Abstract
Herein, bacterial isolate HIS7 was obtained from contaminated soil and exhibited high efficacy to degrade pyrethroid insecticide cypermethrin. The HIS7 isolate was identified as Lysinibacillus cresolivuorans based on its morphology and physiology characteristics as well as sequencing of 16S rRNA. The biodegradation percentages of 2500 ppm cypermethrin increased from 57.7% to 86.9% after optimizing the environmental factors at incubation condition (static), incubation period (8-days), temperature (35 °C), pH (7), inoculum volume (3%), and the addition of extra-carbon (glucose) and nitrogen source (NH4Cl2). In soil, L. cresolivuorans HIS7 exhibited a high potential to degrade cypermethrin, where the degradation percentage increased from 54.7 to 93.1% after 7 to 42 days, respectively. The qualitative analysis showed that the bacterial degradation of cypermethrin in the soil was time-dependent. The High-Performance Liquid Chromatography (HPLC) analysis of the soil extract showed one peak for control at retention time (R.T.) of 3.460 min and appeared three peaks after bacterial degradation at retention time (R.T.) of 2.510, 2.878, and 3.230 min. The Gas chromatography–mass spectrometry (GC–MS) analysis confirmed the successful degradation of cypermethrin by L. cresolivuorans in the soil. The toxicity of biodegraded products was assessed on the growth performance of Zea mays using seed germination and greenhouse experiment and in vitro cytotoxic effect against normal Vero cells. Data showed the toxicity of biodegraded products was noticeably decreased as compared with that of cypermethrin before degradation.
Highlights
Chemical insecticides, pesticides, and heavy metals are considered to be among the main pollution sources for soil, groundwater, and other water ecosystems [1,2]
Data showed that the most potent bacterial isolate designated as HIS7 showed high efficiency in degrading cypermethrin insecticide and was identified as Lysinibacillus cresolivuorans based on a morphological and physiological test as well as amplification and sequencing of 16S rRNA
Data analysis revealed that the degradation percentages were increased from 57.7% to 86.9% after optimizing the environmental factors of incubation condition, incubation period (8-days), incubation temperature (35 ◦C), pH (7), inocula size (3%), in addition of extra-carbon source and nitrogen source (NH4Cl2), and 2500 ppm of cypermethrin
Summary
Pesticides, and heavy metals are considered to be among the main pollution sources for soil, groundwater, and other water ecosystems [1,2]. These chemical compounds have crucial roles in saving crops and human health by controlling the plant infectious pests and suppressing the vectors that cause different diseases such as malaria and other household insects [3], the overuse of these compounds causes their long-term presence in the soil and directly disrupts the soil microbiota and terrestrial invertebrates, and indirectly has negative impacts on human health through contaminants interfere within the food chain and natural resources [4]. The hydrophobic characteristic of pyrethroid compounds causes the tight binding with soil organic matter and particles, and prevents the passage of these compounds to groundwater and forming residues that decrease soil fertility, hinder plant growth, and disturb the soil microbiota [10,11,12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
