Nenadović Marija, Ponjavić Marijana, Pantelic Brana, Guzik Maciej, Majka Tomasz M, Sourkouni Georgia, Maršavelski Aleksandra, Nikodinovic-Runic Jasmina
Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade 11000, Serbia.
Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, Krakow 30-239, Poland.
ACS Sustain Chem Eng. 2025 Jun 9;13(24):9269-9278. doi: 10.1021/acssuschemeng.5c03378. eCollection 2025 Jun 23.
Poly-(lactic acid) (PLA) is the most widely produced biopolymer globally, with 920,000 tons reaching the market in 2024. Although it is a biobased polymer and biodegradable, it currently poses a threat by generating a considerable waste stream in the environment unless its end-of-life options are further developed. Biorecycling of PLA is a promising solution and is critical for PLA to be a truly sustainable alternative to conventional plastics, further enabling the (bio)-plastics circular economy. This work investigates the repurposing of commercial Savinase 12T preparation, already produced on a large scale for the detergent industry, for the degradation of consumer-grade PLA. Savinase-degraded postconsumer PLA single-use cups at a rate of 166 mg·day·mg enzyme for the lid part (crystallinity ( ) 22.9%) and 40 mg·day·mg enzyme for the body part ( 42.0%). The average degradation rate of PLA 3D printer filaments was determined to be 56 mg·day·mg enzyme under optimized conditions of pH 8.5 and 42 °C. Lactic acid was identified as the main PLA degradation product of Savinase depolymerizing activity. Molecular modeling revealed Asn155 and Ser125 as key residues involved in PLA tetramer binding.
聚乳酸（PLA）是全球产量最高的生物聚合物，2024年有92万吨投放市场。尽管它是一种生物基聚合物且可生物降解，但除非进一步开发其生命周期末期的处理方案，否则目前它会因在环境中产生大量废物流而构成威胁。PLA的生物回收是一个有前景的解决方案，对于PLA成为传统塑料真正可持续的替代品至关重要，这将进一步推动（生物）塑料循环经济。这项工作研究了已大规模生产用于洗涤剂行业的商用Savinase 12T制剂对消费级PLA的降解用途。Savinase对消费后PLA一次性杯子的降解速率，盖子部分为166毫克·天·毫克酶（结晶度22.9%），杯身部分为40毫克·天·毫克酶（42.0%）。在pH 8.5和42℃的优化条件下，PLA 3D打印细丝的平均降解速率测定为56毫克·天·毫克酶。乳酸被鉴定为Savinase解聚活性产生的主要PLA降解产物。分子建模显示Asn155和Ser125是参与PLA四聚体结合的关键残基。
