 产生 PLA 的 10 倍以上。此外，奥默毕赤酵母 w5 能够在 20%NaCl（w/v）和 50%葡萄糖（w/v）的极端高渗条件下生长，并分别产生 57.12±0.42mg/L 和 1609.22±36.26mg/L 的 PLA。此外，奥默毕赤酵母 w5 的发酵上清液对食源性致病菌黄曲霉和蜡状芽孢杆菌具有直接的抑制作用。然而，其抑制效果弱于相同浓度的 PLA 标准品。此外，通过测序和组装获得了 w5 全基因组的 12497932bp 信息。并基于转录组证据预测了其基因模型，结果表明在 w5 基因组中总共鉴定出 7 个与 PLA 合成相关的基因。基于 qRT-PCR、结构预测和分子对接，发现了奥默毕赤酵母 w5 中一个可能与 PLA 生产相关的关键遗传资源。该结果为 PLA 生产提供了新的生产菌及其潜在的遗传资源。
