This study was designed to explore the key impact of Proteinase K (PK) on every step of anaerobic co-digestion. The results of step-by-step experiments indicated that PK promoted the hydrolysis of biodegradable plastic by initiating self-hydrolysis reactions, directly promoting the hydrolysis step of anaerobic co-digestion. Subsequently, PK indirectly promoted the acidogenesis and acetogenesis steps by impacting the proliferation of acid-producing bacteria. Besides, it could also hydrolyze PLA. Thus, the lactic acid content peaked at 255.7 mg/L on the 5th day, representing an increase of 35.9 % compared to the condition without PK. Finally, PK indirectly promoted the methanogenesis step through its impact on the composition of methanogenic bacteria. This led to more food waste being digested into methane, 41.5 % compared to the condition without PK. This work served as an essential foundation for advancing the application of PK modified BP as a replacement for traditional plastics.

中文翻译：

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蛋白酶 K 对改性可生物降解塑料和食物垃圾厌氧共消化的影响：微生物的分步分析


本研究旨在探讨蛋白酶 K （PK） 对厌氧共消化每个步骤的关键影响。逐步实验结果表明，PK 通过引发自水解反应促进可生物降解塑料的水解，直接促进了厌氧共消化的水解步骤。随后，PK 通过影响产酸细菌的增殖间接促进了酸化和乙酸发生步骤。此外，它还可以水解 PLA。因此，乳酸含量在第 5 天达到峰值 255.7 mg/L，与未 PK 的情况相比增加了 35.9%。最后，PK 通过其对产甲烷菌组成的影响间接促进了产甲烷步骤。这导致更多的食物垃圾被消化成甲烷，与没有 PK 的情况相比，甲烷蒸发了 41.5%。这项工作为推进 PK 改性 BP 作为传统塑料替代品的应用奠定了重要基础。