KOSEN 한인과학기술자네트워크

안녕하세요~ 얼마전에 What is에 글을 남겼다가 조언을 얻은 학생입니다. 논문을 완전히 이해하고 모르는 부분을 물어볼려다가 이렇게 늦게 질문을 하게 되었습니다. Comparison of TNT removal from seawater by three marine macroalgae논문의 result and discussion부분에서요 TNT의 농도가 높아짐에따라 first-order rate constant가 낮아진다고 이해를 했는데요 확실히 무엇을 의미하는지 모르겠습니다. first-order rate constant가 높아지고 낮아지는게 무엇을 의미하는지를 모르겠구요... 또 다른 질문은 이 저자가 빛에 대한 control실험을 했다고 적어놓았는데 그 단락은 잘 이해를 못하겠습니다. 실험방법에도 안나오고 갑자기 결론부분에 쌩뚱맞게 나와서 이해하기가 좀 힘드네요 Illuminated control experiments containing seawater medium were conducted in parallel with the TNT uptake and metabolism experiments. The TNT concentration decreased with time due to degradation by a first-order process (see Fig. 1), consistent with previous studies for photolysis of TNT in aquatic systems (Mabey et al., 1983). The abiotic TNT oxidation product 1,3,5-TNB was found in the seawater liquid medium of the control experiments, consistent with previous studies for the photolytic degradation of TNT in water (Schmelling and Gray, 1995), but did not account for all of the TNT loss. A representative time course for 1,3,5-TNB formation during the illuminated TNT control experiment is presented in Fig. 1a, where 1,3,5-TNB formation can be attributed to no more than 17% of total TNT loss. Apparent first-order rate constants for TNT disappearance in the illuminated control experiments are presented in Table 2. For example, the apparent first-order rate constants for abiotic degradation of TNT in seawater at 150 μE m?2 s?1 light intensity and 22 °C, which ranged from 0.0022 to 0.0023 h?1 at initial TNT concentrations ranging from 1.0 to 10 mg l?1, were at least 10 times smaller than the apparent first-order rate constants for TNT removal in the uptake and metabolism experiments conducted at the same conditions. 이단락이 좀 힘드네요....그리고 마지막 질문입니다. These results suggest that intracellular ADNTs were further biotransformed into uncharacterized products. In terrestrial vascular plants, several studies confirmed that the TNT metabolites that were not excreted did not mineralize to CO2 but instead were ultimately incorporated into the “nonextractable” cell wall component of the plant tissue (Hughes et al., 1997, Vanderford et al., 1997, Burken et al., 2000 and Hannink et al., 2002). One possible route identified in vascular terrestrial plants is the conjugation of ANDT metabolites with sugars via N-glycosylation of the reactive amine group (Bhadra et al., 1999 and Vila et al., 2005 M. Vila, S. Pascal-Lorber, E. Rathahao, L. Debrauwer, C. Canlet and F. Laurent, Metabolism of [14C]-2,4,6-trinitrotoluene in tobacco cell suspension cultures, Environ. Sci. Technol. 39 (2005), pp. 663?672. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (19)Vila et al., 2005), followed by continued polymerization of the sugar adduct into cell wall polysaccharides. This study did not determine if the products of TNT transformation by marine macroalgae followed a similar route. Furthermore, it was beyond the scope of this study to challenge the macroalgal tissue cultures with 2-ADNT or 4-ADNT and look for biotransformation products from these substrates, as the focus of this study was on TNT removal from seawater. 이부분에서 앞쪽부분에 CO2와 관련된 부분이 이해가 안됩니다. 기존에 밝혀진 관다발 식물에 관한 연구에서 배출되어지지 않는 TNT대사산물이 CO2와 mineralize되지 않는다고 해석을 했는데요...여기서 mineralize되지 않는 다는 말이 무슨말인지 모르겠습니다. 질문이 꾀 많은데..... 시간가 여유가 되신다면 가르침 부탁드립니다. 꾸뻑~!!!