Combined Effects Of Ammonia Research Articles

Effects of ammonia and roxithromycin exposure on skin mucus microbiota composition and immune response of juvenile yellow catfish Pelteobagrus fulvidraco

As an inevitable factor in aquaculture, ammonia plays a critical role in macrolide antibiotic resistance, leading to accumulating of antibiotic-resistant bacteria in fish skin mucus. In this study, four experimental groups were implemented to test the effects of ammonia alone or in combination with roxithromycin for 28 days on skin mucus microbial composition and the immune response of yellow catfish: CON (control), AN (50.00 mg L−1 total ammonia nitrogen, TA-N), ROX (100 μg L−1 roxithromycin), and HR (50.00 mg L−1 TA-N, 100 μg L−1 ROX). This study demonstrated that ammonia or roxithromycin exposure resulted in increased plasma ammonia content and decreased total antioxidant capacity. Compared with AN group, the combined exposure of ammonia and roxithromycin inhibited the skin mucus immune response. Microbial composition analysis showed that combined exposure of ammonia and roxithromycin had no significant effect on skin mucus α-diversity as compared with CON group. The abundance of Cetobacterium, Rhizobiales_Incertae_Sedis_uncultured and Acinetobacter was increased significantly with the combined effect of ammonia and roxithromycin, these bacteria may be potentially antibiotic-resistant. As compared with CON group, the combined exposure of ammonia and roxithromycin did not affect skin goblet cell counts. This study suggests that combined exposure to ammonia and ROX increases the risk of the emergence of antibiotic-resistant bacteria.

Response of antioxidation and immunity to combined influences of ammonia and temperature in red swamp crayfish (Procambarus clarkii)

As important environmental factors, ammonia and temperature have important effects on aquatic crustaceans. The combined effects of ammonia and temperature on the anti-oxidation and immunity of Procambarus clarkii were examined using the factorial experimental design in this study. A total of 9 ammonia-temperature combinations (3 replicates for each combination) were set up with each factor having 3 regimes. The results showed that most indicators varied quadratically with ammonia concentration and temperature in the ranges of the two factors. The interaction between ammonia and temperature was significant on most indicators, demonstrating that ammonia and temperature affected the anti-oxidation and immunity of P. clarkii in a combined manner. Ammonia accumulation and oxidative stress occurred more likely under the combined influences of ammonia and temperature. The enzymatic activities and gene expressions that are closely related to the antioxidation and immunity were easier to be activated or inhibited due to presence of the interaction between ammonia and temperature. This study provides new insights into the mechanism for adaption of P. clarkii to the combined impacts of ammonia and temperature. The results contribute to increased immunity and resistance of this commercially important species against diseases through improvement of multiple culture conditions.

Biomineralization of Carbonates Induced by Mucilaginibacter gossypii HFF1: Significant Role of Biochemical Parameters

Although the precipitation of carbonate minerals induced by various bacteria is widely studied, the changes in the biochemical parameters, and their significant role in the biomineralization processes, still need further exploration. In this study, Mucilaginibacter gossypii HFF1 was isolated, identified, and used to induce carbonate minerals at various Mg/Ca ratios. The biochemical parameters were determined in order to explore the biomineralization mechanisms, including cell concentration, pH, ammonia, carbonic anhydrase activity, and alkaline phosphatase activity. The characteristics of extracellular minerals and intracellular inclusions were both analyzed. In addition, the amino acid composition of the extracellular polymeric substance was also tested. Results show that the biochemical parameters provide an alkaline environment for precipitation, due to the combined effect of ammonia, carbonic anhydrase, and alkaline phosphatase. Biotic minerals are characterized by preferred orientation, specific shape, and better crystalline and better thermal stability, indicating their biogenesis. Most of the amino acids in the extracellular polymeric substance are negatived charged, and facilitate the binding of magnesium and calcium ions. The particles with weak crystalline structure in the EPS prove that it acts as a nucleation site. Intracellular analyses prove the presence of the intracellular amorphous inclusions. Our results suggest that the changes in the biochemical parameters caused by bacteria are beneficial to biomineralization, and play a necessary role in its process. This offers new insight into understanding the biomineralization mechanism of the bacteria HFF1.

