Acute Toxicity of NH4Cl to Tambra Fish (Tor Tambroides) Fry

Ammonia is one of the nutrient wastes products which can be toxic to all vertebrates, including fish. Usually, ammonia toxicity is expressed as Total Ammonia Nitrogen (TAN, mgN/L). Tambra fish (Tor tambroides) is freshwater fish with important economic value in some areas in Indonesia. According to overfishing and forest degradation, the fish has become threatened. This research aimed to calculate the LC50 value of ammonia to Tambra fish (Tor tambroides) and estimate NOEC, LOEC, and MATC values of ammonia to Tambra fish (Tor tambroides). This study was conducted using the static test method with two steps. The first stage is a preliminary test, where the preliminary test is observed for 24 hours With five concentrations excluding control. Whereas in the second stage that is carried out, observation for 96 hours with four concentrations excluding control. The Probit test is Performed to obtain LC50 value results, then proceed with ammonia analysis using the Salicylate Test Kit method. The results showed that ammonia had acute toxicity with LC50-96 hour value of NH4Cl against Tambra fish fry (Tor tambroides) in the amount of 354.615 mg/L. Ammonia caused acute toxicity to Tambra fish fry (Tor tambroides).The LC50-96 hour value was 354.615 mg/L in the form of Total Ammonia Nitrogen (TAN) or it was equivalent to un-ionized Ammonia (NH3) of 9.8937 mg/L, while values of the Lowest Observed Effect Concentration (LOEC) and No Observed Effect Concentration (NOEC) of ammonia on Tambra fish (Tor tambroides) were 578.24 mg/L and 280.18 mg/L, respectively.

High NH4+/NO3− Ratio Inhibits the Growth and Nitrogen Uptake of Chinese Kale at the Late Growth Stage by Ammonia Toxicity

The aim of this study was to determine the effects of various NH4+/NO3− ratios in a nutrient solution on the growth and nitrogen uptake of Chinese kale under hydroponic conditions. The four NH4+/NO3− ratios in the nutrient solution were CK (0/100), T1 (10/90), T2 (25/75), and T3 (50/50). An appropriate NH4+/NO3− ratio (10/90, 25/75) promoted the growth of Chinese kale. T2 produced the highest fresh and dry weight among treatments, and all indices of seedling root growth were the highest under T2. A high NH4+/NO3− ratio (50/50) promoted the growth of Chinese kale seedlings at the early stage but inhibited growth at the late growth stage. At harvest, the nutrient solution showed acidity. The pH value was the lowest in T3, whereas NH4+ and NH4+/NO3− ratios were the highest, which caused ammonium toxicity. Total N accumulation and N use efficiency were the highest in T2, and total N accumulation was the lowest in T3. Principal component analysis showed that T2 considerably promoted growth and N absorption of Chinese kale, whereas T3 had a remarkable effect on the pH value. These findings suggest that an appropriate increase in NH4+ promotes the growth and nutrient uptake of Chinese kale by maintaining the pH value and NH4+/NO3− ratios of the nutrient solution, whereas excessive addition of NH4+ may induce rhizosphere acidification and ammonia toxicity, inhibiting plant growth.

The Role of Nrf2 Transcription Factor and Sp1-Nrf2 Protein Complex in Glutamine Transporter SN1 Regulation in Mouse Cortical Astrocytes Exposed to Ammonia

