An alkaline phosphatase from Bacillus amyloliquefaciens YP6 of new application in biodegradation of five broad-spectrum organophosphorus pesticides

Abstract

In recent decades, biodegradation has been considered a promising and eco-friendly way to eliminate organophosphorus pesticides (OPs) from the environment. To enrich current biodegrading-enzyme resources, an alkaline phosphatase (AP3) from Bacillus amyloliquefaciens YP6 was characterized and utilized to test the potential for new applications in the biodegradation of five broad-spectrum OPs. Characterization of AP3 demonstrated that activity was optimal at 40 °C and pH 10.3. The activity of AP3 was enhanced by Mg²⁺, Ca²⁺, and Cu²⁺, and strongly inhibited by Mn²⁺, EDTA, and L-Cys. Compared to disodium phenyl phosphate, p-nitrophenyl phosphate (pNPP) was more suitable to AP3, and the V_m, K_m, k_cat, k_cat/K_m values of AP3 for pNPP were 4,033 U mg⁻¹, 12.2 mmol L⁻¹, 3.3 × 10⁶ s⁻¹, and 2.7 × 10⁸ s⁻¹mol⁻¹L, respectively. Degradation of the five OPs, which included chlorpyrifos, dichlorvos, dipterex, phoxim, and triazophos, was 18.7%, 53.0%, 5.5%, 68.3%, and 96.3%, respectively, after treatment with AP3 for 1 h. After treatment of the OP for 8 h, AP3 activities remained more than 80%, with the exception of phoxim. It can be postulated that AP3 may have a broad OP-degradation ability and could possibly provide excellent potential for biodegradation and bioremediation in polluted ecosystems.

Keywords:

• Alkaline phosphatase
• broad spectrum
• organophosphorus pesticide
• biodegradation
• Bacillus amyloliquefaciens

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Collaborative Innovation Involving Production, Teaching & Research Funds of Jiangsu Province [grant number BY2014023-28] and the Agricultural Support Project, Wuxi Science & Technology Development [grant number CLE01N1310].