Pereyra-Camacho Marco A, Balderas-Hernández Victor E, De Leon-Rodriguez Antonio
IPICyT, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José No. 2055, Lomas 4a sección, San Luis Potosí, San Luis Potosí, 78216, México.
Appl Microbiol Biotechnol. 2021 Apr;105(8):3369-3380. doi: 10.1007/s00253-021-11255-5. Epub 2021 Apr 2.
Diisononyl phthalate (DINP) is one of plasticisers most employed in the production of plastic materials and belongs to the most important environmental contaminants. In this work, a consortium of saline soil bacterial (SSB) capable of degrading DINP is presented. The genera of SSB-consortium were Serratia sp., Methylobacillus sp., Achromobacter sp., Pseudomonas sp., Stenotrophomonas sp., Methyloversatilis sp., Delftia sp. and Brevundimonas sp. Response surface methodology (RSM) study was employed to optimise and evaluate the culture conditions to improve the biodegradation of DINP. The optimal conditions were a pH 7.0, 31 °C and an initial DINP concentration of 500 mg L, resulting in almost complete biodegradation (99%) in 168 h. DINP degradation followed a first-order kinetic model, and the half-life was 12.76 h. During the biodegradation of DINP, 4-derived compounds were identified: monoisononyl phthalate, methyl nonyl phthalate, iso-nonanol and dimethyl phthalate. The metabolite profiling indicated that DINP was degraded through simultaneous pathways of de-esterification and β-oxidation. Results suggest that the SSB-consortium could be useful for efficient biodegradation of the DINP-contaminated environments. KEY POINTS: • DINP degradation is mediated by de-esterification and β-oxidation processes. • Temperature and the concentration of the substrate are key factors for DINP biodegradation • The SSB-consortium has the ability to biodegrade 99% of DINP (500 mg L).
邻苯二甲酸二异壬酯（DINP）是塑料材料生产中使用最广泛的增塑剂之一，也是最重要的环境污染物之一。在本研究中，我们展示了一个能够降解DINP的盐渍土细菌联合体（SSB）。该联合体中的细菌属包括沙雷氏菌属、甲基芽孢杆菌属、无色杆菌属、假单胞菌属、嗜麦芽窄食单胞菌属、甲基嗜盐碱杆菌属、代尔夫特菌属和短波单胞菌属。我们采用响应面法（RSM）来优化和评估培养条件，以提高DINP的生物降解率。最佳条件为pH 7.0、31℃和初始DINP浓度500 mg/L，在此条件下，168小时内几乎可实现完全生物降解（99%）。DINP的降解遵循一级动力学模型，半衰期为12.76小时。在DINP生物降解过程中，鉴定出4种衍生化合物：单异壬基邻苯二甲酸酯、甲基壬基邻苯二甲酸酯、异壬醇和邻苯二甲酸二甲酯。代谢物谱分析表明，DINP通过脱酯和β-氧化的同时途径进行降解。结果表明，该SSB联合体可用于高效生物降解受DINP污染的环境。要点：• DINP的降解由脱酯和β-氧化过程介导。• 温度和底物浓度是DINP生物降解的关键因素。• 该SSB联合体能够生物降解99%的DINP（500 mg/L）。
