Isolating and characteristics of a Cd-resistant microorganism used in the biodegradation of di-<i>n</i>-octyl phthalate

• Main Authors: LIU Biao, YU Meng-yuan, WANG Zhen, DU Dong-xia, CHEN Wei, XU Li-juan, WU Ying-ben, WU Min-xi, LIU Hui-zhi, YIN Hong-mei
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2021-03-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: cadmium resistance; di-n-octyl phthalate; biodegradation; <i>hyphomicrobium</i> sp.
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2021/2/20210208.htm

To produce highly efficient di-<i>n</i>-octyl phthalate(DOP)-degrading microorganisms resistant to Cd, effective strains were screened out using selective media with DOP as the sole carbon source. The phylogenetic position and degradation characteristics of PD-2 were analyzed. Five strains of DOP-degrading and Cd-resistant bacteria were isolated from phthalate-contaminated soil. The strain PD-2 degraded DOP by more than 93.1% within 120 h, which was more than other strains did in the same time period. Based on its morphology and a 16S rDNA sequence analysis, strain PD-2 was identified as <i>Hyphomicrobium</i> sp. The DOP degradation rate changed in relation to the strain growth. PD-2 could efficiently degrade DOP over a wide range of DOP and Cd concentrations(100~800 mg·L^-1 and 0~600 mg·L^-1, respectively). Furthermore, PD-2 could utilize dimethyl phthalate, diethyl phthalate, di-<i>n</i>-butyl phthalate, di(2-ethylhexyl) phthalate, DOP, and phthalic acid as carbon sources, suggesting that PD-2 had a broad substrate spectrum. The inoculation of PD-2 to contaminated soil could markedly increase the rate at which DOP could be removed from soil. These results indicate that PD-2 is an efficient strain of <i>Hyphomicrobium</i> sp. for use in biodegradation and has potential for application in the bioremediation of cadmium and phthalate compoundcontaminated soil.