苯酚降解菌DF51的分离鉴定、降解特性及其固定化的研究

Isolation, Identification and Immobilization of Rhodococcus sp. DF51 and It’s Characterization of Phenol Degradation

为了研究焦化废水污染土样中微生物的降解性能,作者特地从太原市郊焦化厂附近的污染土样中采样,以便从中加氧酶催化开环,表明菌株DF51兼有混浊红球菌(Rhodoccocus opacus R7)和红球菌PNAN5(Rhodoccocus sp.strain DF51)降解苯酚的途径。菌株DF51固定化试验表明,该菌的固定化细胞具有降解苯酚的潜在应用价值。

In order to investigate the degradation properties of microorganism in the contaminated soil, the soil sample from the waste sludge in the coke-oven plant near Taiyuan city was drawn to isolate a high-performance aromatic degrader. The isolated was identified by morphological characteristics and a complete sequence analysis of its 16S rRNA gene, meanwhile the degradation pathway of phenol was analyzed by HPLC together with its characterization of phenol and immobilization. The results showed that the strain was assigned to the genus Rhodococcus, and given the name Rhodococcus sp. DF51. The strain DFS1 was grown using phenol, benzoate, naphthalene, biphenyl and benzothiophene as sole carbon and energy sources, and was able to degrade polycyclic aromatics such as naphthalene and biphenyl as well as monocyclic aromatics such as phenol. Under experimental conditions, strain DF51 was capable of degrading at concentrations of phenol ranging from 100 mg to 800 rag, which is catabolized mainly through the catechol 1,2-dioxygenase pathway with a minor catechol 2,3-dioxygenase pathway. It is suggested the degradation way of phenol in the strain DF51 is differed from that of the reported phenol degrader. The results of immobilization of the strain DF51 revealed the optimum operation immobilization temperature is 4 ℃ with 3wt% sodium alginate （SA）, the ratio of 1：10 [ cells （g） to SA （ml） ] and 3wt% CaCl2, showing that the immobilized strain DFS1 has a certain potential of degrading phenol.