Biochemical degradation of phenols by yeast

研究了一株红酵母菌对苯酚和一氯酚的降解作用。该菌株完全降解5 mM的苯酚，并利用苯酚作为唯一的碳源。该菌株可能是通过“邻位”开环方式降解苯酚的，因为在发酵液中观察到粘康酸内酯。3-3-氯酚和4-氯酚的降解效果较好，氯离子的释放量为化学计量比，而2-氯酚的降解率较低，氯离子的释放量较少。在细胞培养过程中添加苯酚或CPs可提高3-CP和4-CP的生物降解性。GC/MS分析表明，4-氯苯酚和马来酰乙酸是3-CP和4-CP的代谢产物，因此，在4-氯苯酚和马来酰乙酸生成之间可能发生脱氯反应。重复分批培养（10天），用于降解苯酚， ...更多信息 或者比较三种由纤维素、壳聚糖和烧结玻璃制成的珠。在初始培养阶段，纤维素微球载体对酵母细胞的固定化能力和对TOC和苯酚的去除率均高于壳聚糖和烧结玻璃微球。用纤维素珠固定的酵母细胞的数量最终达到2.5 × 10^8个细胞/ml珠。该结果与壳聚糖和烧结玻璃珠几乎相同。用纤维素珠进行连续培养。苯酚（5 mM）和3-CP（0.05 mM）在该系统中稳定降解100 d，用甲氧基-三甲基硅烷基（MO-TMS）衍生物抑制烯醇醚的形成，对红色红酵母粗提物代谢产物粘康酸内酯和原儿茶酸中的β-酮基己二酸进行了鉴定。β-酮己二酸成功地转化为MO-TMS衍生物，并且没有观察到烯醇醚形成。β-酮基己二酸的MO-TMS衍生物的两种异构体的质谱在其裂解模式上彼此相似;它们在m/z 333处具有足够的分子离子强度和其他特征离子。少

Biodegradation of phenol and monochlorophenols (CPs) by a yeast strain of Rhodotorula glutinis was exmined. The strain completely degraded 5 mM of phenol and utilized phenol as a sole carbon source. The strain may degrade phenol by the "ortho" type of ring fission because muconolactone was observed in the cultured broth. 3-Chlorophenol (3-CP) and 4-chlorophenol (4-CP) were well degraded and stoichiometric release of chloride ion was observed, but degradation of 2-Chlorophenol was low with few amount of chloride ion. Biodegradability of 3-CP and 4-CP was increased by the addition of phenol or CPs to the medium at the cell cultivation. Since 4-chlorophenol and maleylacetic acid were determined as metabolites of 3-CP and 4-CP by GC/Ms analysis, dechlorination may take place between the formation of 4-chlorophenol and maleylacetic acid.Biochemical degradation of phenols by immobilized yeast cells was examined. Repeated batch cultures (10 days) for the degradation of phenol were performed f … More or comparing three kinds of beads, made from cellulose, chitosan and sintered glass. In the initial incubation period, cellulose beads as a carrier had higher yeast cells immobilizing capacity and had higher removal of TOC and phenol(%) than chitosan and sintered glass beads. The numbers of immobilized yeast cells with cellulose beads finally reached 2.5 X 10^8 cells/ml-beads. This result was almost the same as with chitosan and sintered glass beads. Continuous culture was performed with cellulose beads. Phenol (5 mM) and 3- and 4-CP (0.05 mM) was degraded stably for 100 days in this system.Identification of beta-ketoadipic acid in muconolactone and protocatechuic acid metabolites by the crude cell extract of yeast Rhodotorula rubra was carried out using methoxime-trimethylsilyl (MO-TMS) derivative to prevent enol ether formation. beta-Ketoadipic acid was converted successfully to MO-TMS derivative, and enol ether formation was not observed. Mass spectra of two isomers of MO-TMS derivative of beta-ketoadipic acid resembled each other in their fragmentation pattern ; they had sufficient intensities of molecular ion at m/z 333, and other characteristic ions. Less