Densitometric quantification for the validation of decolorization of Disperse Orange ERL by lichen Parmelia sp.

Densitometric high performance thin layer chromatography (HPTLC) quantification method was developed to validate the decolorization/biotransformation of Disperse Orange ERL and dye mixture by lichen Parmelia sp. which release several colored compounds during decolorization process, hence unable to use colorimetric estimation. Percent decolorization of Disperse Orange ERL and dye mixture by lichen Parmelia sp. was observed when estimated using developed HPTLC method. Limit of detection and limit of quantification for both dyes in mixture were obtained as 0.3 and 1 µg/µl, respectively. Area of peak of control Disperse Orange ERL was reduced by 43% after 12 h, 71% after 48 h and upto 82% after 72 h of incubation. Precision and repeatability of data elucidated the % relative standard deviation less than 3 for all the values thus indicating statistically acceptable. Biodegradation of dye and mixture was confirmed with Fourier transform infrared spectroscopy analysis, i.e., altered fingerprinting spectral pattern.

Decolorization and detoxification of dye mixture and textile effluent by lichen Dermatocarpon vellereceum in fixed bed upflow bioreactor with subsequent oxidative stress study.

Navy Blue HE22 (NBHE22), dye mixture and real textile effluent were decolorized and degraded by lichen Dermatocarpon vellereceum. Up-flow bioreactor showed about 80%, 70%, 80% and 65% removal of American dye manufacturer index (ADMI), biological oxygen demand (BOD), total suspended solids (TSS) and total dissolved solids (TDS), respectively of dye mixture at flow rate of 25mlh-1. The removal of ADMI, BOD, TSS and TDS of real textile effluent were 75%, 65%, 82% and 70%, respectively at flow rate of 30mlh-1. Significant induction of extracellular enzymes such as manganese peroxidase and lignin peroxidase was observed up to 46% and 36% during decolorization of dye mixture, while 43% and 24% during effluent treatment, respectively. Exponential enhancement in the activities of stress enzymes such as catalase (CAT) and guaiacol peroxidase (GPX) was observed after exposure to NBHE22 (116% and 125%, respectively), dye mixture (150% and 300%, respectively) and effluent (400% and 350%, respectively) endorsing the stress tolerance ability of model lichen. Phytotoxicity and genotoxicity studies demonstrated less toxic nature of metabolites resulted from biodegradation.

Lichen Permelia perlata: a novel system for biodegradation and detoxification of disperse dye Solvent Red 24.

Lichen is a self-supporting symbiotic association of fungi and algae which was not yet explored for its bioremediation potential. Lichen Permelia perlata showed potential of decolorization and biodegradation of Solvent Red 24 (SR24). Optimum pH and temperature for decolorization was found to be 8 and 50°C, respectively. Induction in the activity of laccase in P. perlata during biodegradation of SR24 showed their involvement. HPTLC, FTIR and GC-HRMS analysis confirmed biodegradation of SR24 in to metabolites such as naphthalen-1-yldiazene, naphthalene, 1-(2-methylphenyl)-2-phenyldiazene and diphenyldiazene. Phytotoxicity and genotoxicity analysis revealed the reduction in toxicity of SR24 after its biodegradation.