臺灣博碩士論文加值系統

曝露於陽光照射的水泥牆表面對微生物而言至少有三種生存的壓力，即養分缺乏、乾燥、與紫外輻射照射。我們有興趣於了解在此種極端環境中存活細菌的本質，尤其它們的中長波紫外光的抗性是否有獨特之處。為此，我們由老舊水泥牆表面刮取細砂樣品進行存活細菌測定與可能的優勢菌分離，並進而測定分離株的UVR抗性。我們對九面老舊水泥牆特定位置進行四次取樣(分別在四個不同季節)的實驗結果顯示: 每1 g細砂樣品的總活菌數約為102 ~ 103 CFU，而且細菌族群中有高比例的產色素細菌。本研究對一株黃色優勢菌(THY1)進行特性分析。實驗結果顯示，THY1類似Micrococcus luteus 為好氧、不產孢的四聯球菌。但是，在UVR抗性方面，我們得到有趣的結果。UVR照射的條件為: (1)細胞在洋菜平板表面照射; (2)混合UVR光劑量有兩種強度(單位是kJ/m2)，分別是UVA=78，UVB=120與UVA=206，UVB=708。在這些UVR照射條件下的實驗結果顯示，THY1的UVR抗性雖然比M.luteus 為顯著較低，但THY1的UVR存活曲線呈現獨特波浪狀，M.luteus則否。存活曲線呈現獨特波浪狀的原因尚待了解，然一個可能的推測是，UVB所造成的細胞傷害作用可以被UVA阻止或糾正。換言之，THY1擁有獨特的UVA-induced UVB resistance 。支持屬於inducible resistance的一個證據是我們以SDS-PAGE分析觀察到inducible proteins的表現。此蛋白質分子量顯示為30 kDa。

Many concrete wall surfaces that lack nutrients, water, and solar-UV protection represent an extreme environment for life. In this study, sands were sampled from nine different weathered concrete wall surfaces for viable bacterial count. Most counts were around 104 CFU/g or less. A yellow-pigmented bacterium (THY1) that appeared to be a predominant inhabitant in the harsh concrete-surface environment was isolated. An UV irradiator that provides broad-spectrum UV radiation (encompassing UVA, UVB, and UVC) was used to compare UV radiation (UVR) resistance of different bacterial strains. The results of the UVR survival suggested that THY1 possesses novel UVR-inducible UVR resistance that was not observed in Escherichia coli and Micrococcus luteus. SDS-PAGE analysis suggested the presence in THY1 of two~ 30 kDa UVR-inducible proteins.

中 文 摘 要 -------------------------------------- 1
英 文 摘 要 -------------------------------------- 3
簡 介 -------------------------------------------- 4
材 料 與 方 法 ----------------------------------- 7
結 果 -------------------------------------------- 10
討 論 -------------------------------------------- 13
參 考 文 獻 -------------------------------------- 15
圖 表 -------------------------------------------- i

