High-throughput sequencing reveals the spatial distribution variability of microbial community in coastal waters in Shenzhen.

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.