A strain TF-1 capable of utilizing cyproconazole (CZ) as sole carbon and nitrogen source was isolated from the activated sludge of a domesticated sewage treatment plant. The strain was identified as Halalkalibacterium halodurans by morphological observation, physiological and biochemical experiments, 16S rRNA gene sequencing and phylogenetic tree analysis. It was named as Halalkalibacterium halodurans strain TF-1. The biodegradation experiment of CZ by TF-1 strain showed that the strain reached the optimum degradation conditions when the temperature reached 30 °C and the pH was 9. When the initial concentration of CZ increased from 20 to 80 mg·L-1, the maximum volume degradation rate also increases, indicating that TF-1 has strong tolerance and excellent degradation performance for refractory CZ. The addition of appropriate amount of external carbon source will accelerate the biodegradation of CZ, but the excessive organic carbon source will delay the degradation. The addition of appropriate amount of NH4+ and NO3- contributes to the biodegradation of CZ, while the addition of NO2- will significantly inhibit the degradation. Seventeen CZ degradation intermediates were detected by LC/MS and GC/MS, and three CZ degradation pathways were obtained, including the reaction of oxidation, hydrolysis ring opening, dehydroxylation, deamination, decarboxylation, dechlorination, hydroxylation, hydration and final mineralization. In the further wastewater small-scale experiments, the degradation efficiency of CZ in the activated sludge reactor inoculated with TF-1 strain increased from about 10% to more than 98%, and the reduction of COD and TOC in the reactor increased by 20 percentage points, which shows that inoculation of microorganisms can effectively improve the removal effect of activated sludge on CZ and reduce the biological toxicity of wastewater. The feasibility of bio-enhanced degradation of CZ wastewater by TF-1 strain was verified to a certain extent.

Yangming Yu, Haobo Wu. Isolation and degradation characterization of a cyproconazole-degrading bacterial strain. Academic Journal of Materials & Chemistry(2025), Vol. 6, Issue 2: 1-16. https://doi.org/10.25236/AJMC.2025.060201.

[1] Chuanying C, Yiran L, Jiye H. Estimation of residue levels and dietary risk assessment of cyproconazole and azoxystrobin in cucumber after field application in China. [J]. Environmental science and pollution research international, 2022, 29(23):  34186-34193.

[2] Nasar, A., Qamruzzaman, Degradation of tricyclazole by colloidal manganese dioxide in the absence and presence of surfactants. [J]. Ind. Eng. Chem. 2014. 20, 897-902.

[3] Paredes J, Cazó L, N, et al. Efficacy of fungicides against peanut smut in Argentina. [J]. Crop Protection, 2021, 140(prepublish): 105403-.

[4] Gillbard E. Tips for rust and chocolate spot control in beans[J]. Farmers Weekly, 2021, 174(24): 50-51.

[5] J. F S, P. V D, P. P Gilbard, et al. Fungicide resistance in Cercospora species causing cercospora leaf blight and purple seed stain of soybean in Argentina[J]. Plant Pathology, 2020, 69(9): 1678-1694.

[6] Li Y B, Dong F S, Liu X G, et al. Enantioselectivity in tebuconazole and myclobutanil non-target toxicity and degradation in soils[J]. Chemosphere, 2015, 122: 145-153.

[7] Roman, D.L., et al., Effects of Triazole Fungicides on Soil Microbiota and on the Activities of Enzymes Found in Soil: A Review. AGRICULTURE-BASEL, 2021. 11(9).

[8] Peffer, R.C., et al., Mouse liver effects of cyproconazole, a triazole fungicide: Role of the constitutive androstane receptor. Toxicological sciences, 2007. 99(1): p. 315-325.

[9] Cao, F.J., et al., Developmental toxicity of the triazole fungicide cyproconazole in embryo-larval stages of zebrafish (Danio rerio). Environmental science and pollution research, 2019. 26(5): p. 4913-4923.

[10] Dajana L, Alexandra L, Jimmy A, et al. An eight-compound mixture but not corresponding concentrations of individual chemicals induces triglyceride accumulation in human liver cells[J]. Toxicology, 2021, 459(prepublish): 152857-.

[11] Ma, P.Q., et al., Association of urinary chlorpyrifos, paraquat, and cyproconazole levels with the severity of fatty liver based on MRI. Bmc public health, 2024. 24(1).

[12] Roman D L, Voiculescu D I, Filip M, et al. Effects of triazole fungicides on soil microbiota and on the activities of enzymes found in soil: A review[J]. Agriculture, 2021, 11(9): 893.

[13] Wang Y, Ning X, Li G, et al.  New insights into potential estrogen agonistic activity of triazole fungicides and coupled metabolic disturbance[J]. Journal of Hazardous Materials 2021, 424: Article 127479.

[14] Lykogianni M, Bempelou E, Karamaouna F, et al. Do pesticides promote or hinder sustainability in agriculture? The challenge of sustainable use of pesticides in modern agriculture[J]. Science of The Total Environment, 2021, 795(6): Article 148625.

