Serafin Muñoz Alma Hortensia, Kubachka Kevin, Wrobel Kazimierz, Gutierrez Corona J Felix, Yathavakilla Santha K V, Caruso Joseph A, Wrobel Katarzyna
Instituto de Investigaciones Científicas, Facultad de Química, Universidad de Guanajuato, L de Retana No. 5, 36000 Guanajuato, Mexico.
J Agric Food Chem. 2006 May 3;54(9):3440-4. doi: 10.1021/jf052973u.
The incorporation of Se to fungi has been studied, focusing on element distribution among different cellular compartments and, in particular, polysaccharide structures contained in cell walls. Se-enriched mycelia of Pleurotus ostreatus were obtained in submerged cultures. The incorporation of selenium from the growth medium to mycelia was observed with the relative distribution between cytosol plus cell membranes fraction (CCM) and cell walls fraction (CW) of about 44 and 56%, respectively. CCM fractions were analyzed by size exclusion chromatography with on-line UV (280 nm) and ICP-MS detection (80Se). The results obtained showed selenium binding to components of different molecular masses (about 24% of total selenium coeluted with the compounds of molecular mass > 10 kDa). A polysaccharide-containing fraction of mycelia was treated alternatively with Tris-HCl at pH 7.5 or with chitinase. Better solubility and increased contribution of low molecular mass compounds were observed in chitinase extracts (UV detection), confirming the degradation of polysacharides by the enzyme. The total area under the ICP-MS chromatogram of chitinase extract was 2 times higher with respect to the area for Tris-HCl extract. Furthermore, the relative contribution of selenium in the low molecular mass fraction (molecular mass < 1 kDa) in chitinase extract was 72% as compared to 45% in Tris-HCl extract (based on peak area measurements with respect to total area under the chromatogram). The results obtained suggest selenium binding to chitin-containing polysaccharide structures in fungi cell walls.
人们对硒在真菌中的掺入情况进行了研究，重点关注元素在不同细胞区室中的分布，特别是细胞壁中所含的多糖结构。在深层培养中获得了富硒的平菇菌丝体。观察到硒从生长培养基掺入到菌丝体中，其中细胞质加细胞膜部分（CCM）和细胞壁部分（CW）之间的相对分布分别约为44%和56%。通过尺寸排阻色谱结合在线紫外（280nm）和电感耦合等离子体质谱检测（80Se）对CCM部分进行分析。所得结果表明硒与不同分子量的成分结合（约24%的总硒与分子量>10kDa的化合物共洗脱）。用pH7.5的Tris-HCl或几丁质酶交替处理菌丝体的含多糖部分。在几丁质酶提取物中观察到更好的溶解性和低分子量化合物贡献的增加（紫外检测），证实了该酶对多糖的降解作用。几丁质酶提取物的电感耦合等离子体质谱色谱图下的总面积相对于Tris-HCl提取物的面积高出2倍。此外，几丁质酶提取物中低分子量部分（分子量<1kDa）中硒的相对贡献为72%，而Tris-HCl提取物中为45%（基于相对于色谱图下总面积的峰面积测量）。所得结果表明硒与真菌细胞壁中含几丁质的多糖结构结合。
