Combined and Individual Effects of Chlorella sp. and Bacterial Probiotics in Biofloc Systems for White Shrimp (Penaeus vannamei)

Abstract

Simple Summary Biofloc technology is an increasingly used strategy for more sustainable shrimp farming. However, new approaches are still needed to improve water quality and animal health. In this study, we evaluated the effects of the green microalga Chlorella sp. and a commercial probiotic, applied separately or in combination, in a biofloc system for Pacific white shrimp culture. A single inoculation of Chlorella sp. maintained a stable population for approximately 40 days. The microalga contributed to nutrient bioremediation in water and increased the nutritional value of the biofloc, a natural food source for shrimp. However, shrimp reared in microalgae treatments showed lower growth performance and survival, which may have been associated with prolonged exposure to the elevated nitrate levels associated with microalgae inoculation. In contrast, the probiotic and control treatments showed comparable zootechnical performance, and both outperformed the microalgae treatments. Probiotic supplementation also reduced the abundance of Flavobacteriaceae, a bacterial family proposed as a bioindicator of White Feces Syndrome (WFS). Overall, these findings suggest that microalgae have considerable potential to improve the sustainability of biofloc systems, provided that the inoculation protocol should be optimized, and confirm the probiotic as an effective strategy to enhance shrimp productivity and health.