Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine,cyanuric acid and biuret in industrial wastewater

An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL^?1, 265.6 and 1805.2 µg mL^?1 and 1.85 and 16.12 µg mL^?1, respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples, however, was degraded up to T4 treatments and was persistent in the T5 treatment. Probably, accumulation of this metabolite inhibited atrazine/cyanuric acid degradation by the enrichment culture in undiluted wastewater.     

Degradation of atrazine using solar driven fenton-like advanced oxidation processes

Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was degraded using cobalt-peroximonosulfate (Co/PMS) advanced oxidation process (AOP). Three Co concentrations (0.00, 0.25 and 0.50 mM) and five peroximonosulfate (PMS) concentrations (0, 5, 8, 16 and 32 mM) were tested. Maximum degradation reached was 88% using dark Co/PMS in 126 minutes when 0.25 mM of cobalt and 32 mM of PMS were used. Complete atrazine degradation was achieved when the samples were irradiated by the sun under the same experimental conditions described. Tests for identification of intermediate products allowed identification and quantification of deethylatrazine in both dark and radiated conditions. Kinetic data for both processes was calculated fitting a pseudo-first order reaction rate approach to the experimental data. Having kinetic parameters enabled comparison between both conditions. It was found that the kinetic approach describes data behavior appropriately (R² ≥ 0.95). Pseudo-kinetic constants determined for both Co/PMS processes, show k value of 10^?4 for Co/PMS and a k value of 10^?3 for Co/PMS/ultraviolet (UV). This means, that, with the same Co/PMS concentrations, UV light increases the reaction rate by around one order of magnitude than performing the reaction under dark conditions.     

Alginate immobilized enrichment culture for atrazine degradation in soil and water system

An atrazine degrading enrichment culture, a consortium of bacteria of genus Bacillus along with Pseudomonas and Burkholderia, was immobilized in sodium alginate and was used to study atrazine degradation in mineral salts medium (MSM), soil and wastewater effluent. Sodium alginate immobilized consortium, when stored at room temperature (24 ± 5°C), was effective in degrading atrazine in MSM up to 90 days of storage. The survival of bacteria in alginate beads, based on colony formation unit (CFU) counts, suggested survival up to 90 days and population counts decreased to 1/5^th on 120 days. Comparison of atrazine degrading ability of the freely suspended enrichment culture and immobilized culture suggested that the immobilized culture took longer time for complete degradation of atrazine as a lag phase of 2 days was observed in the MSM inoculated with alginate immobilized culture. The free cells resulted in complete degradation of atrazine within 6 days, while immobilized cells took 10 days for 100% atrazine degradation. Further, immobilized cultures were able to degrade atrazine in soil and wastewater effluent. Alginate beads were stable and effective in degrading atrazine till 3rd transfer and disintegrated thereafter. The study suggested that immobilized enrichment culture, due to its better storage and application, can be used to degrade atrazine in soil water system.     

2种低温等离子体降解土壤中乙草胺和阿特拉津

研究了沿面放电和平板介质阻挡放电处理土壤中阿特拉津和乙草胺的效果。主要以沙子作为研究体系,考察了水分、氧气流速、活性炭和过硫酸钠对降解的影响。结果表明:沿面放电装置和平板介质阻挡放电都能高效降解沙子中的乙草胺、阿特拉津;水分和氧气流速对降解的影响较大,在一定限度内,它们的增加能迅速提高降解效果,但过多的水分反而会抑制污染物的降解。活性炭显著抑制沿面放电降解乙草胺和阿特拉津效果,过硫酸钠与沿面放电、平板介质阻挡放电联用方法没有表现出协同效应。     

莠去津对土壤过氧化氢酶活性的影响研究

研究了除草剂莠去津对土壤过氧化氢酶活性的影响。试验结果表明,莠去津浓度不同对土壤过氧化氢酶活性影响会不同,随着浓度的升高,对过氧化氢酶活性激活作用有所增强,莠去津对离体过氧化氢酶有一定的激活;336nm处的相对荧光强度不断减弱,酶分子的构象发生了变化．过氧化氢酶分子渐趋紧密。莠去津对过氧化氢酶荧光的猝灭作用主要是由于静态猝灭引起的。     

