Abstract

Polylactic acid (PLA) and polycaprolactone (PCL) are commercially available bioplastics that are exploited worldwide, and both are biodegradable. The PLA and PCL polymer-degrading activity of 30 fungal strains that were isolated from terrestrial environments were screened based on the formation of a clear zone around fungal colonies on agar plates containing emulsified PLA or PCL. Among them, five strains yielded positive results of biodegradation. Strains Korean Agricultural Culture Collection (KACC) 83034BP and KNUF-20-PPH03 exhibited PCL degradation; two other strains, KACC 83035BP and KNUF-20-PDG05, degraded PLA; and the fifth strain, KACC 83036BP, biodegraded both tested plastics. Based on phylogenetic analyses using various combinations of the sequences of internal transcribed spacer (ITS) regions, RPB2, LSU, CAL, and β-TUB genes, the above-mentioned strains were identified as Apiotrichum porosum, Penicillium samsonianum, Talaromyces pinophilus, Purpureocillium lilacinum, and Fusicolla acetilerea, respectively. Based on our knowledge, this is the first report on (i) plastic biodegraders among Apiotrichum and Fusicolla species, (ii) the capability of T. pinophilus to degrade biodegradable plastics, (iii) the biodegradative activity of P. samsonianum against PCL, and (iv) the accurate identification of P. lilacinum as a PLA biodegrader. Further studies should be conducted to determine how the fungal species can be utilized in Korea.

摘要

聚乳酸 (PLA) 和聚己内酯 (PCL) 是可在全球范围内开发的商用生物塑料，两者都是可生物降解的。基于在含有乳化 PLA 或 PCL 的琼脂平板上真菌菌落周围形成清晰区域，筛选了从陆地环境中分离的 30 种真菌菌株的 PLA 和 PCL 聚合物降解活性。其中，5株菌株的生物降解效果良好。菌株韩国农业文化保藏中心 (KACC) 83034BP 和 KNUF-20-PPH03 表现出 PCL 降解；另外两种菌株，KACC 83035BP 和 KNUF-20-PDG05，降解 PLA；第五个菌株 KACC 83036BP 可生物降解两种测试塑料。基于使用内部转录间隔区 (ITS) 区域序列的各种组合的系统发育分析，RPB2、LSU、CAL和β-TUB基因，上述菌株分别鉴定为Apiotrichum porosum、Penicillium samsonianum、Talaromyces pinophilus、Purpureocillium lilacinum和Fusicolla acetilerea。根据我们的知识，这是关于 (i)芹菜属和Fusicolla物种中的塑料生物降解剂，(ii) T. pinophilus降解可生物降解塑料的能力，(iii) P. samsonianum对 PCL 的生物降解活性，以及(iv)紫丁香的准确鉴定作为 PLA 生物降解剂。应进行进一步的研究以确定如何在韩国利用这种真菌。