Balasubramanian1,2*, R. Neethu Raj1,
V. Gayathri1, K.M. Maria John3
1- Department of
Biotechnology, School of Biotechnology and Genetic Engineering, Bharathiar University, Coimbatore - 641 046, Tamil Nadu,
2- Department of
Biotechnology, KSR college of Technology, Tiruchengode,
Namakkal - 637 215, Tamil Nadu, India.
3- Laboratory of
Functional Metabolomics, Department of Bioscience
and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu,
Seoul - 143 701, South Korea.
Abstract Benzidine (BZ), O-dianisidine
(OD) and Paraphenylenediamine (PPD) compounds are
commonly used in hair dyes, textile dying and paper coloring industries.
These dyes are reported to have genotoxic property.
When such dyes are let it to effluent adds significant carcinogenicity to the
rodent and human, removal of such dyes remain essential. Application of Calotropis gigantea peroxidase (CgPOD) for
biotransformation of these genotoxic dyes found to
be one of the effective processes to reduce the toxicity. When BZ and OD were
exposed to CgPOD, get transferred from genotoxic to non-genotoxic
form, whereas the PPD transformed to the genotoxic
form due to the formation of cyclohexa-2,5-dione-1,4-diylidenediamine
compound. The structural changes were elucidated using FT-IR & 1H NMR,
which confirmed the biotransformed structure of
PPD, BZ and OD to cyclohexa-2,5-dione-1,4-diylidenediamine, bis-(4-amino-biphenyl-4-yl)-diazene
and bis-(3,3-dimethoxy-4-amino-biphenyl-4-yl)-diazene, respectively. In conclusion, although the BZ and
OD are genotoxic and not in the case of PPD when
exposed to human systems, the CgPOD mediated
metabolites of BZ and OD were non-genotoxic as
shown in DNA fragmentation assay and fluorescence assay. Whereas the PPD
metabolite induce or activate genotoxicity when
exposed to lymphocytes and it shows 13.05% residual fluorescence intensity at
0.15 mg/ml. Hence the CgPOD mediated
biotransformation can be effectively used in the treatment of BZ and OD
containing dye effluents and should not be used in dyes having PPD.
Index Terms Benzidine, Biotransformation, Calotropis
gigantean, O-dianisidine, Paraphenylenediamine,