title: Genotoxicity assessment of pulp and paper mill effluent before and after bacterial degradation using Allium cepa test.
abstract: A lignin peroxidases-producing Serratia liquefaciens was used for bioremediation of pulp and paper (P&P) mill effluent. The treatment led to reduction of chemical oxygen demand (COD), colour, lignin and phenolic content by 84%, 72%, 61% and 95%, respectively. The effluent detoxification was studied by genotoxicity assays using Allium cepa L. (onion) root tip cells. Genotoxicity studies included measuring mitotic index (MI), chromosomal aberrations (CA) and nuclear abnormalities (NA) in root tip cells following treatment with 25, 50, 75 and 100% (v/v) of effluent. The root tip cells grown in untreated effluent showed a significant decrease in MI from 69% (control) to 32%, 27%, 22% and 11% at 25%, 50%, 75% and 100% effluent concentration, respectively. This indicated that the untreated effluent was highly cytotoxic in nature. Further, root tip cells, when treated with different concentrations of effluent showed various CA and NA including c-mitosis, stickiness, chromosome loss, chromosome break, anaphase bridge, multipolar anaphase, vagrant chromosomes, micronucleated and binucleated cells. The MI observed in root tip cells grown in bacterial treated effluents at similar concentrations (25, 50, 75 and 100% v/v) showed an increase of 33%, 36%, 42% and 66%. CA showed a substantial decrease and in some instances, complete absence of CA was also observed. The findings suggest that S. liquefaciens culture could be a potential bacterial culture for bioremediation of P&P mill effluent, as it is effective in substantial lowering of pollutants load as well as reduces the cytotoxic and genotoxic effects of effluent.
authors.affiliation: Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Department of Biosciences, Integral University, Bas-ha Kursi Road, Dashauli, Lucknow, Uttar Pradesh, 226026, India.
authors.forename: Izharul
authors.initials: I
authors.lastname: Haq
authors.affiliation: Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.
authors.forename: Sharad
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India. Electronic address: araj@iitr.res.in.
authors.forename: Abhay
authors.initials: A
authors.lastname: Raj
authors.affiliation: Department of Biosciences, Integral University, Bas-ha Kursi Road, Dashauli, Lucknow, Uttar Pradesh, 226026, India.
authors.forename: Mohtashim
authors.initials: M
authors.lastname: Lohani
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.
authors.forename: G N V
authors.initials: GN
authors.lastname: Satyanarayana
mesh_terms: D001673:Biodegradation, Environmental; D002869:Chromosome Aberrations / Q000139:chemically induced*; D004755:Enterobacteriaceae / Q000201:enzymology / Q000254:growth & development*; D008031:Lignin / Q000032:analysis; D018519:Meristem / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D008940:Mitotic Index; D009152:Mutagenicity Tests / Q000379:methods; D019697:Onions / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D010209:Paper; D010544:Peroxidases / Q000378:metabolism; D062065:Wastewater / Q000032:analysis / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification / Q000379:methods*
chemical_list: D008031:Lignin; D010544:Peroxidases; D062065:Wastewater; D014874:Water Pollutants, Chemical; C042858:lignin peroxidase
keywords: Allium cepa; Bioremediation; Chromosomal aberrations; Mitotic index; Pulp and paper mill effluent; Serratia liquefaciens