Successional changes of microalgae community in response to commercial probiotics in the intensive shrimp (Litopenaeus vannamei Boone) culture systems

Probiotics with antimicrobial properties can be used to regulate the microflora, control the pathogenic algae, and improve the mineralization of organic substances in the aquaculture environment. However, the efficacy of the probiotics on the succession of microalgae in the shrimp (Litopenaeus vannamei Boone) culture remains inadequate. A field experiment in mesocosm was performed to explore the impacts of probiotics on the succession of microalgae and nutrient enrichment of the shrimp culture systems. The enormous changes in the microalgae community structure (MCSs) was significantly influenced by probiotic colonization. Probiotics shifted MCSs into three seral phases and their sequential replacements of the dominant taxa were identified by cluster analysis. Moreover, each seral stage of the keystone species turnover in MCSs represents distinguished ecological functions. At the final seral stage probiotics significantly constrained the succession of the most competitive species of Cyanobacteria (Oscillatoria and Anabaena) which was disagreed with the normal seral stage. Similarly, the probiotics increased and maintained the sequel of the nutritional value of Nannochloropsis and Chlorella from Chlorophyta and Oocystics and Navicula from the Bacillariophyta. Furthermore, the probiotic-based ponds had a higher shrimp survival rate compared to the control. Nutrients concentration of nitrite (NO2−) and nitrate (NO3−) were lower in treatments than in the control. Consequently, chemical oxygen demand (COD), nitrite (NO2−), water temperature (WT), total ammonium nitrogen (TAN) and dissolved oxygen (DO) were strongly explanatory variables controlled the sequel of MCSs. These findings imply that the probiotics have potential in the succession, redistribution of beneficial microalgae, inhibit the growth of harmful Cyanobacteria and sustain the MCSs stability in shrimp aquaculture activities.