苯酚和喹啉降解菌Alcaligenes faecalis的降解特性及固定化应用

Biodegradation characteristics of phenol and quinoline by Alcaligenes faecalis and its immobilization application

  • 摘要: 苯酚和喹啉单基质降解菌在实际应用中局限性较大,筛选共基质条件下具有生物降解活性的菌株更具有实际价值。从焦化厂废水处理系统的污泥中经过驯化、分离,筛选出一株能同时降解苯酚和喹啉的菌株KD1,根据形态特征、生理生化和16S rDNA序列等分析,鉴定其为粪产碱杆菌(Alcaligenes faecalis)。降解条件优化表明,菌株KD1有较好的酸碱度适用性,在接菌量为10 %、初始pH值为7.0、温度35 ℃、振荡器转速150 r/min时,对苯酚和喹啉的降解效率最高;氮源能影响菌株KD1对苯酚的降解,而共基质下菌株KD1能协同降解苯酚和喹啉。菌株KD1能完全降解700 mg/L的苯酚和400 mg/L的喹啉,降解过程均呈零级反应特征,其在不同浓度的苯酚和喹啉中的生长符合Haldane底物抑制模型,抑制浓度分别为293 mg/L和229 mg/L。固定化研究表明,通过包埋和吸附制备的新型固定化载体能提高菌株KD1对苯酚和喹啉共基质的降解效率。

     

    Abstract: The strains that can only degrade phenol or quinoline are limited in practical application. It is more practical to select the tolerant strains which can degrade the compound pollutants. A phenol-quinoline degrading strain KD1 was isolated from activated sludge in a coke-plant wastewater treatment system. KD1 was identified as Alcaligenes faecalis on the basis of morphological characteristics, physiological and biochemical characteristics and the analysis of its 16S rDNA sequence. The optimal degradation conditions showed that strain KD1 had good pH applicability, and the optimal conditions were as follow: inoculation volume 10 %, rotation rate 150 r/min, culture temperature 30 ℃, initial pH value 7.0 respectively. Nitrogen source can affect the degradation of phenol by strain KD1, while strain KD1 can synergistically degrade phenol and quinoline under co-substrate. The degradation reaction of phenol and quinoline can be described with zero order kinetic equation within 700 mg/L phenol and 400 mg/L respectively. The growth kinetics of Strain KD1 could be described with Haldanes inhibition model, and the inhibition concentrations of it were 293 mg/L and 229 mg/L, respectively. The new immobilized carrier prepared by embedding and adsorption can improve the degradation efficiency of co-substrate pollutants.

     

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