為「世紀之毒」找解藥!- 探討以Pseudomonas mendocina 菌株降解污染土壤中戴奧?
本研究採自中石化安順廠戴奧辛污染場址之土壤,篩選出一株純 菌微生物(Pseudomonas mendocina NSYSU) , 其含有PCDD/Fs (Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, PCDD/Fs)土壤於實驗室進行微生物降解試驗,結果顯示約21 天即有 明顯降解結果;本研究同時觀察到該微生物能在汞濃度達50 ppm 之 戴奧辛土壤中,仍具有相當程度之耐受度,並進一步降解戴奧辛化合 物。 我更以標準品探討菌種對於戴奧辛類化合物(Dioxin like congener) 之降解效果,成功地發現這株菌種不僅對於PCDD/Fs 有降 解能力,對於戴奧辛類化合物也有明顯之降解效果。 由研究結果,明顯看出P. mendocina 菌株為「世紀之毒」找到了 解藥,開發出以生物復育改善污染環境的一種新方法。A dioxin-degrading bacterial strain Pseudomonas mendocina NSYSU was isolated from dioxin contaminated soil by selective enrichment techniques. In our previous study, P. mendocina NSYSU was found to be able to use pentachlorophenol (PCP) as its sole carbon source and energy source and was capable of completely degrading this compound. Moreover, P. mendocina NSYSU was also able to mineralize a high concentration of PCP up to 150 mg/L. In this study, P. mendocina NSYSU was investigated for its ability to degrade polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs). Results show that P. mendocina NSYSU could grow well in media containing both PCDFs and PCDDs, and was able to degrade both compounds efficiently. In this study, isotope dilution method and a high resolution gas chromatography-mass spectrometry (HRGC/HRMS) technique were applied for the analyses of PCDFs and PCDDs. Investigation results reveal that significant biodegradation of octachlorinated dibenzo-p-dioxin (OCDD) and octachlorinated dibenzofuran (OCDF) by treating with P. mendocina NSYSU resting cells was observed. The results also indicate that this bacterial strain is able to biodegrade OCDD and OCDF effectively under anoxic conditions due to its facultative anaerobic character. No accumulation of inhibitory toxic byproducts was found in this study. These findings suggest that in situ or on-site bioremediation of dioxin-contaminated soils by using indigenous microorganisms or inoculated P. mendocina NSYSU strain would be a feasible technology for field application.
紫茉莉生物時鐘機制的研究
Mirabilis Jalapa is a wild flower, which is often seen in countryside of Taiwan. This plant blossom regularly every day around PM 3:00-6:00. Since its regular behavior, it has the potential to become a model plant for research on circadian ryhtem. According to the on spot observation, a Mirabilis Jalapa will bloom consistently, whereas a minority of flower will bloom earlier or later. First, we observe how Mirabilis Jalapa response to disparate environmental conditions. Under a short period of light(8h) and an average period of light(12), Mirabilis Jalapa acts as normal. But under a long period of light, it flowers approximately 1h ahead of time. When under a continuous light, Mirabilis Jalapa shows a regular flowering in the first four day, and after that, circadian rythem of flowering terminate. The ripe flower buds mentain unbloom for 10 days or more, finally end up withered. Meanwhile, floral meristems are also suppressed. Temperature alter seems affct the flowering slightly. Second, we use SDS-page to detect protein divergence 6h interval.But as many of the earlier attempt, the floral stimuli is not sensible for average protein qualitative analysis. So we decide to take more direct approch by genetic experiment. From supplemental material of article” Orchestrated Transcription of Key Pathways in Arabidopsis by the Circadian” we obtain a group of genes regulared by bioclock in Arabidopsis.With Bio Informatics we choose 41 single gene, and compare with sequences in other species, designing promotors to isolate similar genes in Mirabilis Jalapa. Use rt-PCR to detect the level of certain gene expression,and compare characters of those genes in Mirabilis Jalapa with those genes in Arabidopsis. We also blast those 453 genes to the database of animal, trying to recognize some genes that is widely separated between disparat species. And test these genes in Mirabilis Jalapa to confirm this result.