Corn stover, mainly composed of lignin, cellulose and hemicellulose, is one of the most abundant agricultural byproducts in China. Approximately 200 million tons of corn stover is produced in China per year. Most of the corn stover is burned or directly discarded resulting in resource waste and environment pollution.

Lignocellulose can be enzymatically hydrolyzed and transformed into important biofuels such as ethanol and butanol. The process can transform 30% energy and reduce environmental pollution. So in this study, Prof.LIU Xiaofeng's team from CAS Chengdu Institute of Biology isolated a newly Trametes hirsuta yj9 to pretreat corn stover in order to enhance enzymatic digestibility.

They demonstrated that T. hirsuta yj9 preferentially degraded lignin to be as high as 71.49% after 42-day pretreatment. Laccase and xylanase was the major ligninolytic and hydrolytic enzyme, respectively and filter paper activity (FPA) increased gradually with prolonged pretreatment time.

Meanwhile, researchers found that sugar yields increased significantly after pretreatment with T. hirsuta yj9, reaching an enzymatic digestibility of 73.99% after 42 days of pretreatment. Scanning electron microscopy (SEM) showed significant structural changes in pretreated corn stover, the surface of pretreated corn stover became increasingly coarse, the gaps between cellulose fibers were visible, and many pores were developed.

Researchers also demonstrated  correlation analysis showed that sugar yields were inversely proportional to the lignin contents, less related to cellulose and hemicellulose contents. LIU’s research got supports from Chinese Academy of Science,  National High Technology Research and Development Program of China. More results have been published inINTERNATIONAL BIODETERIORATION & BIODEGRADATION  in Oct of 2011.