Preah Vihear temple is one of the most significant representatives of the ancient Angkorian temples listed as United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites. The surfaces of this Angkor sandstone monument are covered with deteriorated materials, broadly called "sediments" here, resulting from a long time of weathering of the sandstone. The sediments might adversely affect the ancient sandstone substratum of this cultural heritage, and the potential risk from them is essential information for current strategies and on-going protection and management. The extracted DNA from the sediment samples of this temple was used for Illumina high-throughput sequencing analysis, resulting in approximately 12 Gb of metagenomic dataset. The results of this shotgun metagenomic analysis provided a thorough information of the phylogenetic groups presented in the microbiome of the sediment samples, indicating that potential metabolic activities, involving different geomicrobiological cycles, may occur in this microbiome. The phylogenetic result revealed that the majority of metagenomic reads were affiliated with Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes at the phylum level. The metabolic reconstruction results indicated that the important geomicrobiological cycling processes include carbon sequestration, and nitrogen and sulfur transformation as the potentially active ones in the sediments of the sampling sites. Specifically, the dissimilatory nitrate reduction to ammonium (DNRA) and the newly discovered complete ammonia oxidation (comammox) were retrieved from this metagenomic dataset. Furthermore, the genetic information on the presence of acid-producing processes by sulfur- and ammonia-oxidizing bacteria and archaea in this metagenomic dataset suggested that the microbial flora in these samples has the potential to participate in the degradation of sandstone cultural heritage by producing acids. N-15 isotope amendment and incubation analysis results confirmed the presence of active denitrification, but not anammox activity at this temple. These results are important for our knowledge on the microbial community composition and microbial biodeterioration processes affecting this sandstone cultural heritage and will aid in the protection and management of the ancient Preah Vihear temple.Key Points• Microbiota on Preah Viher temple was analyzed using NGS.• Nitrate-N transformation by DNRA, comammox, and denitrifcation was detected.• N-15 isotope analysis confirmed the active denitrifcation, but not Anammox.• Accumulation of nitrate is a result of less active removal by denitrification.

中文翻译：

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宏基因组学和N-15同位素分析揭示了柬埔寨古老的柏威夏神庙上微生物对微生物组和硝酸盐的去除过程。

柏威夏神庙是被列为联合国教育，科学及文化组织（教科文组织）世界遗产的古老的安哥拉神庙的最重要代表之一。吴哥砂岩纪念碑的表面覆盖着变质的材料，在这里被广泛称为“沉积物”，这是由砂岩长时间的风化引起的。这些沉积物可能对该文化遗产的古代砂岩底层产生不利影响，而它们的潜在风险是当前战略以及正在进行的保护和管理的重要信息。从该庙宇的沉积物样品中提取的DNA用于Illumina高通量测序分析，从而产生了约12 Gb的宏基因组数据集。shot弹枪宏基因组学分析的结果提供了沉积物微生物组中存在的系统进化组的详尽信息，表明该微生物组中可能发生涉及不同地球微生物学循环的潜在代谢活动。系统发育结果表明，大多数宏基因组读物在门廊水平上与变形杆菌，酸性杆菌，放线菌和拟杆菌属有关。代谢重建结果表明，重要的地球微生物循环过程包括碳固存，以及氮和硫的转化，它们是采样点沉积物中潜在的活性物质。特别，从该宏基因组数据集中检索了异化硝酸盐还原为铵盐（DNRA）和新发现的完全氨氧化（comammox）。此外，在此宏基因组学数据集中，有关由硫和氨氧化细菌和古细菌产生酸的过程的遗传信息表明，这些样品中的微生物菌群有可能通过产生酸而参与砂岩文化遗产的降解。 。N-15同位素修正和孵育分析结果证实了该庙宇存在主动反硝化作用，但没有厌氧氨氧化作用。