Seashore habitats are located between terrestrial and marine ecosystems, which are a hotspot for anthropogenic impacts. Shenzhen is one of the most developed cities in south China, but the microbial functions of its coastal ecosystems remain poorly understood. The study applied 16S rRNA gene sequencing methods to identify the bacterial community from twenty sites of Shenzhen inshore waters. The microbial structure of the samples between eastern Shenzhen and western Shenzhen seashores is notably different, suggesting the spatial variability. Proteobacteria, Cyanobacteria, Actinobacteria, and Bacteroidetes were dominant phyla in the community, and the relative abundance of Bacteroidetes was significantly higher in eastern seashores. Specifically, samples from western Shenzhen contained much more Prochlorococcus, while Synechococcus was more abundant in eastern samples. Moreover, the metabolism of terpenoids and polyketides, and transport and catabolism were significantly more abundant in eastern samples, while antibiotic-resistant pathways were enriched in western samples. The results have important significance to understand bacterial ecosystem of coastal water and promote water quality management and protection activity in Shenzhen. This study can also help developing an optimal strategy for the green economy development and the policy planning of Guangdong-Hong Kong-Macao Greater Bay Area.

海滨栖息地位于陆地和海洋生态系统之间，是人为影响的热点。深圳是华南最发达的城市之一，但对其沿海生态系统的微生物功能仍知之甚少。该研究应用16S rRNA基因测序方法对深圳近海20个地点的细菌群落进行了鉴定。深圳东部和深圳西部沿海样本的微生物结构存在显着差异，表明存在空间变异性。Proteobacteria、Cyanobacteria、Actinobacteria和Bacteroidetes是群落中的优势门，Bacteroidetes的相对丰度东部沿海地区明显偏高。具体来说，深圳西部样品中原绿球藻含量更高，而东部样品中聚球藻含量更高。此外，东部样品中萜类化合物和聚酮化合物的代谢以及运输和分解代谢显着丰富，而西部样品中抗生素抗性途径丰富。研究结果对了解近岸水域细菌生态系统，促进深圳市水质管理与保护活动具有重要意义。本研究也有助于制定绿色经济发展的最佳战略和粤港澳大湾区的政策规划。