Core Viewpoint - Lignocellulosic biomass, a renewable organic resource, can be efficiently converted into fermentable sugars using engineered strains of Clostridium thermocellum through consolidated bioprocessing (CBP) and consolidated bioconversion (CBS) strategies, which significantly reduce costs and enhance economic feasibility [2][3]. Group 1: Engineering Strains Development - The research team at Qingdao Energy Institute introduced an exogenous β-glucosidase (CaBglA) into Clostridium thermocellum to address feedback inhibition from cellobiose, resulting in the development of a third-generation CBS strain that significantly improved cellulose saccharification performance [3]. - The fourth-generation CBS strain, GB2, was constructed by integrating the CaBglA gene into the genome, achieving a cellulose-glucose conversion rate of up to 94% without relying on antibiotics, demonstrating stable and efficient cellulose degradation capabilities [4]. - Further enhancements were made by introducing a bifunctional xylanase/xylosidase (CcXyl0074) from Clostridium clariflavum into GB2, which improved the hemicellulose degradation ability of Clostridium thermocellum [4]. Group 2: Performance and Cost Efficiency - The engineered strain expressing CcXyl0074 was able to convert 84% of xylan into xylose within three days while maintaining high cellulose conversion efficiency, indicating a significant enhancement in hemicellulose degradation [4]. - The integration of both CcXyl0074 and CaBGL into the genome resulted in the GBX1 strain, which exhibited a 1.5 times higher maximum saccharification rate compared to GB2, showcasing synergistic degradation of cellulose and hemicellulose components [4]. - Optimization of the saccharification medium formulation led to an 87.3% reduction in cultivation costs, further improving the technical and economic viability of the CBS process [4]. Group 3: Research Contributions and Recognition - The research findings were published in the journal Bioresource Technology, with significant contributions from doctoral and master's students, as well as researchers from the Japan International Research Center for Agricultural Sciences [6]. - A patent application has been filed for the engineered strain expressing bifunctional enzymes, indicating the potential for commercialization and industrial application of the developed technology [6].