Analysis of the cytochrome oxidase system in Deinococcus radiodurans under different culture conditions

• Main Authors: Hsiao-Yun Lai, 賴筱芸
• Other Authors: Jong-Kang Liu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/05314061062150852968

碩士 === 國立中山大學 === 生物科學系研究所 === 102 === Deinococcus radiodurans is a highly radioresistant Gram-positive tetrad. Previously studies show that the addition of 2.5 μM of manganese (Ⅱ) into a stationary phase culture could trigger a new cycle of cell division (Mn-CD effect). In this study, we analyzed the cytochrome oxidase system in D. radiodurans under different culture conditions with the addition of manganese (Ⅱ) to further understand the pathway and efficiency of energy production. Results show that D. radiodurans grew well in all TY (per 100 ml containing 0.5 g tryptone and 0.3 g yeast extract), TGY (per 100 ml containing 0.5 g tryptone, 0.3 g yeast extract and 0.1 g D (+)-glucose), and TFY medium (per 100 ml containing 0.5 g tryptone, 0.3 g yeast extract and 0.1 g D-fructose). In which, the TFY medium provided the best nutrients for D. radiodurans to grow. The occurance of Mn-CD effect is related to the age of cells. The N, N, N '', N''-tetramethyl-p-phenylenediamine (TMPD), oxidase activities were found to be similiar in both TY and TGY grown cells. Both cells had the highest specific activity in the early log phase and the lowest specific activity in the stationary phase. However, the TFY medium grown cells were different, which performed the highest specific activity in the mid log phase. The specific activities of the Mn (Ⅱ)-free cells in all three media were found to be similiar, no matter in the early log phase, the mid log phase, and the stationary phase. For the cells with the addition of Mn (Ⅱ) from the beginning of cultivation, TY medium cells shew the highest specific activity in the early log phase, but decreased significantly in the stationary phase. For the cells with the addition of Mn (Ⅱ) to the eighteenth hour cultures, the TFY medium cells shew the highest specific activity in the mid log phase, but decreased significantly in the stationary phase. Therefore, the addition of Mn (Ⅱ) had a drastically effect to the TMPD specific activity during stationary phase. All D. radiodurans cells possessed cytochrome a1, a+a3, b, c, c+c1, and o, no matter cultured in the TY, TGY, or TFY medium. However, the content of each component, were various with different culture conditions. Results also show that the TMPD oxidase activity was not related to the amount of cytochrome c, which was different from previous literatures and need further study.