Evaluation of flow injection analysis method with spectrophotometric detection for the determination of atrazine in soil extracts

A method for determining atrazine in soil extracts was evaluated by flow injection analysis with spectrophotometric detection. The method is based on the reaction of atrazine with pyridine in an acid medium followed by the reaction with NaOH and sulfanilic acid. Several analytical conditions were previously studied and optimized. Under the best conditions of analysis, the limits of detection and quantification were 0.15 and 0.45 mg L^?1, respectively, for a linear response between 0.50 and 2.50 mg L^?1, and a sampling throughput of 21 determinations per hour. Using the standard addition method, the maximum relative standard deviation of 17% and recovery values between 80 and 100% were observed for three extracts from soil samples with different composition. The proposed method is simple, low-cost and easy to use, and can be employed for studies involving atrazine in soil samples or for screening of atrazine in soils.     

Degradation of atrazine by catalytic ozonation in the presence of iron scraps: performance,transformation pathway,and acute toxicity

Degradation of atrazine by catalytic ozonation in the presence of iron scraps (ZVI/O₃) was carried out. The key operational parameters (i.e., initial pH, ZVI dosage, and ozone dosage) were optimized by the batch experiments, respectively. This ZVI/O₃ system exhibited much higher degradation efficiency of atrazine than the single ozonation, ZVI, and traditional ZVI/O₂ systems. The result shows that the pseudo-first-order constant (0.0927?min^?1) and TOC removal rate (86.6%) obtained by the ZVI/O₃ process were much higher than those of the three control experiments. In addition, X-ray diffraction (XRD) analysis indicates that slight of γ-FeOOH and Fe₂O₃ were formed on the surface of iron scrap after ZVI/O₃ treatment. These corrosion products exhibit high catalytic ability for ozone decomposition, which could generate more hydroxyl radical (HO^?) to degrade atrazine. Six transformation intermediates were identified by liquid chromatography-mass spectrometry (LC-MS) analysis in ZVI/O₃ system, and the degradation pathway of atrazine was proposed. Toxicity tests based on the inhibition of the luminescence emitted by Photobacterium phosphoreum and Vibrio fischeri indicate the detoxification of atrazine by ZVI/O₃ system. Finally, reused experiments indicate the approving recyclability of iron scraps. Consequently, the ZVI/O₃ system could be as an effective and promising technology for pesticide wastewater treatment.     

Bioremediation model for atrazine contaminated agricultural soils using phytoremediation (using Phaseolus vulgaris L.) and a locally adapted microbial consortium

The objective of the present study was to examine a biological model under greenhouse conditions for the bioremediation of atrazine contaminated soils. The model consisted in a combination of phytoremediation (using Phaseolus vulgaris L.) and rhizopheric bio-augmentation using native Trichoderma sp., and Rhizobium sp. microorganisms that showed no inhibitory growth at 10,000 mg L^?1 of herbicide concentration. 33.3 mg of atrazine 50 g^?1 of soil of initial concentration was used and an initial inoculation of 1 × 10⁹ UFC mL^?1 of Rhizobium sp. and 1 × 10⁵ conidia mL^?1 of Trichoderma sp. were set. Four treatments were arranged: Bean + Trichoderma sp. (B+T); Bean + Rhizobium sp. (BR); Bean + Rhizobium sp. + Trichoderma sp. (B+R+T) and Bean (B). 25.51 mg of atrazine 50 g^?1 of soil (76.63%) was removed by the B+T treatment in 40 days (a = 0.050, Tukey). This last indicate that the proposed biological model and methodology developed is useful for atrazine contaminated bioremediation agricultural soils, which can contribute to reduce the effects of agrochemical abuse.     