[15] Yu X W, Xiao F S, Jun Q Z, et al. Fabrication of β-cyclodextrin-polyacrylamide/covalent organic framework hydrogel at room temperature for the efficient removal of triazole fungicides from environmental water[J]. Environmental pollution (Barking, Essex: 1987), 2023, 333, 121971.

[16] Yahiat, S., et al., Photocatalysis as a pre-treatment prior to a biological degradation of cyproconazole. Desalination, 2011. 281: p. 61-67.

[17] Lhomme, L., S. Brosillon and D. Wolbert, Photocatalytic degradation of pesticides in pure water and a commercial agricultural solution on TiO2 coated media. Chemosphere, 2008. 70(3): p. 381-386.

[18] Qamruzzaman and A. Nasar, Degradation of tricyclazole by colloidal manganese dioxide in the absence and presence of surfactants. Journal of Industrial and Engineering Chemistry, 2014. 20(3): p. 897-902.

[19] Zhong, C.Q., et al., Electrochemical degradation of tricyclazole in aqueous solution using Ti/SnO2-Sb/PbO2 anode. Journal of Electroanalytical Chemistry, 2013. 705: p. 68-74.

[20] Liang, J., et al., Coaggregation mechanism of pyridine-degrading strains for the acceleration of the aerobic granulation process. Chemical Engineering Journal, 2018. 338: p. 176-183.

[21] Yun, H., et al., Functional Characterization of a Novel Amidase Involved in Biotransformation of Triclocarban and its Dehalogenated Congeners in Ochrobactrum sp TCC-2. Environmental Science & Technology, 2017. 51(1): p. 291-300.

[22] Rani L, Kanwar V S, Sharma A, et al. Phytoremediation of toxic metals present in soil and water environment: A ritical review[J]. Environmental Science and Pollution Research, 2020, 27(36): 44835-44860.

[23] Shen, J.Y., Zhang, J.F., Zuo, Y., Wang, L.J., Sun, X.Y., Li, J.S., Han, W.Q., He, R., 2009. Biodegradation of 2, 4, 6-trinitrophenol by Rhodococcus sp. isolated from a picric acid-contaminated soil. J. Hazard. Mater. 163, 1199–1206.

[24] Vreeland R H, Rosenzweig W D, Powers D W. Isolation of a 250million-year-old halotolerant bacterium from a primary salt crystal[J]. Nature, 2000, 407(6806): 897-900. 

[25] Haghighat S, Sepahy A A, Mazaheri M, et al. Ability of indigenous Bacillus licheniformis and Bacillus subtilis in microbial enhanced oil recovery[J]. International Journal of Environmental Science and Technology, 2008, 5(3): 385.

[26] Rohit S, Teenu J, Ahmad U, et al. Effective removal of Pb(II) and Ni(II) ions by Bacillus cereus and Bacillus pumilus: An experimental and mechanistic approach.[J]. Environmental research, 2022, 212(PB): 113337.

[27] Miao J, Fan Q, Li H, et al. Combination of the degrading bacterium Bacillus cereus MZ-1 and corn straw biochar enhanced the removal of imazethapyr from water solutions[J]. Next Sustainability, 2025, 5,100077.

[28] Yimin X, Naiwen C, Zhiwei L, et al. Biodegradation of dibutyl phthalate and diethyl phthalate by indigenous isolate Bacillus sp. MY156: Characterization, stoichiometry, enzyme activity, and physiological response to cell surface[J]. Journal of Water Process Engineering, 2023, 53

[29] Yawen G, Xiaoxia C, Liqiang L, et al. Cr(VI)-bioremediation mechanism of a novel strain Bacillus paramycoides Cr6 with the powerful ability to remove Cr(VI) from contaminated water[J]. Journal of Hazardous Materials, 2023, 455, 131519.

[30] Wernick, D.G., et al., Sustainable biorefining in wastewater by engineered extreme alkaliphile Bacillus marmarensis. Scientific Reports, 2016. 6.

[31] Kang Z, Dong J, Zhang J. Optimization and characterization of nicosulfuron-degrading enzyme from Bacillus subtilis strain YB1[J]. Journal of Integrative Agriculture, 2012, 11(9): 1485-1492.

[32] Chen Q, Xiong Q, Zhou Z, et al. Screening of oxytetracycline-degrading strains in the intestine of the black soldier fly larvae and their degradation characteristics[J]. Environmental pollution (Barking, Essex: 1987), 2024, 362124929.

[33] Shen J, Zhang X, Chen D, Liu X, Zhang L, Sun X, Li J, Bi H, Wang L. Kinetics study of pyridine biodegradation by a novel bacterial strain, Rhizobium sp. NJUST18[J]. Bioprocess and Biosystems Engineering, 2014, 37(6): 1185-1192.

[34] Bollag J M, Henninger N M. Effects of nitrite toxicity on soil bacteria under aerobic and anaerobic conditions[J]. Soil Biology and Biochemistry, 1978, 10(5): 377-381.