Full Length Research Paper

Isolation, identification and cadmium adsorption of a high cadmium-resistant Paecilomyces lilacinus

Xiaoxi Zeng^1,2*, Jianxin Tang², Huaqun Yin¹, Xueduan Liu¹, Pei Jiang² and Hongwei Liu¹

¹School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, P.R.China.

²Hunan Key Lab of Green Packaging and Biological Nanotechnology, Hunan University of Technology, Zhuzhou, 412007, P. R.China.

*Corresponding author. Email: zengxiaoxi2003@gmail.com.  Tel: +86 -731-26241803.

Abbreviations: ITS, Internal transcribed spacers; SEM, scanning electron microscopy; EDX, energy dispersive X-ray; ROS, reactive oxygen species; PDA, potato dextrose agar; PCR, polymerase chain reaction; MIC, minimum inhibitory concentration; BLAST, basic local alignment search tool; PHB, poly-3-hydroxybutyrate; PCL, polycaprolactone.

Accepted 23 March, 2010

   Abstract

Microorganisms play important roles in bioremediation. The present study was carried out to investigate metal resistance and adsorption strains. A cadmium-resistant fungus M1 was isolated from Zhuzhou smelter in China. The 18S rRNA, internal transcribed spacers (ITS) region and β-tubulin gene of the strain were sequenced and aligned with the high similar sequences published in GenBank. The morphology was analyzed under scanning electron microscopy (SEM). The growth in the 100 mg/l cadmium medium was investigated and the biomass was analyzed by energy dispersive X-ray (EDX) spectroscopy. The results showed that strain M1 which tolerated 80 mM cadmium belong to Paecilomyces lilacinus. Except for cadmium, the fungus showed resistance to zinc, manganese, copper, lead, and cobalt. The cadmium bisorption capacity of the fungus reached 24.23 mg/g during growth. EDX confirmed that cadmium biosorption occurred on the fungus biomass. The work suggested that P. lilacinus M1 was a potential strain on cadmium bioremediation.

Key words: Paecilomyces lilacinus, cadmium-resistant, biosorption.