Biodegradation of s-triazine herbicide atrazine by Enterobacter cloacae and Burkholderia cepacia sp. from long-term treated sugarcane-cultivated soils in Kenya

In this study soils from sugarcane-cultivated fields were screened for bacterial species capable of atrazine (6-chloro-N²-ethyl-N⁴-isopropyl-1,3,5-triazine-2,4-diamine) degradation due to long exposure of the soils to this herbicide. To enrich for atrazine degraders, Minimal Salt Medium containing atrazine as the sole N source and glucose as the C source was inoculated with soils impacted with this herbicide and incubated. Bacterial growth was monitored by measuring optical density. The degradation of atrazine was followed by measuring residual atrazine in liquid cultures over a given time period by high performance liquid chromatography. Bacterial strains isolated from the enrichment cultures were characterized by biochemical tests and identified by 16S rRNA gene sequencing. Two bacterial strains coded ISL 8 and ISL 15 isolated from two different fields were shown to have 94 and 96% 16S rRNA gene sequence similarity to Burkholderia cepacia respectively. Another bacterial sp., ISL 14 was closely related to Enterobacter cloacae with a 96% 16S rRNA gene sequence similarity. There was not much difference between the extents of atrazine degradation by the enrichment cultures with communities (79–82% applied amount) from which pure strains were isolated and the pure strains themselves in liquid cultures that showed a degradation of 53–83% of applied amount. The study showed existence of bacterial strains in different sugarcane-cultivated fields which can use atrazine as a nitrogen source. The bacterial strains isolated can be used to enhance the degradation of atrazine in contaminated soils where atrazine is still considered to be recalcitrant.     

阿散酸在土壤中的降解与形态变化

通过土壤培养实验,研究畜牧养殖过程中阿散酸污染在土壤中的降解规律和形态变化特征。设计阿散酸污染水平为0、30、75、150、225和300 mg·kg-1,分别于培养的2~48 h和5~60 d采集土样,测定其中砷(As)、阿散酸、水溶态As、吸附态As、铁型砷(Fe-As)、铝型砷(Al-As)、钙型砷(Ca-As)、可还原态As和残渣态As。结果表明:阿散酸水平为30~75mg·kg-1时,48 h内降解率为42.99%~71.77%,40 d时降解率100%;阿散酸水平为150~300 mg·kg-1时,降解较慢,降解最快时间段为5~10 d时,但60 d时各组仍有部分阿散酸未被降解;阿散酸污染水平对土壤砷形态的影响表明,随着污染水平增加,对土壤水溶态As和吸附态As影响最大,对Ca-As和残渣态As影响最小。阿散酸污染水平从30~300 mg·kg-1变化时,土壤水溶态As和吸附态As分别增加了4.84~50.29倍和10.43~106.14倍;相反,Ca-As和残渣态As仅增加1.6~1.3倍和1.3~1.62倍;阿散酸污染时间对土壤砷形态的影响表明,污染后10~60 d,随着时间延长,土壤中水溶态As和交换态As呈逐渐下降趋势,而 Ca-As、Fe-As和Al-As含量逐渐增加,残渣态As相对稳定。阿散酸在土壤中降解因污染水平而存在差异,低污染水平降解快,高污染水平降解慢。同时,阿散酸污染能够不同程度改变土壤各种砷形态,并随着污染时间延长,由可利用态逐渐变为稳定态。     

Biotransformation of atrazine and metolachlor within soil profile and changes in microbial communities

