Rehman Hamid, Rehman Ziafat, Das Tonoy K, Rehman Maha, Khan Basit Ahmed, Nandi Sunny, Ahmad Khurshid, Mohanty Sanjay K, Ur Rehman Wasif, Naeem Rehan, Bajaj Mohit, Tuka Milkias Berhanu
Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
Department of Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, CA, USA.
Sci Rep. 2024 Dec 2;14(1):29892. doi: 10.1038/s41598-024-81588-4.
Cypermethrin (Cyp), a persistent synthetic pyrethroid insecticide widely used for insect control. The persistence of Cyp creates toxicity to both humans and the environment This study investigates biochar and Bacillus cereus distinct and collective effects on Cyp -contaminated soil during a 90-day incubation. This study also investigates the effects of different concentrations of Cyp (50, 100, ,500 to 1000 mg kg) on soil physicochemical and biological activities during a 90-day incubation period. Microbial biomass carbon and soil respiration rates decreased significantly across all cypermethrin concentrations, with the most substantial reductions observed at 1000 mg kg. However noticeable variations in soil enzymes and MBC over time during the entire incubation period. On 1st day, the GMean Enz and MBC rate for Cyp treatments (50, 100, ,500 to 1000 mg kg) ranged from 0.98 to 0.63, and 9.06, to 5.03, respectively. Under Cyp pollution, microbial biomass carbon exhibited significant decreases, with the highest inhibition (86.2%) at 1000 mg kg on 1st day of incubation. Soil respiration rates dropped 77%, at 1000 mg kg, and Integrated biomarker response (IBR) values peaked on day 30, indicating environmental stress. Biochar and Bacillus cereus effectively facilitated the degradation of Cyp, achieving approximately 85% degradation within the first 45 days of the experiment. The combined application of biochar and Bacillus cereus increased soil pH to a neutral level from 5.9, to 7.1, reduced electrical conductivity from 1.41 µS cm to 1.20 µS cm, and elevated cation exchange capacity from 1.54 ± 0.04 to 6.18 C mol kg, while also improving organic carbon content to 3.135%. However, the dehydrogenase activity was decresed upto 47% in the combined application and all other enzymes including urasese catlayse and phostasese enzymes with Gmean enzymeatic activities were significantly improved. These findings suggest biochar and bacterial interaction for soil management to enhance soil resilience against pesticide stress.
氯氰菊酯（Cyp）是一种广泛用于害虫防治的持久性合成拟除虫菊酯类杀虫剂。Cyp的持久性对人类和环境均产生毒性。本研究调查了生物炭和蜡样芽孢杆菌在90天培养期内对受Cyp污染土壤的单独及联合作用。本研究还调查了不同浓度的Cyp（50、100、500至1000毫克/千克）在90天培养期内对土壤理化和生物活性的影响。在所有氯氰菊酯浓度下，微生物生物量碳和土壤呼吸速率均显著下降，在1000毫克/千克时下降最为显著。然而，在整个培养期内，土壤酶和微生物生物量碳随时间有明显变化。在第1天，Cyp处理（50、100、500至1000毫克/千克）的几何平均酶活性和微生物生物量碳速率分别为0.98至0.63以及9.06至5.03。在Cyp污染下，微生物生物量碳显著下降，在培养第1天，1000毫克/千克时抑制率最高（86.2%）。在1000毫克/千克时，土壤呼吸速率下降了77%，综合生物标志物响应（IBR）值在第30天达到峰值，表明存在环境压力。生物炭和蜡样芽孢杆菌有效促进了Cyp的降解，在实验的前45天内降解率达到约85%。生物炭和蜡样芽孢杆菌的联合应用使土壤pH值从5.9提高到中性水平7.1，电导率从1.41微西门子/厘米降至1.20微西门子/厘米，阳离子交换容量从1.54±0.04提高到6.18厘摩尔/千克，同时有机碳含量提高到3.135%。然而，联合应用时脱氢酶活性降低了47%，而包括脲酶、过氧化氢酶和磷酸酶在内的所有其他酶的几何平均酶活性均显著提高。这些发现表明生物炭与细菌相互作用可用于土壤管理，以增强土壤对农药胁迫的恢复力。
