Bacillus improves the health and growth performance of Penaeus vannamei in an intensive nursery without water exchange

The objective of this study was to investigate the effect of a bioremediator on the production of juveniles (Penaeus vannamei) in intensive nursery systems, on the zootechnical performance, water quality and health status of the animals. Two groups were used (control and bioremediation). In the treatment with bioremediator, 0.1g.m⁻³ of the product Arkhon Aqua® (Bacillus subtilis, B. licheniformes, B. amyloliquefaciens, B. megaterium) was applied daily, at concentrations of 1.0 x 10⁻¹¹ UFC.g⁻¹). The physical-chemical parameters of the water were monitored; health status, through presumptive analyzes evaluating the shape and filling of the hepatopancreas tubules and the prevalence of dirt on the gills and quantified Vibrios spp. and total heterotrophic bacteria in water and juveniles. The bioremediator provided a significant reduction in the volume of total dissolved solids (36.9%), settleable solids (68.9%) and the presence of organic matter in the gills (50.0%), in addition to showing an increase in the final mean weight (28.3%) and yield (20.0%), in addition to reducing feed conversion (18.7%) than control group. The bioremediation demonstrated a higher concentration of Vibrios spp. in water, however, it did not influence the concentration of Vibrios spp. in juveniles. It is concluded that the bioremediator improved the culture water, consequently enhancing the zootechnical performance of the shrimp.