An investigation on the immunoassays of an ammonia nitrogen-degrading bacterial strain in aquatic water

摘要

Probiotics have widely been used to maintain and improve water quality condition by removal of ammonia nitrogen in aquaculture. To determine the relationship between the efficiency and quantity of probiotics, the method for detection and quantification and safety of the shrimp Litopenaeus vannamei were explored using an ammonia nitrogen-degrading bacterial strain Vibrio alginolyticus. The polyclonal antibodies (Pabs) for immunosorbent assay (indirect ELISA) were used to quantify the probiotics. The results showed that: (1) the ammonia nitrogen degradation rate of the candidate strain was 67.49%; (2) no significant differences in the accumulative mortalities of the shrimp between the treatments and the control (P > 0.05); and (3) for the use of indirect ELISA test, detection limit is 10(4) CFU ml(-1) and an acceptable linear correlation (R-2 = 0.95) was obtained with the range of quantification between 10(4) and 10(8) CFU mL(-1) of the specific target bacteria. The results suggest that the indirect ELISA is a very rapid and sensitive technique for detecting V. alginolyticus in the cultured water.