Li Jianghua

Isolation and Characterization of a Microorganism Degrading Starch/polyethylene Blends

In order to speed up plastic degradation and reduce contamination,a microorganism degrading starch/polyethylene blends was isolated from the soil of a wastes disposal site by the means of enrichment,clear zone and optical density(OD) detection.From the genetic homology analysis based on 16S rDNA sequence,the isolated strain was identified to be closely related to Bacillus amyloliquefaciens.To clarify the microbial degradability for starch/polyethylene blends,the degradation was investigated in minimal salt medium(MSM) with starch/polyethylene blend particles as sole carbon source,with its biodegradability verified by weight loss,thermogravimetric analysis and scanning electron microscope(SEM) analysis.After 14 days of biodegradation,23.2% of the particles,13.8% of starch and 9.4% of PE in particles were degraded,accompanied with obvious surface morphologic changes.The results show that the isolated strain can degrade starch/polyethylene blends efficiently and be applied in plastic recycle and rapid evaluation of biodegradability.