聚乳酸 (Polylactic acid, PLA) 為近年來最普遍用來取代塑膠的材料之一，雖然PLA能完全分解，但PLA堆肥分解所需的條件相對嚴苛，無法在一般自然條件下分解，因此仍多以燃燒處理。為了找出加速PLA分解的方法，本研究以固態醱酵方式測試不同因子對PLA的分解效果。以農業廢棄物，比如稻草、禽畜糞、豆粉、羽毛粉作為醱酵材料，調整各個反應條件，如：溫度、供氣、碳氮比等，以及各種不同的前處理條件。研究結果發現，當PLA有以UVC光進行前處理，在60%水含量、以雞糞和稻稈調整至碳氮比20的條件下進行固態醱酵，能在50度反應下達到最佳的降解效果。

Polylactic acid (PLA) is one of the most popular substitutes for plastics. Although PLA can decompose completely, its degradation can only happen in stringent compost condition but not in natural environment. Thus, PLA waste is still usually treated by combustion. To find out how to accelerate the degradation of PLA, we tested different factors of PLA decomposition in aerobic solid-state fermentation. Different agricultural wastes, like rice straw, poultry manure, soybean flour, or feather powder were used as the fermentation materials. Various reaction conditions, temperature, gas supply, carbon to nitrogen (C/N) ratio, etc. and different pre-treatment conditions were included in the tests. This study found PLA can achieve the best degradation condition at 50oC when PLA was pretreated with UVC and then incubated in the fermentation condition made with chicken manure and rice straw at the C/N ratio of 20 and with 60% water content.