Dufrêne Y F, Boonaert C J, Gerin P A, Asther M, Rouxhet P G
Unité de Chimie des Interfaces, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium.
J Bacteriol. 1999 Sep;181(17):5350-4. doi: 10.1128/JB.181.17.5350-5354.1999.
Atomic force microscopy (AFM) has been used to probe, under physiological conditions, the surface ultrastructure and molecular interactions of spores of the filamentous fungus Phanerochaete chrysosporium. High-resolution images revealed that the surface of dormant spores was uniformly covered with rodlets having a periodicity of 10 +/- 1 nm, which is in agreement with earlier freeze-etching measurements. In contrast, germinating spores had a very smooth surface partially covered with rough granular structures. Force-distance curve measurements demonstrated that the changes in spore surface ultrastructure during germination are correlated with profound modifications of molecular interactions: while dormant spores showed no adhesion with the AFM probe, germinating spores exhibited strong adhesion forces, of 9 +/- 2 nN magnitude. These forces are attributed to polysaccharide binding and suggested to be responsible for spore aggregation. This study represents the first direct characterization of the surface ultrastructure and molecular interactions of living fungal spores at the nanometer scale and offers new prospects for mapping microbial cell surface properties under native conditions.
原子力显微镜（AFM）已被用于在生理条件下探测丝状真菌黄孢原毛平革菌孢子的表面超微结构和分子相互作用。高分辨率图像显示，休眠孢子的表面均匀覆盖着周期为10±1纳米的小杆，这与早期的冷冻蚀刻测量结果一致。相比之下，正在萌发的孢子表面非常光滑，部分覆盖着粗糙的颗粒结构。力-距离曲线测量表明，孢子萌发过程中表面超微结构的变化与分子相互作用的深刻改变相关：休眠孢子与AFM探针没有粘附，而正在萌发的孢子表现出强大的粘附力，大小为9±2纳牛。这些力归因于多糖结合，并被认为是孢子聚集的原因。这项研究首次在纳米尺度上直接表征了活真菌孢子的表面超微结构和分子相互作用，并为在自然条件下绘制微生物细胞表面特性提供了新的前景。
