School of Undergraduate Studies, College of Transdisciplinary Studies, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Republic of Korea.
Department of Brain and Cognitive Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Republic of Korea.
Environ Sci Technol. 2020 Jun 2;54(11):6987-6996. doi: 10.1021/acs.est.0c01495. Epub 2020 May 18.
Recently, various attempts have been made to solve plastic waste problems, such as development of biodegradation without producing pollution. Polystyrene (PS) is the fifth most used plastic in many industries; therefore, degrading PS becomes a critical global issue. Here, we reported strain DSM 50071, initially isolated from the gut of the superworms, and the PS degradation by sp. DSM 50071. We examined PS degradation using electronic microscopy and measured changes in atomic composition and contact angles with water droplets on the PS surface that represents a chemical change from hydrophobicity to hydrophilicity. We have further examined chemical structural changes using X-ray photoelectron spectroscopy, Fourier-transform-infrared spectroscopy, and nuclear magnetic resonance (NMR) to confirm the formation of carbonyl groups (C═O) in the oxidation pathway during PS biodegradation. In reverse transcription quantitative polymerase chain reaction analysis, the gene expression level of serine hydrolase (SH) in sp. DSM 50071 was highly increased during PS degradation, and the enzyme-mediated biodegradation of PS was further confirmed by the SH inhibitor treatment test. Thus, the significance of these findings goes beyond the discovery of a novel function of sp. DSM 50071 in the gut of superworms, highlighting a potential solution for PS biodegradation.
最近，人们尝试了各种方法来解决塑料废物问题，例如开发不产生污染的可生物降解材料。聚苯乙烯（PS）是许多行业中第五大常用塑料；因此，PS 的降解成为一个全球性的关键问题。在这里，我们报告了最初从超级蠕虫肠道中分离出来的菌株 DSM 50071，以及 sp. DSM 50071 对 PS 的降解。我们使用电子显微镜检查 PS 的降解，并测量 PS 表面水滴的原子组成和接触角的变化，这代表了从疏水性到亲水性的化学变化。我们进一步使用 X 射线光电子能谱、傅里叶变换红外光谱和核磁共振（NMR）检查化学结构变化，以确认 PS 生物降解过程中氧化途径中羰基（C═O）的形成。在反转录定量聚合酶链反应分析中，sp. DSM 50071 中丝氨酸水解酶（SH）的基因表达水平在 PS 降解过程中高度增加，并且通过 SH 抑制剂处理试验进一步证实了酶介导的 PS 生物降解。因此，这些发现的意义不仅在于发现了超级蠕虫肠道中 sp. DSM 50071 的新功能，还突出了 PS 生物降解的潜在解决方案。
