Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.
Biology Department, Duke University, Durham, North Carolina, USA.
mSystems. 2024 Sep 17;9(9):e0091924. doi: 10.1128/msystems.00919-24. Epub 2024 Aug 27.
Elemental profiling of fungal species as a phenotyping tool is an understudied topic and is typically performed to examine plant tissue or non-biological materials. Traditional analytical techniques such as inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) have been used to identify elemental profiles of fungi; however, these techniques can be cumbersome due to the difficulty of preparing samples. Additionally, the instruments used for these techniques can be expensive to procure and operate. Laser-induced breakdown spectroscopy (LIBS) is an alternative elemental analytical technique-one that is sensitive across the periodic table, easy to use on various sample types, and is cost-effective in both procurement and operation. LIBS has not been used on axenic filamentous fungal isolates grown in substrate media. In this work, as a proof of concept, we used LIBS on two genetically distinct fungal species grown on a nutrient-rich and nutrient-poor substrate media to determine whether robust elemental profiles can be detected and whether differences between the fungal isolates can be identified. Our results demonstrate a distinct correlation between fungal species and their elemental profile, regardless of the substrate media, as the same strains shared a similar uptake of carbon, zinc, phosphorus, manganese, and magnesium, which could play a vital role in their survival and propagation. Independently, each fungal species exhibited a unique elemental profile. This work demonstrates a unique and valuable approach to rapidly phenotype fungi through optical spectroscopy, and this approach can be critical in understanding these fungi's behavior and interactions with the environment.
Historically, ionomics, the elemental profiling of an organism or materials, has been used to understand the elemental composition in waste materials to identify and recycle heavy metals or rare earth elements, identify the soil composition in space exploration on the moon or Mars, or understand human disorders or disease. To our knowledge, ionomic profiling of microbes, particularly fungi, has not been investigated to answer applied and fundamental biological questions. The reason is that current ionomic analytical techniques can be laborious in sample preparation, fail to measure all potential elements accurately, are cost-prohibitive, or provide inconsistent results across replications. In our previous efforts, we explored whether laser-induced breakdown spectroscopy (LIBS) could be used in determining the elemental profiles of poplar tissue, which was successful. In this proof-of-concept endeavor, we undertook a transdisciplinary effort between applied and fundamental mycology and elemental analytical techniques to address the biological question of how LIBS can used for fungi grown axenically in a nutrient-rich and nutrient-poor environment.
作为表型工具的真菌物种元素分析是一个研究较少的课题，通常用于检查植物组织或非生物材料。电感耦合等离子体-原子发射光谱（ICP-OES）和电感耦合等离子体质谱（ICP-MS）等传统分析技术已被用于鉴定真菌的元素图谱;然而，由于样品制备困难，这些技术可能很繁琐。此外，用于这些技术的仪器在采购和操作方面可能成本高昂。激光诱导击穿光谱（LIBS）是一种替代元素分析技术——在整个元素周期表中都很灵敏，易于在各种样品类型上使用，并且在采购和操作方面都具有成本效益。LIBS 尚未用于在富含营养和贫营养基质培养基中生长的无菌丝状真菌分离物上。在这项工作中，作为概念验证，我们在两种遗传上不同的真菌物种上使用 LIBS，这些真菌物种在富含营养和贫营养基质培养基上生长，以确定是否可以检测到稳健的元素图谱，以及是否可以识别真菌分离物之间的差异。我们的结果表明，真菌物种与其元素图谱之间存在明显的相关性，无论基质培养基如何，因为相同的菌株对碳、锌、磷、锰和镁的吸收相似，这可能对它们的生存和繁殖起着至关重要的作用。独立地，每种真菌物种都表现出独特的元素图谱。这项工作展示了一种通过光学光谱快速表型真菌的独特而有价值的方法，这种方法对于理解这些真菌的行为及其与环境的相互作用至关重要。
从历史上看，离子组学，即生物体或材料的元素分析，已被用于了解废物材料中的元素组成，以识别和回收重金属或稀土元素，识别月球或火星上太空探索的土壤成分，或了解人类疾病或疾病。据我们所知，微生物，特别是真菌的离子组学分析尚未被研究以回答应用和基础生物学问题。原因是目前的离子分析技术在样品制备方面可能很繁琐，无法准确测量所有潜在元素，成本过高，或者在重复实验中提供不一致的结果。在我们之前的努力中，我们探索了激光诱导击穿光谱（LIBS）是否可用于确定杨树组织的元素图谱，结果是成功的。在这个概念验证的努力中，我们在应用真菌学和基础真菌学以及元素分析技术之间进行了跨学科努力，以解决在富含营养和贫营养环境中无菌生长的真菌如何使用 LIBS 的生物学问题。