Biotransformation studies of atrazine, metolachlor and evolution of their metabolites were carried out in soils and subsoils of Northern Greece. Trace atrazine, its metabolites and metolachlor residues were detected in field soil samples 1 year after their application. The biotransformation rates of atrazine were higher in soils and subsoils of field previously exposed to atrazine (maize field sites) than in respective layers of the field margin. The DT₅₀ values of atrazine ranged from 5 to 18 d in the surface layers of the adapted soils. DT₅₀ values of atrazine increased as the soil depth increased reaching the value of 43 d in the 80-110 cm depth layer of adapted soils. Metolachlor degraded at slower rates than atrazine in surface soils, subsoils of field and field margins with the respective DT₅₀ values ranging from 56 to 72 d in surface soils and from 165 to 186 d in subsoils. Hydroxyatrazine was the most frequently detected metabolite of atrazine. The maximum concentrations of metolachlor-OXA and metolachlor-ESA were detected in the soil layers of 20-40 cm depth after 90 d of incubation. Principal Component Analysis (PCA) of soil Phospholipid Fatty Acids (PLFAs), fungal/bacterial and Gram-negative/Gram-positive ratios of the PLFA profiles revealed that the higher biotransformation rates of atrazine were simultaneously observed with the abundance of Gram-negative bacteria while the respective rates of metolachlor were observed in soil samples with abundance of fungi.     

Sorption of atrazine and phenanthrene by organic matter fractions in soil and sediment

Atrazine and phenanthrene (Phen) sorption by nonhydrolyzable carbon (NHC), black carbon (BC), humic acid (HA) and whole sediment and soil samples was examined. Atrazine sorption isotherms were nearly linear. The single-point organic carbon (OC)-normalized distribution coefficients (K_OC) of atrazine for the isolated HA1, NHC1 and BC1 from sediment 1 (ST1) were 36, 550, and 1470 times greater than that of ST1, respectively, indicating the importance of sediment organic matter, particularly the condensed fractions (NHC and BC). Similar sorption capacity of atrazine and Phen by NHC but different isotherm nonlinearity indicated different sorption domains due to their different structure and hydrophobicity. The positive relationship between (O + N)/C ratios of NHC and atrazine log K_OC at low concentration suggests H-bonding interactions. This study shows that sediment is probably a less effective sorbent for atrazine than Phen, implying that atrazine applied in sediments or soils may be likely to leach into groundwater.     

Competitive biodegradation of dichlobenil and atrazine coexisting in soil amended with a char and citrate

The role of char nutrients in the biodegradation of coexisting dichlobenil and atrazine in a soil by their respective bacterial degraders, DDN and ADP, was evaluated. Under growing conditions, their degradation in soil extract was slow with <40% and <20% degraded within 64 h, respectively. The degradation in extracts and slurries of char-amended solids increased with increasing char content, due to nutritional stimulation on microbial activities. By supplementing soil extract with various major nutrients, the measured degradation demonstrated that P was the exclusive limiting nutrient. The reduction in the degradation of coexisting dichlobenil and atrazine resulted apparently from the competitive utilization of P by DDN and ADP. With a shorter lag phase, ADP commenced growing earlier than DDN with the advantage of utilizing P first in insufficient supply. This resulted in an inhibition on the growth of DDN and thus suppression on dichlobenil degradation.     

Phytotoxicity of atrazine and alachlor in soil amended with sludge,manure and activated carbon

Abstract

Greenhouse studies were conducted to determine the influence of waste‐activated carbon (WAC), digested municipal sewage sludge (DMS), and animal manure on herbicidal activity of atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐trazine] and alachlor [2‐chloro‐2’,6'‐diethyl‐N‐(methoxymethyl)acetanilide] in a Plainfield sandy soil. Amendments generally reduced bioactivity against oat (Avena sativa L.) and Japanese millet (E. crus‐galli frumentacea). The extent to which herbicide phytotoxicity was inhibited depended upon the application rate and the kind of soil amendment. WAC, applied at the loading rate of 2.1 mt C/ha, showed a significant inhibitory effect on both herbicides. In DMS‐ and manure‐amended soil, the reduction of atrazine activity was not significant at the rate of 8.4 mt C/ha, but reduction of alachlor activity was significant at the rate of 4.2 mt C/ha. Despite inhibition of herbicidal activity, the ED₅₀ of atrazine and alachlor was below 2 ppm in most of the amendment treatments. Before adopting carbon‐rich waste amendments as management practices for controlling pesticide leaching in coarse‐textured soils, further studies are needed to characterize how alterations in sorption, leaching and degradation may affect herbicidal activity.     

