Isolation and identification of microorganisms that resist to tellurite from heavy metal contaminated soil

• Main Authors: Chu-Ting Han, 韓竹婷
• Other Authors: Chih-Ching Chien
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/49136533461804883114

碩士 === 元智大學 === 生物科技暨生物資訊研究所 === 95 === Microorganisms reside in heavy metal contaminated area may evolve mechanisms for resistance to these toxic ions. In this study, I isolated three strains of microorganisms that are able to resist tellurite ion (TeO32-) from sediments from Er-Ren River, Tainan by enrichment culture techniques. The three bacteria were designed as strain TeB, TeC and TeW. Strain TeB and TeC were identified as Shewanella sp. and strain TeW was identified as a Paenibacillus sp. by 16S rDNA sequence analysis. Black precipitates (presumably the product of reduction of tellurite such as tellurium) occurred in cultures of all three strains after growth in medium containing tellurite. Quantitative determination of tellurite concentration in the liquid culture was carried out by using diethyldithiocarbamate (DDTC). The results showed that the concentration of tellurite was reduced from 100 μM to 50 μM in 20 hours in these cultures. Observation of cells of TeB, TeC and TeW grown in medium with and without tellurite by transmission electron microscopy and scanning electron microscopy were also performed in this study.