本實驗先針對紫茉莉開花生物時鐘的特性進行觀察,並以不同的變因測試對紫茉莉開花時鐘的影響,紫茉莉個別花朵開花生物時鐘並不一致,長日照會對植株造成開花時間提早(約1 小時)的影響,全日照則會對花芽分生及開花行為造成抑制,溫度對於開花影響不明顯。而後利用蛋白質電泳對不同時間點的樣本進行分析,由於開花激素存量極微,故並電泳結果無明顯差異。再來以阿拉伯芥已知與生物時鐘有關的基因中經過生物資訊(Bio Informatics)預測在紫茉莉中存在與開花及光週期有關之基因(CAA75629 CAB56039 AAB60305 AAC49807 AAA82068),針對該基因進行表現量的測定,驗證該基因與開花生物時鐘的關聯性。針對動物界與植物界中已知與生物時鐘相關的基因進行交叉比對,希望找出跨界廣泛存在的生物時鐘基因,接著測試紫茉莉中該基因的存在與否及表現狀況與其他物種的差異,驗證該基因分布的廣泛性。
太陽系外行星光度研究
搜尋太陽系外行星(extra-solar planet;exoplanet)是當今天文學家最重要的計畫之ㄧ;其中,當系外行星經過其主恆星碟面時,會造成光度略微下降,稱之為凌日現象(transit) 。本研究便是利用鹿林天文台SLT(Sne Little Telescope)望遠鏡來拍攝兩顆已知的系外行星HD 189733 b 和HD 209458 b在凌日時的影像。 我們得到約4000 張影像,再經過影像修正與資料分析後,我們作出凌日光變曲線圖、Bin圖及相位圖,並從中探討其特性。 經分析判斷後,HD 189733 看到一個剛開始發生和一個完整的凌日現象,分別由B濾鏡和 R 濾鏡所拍攝;而 HD 209458 則看到兩個剛開始發生,三個要結束的凌日現象,分別由B濾鏡、R 濾鏡和 Hα 濾鏡。 並由光變曲線,推得HD 189733 的基本參數,包括:行星半徑為 1.242個木星半徑、軌道傾角為88.94 度以及軌道半徑為 0.03115 天文單位。 Since 1995, more than 200 extra-solar planets have been found. Until today, astronomers still make efforts in searching extra-solar planets because it’s one of the most important projects in this century. During the crossing by the stellar disks (i.e., transits), the exoplanets will cause the brightness to decrease by a small amount. In the project, we have focused on the observations of two known transit exoplanets, HD 189733 b and HD 209458 b. The photometric observations were performed with the 40-cm SLT telescope on the Lulin Observatory. The results from the image procuring, data reduction and analysis are presented. We accrue and plot the light curve, bin and phase. We found out that HD 189733 has two transit ingresses with B, R band, and HD 209458 has two transit ingresses, two transit egresses with B, R, Hα band on phase. We figure out planetary parameters, RP is 1.242 RJ, inclination is 88.94° and orbital semi-major axis is 0.03115 AU by transit light curve.
長方體內最少完全城堡數
我們試著尋找所需最小的城堡個數以看守整個a × b × c (a,b,c ? N) 的長方體。所謂城堡是一種棋子,當放置城堡的位置是(x, y, z) ,則(x, y,t)、(x,t, z)、(t, y, z) (t 是任何不超出邊界的正整數)是這個城堡可以看守的格子。我們用這些城堡來完全看守長方體,試著找出其最小值。在2005 年我們猜測了a = b = c 、a = b c 、a > b > c 的上界,而在2006 年時完成了a = b = c 、a = b c 的大部分情況的證明,少數不能解決的部份也提供了不錯的上界。目前我們在a = b = c 、a = b c 的情況幾乎完全解決,目前正在向a > b > c 的部份發展。A generalized searching method of finding the minimum number of castle which can oversee all over the rectangular box, defined as a × b× c (a,b,c ? N) , is presented. The castle here is defined as one kind of chess. The castle positioned as (x, y, z) can direct the lattice points of (x, y,t) 、(x,t, z) 、(t, y, z) (t is the positive integer and smaller than the box size). These castles we use here is to oversee the rectangular box and to help us to find the minimum number. In 2005, we got the upper bound of overseeing the rectangular box in the conditions of a = b = c、a = b c、a > b > c , while in 2006 we complete the proofs of the minimum number of castles based on the conditions of a = b = c 、a = b c . The further work we want to attain is to complete the case of a > b > c.