氧化亞鐵硫桿菌及氧化硫硫桿菌之胞外聚合物對銅金屬蝕刻之研究

Etching of Copper by Extracellular Polymeric Substance from Thiobacillus ferrooxidans and Thiobacillus thiooxidans

徐慧馨(Huei-Shin Shiu)

指導教授 ： 賀陳弘

國立清華大學/工學院/動力機械工程學系/碩士(2007年)

摘要

本文旨在針對微生物氧化亞鐵硫桿菌及氧化硫硫桿菌分泌之胞外聚合物對銅金屬進行蝕刻之研究。此二菌種對金屬有其特定的蝕刻能力，可對金屬進行加工。而其加工機制為菌體生長時會產生代謝物（胞外聚合物，EPS），此代謝物可將金屬氧化得到電子，菌體可於此過程中獲得所需能量。藉由此代謝過程，可對所需的工件進行加工。蝕刻過程中影響結果的因素有：微生物預培養時間、氧化亞鐵硫桿菌之EPS溶液中的三價鐵離子濃度、EPS溶液體積及銅試片面積等等，本研究探討不同參數與蝕刻行為對應之關係。
　　研究中顯示，氧化亞鐵硫桿菌經過三天的預培養時間產生的EPS已足夠對銅造成蝕刻，蝕刻過程中初始速率極快，蝕刻效果比純粹使用微生物進行蝕刻更好，但受溶液中銅離子濃度限制，當銅離子濃度隨著時間提高，蝕刻量會達到飽和，適合用於微量加工之工件。蝕刻過程中可採用二價鐵離子及三價鐵離子的濃度變化作為蝕刻效率的指標。
　　而氧化硫硫桿菌需八天的預培養時間，其EPS溶液對銅試片初始蝕刻速率較慢，但隨著時間逐漸加快，蝕刻速率隨之增加。可得到較高的總蝕刻量，適合需較大蝕刻量試片之加工。加工時氧化硫硫桿菌之EPS溶液中含有元素硫的成份，其功能為促進蝕刻作用的進行並能防止產生沉澱附著於試片上。

關鍵字

氧化亞鐵硫桿菌 ； 氧化硫硫桿菌 ； 材料移除 ； 代謝物 ； 微生物加工

並列摘要

This study uses extracellular polymeric substance (EPS) secreted by bacteria Thiobacillus ferrooxidans and Thiobacillus thiooxidans to etch the copper. These two bacteria have the ability of etching metal. The etching mechanism is based on the metabolite (EPS) from growing bacteria. The EPS can oxidize metal by acquiring electron, and bacteria obtain the necessary energy in the course. Through the metabolism, one can machine the work piece. The factors influencing etching results include the pre-cultivation time, the concentration of ferric ion in the EPS solution of Thiobacillus ferrooxidans, the area of copper, and volume of solution. This study explores the correlation between these parameters and etching behavior.
　　In this study, the EPS of Thiobacillus ferrooxidans reaches maximum material removal rate after culture of 3 days. At the beginning of etching, the rate of etching is very fast, but the copper removal amount is limited by the concentration of copper ion in the solution. It is suitable for the work piece with small amount of machining. The indicator of material removal rate is the concentration of ferrous ion during the etching process.
　　The initial material removal rate of the EPS of thiobacillus thiooxidans is slow, but it is faster and faster. The total copper removal amount is more than thiobacillus ferrooxidans. It is suitable for large amount of machining. There is sulfur powder in the solution when etching copper, which increases the rate of machining and prevent the residue on copper sample.

並列關鍵字

Thiobacillus ferrooxidans ； Thiobacillus thiooxidans ； material removal ； metabolite ； biomachining ； bioleaching

參考文獻

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