dc.description.abstract | Itaconic acid (IA) has been declared to be one of the most promising and flexible building blocks derived from biomass, it is a monomer for the manufacturing of synthetic fibers, synthetic resins, plastics, rubbers or other polymeric materials.
A. terreus strains can achieve high product yields of IA by utilizing glucose. For several decades, some studies focus on metabolic pathway for IA production, pH, oxygen supply and bioreactor. However, the investigation of mesophilic or thermophilic temperature and utilizing rice straw for IA fermentation is deficient.
At present, T. reesei has been reported as the excellent cellulose producer. So first, the rice straw by alkaline pretreatment and soybean powder is used for cellulase production by T. reesei Rut C-30 at 30°C, the crude enzyme with the highest activity of CMCase, Avicelase and β-glucosidase was 0.193, 0.152 and 0.146 IU/mL, and the filter paper activity was 0.754 FPU/mL. The crude enzyme is used for saccharification of 20、40 and 60 g/L rice straw at 50°C, it obtains 19.14、32.88 and 45.13 g/L reducing sugar. The saccharification efficiency is 84.6、73.3 and 66.6% respectively.
In IA fermentation, the inoculum from 10 to 30% directly increases the IA productivity 3.4 times, it were obtained 0.826 g/L day. Using soybean powder as nitrogen source is better than (NH4)2SO4 and CSL at 40°C, the higher IA productivity and Yp/s, can be obtained 0.22 g IA/g glucose and 1.28 g/L day, respectively. If using half of 2.1 g/L soybean powder, the IA productivity can be increased to 1.57 g/L day and Yp/s is 0.3 g/g. At last, 32 g/L reducing sugar and 0.67 g/L soybean powder is used for IA production by nitrogen limitation, the IA productivity is 0.4 g/L day, it slightly less than the control group of glucose.
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