Temperature rise alters phosphorus pool in corpse polluted water by inhibiting organic phosphorus mineralization and phosphorus transports

Abstract

Phosphorus (P) cycle is an important component of biogeochemical cycle and plays a crucial role in nutritional cycle of aquatic ecosystems. However, the responses of microbial P cycling genes and water P pool to temperature and corpse decay remains unclear. Here, we explored the changes of P cycling genes in Yellow River with animal carcasses decay under five temperature gradients (23, 26, 29, 32 and 35 °C) through metagenomic sequencing. Temperature may predict about 37% of P cycling genes in water polluted by corpse, among which phoR (slope = 31.60), ugpB (slope = −27.66) and ppa (slope = 12.45) were most sensitive to the rising temperature. Besides, elevating temperature inhibited organic P mineralization and P transport processes in water with the addition of corpse. The phyla harboring P cycling genes mainly included Proteobacteria, Actinobacteria and Bacteroidetes. Notably, temperature rise directly reduced the total organic P concentration, and increased the total inorganic P concentration by inhibiting organic P mineralization and P transports pathways. However, corpse decay increased the concentration of total organic P and inorganic P, and enriched P transports and P regulatory processes. Corpse decay led to more complex networks of P cycling genes, and enhanced the competition among genes. The elucidation of the responses of P cycling genes to temperature and corpse decay in our study is significant for artificial management and removal of phosphorus from the water polluted by animal corpse under global warming.