Combined effect of ammonia and nitrite for Macrobrachium amazonicum (Heller, 1862) and Macrobrachium rosenbergii (De man, 1879) post-larvae

This study aimed to determine the median lethal concentration (LC50) of total ammonia and nitrite's combined effect for Macrobrachium amazonicum and Macrobrachium rosenbergii post-larvae at 96 h of exposure and then present their safety levels. In the trial 640 post-larvae of M. amazonicum (2.2 ± 0.2 cm and 0.08 ± 0.02 g) and 640 post-larvae of M. rosenbergii (2.2 ± 0.3 cm and 0.07 ± 0.02 g) were distributed in a completely randomized 4 × 4 factorial design, consisting of four concentrations of total ammonia (0, 11, 22 and 44 mg.L−1 NH4Cl) and four concentrations of nitrite (0, 0.5, 1.5 and 3 mg.L−1 NaNO2) with four replicates for each treatment. All total ammonia concentrations were combined with all nitrite concentrations. According to the LC50 96 h obtained from the combined compounds, the safety levels for both species were determined, being 2.39 mg.L−1 of total ammonia and 0.14 mg.L−1 of nitrite for M. amazonicum. In contrast, for M. rosenbergii, the value was 2.50 mg.L−1 of total ammonia and 0.15 mg.L−1 of nitrite. Moreover, the additivity index demonstrated that, when combined, the compounds have an antagonistic effect on prawns. Additionally, considering the results obtained for both species, it was concluded that M. rosenbergii is more resistant to the combined effect of total ammonia and nitrite than M. amazonicum under the experimental conditions evaluated.

Single and combined effects of ammonia and nitrite on common carp, Cyprinus carpio: Toxicity, hematological parameters, antioxidant defenses, acetylcholinesterase, and acid phosphatase activities

Ammonia and nitrite are two of the most toxic substances for ecosystems and aquatic organisms. The present study aimed to investigate the single and combined effects of ammonia and nitrite on hematological parameters, antioxidant defenses, acetylcholinesterase, and acid phosphatase activities in common carp. First, LC50–96 h of ammonia and nitrite in common carp were determined. Second, fish were exposed to four experimental groups contained control, 30% LC50–96 h ammonia, 30% LC50–96 h nitrite, and 30% LC50–96 h ammonia+30% LC50–96 h nitrite for 96 h. WBCs were significantly elevated in fish exposed to 30% LC50–96 h ammonia and nitrite in all treated groups compared to the control group. RBCs and hemoglobin amount in all exposed groups were significantly decreased compared to the control after 96 h of exposer. Moreover, a significant decrease was observed in the hematocrit level in ammonia and ammonia+nitrite groups compared to the control group. Furthermore, exposure to 30% LC50–96 h ammonia and nitrite resulted in a significant alteration in blood indices (MCV, MCH, and MCHC) after 96 h. The serum CAT activity was significantly higher in the exposed groups than the control group after 96 h. The serum MDA activity was considerably higher in fish exposed to nitrite compared to the control group. Levels of serum total antioxidant were strongly lower in all exposed groups after 96 h. Moreover, the serum AChE activity reduced considerably in all groups compared with the control group. Serum ACP levels were significantly elevated in all exposed groups compared to the control group. Overall, our findings suggest that the single and combined presence of nitrite and ammonia in water can cause adverse effects in some blood indices, serum AChE, ACP activities, and antioxidant defenses in common carp.

