Waste Management ( IF 8.1 ) Pub Date : 2021-02-04 , DOI: 10.1016/j.wasman.2021.01.007 Samy Yousef , Neringa Kuliešienė , Sandra Sakalauskaitė , Tomas Nenartavičius , Rimantas Daugelavičius
Usually, Euro banknotes are made from cotton substrates and their waste is disposed of in landfill or is incinerated. In order to valorize the end-of-life euro banknotes (ELEBs), the substrates were used in this research for cellulase production via submerged fungal fermentation (SFF), and the resultant fungal cellulase w s used in ELEBs hydrolysis process for extraction of glucose. The experiments were started by exposing the ELEBs to different types of pretreatments, including milling process, alkali (NaOH/urea solution), and acid leaching to remove any contamination (e.g. dyes) and to decrease the crystallinity of cellulose (the main element in cotton substrate) thus increasing the degradation rate during the fermentation process. The effect of pretreatments on the morphology and chemical composition of ELEBs was observed using Scanning Electron Microscope and Energy Dispersive Spectrometry. Afterwards, Trichoderma reesei-DSM76 was used for cellulase production from the treated ELEBs with high cellulase activity (12.97 FPU/g). The resultant cellulase was upscaled in a bioreactor and used in ELEBs hydrolysis. Finally, the results showed that the optimized pretreatment methods (milling followed by leaching process) significantly improved the cellulase activity and glucose recovery, which was estimated by 96%. According to the obtained results, the developed strategy has a great potential for conversion of ELEBs into a glucose product that could be used in biofuels and bioplastics applications.
中文翻译:
从报废欧元纸币中回收葡萄糖的可持续绿色战略
通常,欧元纸币是由棉质基材制成的,其废物会被垃圾掩埋或焚化。为了使报废的欧元纸币(ELEB)物有所值,本研究将底物用于通过沉没真菌发酵(SFF)的纤维素酶生产,并将所得的真菌纤维素酶用于ELEBs水解过程中以提取葡萄糖。通过将ELEB暴露于不同类型的预处理开始实验,包括研磨过程,碱(NaOH /尿素溶液)和酸浸以去除任何污染物(例如染料)并降低纤维素(棉花中的主要元素)的结晶度底物),从而增加了发酵过程中的降解率。使用扫描电子显微镜和能量色散光谱法观察预处理对ELEBs的形态和化学组成的影响。之后,里氏木霉-DSM76用于从处理过的具有高纤维素酶活性(12.97 FPU / g)的ELEB中生产纤维素酶。所得纤维素酶在生物反应器中进行了规模放大,并用于ELEBs水解。最后,结果表明,优化的预处理方法(碾磨,然后进行浸出工艺)显着提高了纤维素酶活性和葡萄糖回收率,估计为96%。根据获得的结果,开发的策略具有将ELEB转化为可用于生物燃料和生物塑料应用的葡萄糖产品的巨大潜力。