The Biodegradation of Low-molecular-weight Urethane Compounds by a Strain of<i>Exophiala jeanselmei</i>
作者:Stephen Owen、Takahito Otani、Satoshi Masaoka、Tatsuhiko Ohe
DOI:10.1271/bbb.60.244
日期:1996.1
To further analyze the biodegradation of polyurethane polymers, we investigated the biodegradation of low-molecular-weight N-tolylcarbamate model compounds with structures closely resembling the urethane linkages found in polyurethanes based on tolylene-diisocyanate (TDI). Soil microflora were screened for microorganisms that were able to utilize toluene-2,4-dicarbamic acid, diethyl ester (compound 1) as the sole source of carbon, and the soil fungus Exophiala jeanselmei strain REN-11A was selected as the most effective strain. Several N-tolylcarhamate compounds were used, and it was found that REN-11A was able to degrade compound 1, as well as the related compound toluene-2,6-dicarbamic acid, diethyl ester, very efficiently. Further investigation showed that compound 1 was biodegraded to tolylene-2,4-diamine via the aromatic amine intermediates carbamic acid, (3-amino-4-methylphenyl)-, ethyl ester and carbamic acid, (5-amino-2-methylphenyl)-, ethyl ester.
为了进一步分析聚氨酯聚合物的生物降解性,我们研究了结构与基于甲苯二异氰酸酯(TDI)的聚氨酯中的氨基甲酸酯键非常相似的低分子量N-甲苯基氨基甲酸酯模型化合物的生物降解性。筛选了能够以甲苯-2,4-二氨基甲酸二乙酯(化合物1)为唯一碳源利用的土壤微生物,并选出土壤真菌外瓶霉菌REN-11A株作为最有效的菌株。使用了几种N-甲苯基氨基甲酸酯化合物,发现REN-11A能够非常有效地降解化合物1及其相关化合物甲苯-2,6-二氨基甲酸二乙酯。进一步的研究表明,化合物1通过芳香胺中间体氨基甲酸乙酯和氨基甲酸乙酯被生物降解为甲苯-2,4-二胺。