Toxicity of ammonia, nitrite and nitrate to Litopenaeus vannamei juveniles in low-salinity water in single and ternary exposure experiments and their environmental implications

Information on toxicity of nitrogen compounds for Litopenaeus vannamei in coastal ecosystems and culture under low salinity is scarce. Acute toxicity trials were conducted in L. vannamei to determine the single and combined effects of ammonia, nitrite and nitrate at a salinity of 3 g/L. The 96 h-LC50 was 29.0 mg/L for total ammonia nitrogen (TAN); 10.6 mg/L for nitrogen as nitrite (NO2−-N); and 900 mg/L for nitrogen as nitrate (NO3−-N). The joint effects of ammonia, nitrite and nitrate exposure were antagonistic at 24–72 h; and additive from 72 to 96 h. The proposed safety levels of single exposure to TAN, NO2−-N and NO3−-N for L. vannamei are 1.45, 0.53 and 45.0 mg/L, respectively. When in mixture, the proposed level of TAN/NO2−-N/NO3−-N is 0.05 TU (Toxicity Unit) corresponding to 0.48, 0.08 and 14.6 mg/L of TAN, NO2−-N and NO3−-N, respectively.

Acute Toxicity of Ammonia and Nitrite to Pacific White Shrimp, Litopenaeus vannamei, at Low Salinities

This study was conducted to determine the individual and combined effects of ammonia and nitrite on Litopenaeus vannamei postlarvae (25- to 45-d old PL) at 10 ppt salinity, 28 C, and a pH of 7.8. The independent variables were salinity, total ammonia nitrogen (TAN), and nitrite nitrogen (NO2-N). The TAN experiments were conducted at 18 and 10 ppt salinity, and the NO2-N test was conducted at 10 ppt salinity. Combined TAN and NO2 tests were also conducted at 10 ppt salinity. The 48-h lethal concentration (LC50) values for TAN at 18 ppt salinity, TAN at 10 ppt salinity, and NO2-N at 10 ppt were observed to be 42.92, 39.72 (2.26 and 2.09 mg/L unionized ammonia-N), and 153.75 mg/L, respectively. When NO2-N was adjusted to the lowest observed effect concentration (LOEC) level and TAN concentrations were varied, synergistic effects were observed, with a 48-h LC50 calculated to be 28.2 mg/L TAN (1.49 mg/L unionized ammonia-N). However, when the ammonia level was adjusted to the LOEC and nitrite was varied, antagonistic effects were observed with a 48-h LC50 calculated to be 163.3 mg/L NO2-N. This study demonstrated that the combined toxic effects of ammonia and nitrite need to be considered when developing standard operating procedures for shrimp culture.

Joint Action of Ammonia and Nitrite on Tiger Prawn Penaeus monodon Postlarvae

AbstractTiger prawn Penaeus monodon postlarvae (PL6) were exposed to a mixture of ammonia and nitrite by the static renewal method. When the toxicity ratio of the ammonia‐nitrite mixture was 1:1, the 48 h, 72 h and 96 h LC50 values were 2.20, 1.43 and 0.84 toxicity units which were equivalent to 12.66 mg/L ammonia‐N (0.60 mg/L NH3‐N) plus 14.91 mg/L nitrite‐N, 8.23 mg/L ammonia‐N (0.39 mg/L NH3‐N) plus 9.69 mg/L nitrite‐N, and 4.83 mg/L ammonia‐N (0.23 mg/ L NH3‐N) plus 5.69 mg/L nitrite‐N. When the toxicity ratio of the ammonia‐nitrite mixture was 51, the 48 h, 72 h and 96 h LC50 values were 2.50, 1.56 and 0.85 toxicity units which were equivalent to 23.98 mg/L ammonia‐N (1.13 mg/L NH3‐N) plus 5.65 mg/L nitrite‐N; 14.96 mg/L ammonia‐N (0.71 mg/L NH3‐N) plus 3.52 mg/L nitrite‐N, and 8.15 mg/L ammonia‐N (0.39 mg/ L NH, N) plus 1.92 mg/L nitrite‐N. A mixture of ammonia and nitrite exerted greater toxicity than high concentrations of either ammonia or nitrite alone. The combined effect of ammonia and nitrite on P. monodon postlarvae was antagonistic for 48 and 72 hours exposure, but synergistic after 96 hours exposure.