グリーンアジアのための国際資源人材育成戦略

[PY-05] 超好酸性古細菌Sulfolobus tokodaii を利用したバイオPd(0)ナノ粒子の生成およびその触媒活性評価　

^○ギッティーヌギット サンティサック, 平島剛, 笹木圭子, 沖部奈緒子 (九州大学大学院　工学研究院)

キーワード：超好酸性古細菌、パラジウム、バイオナノ粒子

Palladium (Pd) is recognized as an important industrial catalyst which has been used to speed up various chemical reactions. As its demand is growing year by year, it is critical to recover it from Pd(II) containing leachates/wastewaters. This study investigated the utilization of the extremely acidophilic archaeon, Sulfolobus tokodaii, as a support for the bio-Pd(0) nanoparticles production. Owing to microbial enzymatic reaction, Pd(II) ions were effectively removed from solution, forming bio-Pd(0) nanoparticles on the cell surface within 5 hours (with 10 mM sodium formate). Fine and well-dispersed bio-Pd(0) nanoparticles were produced only in the presence of active cells. Those were not formed in the absence of cells (control), in the presence of enzyme inhibitor or inactivated enzyme (heat-killed cells). Catalytic activities of bio-Pd(0) nanoparticles were evaluated using Cr(VI) reduction reaction in the presence of electron donor (formate or hydrogen gas) in the acidic condition. Highly toxic Cr(VI) anions were completely reduced to less toxic Cr(III)　anions within 12 hours in the presence of 0.025 mg/ml bio-Pd(0) nanoparticles (weight including dried cell mass) and 10 mM sodium formate. The results suggest the potential of microorganisms to produce highly catalytic bio-Pd(0) nanoparticles using an environmental friendly approach.（企画講演で発表）