PDF(Pubmed)
Abstract：
Aureobasidium pullulans (A. pullulans), a commonly found yeast-like fungus, exhibits adaptability to a wide range of pH environments. However, the specific mechanisms and regulatory pathways through which A. pullulans respond to external pH remain to be fully understood. In this study, we first sequenced the whole genome of A. pullulans using Nanopore technology and generated a circle map. Subsequently, we explored the biomass, pullulan production, melanin production, and polymalic acid production of A. pullulans when cultivated at different pH levels. We selected pH 4.0, pH 7.0, and pH 10.0 to represent acidic, neutral, and alkaline environments, respectively, and examined the morphological characteristics of A. pullulans using SEM and TEM. Our observations revealed that A. pullulans predominantly exhibited hyphal growth with thicker cell walls under acidic conditions. In neutral environments, it primarily displayed thick-walled spores and yeast-like cells, while in alkaline conditions, it mainly assumed an elongated yeast-like cell morphology. Additionally, transcriptome analysis unveiled that A. pullulans orchestrates its response to shifts in environmental pH by modulating its cellular morphology and the expression of genes involved in pullulan, melanin, and polymalic acid synthesis. This research enhances the understanding of how A. pullulans regulates itself in diverse pH settings and offers valuable guidance for developing and applying engineered strains.
摘要：
普鲁兰梭子花（A.普鲁兰)，一种常见的酵母样真菌，对各种pH环境具有适应性。然而,具体的机制和调节途径，通过这些机制和普鲁兰响应外部pH仍然是完全了解。在这项研究中,我们首先使用Nanopore技术对普鲁兰的全基因组进行了测序，并生成了一个圆图。随后，我们探索了生物质，普鲁兰多糖生产,黑色素的产生，当在不同的pH水平下培养时,以及多苹果酸的产生。我们选择pH4.0，pH7.0和pH10.0代表酸性，中性,和碱性环境，分别,并利用扫描电镜和透射电镜研究了普鲁兰的形态特征。我们的观察结果表明，在酸性条件下，支链淀粉主要表现出菌丝生长，细胞壁较厚。在中性环境中,它主要展示厚壁孢子和酵母样细胞，而在碱性条件下，它主要呈现细长的酵母样细胞形态。此外,转录组分析揭示了支链淀粉通过调节其细胞形态和参与支链淀粉基因的表达来协调其对环境pH变化的反应。黑色素,和聚苹果酸合成。这项研究增强了对支链淀粉在不同pH设置中如何调节自身的理解，并为开发和应用工程菌株提供了有价值的指导。