Ammonia toxicity in the brain primarily affects astrocytes via a mechanism in which oxidative stress (OS), is coupled to the imbalance between glutamatergic and GABAergic transmission. Ammonia also downregulates the astrocytic N system transporter SN1 that controls glutamine supply from astrocytes to neurons for the replenishment of both neurotransmitters. Here, we tested the hypothesis that activation of Nrf2 is the process that links ammonia-induced OS formation in astrocytes to downregulation and inactivation of SN1 and that it may involve the formation of a complex between Nrf2 and Sp1. Treatment of cultured cortical mouse astrocytes with ammonia (5 mM NH4Cl for 24 h) evoked Nrf2 nuclear translocation, increased its activity in a p38 MAPK pathway-dependent manner, and enhanced Nrf2 binding to Slc38a3 promoter. Nrf2 silencing increased SN1 mRNA and protein level without influencing astrocytic [3H]glutamine transport. Ammonia decreased SN1 expression in Nrf2 siRNA treated astrocytes and reduced [3H]glutamine uptake. In addition, while Nrf2 formed a complex with Sp1 in ammonia-treated astrocytes less efficiently than in control cells, treatment of astrocytes with hybrid-mode inactivated Sp1-Nrf2 complex (Nrf2 silencing + pharmacological inhibition of Sp1) did not affect SN1 protein level in ammonia-treated astrocytes. In summary, the results document that SN1 transporter dysregulation by ammonia in astrocytes involves activation of Nrf2 but does not require the formation of the Sp1-Nrf2 complex.

EFFECT OF ZEOLITE ON AMMONIA TOXICITY AND ON SOME OF BLOOD PARAMETERS IN COMMON CARP CYPRINUS CARPIO

The current study was undertaken to investigate the efficacy of different levels of natural zeolite on ammonia and on some of blood parameters of Cyprinus carpio. The experimental treatments included adding zeolite as stones placed in the bottom of aquarium : Control( 0 zeolite); T1, T2 and T3 zeolite stones were added in the water at concentrations of 6 , 8 and 10 mg/l respectively. Results of ammonia concentrations ranged between 0.17 – 1.25 mg/l in T2 and in control treatment respectively from the first week up to fourth week. In T1 values of ammonia were 0.18mg/l in first week with gradually increase from 0.48 mg/l in second week and 0.78mg/l in the third week, then decline to 0.66mg/l in the fourth week, same condition was found in T2 and T3. In the second week level of ammonia was increased highly in control treatment , compared to other treatments. In the third week the increasing level of ammonia was continuously especially in control treatment followed by T3,T2 and T1 respectively. In the fourth week the level of ammonia recorded 1.25 mg/l , but decrease in T3 which reached 0.62mg/l. No mortalities were recorded in the first week for all treatments during the experimental period, while, in the fourth week in control reached up to 100% mortality compared with the T1,T2 and T3 which recorded 50, 33.33 and 33.33% respectively . Generally results showed that ammonia and mortality were decreased with increased zeolite level in water. Results of RBC ranged between 2.05 – 2.33 ×106/mm3 in control treatment and T3 respectively .The highest number of WBC in the control treatment which recorded 24.55 ×103/mm3 , while the lowest number was document in T2 (23.01×103/mm3) . The highest PCV(%) was registered inT3(26.50%). For Hb content the highest mean was reported in T3 (9.70g/dl). T3 can be considered as better treatment which contained zeolite in blood parameters followed by T2.

The Effect of Ammonia Toxicity on Methane Production of a Full-Scale Biogas Plant—An Estimation Method

Ammonia accumulation in biogas plants reactors is becoming more frequently encountered, resulting in reduced methane (CH4) production. Ammonia toxicity occurs when N-rich substrates represent a significant part of the biogas plant’s feedstock. The aim of this study was to develop an estimation method for the effect of ammonia toxicity on the CH4 production of biogas plants. Two periods where a biogas plant operated at 3200 mg·L−1 (1st period) and 4400 mg·L−1 (2nd period) of ammonium nitrogen (NH4+–N) were examined. Biomethane potentials (BMPs) of the individual substrates collected during these periods and of the mixture of substrates with the weight ratio used by the biogas plant under different ammonia levels (2000–5200 mg·L−1 NH4+–N) were determined. CH4 production calculated from the substrates’ BMPs and the quantities used of each substrate by the biogas plant was compared with actual CH4 production on-site. Biogas plant’s CH4 production was 9.9% lower in the 1st and 20.3% in the 2nd period in comparison with the BMP calculated CH4 production, of which 3% and 14% was due to ammonia toxicity, respectively. BMPs of the mixtures showed that the actual CH4 reduction rate of the biogas plant could be approximately estimated by the ammonia concentrations levels.