泰国锡昌岛沿海地区自由生活的古菌、细菌和小型真核生物的宏基因组特征。

BACKGROUND: Tha Wang and Tham Phang coasts, though situated at similar oceanographic positions on Sichang island, Chonburi province, Thailand, are different in bay geography and amount of municipal disturbances. These affect the marine ecosystems. The study used metagenomics combined with 16S and 18S rDNA pyrosequencing to identify types and distributions of archaea, bacteria, fungi and small eukaryotes of sizes ranges 0.45 and ~30 μm. RESULTS: Following the open bay geography and minimal municipal sewages, Tham Phang coast showed the cleaner water properties, described by color, salinity, pH, conductivity and percent dissolved oxygen. The 16S and 18S rDNA metagenomic profiles for Tha Wang and Tham Phang coasts revealed many differences, highlighting by low Lennon and Yue & Clayton theta similarity indices (66.03-73.03% for 16S rDNA profiles, 2.85-25.38% for 18S rDNA profiles). For 16S rDNA, the percent compositions of species belonging to Proteobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Verrucomicrobia, Gammatimonadetes, Tenericutes, Acidobacteria, Spirochaetes, Chlamydiae, Euryarchaeota, Nitrospirae, Planctomycetes, Thermotogae and Aquificae were higher or distinctly present in Tha Wang. In Tham Phang, except Actinobacteria, the fewer number of prokaryotic species existed. For 18S rDNA, fungi represented 74.745% of the species in Tha Wang, whereas only 6.728% in Tham Phang. Basidiomycota (71.157%) and Ascomycota (3.060%) were the major phyla in Tha Wang. Indeed, Tha Wang-to-Tham Phang percent composition ratios for fungi Basidiomycota and Chytridiomycota were 1264.701 and 25.422, respectively. In Tham Phang, Brachiopoda (lamp shells) and Mollusca (snails) accounted for 80.380% of the 18S rDNA species detected, and their proportions were approximately tenfold greater than those in Tha Wang. Overall, coastal Tham Phang comprised abundant animal species. CONCLUSIONS: Tha Wang contained numerous archaea, bacteria and fungi, many of which could synthesize useful biotechnology gas and enzymes that could also function in high-saline and high-temperature conditions. Tham Phang contained less abundant archaea, bacteria and fungi, and the majority of the extracted metagenomes belonged to animal kingdom. Many microorganisms in Tham Phang were essential for nutrient-recycling and pharmaceuticals, for instances, Streptomyces, Pennicilium and Saccharomyces. Together, the study provided metagenomic profiles of free-living prokaryotes and eukaryotes in coastal areas of Sichang island.

背景：泰国春武里府锡昌岛的达汪和塔姆邦海岸虽然位于相似的海洋地理位置，但在海湾地理和城市干扰方面存在差异。这些因素影响了海洋生态系统。本研究采用宏基因组学结合 16S 和 18S rDNA 焦磷酸测序，鉴定了大小在 0.45 到 30 μm 之间的古菌、细菌、真菌和小型真核生物的类型和分布。

结果：塔姆邦海岸具有开阔的海湾地理和最小的城市污水排放，水质较清洁，表现在颜色、盐度、pH 值、电导率和溶解氧百分比等方面。达汪和塔姆邦海岸的 16S 和 18S rDNA 宏基因组图谱显示出许多差异，其中 Lennon 和 Yue & Clayton 相似性指数较低（16S rDNA 图谱为 66.03-73.03%，18S rDNA 图谱为 2.85-25.38%）。在 16S rDNA 方面，属于变形菌门、拟杆菌门、蓝藻门、厚壁菌门、疣微菌门、γ-变形菌门、无壁菌门、酸杆菌门、螺旋体门、衣原体门、古菌门、硝化螺旋菌门、浮霉菌门、热网菌门和泉古菌门的物种的百分组成较高或明显存在于达汪。在塔姆邦，除了放线菌门外，其他原核生物的种类较少。在 18S rDNA 方面，真菌在达汪的物种中占 74.745%，而在塔姆邦仅占 6.728%。担子菌门（71.157%）和子囊菌门（3.060%）是达汪的主要门。事实上，达汪和塔姆邦的真菌担子菌门和壶菌门的比例分别为 1264.701 和 25.422。在塔姆邦，腕足动物（笠贝）和软体动物（蜗牛）占 18S rDNA 检测到的物种的 80.380%，其比例大约是达汪的十倍。总的来说，塔姆邦海岸有丰富的动物物种。

结论：达汪含有大量的古菌、细菌和真菌，其中许多可以合成有用的生物技术气体和酶，也可以在高盐和高温条件下发挥作用。塔姆邦含有较少的古菌、细菌和真菌，提取的宏基因组主要属于动物界。塔姆邦的许多微生物对营养物质的循环和药物的合成至关重要，例如链霉菌属、青霉菌属和酿酒酵母属。本研究提供了锡昌岛沿海地区自由生活原核生物和真核生物的宏基因组图谱。