Effect of medium composition and cultural condition on cellulase production by Aspergillus terreus

The effect of medium composition and environmental condition on the production of cellulase by Aspergillus terreus was investigated using shake flask culture with oil palm empty fruit bunch (OPEFB) as substrate. The highest activity of FPase (0.76 U ml-1), CMCase (8.64 U ml-1) and β-glucosidase (6.81 U ml-1) was obtained in medium containing 6 g L-1 yeast extract and 10 g L-1 delignified OPEFB fiber. In fermentation with the addition of Tween 80 (2 ml L-1) as surfactant, the production of cellulase was increased by two-fold as compared to fermentation without surfactant. Cellulase production by A. terreus was also enhanced with the addition of calcium chloride (3 mM) and magnesium sulfate (5 mM) in the medium. Optimum pH and temperature for cellulase production by A. terreus was 5.5 and 28°C, respectively. Cellulase production in agitated shake flask fermentation at 200 rpm was four times higher as compared to fermentation in static flask.Key words: Optimization, Aspergillus terreus, submerged fermentation, cellulase, oil palm empty fruit bunch

Performance measurement of a new concept reciprocating piston expander (RPE) using a newly developed small-scale dynamometer unit

This paper presents the progress of a small-scale dynamometer prototype development for performance measurement of a reciprocating piston expander (RPE). Since the available dynamometer systems in the market are limited to specific applications that require for the customization, their price normally very expensive. Since the current study on the RPE required a dynamometer unit, therefore, a new and cheaper dynamometer prototype that was suitable for RPE application has been developed. Using air as RPE working fluid, a case study has been carried out to measure its performance at different inlet fluid conditions, i.e., within 20°C–140°C and 3–5 bars. The results observed that the performance of RPE was proportionally increased to the increased of inlet fluid pressure and temperature. The maximum brake power produced was 27 Watt when the RPE operated at 140°C, 5 bars and the speed of 820 rpm. It also revealed that the changes in the pressure of inlet fluid can give significant change on the performance of the RPE due to its direct relation to the RPE actual rotating force. Although the RPE and dynamometer seem good being adapted to each other, both of them require some improvements to ensure both systems well operated and reliable

Performance measurement of a new concept reciprocating piston expander (RPE) using a newly developed small-scale dynamometer unit

This paper presents the progress of a small-scale dynamometer prototype development for performance measurement of a reciprocating piston expander (RPE). Since the available dynamometer systems in the market are limited to specific applications that require for the customization, their price normally very expensive. Since the current study on the RPE required a dynamometer unit, therefore, a new and cheaper dynamometer prototype that was suitable for RPE application has been developed. Using air as RPE working fluid, a case study has been carried out to measure its performance at different inlet fluid conditions, i.e., within 20°C–140°C and 3–5 bars. The results observed that the performance of RPE was proportionally increased to the increased of inlet fluid pressure and temperature. The maximum brake power produced was 27 Watt when the RPE operated at 140°C, 5 bars and the speed of 820 rpm. It also revealed that the changes in the pressure of inlet fluid can give significant change on the performance of the RPE due to its direct relation to the RPE actual rotating force. Although the RPE and dynamometer seem good being adapted to each other, both of them require some improvements to ensure both systems well operated and reliable