Biodegradation of nitenpyram (neonicotinoid insecticide) by endophytic bacterium, Bacillus thuringiensis strain NIT-2, isolated from neonicotinoid-treated plant samples

• Published in: Journal of Pesticide Science Vol. 49; no. 2; pp. 94 - 103
• Main Authors: Salam, Md. Tareq Bin, Ito, Koji, Kataoka, Ryota
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Pesticide Science Society of Japan 20-05-2024; Japan Science and Technology Agency
• Subjects: Bacillus thuringiensis; Bacillus thuringiensis strain NIT-2; Bacteria; Biodegradation; Brassica rapa; Endophytes; Gene sequencing; Insecticides; Metabolites; nitenpyram; Pests; Plant protection; Regular; rRNA 16S; biodegradation; Brassica rapa; Bacillus thuringiensis strain NIT-2; nitenpyram
• ISSN: 1348-589X; 1349-0923
• DOI: 10.1584/jpestics.D24-002

Nitenpyram (neonicotinoid insecticide) is commonly used for crop protection from pests. Currently, due to its widespread use, the nitenpyram accumulation in the environment is anticipated to be high. Hence, the removal of nitenpyram residue from the environment is essential. However, the biodegradation of nitenpyram by endophytes is still unreported. Therefore, we aimed to isolate and identify a bacterial strain capable of degrading nitenpyram. We isolated approximately 300 endophytic strains from Brassica rapa var. perviridis that had been exposed to different neonicotinoid insecticides. After 14 days of incubation, a bacterial strain, NIT-2, with nitenpyram degradation capability (approximately 65%) was found. Via 16S rRNA gene sequencing, the strain was identified as Bacillus thuringiensis. In addition, metabolites, 2-[N-(6-chloro-3-pyridylmethyl)-N-ethyl]amino-2-methyliminoacetic acid, N-(6-chloro-3-pyridilmethyl)-N-ethyl-N-methylformamidine (CPMF), and N-(6-chloro-3-pyridilmethyl)-N-ethylformamide (CPF), were identified during the degradation. Moreover, CPMF and CPF were further degraded 71% and 18%, respectively by NIT-2. Thus, B. thuringiensis strain NIT-2 is the first reported endophytic bacterium capable of degrading nitenpyram.