Monitoring of atrazine in milk using a rapid tube-based ELISA and validation with HPLC

Although atrazine has been banned in the European Union since 2007 it still persists in soil from where it can enter the food chain. Milk-producing animals accumulate atrazine from contaminated feed and water and since large quantities of milk and milk products are consumed its quality should be constantly monitored. The objective of this investigation was to develop a simple tube ELISA procedure suitable for use in non-specialised laboratories and in the field. A polyclonal antibody raised in sheep and the hapten-gelatine conjugate was immobilised onto polystyrene tubes. This enables the colour produced to be read on a basic spectrophotometer. Milk samples were collected from three farms in different regions of Poland and diluted before immunoassay was performed. Samples were extracted with hexane-acetone for HPLC analysis. The amount of fat in the milk samples interferes with the dose response so it essential that the standards are prepared in the same samples matrix. A good correlation between 1% and 2% was found between the two methods in the analysis of real samples. However the ELISA procedure was more sensitive that the HPLC method since atrazine was detected in some samples by the ELISA but was not confirmed by the HPLC method. The study demonstrated that the simple antigen-coated tube assay provides a cost effective and valuable screening test that can be easily modified for direct use as a screening tool in the field.     

Continuous time random walk model better describes the tailing of atrazine transport in soil

Contaminant transport in soils is complicated and involves some physical and chemical nonequilibrium processes. In this research, the soil column displacement experiments of Cl⁻ and atrazine under different flow velocities were carried out. The data sets of Cl⁻ transport in sandy loam fitted to the convection dispersion equation (CDE) and the two-region model (TRM) indicated that the effects of physical nonequilibrium process produced by immobile water on the breakthrough curves (BTCs) of Cl⁻ and atrazine transport through the repacking soil columns were negligible. The two-site model (TSM) and the continuous time random walk (CTRW) were also used to fit atrazine transport behavior at the flow rate of 19.86 cm h⁻¹. The CTRW convincingly captured the full evolution of atrazine BTC in the soil column, especially for the part of long tailing. However, the TSM failed to characterize the tailing of atrazine BTC in the soil column. The calculated fraction of equilibrium sorption sites, F, ranging from 0.78 to 0.80 for all flow rates suggested the contribution of nonequilibrium sorption sites to the asymmetry of atrazine BTCs. Furthermore, the data sets for the flow rates of 6.68 cm h⁻¹ and 32.81 cm h⁻¹ were predicted by the TSM and the CTRW. As to the flow rate of 6.68 cm h⁻¹, the CTRW predicted the entire BTC of atrazine transport better than the TSM did. For the flow rate of 32.81 cm h⁻¹, the CTRW characterized the late part of the tail better, while the TSM failed to predict the tailings of atrazine BTC.     

Behavior of atrazine in soils of tropical zone

Abstract

Movement and degradation of ¹⁴C‐atrazine (2‐chloro 4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine, was studied in undisturbed soil columns (0.50m length × 0.10m diameter) of Gley Humic and Deep Red Latosol from a maize crop region of Sao Paulo state, Brazil. Atrazine residues were largely confined to the 0–20cm layers over a 12 month period Atrazine degraded to the dealkylated metabolites deisopropylatrazine and deethylatrazine, but the major metabolite was hydroxyatrazine, mainly in the Gley Humic soil. Activity detected in the leachate was equivalent to an atrazine concentration of 0.08 to 0.11μg/1.

