Thomas Seth, Lengger Sabine K, Bird Kimberley E, Allen Ro, Cunliffe Michael
Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK.
School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.
FEMS Microbes. 2022 Jan 24;3:xtab019. doi: 10.1093/femsmc/xtab019. eCollection 2022.
Marine fungi exist as three major cell types: unicellular yeasts, filamentous hyphae and zoosporic early-diverging forms, such as the Chytridiomycota (chytrids). To begin to understand the ecological and biogeochemical influence of these cell types within the wider context of other plankton groups, cell size and macromolecular composition must be assessed across all three cell types. Using a mass-balance approach to culture, we describe quantitative differences in substrate uptake and subsequent macromolecular distribution in three model marine fungi: the yeast , the filamentous and chytrid . We compared these model cell types with select oleaginous phytoplankton of specific biotechnological interest through metanalysis. We hypothesise that fungal cell types will maintain a significantly different macromolecular composition to one another and further represent an alternative grazing material to bacterioplankton and phytoplankton for higher trophic levels. Assessment of carbon substrate range and utilisation using phenotype arrays suggests that marine fungi have a wide substrate range. Fungi also process organic matter to an elevated-lipid macromolecular composition with reduced-protein content. Because of their size and increased lipid composition compared to other plankton groups, we propose that fungi represent a compositionally distinct, energy-rich grazing resource in marine ecosystems. We propose that marine fungi could act as vectors of organic matter transfer across trophic boundaries, and supplement our existing understanding of the microbial loop and carbon transfer in marine ecosystems.
单细胞酵母、丝状菌丝以及游动孢子的早期分化形式，如壶菌门（壶菌）。为了在其他浮游生物群体的更广泛背景下开始理解这些细胞类型的生态和生物地球化学影响，必须对所有这三种细胞类型的细胞大小和大分子组成进行评估。我们采用质量平衡培养方法，描述了三种海洋真菌模型——酵母、丝状真菌和壶菌——在底物摄取和随后大分子分布方面的定量差异。我们通过荟萃分析将这些模型细胞类型与具有特定生物技术意义的选定产油浮游植物进行了比较。我们假设真菌细胞类型彼此之间将保持显著不同的大分子组成，并且进一步代表了一种与浮游细菌和浮游植物不同的、可供更高营养级摄食的物质。使用表型阵列评估碳底物范围和利用情况表明，海洋真菌具有广泛的底物范围。真菌还将有机物加工成脂质含量升高、蛋白质含量降低的大分子组成。由于与其他浮游生物群体相比，它们的大小和脂质组成增加，我们认为真菌在海洋生态系统中代表了一种组成独特、能量丰富的摄食资源。我们提出海洋真菌可以作为跨越营养边界的有机物转移载体，并补充我们对海洋生态系统中微生物环和碳转移的现有理解。
