It is important for civil engineering applications to investigate resistance to wood decay in aqueous environments. DNA from microorganisms inhabiting logs (groynes) that had been used for about 15 years as a water control system to prevent riverbank erosion was extracted and the microbial community structure was examined. DNA was extracted from specimens in four sections, above and under the water, under the ground and from the bottom parts of the logs that were pulled out from the river. Then, barcode sequences for the detection of fungi and bacteria were amplified from each DNA sample by polymerase chain reaction. Microbes were identified from the nucleotide sequences, and the relationships between microbes and environmental conditions were discussed. The wood in the section above the water was significantly decayed, while slight decay and strength loss were observed in the other sections. The white-rot basidiomycete Xeromphalina sp. was detected in the section above the water, suggesting that this fungal species was responsible for the significant decay of the logs in this study. Wood in the sections under the water and under the ground including the bottom of the logs was not decayed even though the fungus was detected in all sections of the logs, suggesting that Xeromphalina sp. could not degrade the wood in the water and underground where the oxygen supply was limited.

中文翻译：

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河岸系统中防波堤原木的微生物群落结构

对于土木工程应用来说，研究在水性环境中对木材腐烂的抵抗力很重要。从已经居住了约15年的微生物中提取DNA，该微生物已被用作防止河岸侵蚀的水控制系统，使用了约15年，并检查了微生物群落结构。从水上，水下，地下和从河中抽出的原木底部四个部分的标本中提取DNA。然后，通过聚合酶链反应从每个DNA样品中扩增出用于检测真菌和细菌的条形码序列。从核苷酸序列中鉴定出微生物，并讨论了微生物与环境条件之间的关系。水上部分的木材已严重腐烂，其他部分则观察到轻微的衰减和强度损失。白腐担子菌Xeromphalina sp。在水上方的区域中检测到这种真菌，这表明该真菌物种是导致本研究中的原木显着腐烂的原因。尽管在原木的所有部分中都检测到了真菌，但在水下和地下的部分（包括原木的底部）中的木材都没有腐烂，这表明Xeromphalina sp。。不能在氧气供应有限的水中和地下降解木材。尽管在原木的所有部分中都检测到了真菌，但在水下和地下的部分（包括原木的底部）中的木材都没有腐烂，这表明Xeromphalina sp。。在氧气供应有限的水中和地下无法降解木材。尽管在原木的所有部分中都检测到了真菌，但在水下和地下的部分（包括原木的底部）中的木材都没有腐烂，这表明Xeromphalina sp。。在氧气供应有限的水中和地下无法降解木材。