It is known that some microorganisms can enhance plant development. However, the use of yeasts as growth-promoting agents has been poorly investigated. The aim of this study was the characterisation of a collection of 69 yeast strains isolated from Spanish vineyards. Phytobeneficial attributes such as solubilisation of nutrients, synthesis of active biomolecules and cell wall-degrading enzyme production were analysed. Strains that revealed multiple growth-promoting characteristics were identified. The in vitro co-culture of Nicotiana benthamiana with yeast isolates showed enhancement of plant growth in 10 strains (up to 5-fold higher shoot dry weight in the case of Hyphopichia pseudoburtonii Hp-54), indicating a beneficial direct yeast-plant interaction. In addition, 18 out of the 69 strains increased dry weight and the number of roots per seedling when tobacco seeds were inoculated. Two of these, Pichia dianae Pd-2 and Meyerozyma guilliermondii Mg-11, also increased the chlorophyll content. The results in tobacco were mostly reproduced in lettuce with these two strains, which demonstrates that the effect of the yeast-plant interaction is not species-specific. In addition, the yeast collection was evaluated in maize seedlings grown in soil in a phytotron. Three isolates (Debaryomyces hansenii Dh-67, Lachancea thermotolerans Lt-69 and Saccharomyces cerevisiae Sc-6) promoted seedling development (increases of 10 % in dry weight and chlorophyll content). In conclusion, our data confirm that several yeast strains can promote plant growth and could be considered for the development of biological fertiliser treatments.

众所周知，一些微生物可以促进植物发育。然而，使用酵母作为生长促进剂的研究很少。本研究的目的是对从西班牙葡萄园中分离出的 69 种酵母菌株进行表征。分析了植物有益的特性，例如营养物质的溶解、活性生物分子的合成和细胞壁降解酶的产生。鉴定出具有多种生长促进特征的菌株。本塞姆氏烟草与酵母分离株的体外共培养显示 10 个菌株的植物生长得到增强（ Hyphopichia pseudoburtonii Hp-54 的芽干重高达 5 倍），表明酵母与植物之间存在有益的直接相互作用。此外，当接种烟草种子时，69 个菌株中有 18 个增加了干重和每株幼苗的根数。其中两种， Pichia dianae Pd-2 和Meyerozyma guilliermondii Mg-11，也增加了叶绿素含量。烟草中的结果大部分在生菜中用这两种菌株重现，这表明酵母-植物相互作用的影响不是物种特异性的。此外，还对生长在植物加速器土壤中的玉米幼苗的酵母收集进行了评估。三种菌株（ Debaryomyces hansenii Dh-67、 Lachancea thermotolerans Lt-69 和Saccharomyces cerevisiae Sc-6）促进幼苗发育（干重和叶绿素含量增加 10%）。总之，我们的数据证实，几种酵母菌株可以促进植物生长，可以考虑用于开发生物肥料处理。