1. Pessi, A. M. , J. Suonketo, M. Pentti, M. Kurkilahti, K. Peltola, and A. Rantio-Lehtimaki . 2002. Microbial growth inside insulated external walls as an indoor air biocontamination source. Appl Environ Microbiol. 68(2):963-7.
2. Vincke, E., N. Boon, and W.Verstraete. 2001.Analysis of the microbial communities on corroded concrete sewer pipes--a case study. Appl Microbiol Biotechnol. 57(5-6):776-85.
3. Sliney, D.H. 1999. Geometrical assessment of ocular exposure to environmental UV radiation--implications for ophthalmic epidemiology. J Epidemiol 9(6 Suppl):S22-32.
4. Johnson, D., C. D. Campbell, J. A. Lee, T.V. Callaghan , and D. Gwynn-Jones. 2002. Arctic microorganisms respond more to elevated UV-B radiation than CO2. Nature 416(6876):82-3.
5. Fujioka, R. S., H. H. Hashimoto, E. B. Siwak, and R. H. Young. 1981.
Effect of sunlight on survival of indicator bacteria in seawater. Appl Environ Microbiol . 41(3):690-6.
6. Oppezzo, O. J., and R. A. Pizarro. 2001. Sublethal effects of ultraviolet A radiation on Enterobacter cloacae. J Photochem Photobiol B. 15;62(3):158-65.
7. Cockell, C. S. and L. J. Rothschild. 1999. The effects of UV radiation A and B on diurnal variation in photosynthesis in three taxonomically and ecologically diverse microbial mats. Photochem Photobiol . 9(2):203-10.
8. Horiguchi, M., K. I. Masumura, H. Ikehata, , T. Ono, Y. Kanke, and T. Nohmi. 2001. Molecular nature of ultraviolet B light-induced deletions in the murine epidermis.Cancer Res. 15;61(10):3913-8.
9. Obiri-Danso ,K., N. Paul, and K. Jones. 2001. The effects of UVB and temperature on the survival of natural populations and pure cultures of Campylobacter jejuni, Camp. coli, Camp. lari and urease-positive thermophilic campylobacters (UPTC) in surface waters.J Appl Microbiol . 90(2):256-67.
10. Akiyama, H., O. Yamasaki, H. Kanzaki, J. Tada, and J. Arata.1998. Effects of various salts and irradiation with UV light on the attachment of Staphylococcus aureus strains. J Dermatol Sci . 16(3):216-25.
11. Babu, G. S., P. C. Joshi, and P. N. Viswanathan. 1998. UVB-induced reduction in biomass and overall productivity of cyanobacteria. Biochem Biophys Res Commun. 6;244(1):138-42.
12. Cockell, C. S., and A. L. Andrady. 1999. The Martian and extraterrestrial UV radiation environment--1. Biological and closed-loop ecosystem considerations. Acta Astronaut . 44(1):53-62.
13. Brown, D. G., and P. R. Jaffe. 2001. Effects of nonionic surfactants on the UV/visible absorption of bacterial cells. Biotechnol Bioeng. 20;74(6):476-82.
14. Karlin ,S., and J. Mrazek. 2001. Predicted highly expressed and putative alien genes of Deinococcus radiodurans and implications for resistance to ionizing radiation damage.Proc Natl Acad Sci USA . 24;98(9):5240-5.
15. Cockell, C. S., and G. Horneck. 2001. The history of the UV radiation climate of the earth--theoretical and space-based observations. Photochem Photobiol . 73(4):447-51.
16. Sommer, R., M. Lhotsky, T. Haider, and A. Cabaj . 2000. UV inactivation, liquid-holding recovery, and photoreactivation of Escherichia
coli O157 and other pathogenic Escherichia coli strains in water. J Food Prot . 63(8):1015-20.
17. Arrieta, J.M., M. G. Weinbauer, and G. J. Herndl. 2000. Interspecific variability in sensitivity to UV radiation and subsequent recovery in selected isolates of marine bacteria. Appl Environ Microbiol. 66(4):1468-73.
18. Gardner, D.W., and G. Shama. 2000 . Modeling UV-induced inactivation of microorganisms on surfaces. Food Prot. 63(1):63-70.
19. Joux, F., W. H. Jeffrey, P. Lebaron, and D. L. Mitchell. 1999. Marine bacterial isolates display diverse responses to UV-B radiation. Appl Environ Microbiol. 65(9):3820-7.
20. Weinbauer, M. G., S.W. Wilhelm, C. A. Suttle, and D. R. Garza. 1997. Photoreactivation compensates for UV damage and restores infectivity to natural marine virus communities. Appl Environ Microbiol. 63(6):2200-5.
21. Horneck, G., P. Rettberg, E. Rabbow, W. Strauch, G. Seckmeyer, R. Facius, G. Reitz, K. Strauch, and J. U. Schott. 1996. Biological dosimetry of solar radiation for different simulated ozone column thicknesses. J Photochem Photobiol B . 32(3):189-96.
22. Arrage, A. A., T. J. Phelps, R. E. Benoit, and D. C. White. 1993. Survival of subsurface microorganisms exposed to UV radiation and hydrogen peroxide. Appl Environ Microbiol. 59(11):3545-50.