Development of metabolic reaction analysis of chlorophenol degradation by mixed culture using in silico analysis

Abstract

2,4-Dichlorophenol (2,4-DCP), C6H4Cl2 is one of the most common and recalcitrant organic waste discharged from chemicals, oil refining and dyestuff industries. There are many proposed degradation pathways but they are not validated yet through Flux Balance Analysis (FBA). This project is to reconstruct the biodegradation pathways and validate using Flux Balance Analysis. It was conducted to analyse and reconstruct the flux distribution of metabolites throughout a metabolic pathway. COBRA Toolbox is used for FBA study. The anaerobic biodegradation of 2,4-DCP in the microbial fuel cell was studied after incubating with mixed culture collected from the waste effluent of Fermpro Sdn. Bhd. After the incubation of mixed culture, 2,4-DCP was added. The phenolic removal from the degradation process were detected everyday by using UV-Visible spectrophotometer. From the result of FBA, 2,4-DCP aerobic removal theoretical percentage was 48.3%, whereas 100% removal percentage can be achieved in anaerobic degradation pathway. The cellular doubling time for aerobic reaction decreased from 39.35 minutes to 38.34 minutes. As for anaerobic reaction, the doubling time reduced significantly from 154.2 minutes to 25.36 minutes. The highest phenolic removal rate (33.3%) was achieved at day 4. The results validated that the reconstructed 2,4-dichlorophenol biodegradation pathways were correct and microbes were able to consume 2,4-dichlorophenol as carbon source.