ISOLATION OF AMYLASE PRODUCING FUNGI FROM CASSAVA FLOUR

Amylases are among the most important enzymes with potential applications in the present-day industry. Thus, isolating pure culture from cassava as the cheap source has manifold importance for food industries. In the present study, eleven amylase producing fungal strains were isolated from cassava flour and growth pattern, as well as optimum growth condition, was determined. All isolates showed amylases activity but isolate BR005, BR001 and GR003 recorded maximum clear zone diameters of 54.75 ± 0.957 mm, 53.25 ±0.645 mm 51.5 ± 1.414 mm, respectively. The submerged fermentation method was employed for crude amylase and biomass production. There were significant differences (p˂0.05) in starch concentrations and growth rates between the three isolates. GR003 and BR005 attained their optimal amylase activities of 4.23±0.25 U/mL and 3.75±3.16 U/mL at 50 °C, respectively, whiles BR001 attained its optimum amylase activity of 3.43±0.77 at 60 °C. Whereas, BR005, BR001 and GR003 attained their optimal amylase activity of 5.14±1.99 U/mL, 4.53±0.01 U/mL and 1.25±1.11 U/mL at a pH range of 6 to 7, making them neutrophilic fungi. Moreover, isolates BR005, BR001 and GR003 recorded the highest amylase activities of 4.31±0.14U/mL, 4.67±1.16±U/mL and 3.16±0.12U/mL at the starch concentrations of 3%, 2%, and 2.5% and fermentation period of 48 h, 66 h and 42 h, respectively. Lastly, BR005, BR001 and GR003 achieved their optimal amylase activities of 5.41±0.11U/mL, 6.24±0.14 U/mL and 6.22±0.12 U/mL at 48 h, 66 h and 42 h of incubation, accordingly. Indicating that cassava flour is a good source of amylolytic fungi with a potential application under wide conditions.

Screening and Degradation Characteristics of Anthracene-Degrading Strains

Two efficient anthracene-degrading strains are isolated from pollution sludge collected from sewage treatment plant and identified by sequencing their 16S rDNA genes, one is Pseudomonas nitroreducens and the other is Bacillus sp.. The proper growth conditions of each bacterium was measured and presented for anthracene-degrading. The optimum growth condition is pH 7.5, 30°C. Biodegradation assays revealed that the degradation rates of two bacterial strains are 82.3% and 80.7% in 7 days. Respectively, the two bacteria had played important roles in the degradation of anthracene.

CHARACTERISTICS OF MgB2 THIN FILMS SYNTHESIZED BY CO-EVAPORATION METHOD

MgB 2 thin films have been synthesized by co -evaporation method by controlling the relative deposition rates of B and Mg on sapphire ( Al 2 O 3) substrate. Before the co -evaporation of Mg and B , the deposition rates of each element have been measured separately with various substrate temperatures. As the substrate temperature increased above the optimum growth condition, Mg started to evaporate from the already reacted MgB 2 and form MgB 12 as a second phase, which resulted in the tendency decreasing the critical temperature. Superconducting properties have been measured by PPMS and the microstructural features have been characterized with XRD, SEM and EDS.

Homoepitaxial Growth on 4H-SiC (03-38) Face by Sublimation Close Space Technique

For preliminary step toward fabrication of MOSFET using 4H-SiC 8) 3 (03 prepared by sublimation method, epitaxial growth of device quality 4H-SiC on 4H-SiC (0001) 8.0° off substrate was carried out and investigated. Smooth and specular surface of 4H-SiC (0001) plane was obtained by optimum growth condition. And epitaxial growth on 4H-SiC 8) 3 (03 and ) 8 3 (03 substrates were carried out with optimum growth conditions of 4H-SiC (0001). Smooth and specular surface was obtained on 4H-SiC 8) 3 (03 and ) 8 3 (03 plane. Growth rate of epilayers of 4H-SiC (0001), 8) 3 (03 and ) 8 3 (03 face were same. Oxidation rate of 4H-SiC (0001), ) 1 (000 , 8) 3 (03 and ) 8 3 (03 face was investigated. The oxidation rate was different depending on the faces. It was observed that the difference of oxidation rate of 8) 3 (03 and ) 8 3 (03 is mainly due to the difference of polarity similar to the case of reported for (0001) and ) 1 (000 .