Identification and real-time qPCR quantification of a nitrite-N degrading bacterial strain in aquatic water

Abstract

Biological nitrogen removal technology using microbe is an efficient process for nitrogen removal from aquatic water. To determine the key of efficient application on how the effect of probiotics lasting, a nitrite nitrogen (nitrite‐N) degrading 8DO17 strain Pseudomonas was screened and a method for quantification was explored. Real‐time qPCR assays based on the 16S rRNA genes (16S rDNA) were used to quantify the probiotics. The results showed that (i) the nitrite‐N degradation rate of the 8DO17 strain was 99%; (ii) a wide spectrum of pH (7.0–9.0) and concentration of nitrite‐N (0.5–10 mg L−1) and the highest rate of nitrite‐N degradation near to 100% under optimum conditions (35°C, salinity 30, pH 7.5) was explored; (iii) no significant differences were found in the survival, total haemocyte count, antibacterial activities and bacteriolytic activity of the shrimp between the treatments and the control (P > 0.05); (iv) for the use of real‐time PCR based on 16S rDNA test, detection limit is 103 DNA copies and an excellent correlation coefficients (R² = 0.999) was obtained; and (v) in the application of real‐time PCR assay in four nitrite‐N degrading samples, highly significant positive correlation relation (P < 0.01) was found between log copy number of 16S rDNA and the rate of nitrite‐N degradation. The results suggest the real‐time PCR is a very rapid and sensitive technique for monitoring the dynamic changes and assessing the effect in practical application of the 8DO17 strain in aquatic water.

The dynamics of bacterial community in a polyculture aquaculture system of Penaeus chinensis , Rhopilema esculenta and Sinonovacula constricta

“…These isolates can accelerate the cycle of nutritive materials and purify the water quality in aquaculture environments (Akhter, Wu, Memon, & Mohsin, 2). Other microorganisms in aquaculture systems can transform the damaging substances for cultural species, such as ammonia, nitrite and hydrogen sulphide, into low‐toxic substances (Su, Li, Pan, & Xue, ; Su, Li, Pan, & Zhang, ). Moreover, various pathogens have been observed from aquaculture environment, which resulted in the death of breeding species and caused enormous losses (Li, Yan, Li, Xu, & An, ; Munang'Andu, ).…”

Bacteria in biofloc technology aquaculture systems: roles and mediating factors

“…The estimation of AOB using RT‐PCR was found to yield results greater in magnitude than culture‐dependent methods 70,71 . RT‐PCR has been used as a rapid and sensitive technique to quantify probiotic effects in BFT aquaculture systems 72 . Some primers used for determining functional bacterial genes involved in ammonium conversion in wastewater treatment systems are presented in Table 2.…”