Trichosporon montevideense WIN提取物合成纳米金及其对硝基芳烃的催化特性

利用生物及其提取物合成纳米金具有反应条件温和、环境友好等优点.以菌株Trichosporon montevideense WIN提取物合成纳米金(Au NPs),考察反应时间、p H和提取物浓度对纳米金合成的影响,并探讨纳米金催化还原硝基芳烃的特性.结果显示,纳米金合成过程可在7 d内稳定,最优p H为7.0,最适提取物浓度为300 mg/L.通过紫外-可见光谱扫描、透射电子显微镜和傅立叶转换红外线光谱分析可知,纳米金为球形和伪球形,尺寸分布范围为4-35 nm,平均粒径为(18.2±0.4)nm,推测提取物中的羟基、氨基和羧基参与了纳米金的还原和稳定过程.纳米金对2-硝基苯酚、3-硝基苯酚、4-硝基苯酚、2-硝基苯胺和3-硝基苯胺具有良好的催化活性,其催化反应速率常数分别为7.5×10^(-3)s^(-1)、6.4×10^(-3) s^(-1)、9.1×10^(-3) s^(-1)、11.8×10^(-3) s^(-1)和20.7×10^(-3) s^(-1).本研究表明T.montevideense WIN在生物合成纳米金方面具有潜在的应用价值,且合成的生物纳米金能够有效应用于硝基芳烃污染物的催化还原.

Trichosporon montevideense WIN合成纳米金的催化特性

【目的】考察菌株Trichosporon montevideense WIN合成纳米金的催化特性及应用。【方法】利用活性WIN菌作用不同浓度HAu Cl_4(1、2和4 mmol/L)合成纳米金的特性,分别利用活性WIN菌和灭活WIN菌合成纳米金,分析合成纳米金的形貌、粒径及其催化特性。【结果】HAu Cl_4浓度为1 mmol/L时,菌株WIN合成了纳米金,HAu Cl_4浓度为2 mmol/L和4 mmol/L时,菌株WIN合成了纳米金及较大尺寸的金颗粒。通过紫外-可见光谱扫描、透射电子显微镜分析,发现活性和灭活WIN菌均能还原Au^(3+)合成纳米金,合成的纳米金均以球形为主,还有少量三角形、四边形及六边形。活性WIN菌合成的纳米金粒径范围为3 nm-252 nm,平均粒径为45.2 nm,而灭活WIN菌合成的纳米金为1 nm-271 nm,平均粒径为38.3 nm。活性和灭活WIN菌合成的纳米金对还原4-硝基苯酚的催化速率分别为2.76×10^(-3)s^(-1)和4.84×10^(-3)s^(-1)。【结论】菌株Trichosporon montevideense WIN的活性及灭活细胞均可以合成纳米金,且合成的纳米金具有良好的催化特性,在催化去除环境中难降解污染物中具有一定的应用前景。

The Evaluation of Bioremediation Potential of a Yeast Collection Isolated from Composting

The influence of xenobiotic compounds on environment and on living organisms has been reported as an imminent public health problem. Among them we can list the contamination by Alkanes present in petroleum, hydrocarbons and organic contaminant substances from industrial effluents. Also, heavy metals are of particular interest because of their persistence in the environment contaminating the food webs. Among the innovative solutions for treatment of contaminated water and soil is the use of biological materials like living or dead microorganisms. Yeasts exhibit the ability to adapt to extreme condition such as temperature, pH and levels of organic and inorganic contaminants that make them a potential material to be used to remediate contaminated environment application. The goal of this work was to search for yeast isolates capable to use n-hexadecane (alkane hydrocarbon) as a primary carbon source and for those able to tolerate high concentration of lead (Pb) within a collection of 90 isolates obtained from the Sao Paulo Zoo composting system. The isolated yeast strains were identified by mass spectrometry (MALDI-TOF-MS) and by sequencing of the ribosomal DNA (18S and D1/D2) conserved regions. We found that the collection bares 23 isolates capable of utilizing n-hexadecane and one which is able to tolerate high concentration of lead (Pb) with a high biosorption index compared to the reference yeast strains (BY4742, PE-2, CAT-1 and BG-1). These results confirm the initial hypothesis that the Sao Paulo Zoo composting is the source for diverse yeasts species with biotechnological application potential.