The persistence of ¹⁴C‐atrazine in a maize‐bean crop rotation was evaluated in lysimeters, using Gley Humic and Deep Red Latosol soils. Uptake of the radiocarbon by maize plants after 14‐days growth was equivalent to a herbicide concentration of 3.9μg/g fresh tissue and was similar in both soils. High atrazine degradation to hydroxyatrazine was detected by tic of maize extracts. After maize harvest, when beans were sown the Gley Humic soil contained an atrazine concentration of 0.29 μg/g soil and the Deep Red Latosol, 0.13 μg/g soil in the 0–30 cm layer. Activity detected in bean plants corresponded to a herbicide concentration of 0.26 (Gley Humic soil) and 0.32μg/g fresh tissue (Deep Red Latossol) after 14 days growth and 0.43 (Gley Humic soil) and 0.50 μg/g fresh tissue (Deep Red Latossol) after 97 days growth. Traces of activity equivalent to 0.06 and 0.02μg/g fresh tissue were detected in bean seeds at harvest. Non‐extractable (bound) residues in the soils at 235 days accounted for 66.6 to 75% (Gley Humic soil and Deep Red Latossol) of the total residual activity.     

寒地黑土中阿特拉津降解菌的筛选及降解特性

从长期施用阿特拉津的寒地黑土耕层(0～10 cm)取样。利用富集培养的方法,筛选到2株阿特拉津降解菌,编号Z₉和Z₄₂。Z₉以阿特拉津为惟一碳氮源生长,Z₄₂以阿特拉津为惟一氮源生长,15 d对阿特拉津的降解率分别为77.7%和65.6%。对其初步鉴定并对降解特性进行研究,结果表明,细菌Z9为微杆菌属（Microbacterium sp.）,细菌Z₄₂为节杆菌属(Arthrobacter sp.)。在室内进行降解条件优化实验,得出2株降解菌对100 mg/L阿特拉津的最佳降解条件为：温度30℃,Z₉ pH值为7,Z₄₂ pH值为8。     

Kinetics of aerobic and anaerobic biomineralization of atrazine in surface and subsurface agricultural soils in Ohio

The purpose of this study was to assess atrazine mineralization in surface and subsurface samples retrieved from vertical cores of agricultural soils from two farm sites in Ohio. The Defiance site (NW-Ohio) was on soybean-corn rotation and Piketon (S-Ohio) was on continuous corn cultivation. Both sites had a history of atrazine application for at least a couple of decades. The clay fraction increased at the Defiance site and the organic matter and total N content decreased with depth at both sites. Mineralization of atrazine was assessed by measurement of ¹⁴CO₂ during incubation of soil samples with [U-ring-¹⁴C]-atrazine. Abiotic mineralization was negligible in all soil samples. Aerobic mineralization rate constants declined and the corresponding half-lives increased with depth at the Defiance site. Anaerobic mineralization (supplemented with nitrate) was mostly below the detection at the Defiance site. In Piketon samples, the kinetic parameters of aerobic and anaerobic biomineralization of atrazine displayed considerable scatter among replicate cores and duplicate biometers. In general, this study concludes that data especially for anaerobic biomineralization of atrazine can be more variable as compared to aerobic conditions and cannot be extrapolated from one agricultural site to another.     

Immunotoxicity of atrazine in Balb/c mice

The present study was designed to investigate the immunotoxicity of atrazine (ATZ) in male Balb/c mice. ATZ (175, 87.5, and 43.75 mg/kg bw/day) was administered by gavage method for 28 days. The following indexes were determined in various groups of mice: body and organ weight; antibody aggregation of serum hemolysin; proliferative response of splenocytes to ConA; delayed-type hypersensitivity (DTH); natural killer cell activity; clearance of neutral red and nitric oxide (NO) release from peritoneal macrophages; apostosis and necrosis of splenocytes and thymocytes; cytokine production; and serum lysozyme. Results showed that cell-mediated, humoral immunity, and non-specific immune function in the high-dose ATZ group were suppressed; NO release and interferon-γ(IFN-γ)/interleukin-4 (IL-4) were also significantly decreased in the high-dose group. In the medium-dose group, the proliferation response and IFN-γ production was significantly decreased. In the low-dose group, the proliferation response was significantly decreased. Serum lysozyme was decreased in the ATZ-treated groups. The percentage of early apoptosis in thymocytes was increased significantly in high- and medium-dose ATZ groups. In conclusion, ATZ elicited an inhibitory effect on cell-mediated immunity, humoral immunity, and non-specific immune function of mice.