Identification of high-strength phenol degrading strain Candida tropicalis Z-04 and degradation condition optimization

A phenol-degrading strain,capable of tolerating high-strength phenol up to 2.0g/L,was isolated from phenol-degrading aerobic granules.According to its morphological and ITS gene analysis,the strain was identified as the genus Candida tropicalis,and was named Candida tropicalis Z-04.A Central Composite Design(CCD) was employed to optimize the phenol degrading conditions.The obtained experiments data were analyzed by Design-Expert software,base on which,the effect of influence factors and their interaction on phenol degradation efficiency were investigated.The results showed that the optimal degradation conditions were: yeast extract 0.41 g/L,phenol 1.03 g/L,inoculum size 1.43%(volume ratio) and temperature 30.04 ℃,and the maximum removal efficiency of phenol(99.10%) was obtained under the optimum conditions.