Sun Fengqin, Shao Zongze
Third Institute of Oceanography, Key Lab of Marine Biogenetic Resources, State Oceanic Administration, Xiamen, Fujian, China.
Extremophiles. 2007 Nov;11(6):853-8. doi: 10.1007/s00792-007-0097-7. Epub 2007 Sep 26.
A lead resistant fungus was isolated from the Pacific sediment. It was associated with Penicillium according to its partial sequences of 18S and ITS. The fungus could grow in the presence of 24 mM Pb(NO(3))(2 )in a liquid medium, and no growth inhibition was observed at 4 mM and below. When growing in the presence of 4 mM Pb(NO(3))(2), the fungus accumulated a large amount of lead granules in the cell, as well as adsorbed on the outer layer of cell wall, as observed under a transmission electron microscope. The intracellular lead deposited either in the vicinity of the cytoplasm membrane or in the vacuoles, and also could aggregate into large particles in the cytoplasm. However, lead was not adsorbed on the thick inner wall of the fungus. Energy dispersive X-ray spectroscopy analysis showed that these granules or particles mainly consisted of lead, and other elements could hardly be detected. Selected area electron diffraction analysis showed that there were regular crystalline lattices in the lead precipitates, indicating that they were actually in the form of crystals to some extent. Therefore, both intracellular bioaccumulation and extracellular biosorption had contributed to the high resistance of this fungus to lead. These results suggest that this fungus can be used in biotreatment as a lead trapper.
从太平洋沉积物中分离出一种抗铅真菌。根据其18S和ITS的部分序列，它与青霉属有关。该真菌能够在液体培养基中24 mM Pb(NO₃)₂存在的情况下生长，在4 mM及以下未观察到生长抑制。当在4 mM Pb(NO₃)₂存在下生长时，在透射电子显微镜下观察到，该真菌在细胞内积累了大量铅颗粒，同时也吸附在细胞壁外层。细胞内的铅沉积在细胞质膜附近或液泡中，也可在细胞质中聚集成大颗粒。然而，铅并未吸附在真菌的厚内壁上。能量色散X射线光谱分析表明，这些颗粒或粒子主要由铅组成，几乎检测不到其他元素。选区电子衍射分析表明，铅沉淀物中存在规则的晶格，表明它们在一定程度上实际上是晶体形式。因此，细胞内生物积累和细胞外生物吸附都导致了这种真菌对铅的高抗性。这些结果表明，这种真菌可作为铅捕获剂用于生物处理。
