This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was o...This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was obtained using wheat bran as substrate at 72 h fermentation with maximum proteolytic activity of 401.42 U/mL, collagenase of 243.0 U/mL and keratinase of 19.1 U/mL. The protease exhibited K<sub>M</sub> = 18.7 mg/mL and Vmax = 28.5 mg/mL/min. The optimal pH was 8.0 and stable in a wide pH range (5.0 - 11.0) during 24 h. The optimum temperature was 40°C. The proteolytic activity was inhibited by Cu<sup>2+</sup> (33.98%) and Hg<sup>2+</sup> (22.69%). The enzyme was also inhibited by PMSF (65.11%), indicating that is a Serine Protease. These properties suggest that alkaline protease from A. tamarii URM4634 is suitable for application in food industries and leather processing. Additionally, the present findings opened new vistas in the utilization of wheat bran and other effective agroindustrial wastes as substrates for SSF.展开更多
The present study investigated the incorporation of sugarcane bagasse ash(SCBA)in red ceramics,sintered in conventional oven and microwave oven,aiming to provide an alternative product,and a sintering process with hig...The present study investigated the incorporation of sugarcane bagasse ash(SCBA)in red ceramics,sintered in conventional oven and microwave oven,aiming to provide an alternative product,and a sintering process with higher energy efficiency in the production of red ceramics.The raw materials were characterized by XRF,XRD,thermogravimetry,particle size distribution and specific mass analyses.The specimens were shaped by extrusion in two different compositions,red clay and red clay with addition of 20%SCBA and sintered at temperatures from 700 to 1100℃.The conventional sintering occurred for 60 min with heating rate of 10℃/min.In the microwave oven the sintering occurred in a hybrid way,with heating rate of 50℃/min for 5,10 and 15 mins.After sintering the tests of linear shrinkage,compressive strength,water absorption,apparent porosity and apparent specific mass were performed.The addition of SCBA causes an increase in the values of water absorption and decreases the compressive strength and specific mass of the red ceramic.This occurs due to the creation of pores inside the material from the volatilization of organic matter present in the ashes.The sintering in microwave oven,when compared to conventional sintering,promotes an increase in the values of compressive strength and specific mass and reduction of water absorption values of ceramics,probably due to the refinement of the microstructure and the higher densification.Thus the incorporation of ashes can be partially compensated by a more efficient sintering.The use of SCBA and the sintering in microwave oven,showed to be viable alternatives in the development of a more sustainable and light material,promoting the management of waste,reduction in the consumption of raw materials and energy saving.展开更多
文摘This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was obtained using wheat bran as substrate at 72 h fermentation with maximum proteolytic activity of 401.42 U/mL, collagenase of 243.0 U/mL and keratinase of 19.1 U/mL. The protease exhibited K<sub>M</sub> = 18.7 mg/mL and Vmax = 28.5 mg/mL/min. The optimal pH was 8.0 and stable in a wide pH range (5.0 - 11.0) during 24 h. The optimum temperature was 40°C. The proteolytic activity was inhibited by Cu<sup>2+</sup> (33.98%) and Hg<sup>2+</sup> (22.69%). The enzyme was also inhibited by PMSF (65.11%), indicating that is a Serine Protease. These properties suggest that alkaline protease from A. tamarii URM4634 is suitable for application in food industries and leather processing. Additionally, the present findings opened new vistas in the utilization of wheat bran and other effective agroindustrial wastes as substrates for SSF.
文摘The present study investigated the incorporation of sugarcane bagasse ash(SCBA)in red ceramics,sintered in conventional oven and microwave oven,aiming to provide an alternative product,and a sintering process with higher energy efficiency in the production of red ceramics.The raw materials were characterized by XRF,XRD,thermogravimetry,particle size distribution and specific mass analyses.The specimens were shaped by extrusion in two different compositions,red clay and red clay with addition of 20%SCBA and sintered at temperatures from 700 to 1100℃.The conventional sintering occurred for 60 min with heating rate of 10℃/min.In the microwave oven the sintering occurred in a hybrid way,with heating rate of 50℃/min for 5,10 and 15 mins.After sintering the tests of linear shrinkage,compressive strength,water absorption,apparent porosity and apparent specific mass were performed.The addition of SCBA causes an increase in the values of water absorption and decreases the compressive strength and specific mass of the red ceramic.This occurs due to the creation of pores inside the material from the volatilization of organic matter present in the ashes.The sintering in microwave oven,when compared to conventional sintering,promotes an increase in the values of compressive strength and specific mass and reduction of water absorption values of ceramics,probably due to the refinement of the microstructure and the higher densification.Thus the incorporation of ashes can be partially compensated by a more efficient sintering.The use of SCBA and the sintering in microwave oven,showed to be viable alternatives in the development of a more sustainable and light material,promoting the management of waste,reduction in the consumption of raw materials and energy saving.
