Institute of Fermentation Technology and Microbiology, Lodz University of Technology, Wolczanska 171/173, 90-924, Lodz, Poland.
Gut Microbes and Health, Quadram Institute Bioscience, Colney Lane, Norwich Research Park, Norwich, NR4 7UA, UK.
Antonie Van Leeuwenhoek. 2019 Oct;112(10):1425-1445. doi: 10.1007/s10482-019-01272-w. Epub 2019 May 20.
This study set out to isolate and identify epiphytic yeasts producing pulcherrimin, and to evaluate their potential as biological control agents (BCAs). We isolated Metschnikowia sp. strains from flowers and fruits collected in Poland. The plant material had been collected between April to September 2017 from two small orchards where traditional organic management is employed. We identified the essential phenotypic features of the yeast, including assimilation and enzymatic profiles, stress resistance, adhesion properties, and antimicrobial activity against various fungi involved in crop and/or food spoilage. Yeast screening was performed using YPD agar supplemented with chloramphenicol and Fe(III) ions. Taxonomic classification was determined by sequence analysis of the D1/D2 domains of the large subunit rRNA gene. The isolates were identified as Metschnikowia andauensis and Metschnikowia sinensis. The yeast isolates were further characterized based on their enzymatic and assimilation profiles, as well as their growth under various stress conditions. In addition, the hydrophobicity and adhesive abilities of the Metschnikowia isolates were determined using a MATH test and luminometry. Their antagonistic action against molds representing typical crop spoiling microflora was also evaluated. The assimilation profiles of the wild isolates were similar to those displayed by collection strains of M. pulcherrima. However, some of the isolates displayed more beneficial phenotypic properties, especially good growth under stress conditions. Several of the epiphytes grew well over a wider range of temperatures (8-30 °C) and pH levels (3-9), and additionally showed elevated tolerance to ethanol (8%), glucose (30%), and peroxides (50 mM). The hydrophobicity and adhesion of the yeast cells were strain- and surface-dependent. The tested yeasts showed potential for use as BCAs, with some exhibiting strong antagonism against molds belonging to the genera Alternaria, Botrytis, Fusarium, Rhizopus, and Verticillium, as well as against yeasts isolated as food spoilage microbiota.
本研究旨在分离和鉴定产生 pulcherrimin 的附生酵母，并评估其作为生物防治剂（BCA）的潜力。我们从波兰收集的花朵和果实中分离出了 Metschnikowia sp. 菌株。这些植物材料是在 2017 年 4 月至 9 月间，从小规模果园中收集的，这些果园采用传统的有机管理方式。我们确定了酵母的基本表型特征，包括同化和酶谱、抗逆性、粘附特性以及对各种参与作物和/或食品腐败的真菌的抗菌活性。酵母筛选是在补充氯霉素和 Fe(III)离子的 YPD 琼脂上进行的。分类学分类是通过大核糖体 RNA 基因的 D1/D2 结构域的序列分析确定的。分离物被鉴定为 Metschnikowia andauensis 和 Metschnikowia sinensis。进一步根据酵母分离物的酶和同化谱以及在各种应激条件下的生长情况对其进行了特征描述。此外，还通过 MATH 测试和发光计测定了 Metschnikowia 分离物的疏水性和粘附能力。还评估了它们对代表典型作物腐败微生物群的霉菌的拮抗作用。野生分离物的同化谱与 M. pulcherrima 集落菌株的同化谱相似。然而，一些分离物表现出更有益的表型特性，特别是在应激条件下的良好生长。一些附着物在较宽的温度（8-30°C）和 pH 值（3-9）范围内生长良好，并且对乙醇（8%）、葡萄糖（30%）和过氧化物（50 mM）的耐受性更高。酵母细胞的疏水性和粘附性取决于菌株和表面。测试的酵母具有作为 BCA 的潜力，一些酵母对属于Alternaria、Botrytis、Fusarium、Rhizopus 和 Verticillium 属的霉菌以及作为食品腐败微生物群落分离出的酵母表现出强烈的拮抗作用。
