Using Ralstonia eutropha produce PHB while denitrifying situation

• Main Authors: Pei-Yuan Chen, 陳沛圓
• Other Authors: Chih-Cheng Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/33117818518854690921

碩士 === 環球技術學院 === 環境資源管理所 === 93 === ABSTRACT It was verified that Ralstonia eutropha could accumulate a large amount of PHB in cells, and PHB is the raw material of plastic which can be decomposed by bacteria. So the aim of this study is to find out the characteristic of PHB accumulation by Ralstonia eutropha while denitrifying situation. It’s expected that Ralstonia eutropha can remove the nitrate from the waste water and the sludge which possesses PHB can be reused. In autotrophic denitrifying condition, hydrogen gas and nitrate are electronic provider and electronic acceptor. So this study is to find out their effects. When providing 50mg NO3--N/L, 100mg NO3--N/L and 150 mg NO3--N/L, we found out the total number of cells would increase with higher nitrate concentration. But when nitrate and nitrite didn’t remove at all in the system. We found out the PHB accumulated in the cells was very low. The PHB accumulated in the cells didn’t increase with higher nitrate concentration. Another situation, we provided 7 mL/min, 35 mL/min and 63 mL/min hydrogen gas to the system. We found out the total number of cells would increase with higher hydrogen gas aeration. But when nitrate and nitrite didn’t remove at all in the system. We found out the PHB accumulated in the cells was very low. In this study, we found out when the activity of bacteria was in better situation, the growth curve had lag phase, log phase and stationary phase. Ralstonia eutropha accumulated less than 1% PHB in the cells when nitrate and nitrite is exist in the system. But when nitrate and nitrite is deficient in the system and hydrogen gas and carbon source are both sufficient, it accumulated 4.62% PHB in the cells gradually. In heterotrophic denitrifying condition, the PHB accumulated was 16.38% in the cells. When organic carbon was is deficient in the system, we found out the nitrite decreased slowly, and the PHB accumulated was 9.17%. The energy of denitrification was come from PHB releasing.