Characterization of <i>Vibrio</i> sp. strain <scp>AB15</scp> and <scp> <i>Pseudomonas fluorescens</i> </scp> strain <scp>NB14</scp> from the biofloc of shrimp culture ponds capable of high ammonia and nitrite removal efficiency

The development of intensive aquaculture industry has aggravated the dangers ammonia and nitrite in aquatic ecosystems. Probiotics have been widely used to maintain improve water quality by removal aquaculture. In this study, two facultative anaerobic strains AB15 NB14, capable efficient removal, were isolated from biofloc, which acts as a natural micro-flora storeroom shrimp culture ponds, identified Vibrio sp. Pseudomonas fluorescens, respectively. efficiency NB14 was 96.8 89.6%, optimum conditions follows: temperature (25°C vs. 30°C), salinity (25‰ both), initial pH (7.5 8.0), C/N ratio (15 10). had great performance on inhibiting common pathogens (Vibrio harveyi, splendidus, anguillarum) at concentrations 105–108 CFU/mL. Biosecurity assessment indicated that both harmless for survival could be beneficial growth immune enhancement Litopenaeus vannamei. All results demonstrate high promise future applications removing maintaining biosecurity ponds.