From organic waste to eco-enzyme: a systematic review of raw materials, antibacterial activity, and applications

Abstract Eco-enzymes produced from the fermentation of organic kitchen waste have proven to be a sustainable solution for waste management which can be turned into more valuable products. This systematic review shows that orange peel and molasses-based formulations exhibit superior antibacterial activity, particularly against Gram-negative bacteria, through organic acid and bioactive compound mechanisms. Their application in cleaning products demonstrates effectiveness comparable to synthetic chemicals, although stability and pH optimization are still required. In wastewater treatment, eco-enzymes can reduce BOD, COD, and nitrate by >90%. However, results vary depending on the waste type, with some cases showing an increase in pollutants. The main challenges include long fermentation times (3-6 months) and performance instability, which require further optimization.