本研究分兩大部分，其一探討光對深層培養無花果曲霉菌Aspergillus ficuum的影響;其二為Microbacterium sp.去除二甲基硫Dimethyl sulfide之研究。 其一探討光對深層培養無花果曲霉菌Aspergillus ficuum的影響:文獻證實Bacillus subtilis，其蛋白質基因具有光接收器，會對光源產生反應。本實驗室先期研究已證實白光強度對納豆菌產生Nattokinase活性有影響;並證實光強度與波長對無花果曲霉菌Aspergillus ficuum產生phytase活性有影響。 本論文觀察到光的波長以不同的方式影響發育和生理作用，提出光強度與波長對Aspergillus ficuum影響生理週期與代謝物之相關性，並透過代謝產物LC圖譜分析，研究光對無花果曲霉菌Aspergillus ficuum代謝物產出的影響，這些發現表示無花果曲霉菌Aspergillus ficuum擁有因應不同光線進行反應和調節的系統。 其二為Microbacterium sp.去除二甲基硫之研究:二甲基硫是工業排放氣體中，優先要被去除的對象，因為只要很少量的二甲基硫就能夠察覺到異味，而且跟其他還原態的硫化物相比，二甲基硫是較難被生物降解的。有多種利用二甲基硫作為碳源或能量來源的菌株已經被研究，而且說明了降解途徑。然而截至目前為止，在工業應用上，使用這類菌株接種至生物反應器，以處理二甲基硫的報告很少。這類系統有個問題是: 中間代謝產物的累積，這會嚴重影響微生物對二甲基硫的去除。在此報告中我們得到的結果是，將降解硫化氫的假單胞菌屬菌株Pseudomonas putida 以及降解二甲基硫的微細菌屬菌株 Microbacterium sp. NTUT26 接種至生物反應器，可以促進中間代謝產物以及二甲基硫的去除。並且根據表觀動力學(apparent kinetics)以及最大去除能力的評估，此生物反應器去除二甲基硫的效能良好(1.71 g-S/day/kg-乾填充材料)。在各種條件下 (不論是開工、進流負荷(inlet loading)、停工或是重新啟動的改變)，同時接種了 Microbacterium sp. NTUT26 以及 P. putida 的生物反應器可提升高濃度的二甲基硫的去除能力。我們的研究結果推薦這一型的生物反應器系統，在處理(工業的)二甲基硫氣體，具有很大的應用潛力。 This research study consists of two major parts. The first part studies the effect of light on the submerged culture of Aspergillus ficcum, and the second part investigates the role of Microbacterium sp. in the removal of dimethyl sulfide. The first part studies on the effect of light on the submerged culture of Aspergillus ficuum confirm that Bacillus subtilis is equipped with photoreceptor protein genes that react to light sources. Prior research conducted by this laboratory verifies that the intensity of white light affects the activity of Nattokinase, while light intensity and wavelength affects the phytase activity of Aspergillus ficuum. By observing that light wavelength influences growth and physiological activity in various ways, this thesis addresses the relevance of light intensity and wavelength on the physiological cycle and metabolite of Aspergillus ficuum and examines light-induced behavior in thees production of metabolites with LC analysis. Results indicate that Aspergillus ficuum possess a response and regulatory system that adapts to different light sources. The second part of this thesis investigates the role of Microbacterium sp. in the removal of dimethyl sulfide. The removal of dimethyl sulfide (DMS) from industrial gas streams has received a high priority due to its very low odorous threshold value and relatively low biodegradability compared to other reduced sulfur compounds. A variety of bacteria that utilize DMS as a carbon/energy source have been studied and the degradation pathway elucidated. However, to date, there have been few reports on the industrial application of such bacteria inoculated into a bioreactor for DMS treatment. An additional problem of such systems is the accumulation of intermediate metabolites that strongly impact on DMS removal by the microbe. The results reported here were obtained using a bioreactor inoculated with the H2S-degrader Pseudomonas putida and the DMS-degrader Microbacterium sp. NTUT26 to facilitate removal of metabolic intermediates and DMS. This bioreactor performed well (1.71 g-S/day/ kg-dry packing material) in terms of DMS gas removal, based on an evaluation of the apparent kinetics and maximal removal capacity of the system. Under varying conditions (changes in start-up, inlet loading, shutdown, and re-start), the bioreactor inoculated with Microbacterium sp. NTUT26 and Pseudomonas putida enhanced removal of high concentrations of DMS. Our results suggest that this type of bioreactor system has significant potential applications in treating (industrial) DMS gas streams.
