Yinbo Qu

　　State key laboratory of microbial technology, Shandong University, Jinan,China

　　Efficient enzymatic depolymerization of lignocellulose for the production of biofuels and bioproducts is a world-wide challenges. It is critical to improve microbe's ability to produce lignocellulose-degrading enzymes and meanwhile the efficiency of the enzymes to depolymerize lignocellulose substrates. Scientists in Shandong University have been taking a systems approach for the cellulase-producing strains of Penicillium sp. and have identified more than 20 genes functioning in the regulation of cellulase production and for the first time established the regulatory network for the expression of cellulases in Penicillium sp. strains. Through knocking out or over-expressing multiple regulatory factors, the regulatory network for cellulase expression in Penicillium sp. strains was rationally reconstructed so that cellulase production capacity was improved by dozens of times. Meanwhile, the efficiency of enzymatic lignocellulose depolymerization was significantly increased by optimizing the composition of cellulases. Coupling optimization of enzyme composition and lignocelulose pretreatment, over 90% of lignocellulose substrates was efficiently depolymerized. Furthermore, industrial wastes were applied as growth media to produce cellulases so that in situ production of crude enzymes could be achieved and thus costs of cellulase production could be significantly reduced.

　　Based on the above progress, an innovative and integrated technology was developed for the production of biofuels and value-added chemicals. A biorefinery demonstration plant has been constructed with a capacity of producing ten thousand tons of cellulosic ethanol from corn cobs. Recently, another innovative biorefinery technology has been developed to integrate the production of cellulosic ethanol, pulp and fulvic acid fertilizer, utilizing straw as feedstock. This provides a great development potential for the cellulosic ethanol biorefinery industry.