Bacterial diversity in phosphorus immobilization of the South China Sea

ABSTRACT

Marine bacteria play indispensable roles in the phosphorus (P) cycle, primarily responsible for P assimilation and remineralization. The aim of this study was to determine diversity of marine aerobic bacteria from the South China Sea capable of P immobilization. Highly efficient P immobilized genera reached 87.72% of all genera, which were mainly distributed in epipelagic seawater zone and semi-deep sediment zone. Accumulated P in extracellular polymeric substances (EPS) accounted for about 70% of immobilized P of representative bacteria. The sum of bioavailable P (non-apatite inorganic phosphorus, organic phosphorus) amounted to more than 90% of total P in representative bacteria, and orthophosphate monoester was identified as the only extracellular P species. Marine bacteria which participated in P cycle were general, not specific genus. EPS of marine bacteria played an important role in P immobilization, and accumulated P species were bioavailable. Our results may provide a better insight for understanding roles of marine bacteria in P cycle.

GRAPHICAL ABSTRACT

KEYWORDS:

• Diversity
• marine bacteria
• phosphorus immobilization
• extracellular polymeric substances, phosphorus species

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key R&D Program of China [grant number 2018YFC0310704]; the Major Program of Shandong Province Natural Science Foundation [grant number ZR2018ZB0211]; the Major Program of Shandong Province Technological Innovation Project [grant number 2018CXGC0307]; the Natural Science Foundation of Shandong Province [grant number ZR2017MEE024].