Effects of consecutive culture of Penaeus vannamei on phosphorus transformation and microbial community in sediment.

Abstract

Phosphorus (P) is highly related to water quality during shrimp culture. Recognizing P transformation in pond-based cultures is crucial for sustainable and healthy aquaculture. However, P transformation remains unclear in the sediment of Penaeus vannamei cultures, although commercial species have been pervasive worldwide. To determine P transformation, samples with different culture years were collected from Zhejiang province, China. Sequential chemical extraction was applied to reveal the composition of inorganic P, while phosphatase activity was used to evaluate the biomineralization of organic P. The results indicated that the consecutive culture of Penaeus vannamei promoted the dissolution potential of sedimentary P. This was attributed to anoxic iron reduction that increased the formation of loosely bound P and Fe (II)-P. However, this phenomenon was dominated by biomineralization, which transformed the organic P to inorganic P. The results suggested that consecutive culture changed the microbial community structure in the sediment as well as the gene functions. The Shannon Wiener index showed that increasing the culture duration significantly decreased the stability of the microbial community. Overall, this study suggests that long-term consecutive culture of Penaeus vannamei may increase the P release potential of the sediment, which increases the risk of pond eutrophication.