Rezácová V, Gryndler M
Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague, Czechia.
Folia Microbiol (Praha). 2006;51(3):215-21. doi: 10.1007/BF02932125.
The ability of eight soil microfungal species, Alternaria alternata, Clonostachys rosea f. rosea, Exophiala cf. salmonis, Fusarium cf. coeruleum, Fusarium redolens, Paecilomyces lilacinus, Penicillium canescens and Phoma sp., and two known basidiomycete humic acid (HA) degraders, Trametes versicolor and Phanerochaete chrysosporium, to modify fluorescence properties of fulvic acids (FA) and/or HAs was determined. Effects of minerals and/or glucose on the modifications were examined. FA purified on polyvinyl-polypyrrolidone (PVPP) chromatography column was used. Purification of FA on PVPP column removed the low-molar-mass FA-structural components and excess of extractant (NaOH) used during FA preparation. Excitation spectra of FA entering the purification, purified FA and the removal solution indicate that organic compounds rich in carboxylic groups dominate in the removal solution and higher content of phenolic groups is a characteristic of purified FA. Many microfungal species shifted the emission maximum (measured at 470 and 468 nm of excitation wavelength) of FA, and also HA to longer wavelengths. The opposite effect (shift of the HA emission maximum to shorter wavelengths) of microfungi was observed for HA complemented by glucose. Depending on the presence of glucose in the medium, most microfungi changed also the shape of the emission spectra of HA and FA and the excitation spectra of FA. HA excitation spectrum measured at 590 nm of emission wavelength was significantly affected by the presence of glucose. Mineral ions caused a minor shift in the position of excitation maximum (measured at 590 nm of emission wavelength) toward longer wavelengths.
测定了8种土壤微真菌物种，即链格孢、粉红粘帚霉粉红变种、疑似鲑鱼外瓶霉、疑似天蓝镰孢、变红镰孢、淡紫拟青霉、灰绿青霉和茎点霉属，以及两种已知的担子菌腐殖酸（HA）降解菌，即云芝和黄孢原毛平革菌，对富里酸（FA）和/或HA荧光特性的修饰能力。研究了矿物质和/或葡萄糖对这些修饰作用的影响。使用在聚乙烯基-聚吡咯烷酮（PVPP）色谱柱上纯化的FA。在PVPP柱上纯化FA可去除低摩尔质量的FA结构成分以及FA制备过程中使用的过量萃取剂（NaOH）。进入纯化过程的FA、纯化后的FA和去除溶液的激发光谱表明，去除溶液中富含羧基的有机化合物占主导，而纯化后的FA具有较高含量的酚羟基。许多微真菌物种使FA以及HA的发射最大值（在激发波长470和468 nm处测量）向更长波长移动。对于添加葡萄糖的HA，观察到微真菌产生了相反的效果（HA发射最大值向更短波长移动）。根据培养基中葡萄糖的存在情况，大多数微真菌还改变了HA和FA发射光谱的形状以及FA的激发光谱。在发射波长590 nm处测量的HA激发光谱受葡萄糖存在的显著影响。矿物离子使激发最大值位置（在发射波长590 nm处测量）向更长波长有轻微移动。
