Gazaloğlu Mehmet, Camarasa Carole, Nevoigt Elke
School of Science, Constructor University, Campus Ring 1, 28759 Bremen, Germany.
UMR SPO, Univ Montpellier, INRAE, Institut Agro, 34000 Montpellier, France.
FEMS Yeast Res. 2025 Jan 30;25. doi: 10.1093/femsyr/foae033.
Pectinolytic enzymes secreted by yeasts have an untapped potential in industry, particularly in wine-making. This study addresses the limitations of the current screening methods in reliably predicting the capacity of pectinolytic yeast strains to secrete polygalacturonase (PGase) under industrial conditions, suggesting a novel screening approach. Using the context of wine-making as an example, a diverse collection of 512 yeast strains from 17 species was analysed for PGase secretion, a key enzyme in pectinolysis. The traditional halo assay on solid yeast-pepton-dextrose (YPD) medium revealed 118 strains from nine genera being PGase positive. Screening these strains by incubating them at 20°C on a solid synthetic grape juice medium containing polygalacturonic acid (PG) significantly reduced the number of promising strains to 35. They belong to five genera: Kluyveromyces sp., Cryptococcus, Pichia, Torulaspora, and Rhodotorula. Afterward, a newly developed pectin-iodine assay was used to precisely quantify the PGase activity of the best-performing strains in a liquid medium. Strains from Kluyveromyces and Cryptococcus sp. stood out regarding high pectinolytic activity. Our methodological advancements tailored to identify highly promising pectinolytic yeasts for industrial use open new avenues for wine-making and other industrial processes encompassing media rich in pectin and sugars.
酵母分泌的果胶分解酶在工业中具有尚未开发的潜力，尤其是在酿酒行业。本研究探讨了当前筛选方法在可靠预测果胶分解酵母菌株在工业条件下分泌聚半乳糖醛酸酶（PGase）能力方面的局限性，并提出了一种新的筛选方法。以酿酒为例，分析了来自17个物种的512株酵母菌株的PGase分泌情况，PGase是果胶分解中的一种关键酶。在固体酵母蛋白胨葡萄糖（YPD）培养基上进行的传统透明圈测定显示，来自9个属的118株菌株PGase呈阳性。通过在含有聚半乳糖醛酸（PG）的固体合成葡萄汁培养基上于20°C培养来筛选这些菌株，可将有潜力的菌株数量显著减少至35株。它们属于5个属：克鲁维酵母属、隐球菌属、毕赤酵母属、圆酵母属和红酵母属。随后，使用新开发的果胶 - 碘测定法精确量化液体培养基中表现最佳的菌株的PGase活性。克鲁维酵母属和隐球菌属的菌株在高果胶分解活性方面表现突出。我们为识别用于工业用途的极具潜力的果胶分解酵母而定制的方法改进，为酿酒及其他包含富含果胶和糖分培养基的工业过程开辟了新途径。
