Stenotrophomonas sp. CD02 抗重金屬鎘之機制探討

Study on the mechanisms of cadmium-resistance of Stenotrophomonas sp. CD02

葉芷微(Chih-Wei Yeh)

指導教授 ： 簡志青

元智大學/工程學院/生物科技暨生物資訊研究所/碩士(2007年)

摘要

Stenotrophomonas sp. CD02 為從重金屬鎘污染的土壤中分離出之菌株，此菌株能在含高濃度的鎘（4 mM）的培養基中生長，同時也能抵抗數種不同之重金屬包括鉻、鉛、鎳、銅以及鋅。此細菌在含鎘的培養基中生長時當其到達生長穩定期時培養液中之鎘濃度呈現減少(移除)的情形。爲了明瞭此菌株對重金屬抵抗的機制，本人進行其在含重金屬與不含重金屬培養條件下蛋白質表現的異同。由生長在不同條件（加入或未加入重金屬以及不同生長期）之 Stenotrophomonas sp. CD02 萃取出蛋白質後經一維或二維凝膠電泳分離分析比較細胞在不同環境下之蛋白質表現情形，再進一步將僅在含重金屬環境下表達(或消失)或不同生長期表達(或消失)之蛋白質進一步利用基質輔助雷射脫附/飛行時間質譜儀鑑定蛋白質種類，以期尋找此菌株內與其抗重金屬及移除鎘機制相關之蛋白質。

關鍵字

重金屬污染；鎘；二維凝膠電泳；基質輔助雷射脫附/飛行時間質譜儀

並列摘要

Stenotrophomonas sp. CD02 was isolated from soil heavily contaminated with the heavy metal cadmium. The bacterium can resist high concentration of Cd2+ (up to 4 mM) and other heavy metals such as chromium, lead, nickel, copper and zinc. This bacterium showed the ability to remove cadmium ions from medium when it reached stationary growth phase. In order to delineate the mechanisms of Cd2+ resistance for strain CD02, we compared the protein profile of the bacterium grown on the medium with and without addition of cadmium. Proteins extracted from cells grown in above mentioned conditions were subjected to two dimensional electrophoresis separations. Proteins expressed (or disappeared) in cells grown on medium contained heavy metal and in different growth phase (e.g. exponential phase vs stationary phase) were then analyzed by MALDI-TOF mass spectrometry. Some proteins that may involved in the mechanisms of Cd2+ resistance for strain CD02 were proposed according to the proteins identified. The specific roles of these proteins in Cd2+ resistance will be further evaluated in the future study.

並列關鍵字

Heavy metal contamination；Stenotrophomonas；Cadmium- resistance；Two-dimensional gel electrophoresis；Matrix-assisted Laser Desorption/ionization Time of Fight

參考文獻

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