The southeast Andaman Sea 52-m off the west coast of Phang Nga province, Thailand, is located in the Indian Ocean, representing a hotspot for marine biodiversity of the world. This study utilized metagenomics combined 16S rRNA gene (V3–V4) sequencing, and firstly revealed the microbiota and their metabolism potentials of this site at an epipelagic depth (150-m depth, TC150M), including comparison with its pelagic depth (30-m depth, TC30M) as well as other nearby Thailand and global ocean sites. Between TC150M and TC30M, the TC150M microbial metagenomics was an eight-fold higher, and the microbiota comprised, for examples more abundant Bacteroidetes while fewer Proteobacteria, than the TC30M. The microbial metabolic potentials of the TC150M were statistically higher in replication repair and metabolisms of amino acids, lipids, nucleotides, and xenobiotics biodegradation, etc. Following comparative microbiota analyses between three Andaman Sea sites and two Gulf of Thailand sites, the relatively great proportions of Bacteroidetes, Nitrospirae, Gemmatimonadetes, and Chlorobi characterized the southeast Andaman Sea. Nevertheless, the microbiota representing Thailand marine sites remained distinguished from the global ocean sites where beta diversities were close. Thai maritime sites showed proportionally higher Proteobacteria, Bacteroides, Nitrospirae, Gemmatimonadetes, and Chlorobi. Thus, the Thai marine microbiota database helps better understand our global ocean microbiota and microbial metabolic potentials. Here, the microbial metabolism potentials between Thailand and the global ocean sites of relatively close microbiota databases encompose the similar functions yet in statistically different frequencies. Our research provided the first preliminary marine microbiome comparison between the epipelagic and pelagic sea levels of the southeast Andaman Sea, Thailand.

位于泰国攀牙府西海岸52米外的东南部安达曼海位于印度洋，是世界海洋生物多样性的热点地区。这项研究利用宏基因组学结合16S rRNA基因（V3-V4）测序，首先揭示了上表层深度（150-m深度，TC150M）上该位点的微生物群及其代谢潜能，包括与上层深度（30-m深度，TC30M）以及其他附近的泰国和全球海洋站点。在TC150M和TC30M之间，TC150M微生物宏基因组学要比TC30M高八倍，并且微生物群包含的细菌更丰富，而变形杆菌则更少。TC150M的微生物代谢潜力在复制修复和氨基酸，脂质，核苷酸，在对三个安达曼海站点和两个泰国湾站点之间的微生物群进行比较分析之后，东南安达曼海东南部具有较大比例的拟杆菌，硝化螺菌，双孢子虫和Chlorobi。尽管如此，代表泰国海洋地点的微生物群仍然与Beta多样性接近的全球海洋地点区分开。泰国的海洋地点显示出按比例较高的变形杆菌，拟杆菌，硝化螺旋菌，芽孢杆菌和Chlorobi。因此，泰国海洋微生物群数据库有助于更好地了解我们的全球海洋微生物群和微生物代谢潜力。这里，泰国和相对较近的微生物群数据库的全球海洋站点之间的微生物代谢潜能构成了相似的功能，但在统计上却不同。我们的研究首次对泰国东南部安达曼海的上，上层海平面进行了初步的海洋微生物组比较。