Novel exploration of endophytic diaporthe sp. for the biosorption and biodegradation of triphenylmethane dyes

An endophytic isolate identified as Diaporthe sp. was explored for its biosorption and biodegradation potential on triphenylmethane (TPM) dyes. Treatment with live cells demonstrated strong decolorization activities towards methyl violet (MV, 100 mg L^-1), crystal violet (CV, 100 mg L^-1), and malachite green (MG, 50 mg L^-1), with 84.87, 78.81, and 87.80 %, respectively. These values are far greater than decolorization by dead cells via biosorption (DE% of 18.82-48.32 %). The absence of peaks in the UV-vis spectra after 14 days further suggested degradation of dye chromophores. Results revealed that Diaporthe sp. removed TPM dyes through biodegradation and biosorption, with the former as a more desirable mechanism due to its ability to degrade most dye chromophore and enhance decolorization efficiency, and as a mechanism to tolerate toxic MG. As such, application of live cells of Diaporthe sp. is advantageous as it allows biodegradation to occur.