Studies on Immobilized Enzyme of Chitosan Modified by Xanthan Gum

• Main Authors: CHANG, YU-TENG, 張育騰
• Other Authors: TSAI, MING-SHIUN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/y3eq26

博士 === 大葉大學 === 生物產業科技學系 === 105 === We used xanthan gum (XG) to modify chitosan (Cs) and to coat or adsorb some enzymes (such as galactomannanase, Gm) by XG-Cs bipolymer, similar to the microparticles. We also used three kinds of different proportions of XG:Cs (X1C1=1:1, X2C1=2:1, X1C2=1:2), to produce them (XG-Cs) in the modified process of compositions. At the same time, the adsorption and release efficiency of the immobilized enzyme were studied by Langmuir equation, and the relationship between the pH value, adsorption time, stirring rate and concentration of immobilized enzyme was studied to improve the optimum and application of each condition. The results of the preliminary experiments showed that X1C2 > X1C1 > X2C1, X1C2=7.210 U/mg, X1C1=7.111 U/mg and X2C1=6.790 U/mg under the condition of 10 mg Gm / 100mL H2O and Cs Itself is 8.469 U/mg. The experiment showed that the first recycling enzyme activity performance efficiency orders was (p<0.05): X1C1 (79.8%) > X1C2 (77.5%) > X2C1 (75.4%) > Cs (73.3%). The second recycling enzyme activity performance efficiency order was (p<0.01): X1C1 (53.6%) > X2C1 (52.4%) > Cs (52.3%) > X1C2 (50.3%). Although the adsorption effect of modified chitosan particles were slightly worse than that of Cs itself, the activity of the immobilized enzyme was stable and could be used repeatedly. The further application research of XG-Cs was the addition of nickel nanowires (nanowire Ni, -Ni) which were used to prepare XG-Cs/Ni to produce nano magnetic biopolymer colloids. The FE-SEM showed that the diameter of the nickel nanowires was about 80 nm and the length was about 10 μm, with high density and high aspect ratio. The crystal planes of Ni-nanowires were analyzed by XRD and showed the polycrystalline structure. The TEM was used to observe the characteristics of the single nanowire as fine nickel grains and the similarities and differences (dislocation) of crystallization and twin crystal structure. The magnetic field was measured with a VSM at a temperature of 300°K. The coercivity (Hc) was 685 Oe, the squareness (Mr/Ms) is 0.866, and the horizontal field (H//) is applied for a magnetic field with a coercive force of 118 Oe and an angular ratio of 0.068. The coercivity of the XG-Cs/-Ni nickel nanowires was 914 ~ 957 Oe and it will be conducive to the study of the application for the magnetic nano-materials or drug delivery system.