Biodegradation and decolourization of methyl red by LH1.

Azo dyes constitute a significant environmental burden due to its toxicity, carcinogenicity, and hard biodegradation. The report here is focused on the decolorization and degradation treatment of azo dye methyl red (MR). Decolorization of MR using LH1 isolated from activated sludge was investigated. The maximum decolorization rate of 92.3% was obtained under the optimized conditions of sucrose as carbon source, 5d incubation age, pH 6.0, 140 mg/L initial concentration of MR and 2.5 g/L initial concentration of NaNO. Biodegradation products of MR were investigated using HPLC-MS, FTIR, and GC-MS assays. It was revealed the three bonds of -C-N = in MR aromatic nucleus were disrupted, and benzoic acid was detected. Micronucleus test with L. and L. demonstrated that MCN‰ (micronucleus permillage) of MR metabolites was less than MR solution. These findings provided evidence that LH1 is a candidate for MR degradation in industrial wastewater treatment.