以連通式溫度梯度培養器研究泥火山微生物活動

Abstract

本論文主要使用連通式溫度梯度培養器，將不同溫度不同培養時間下採集之樣本藉由氣相層析儀(Gas Chromatography)、離子層析儀(Ion Chromatography)分析，由其火山泥細菌代謝物之化學成分，來觀察火山泥細菌在連通式溫度梯度培養器的活動情形。由於泥火山微生物為一種厭氧細菌，所以需設計一個封閉系統當作泥火山微生物的棲息地，另外設計有可以讓使用者抽取樣本的機構。目前之設計為有旁支小管之金屬培養器，旁支小管以橡膠塞隔絕外界環境，以期能達到封氧的效果。此系統仍需進一步之實驗測試。而本論文之火山泥細菌實驗先以鑲埋填充火山泥之密閉試管於等溫度梯度培養器進行。經由熱傳模擬及實際溫度量測，實驗之系統確實能使填充之火山泥達到等溫度梯度之條件。目前的實驗加熱裝置將火山泥的溫度範圍訂於40~60℃，一次培養七支試管的火山泥，經過不同的時間後分析產生的甲烷濃度和試管內的有機酸濃度，發現隨著時間甲烷菌逐漸分解有機酸產生甲烷，而且分解有機酸的速率是隨著溫度昇高而加快。和之前的等溫度火山泥培養實驗結果有些許差異。經由和其他實驗的交叉比較，可以更進一步了解火山泥細菌於不同溫度條件下之生物化學反應。

We use a connected thermal gradient incubator to monitor microbial activity in volcano mud. The extracted samples are analyzed by gas chromatography and ion chromatography techniques. We monitor the microbial activity from the physiological species generated by the mud volcano microbes. The majority mud volcano microbe is a kind of anaerobic bacteria. The incubator must be shielded from the outside environment. The optimized design so far is a hollow metal cylinder with branched sampling holes on the sides. Through the heat transfer simulation and in-situ temperature measurements, we confirmed that the designed incubator can support a steady constant thermal gradient. This design has to be further tested. The current experiments are conducted using testing tubes, which are stuffed with volcano mud, embedded in an iron sand stuffed hollow cylinder incubator, which can support a constant thermal gradient. Seven testing tubes are installed in a constant thermal gradient with temperature spanned from 40 to 60 oC. We analyze the methane and organic acid concentrations at different incubation durations. We discover that the organic acid decomposition rate by the methane bacteria is increased as the incubation temperature increased. This result is different from that obtained by previous incubation experiment performed using separate testing tubes at different temperatures. In conjunction with the experiments performed at fixed temperatures, this experiment method can help us further understand the microbial activity of mud volcano under the influence of thermal gradients.