title: Evaluation of bioremediation potentiality of ligninolytic Serratia liquefaciens for detoxification of pulp and paper mill effluent.
abstract: Due to high pollution load and colour contributing substances, pulp and paper mill effluents cause serious aquatic and soil pollution. A lignin-degrading bacterial strain capable of decolourising Azure-B dye was identified as lignin peroxidase (LiP) producing strain LD-5. The strain was isolated from pulp and paper mill effluent contaminated site. Biochemical and 16S rDNA gene sequence analysis suggested that strain LD-5 belonged to the Serratia liquefaciens. The strain LD-5 effectively reduced pollution parameters (colour 72%, lignin 58%, COD 85% and phenol 95%) of real effluent after 144h of treatment at 30°C, pH 7.6 and 120rpm. Extracellular LiP produced by S. liquefaciens during effluent decolourisation was purified to homogeneity using ammonium sulfate (AMS) precipitation and DEAE cellulose column chromatography. The molecular weight of the purified lignin peroxidase was estimated to be ∼28kDa. Optimum pH and temperature for purified lignin peroxidase activity were determined as pH 6.0 and 40°C, respectively. Detoxified effluent was evaluated for residual toxicity by alkaline single cell (comet) gel electrophoresis (SCGE) assay using Saccharomyces cerevisiae MTCC 36 as model organism. The toxicity reduction to treated effluent was 49.4%. These findings suggest significant potential of S. liquefaciens for bioremediation of pulp and paper mill effluent.
authors.affiliation: Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Lucknow, Uttar Pradesh 226 001, 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), M.G. Marg, Lucknow, Uttar Pradesh 226 001, 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), M.G. Marg, Lucknow, Uttar Pradesh 226 001, India.
authors.forename: Vineeta
authors.initials: V
authors.lastname: Kumari
authors.affiliation: Microbiology Division, CSIR-Central Drug Research Institute (CDRI), Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, Uttar Pradesh 226 031, India.
authors.forename: Sudheer Kumar
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), M.G. Marg, Lucknow, Uttar Pradesh 226 001, India. Electronic address: araj@iitr.res.in.
authors.forename: Abhay
authors.initials: A
authors.lastname: Raj
mesh_terms: D001399:Azure Stains / Q000378:metabolism / Q000633:toxicity; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000737:chemistry / Q000633:toxicity; D020552:Comet Assay; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D007220:Industrial Waste; D010209:Paper; D010544:Peroxidases / Q000378:metabolism*; D044090:Serratia liquefaciens / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D001399:Azure Stains; D004396:Coloring Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C025819:Azure B; D010544:Peroxidases; C042858:lignin peroxidase
keywords: Bioremediation; Comet assay; Lignin peroxidase (LiP); Paper mill effluent; Serratia liquefaciens