title: Investigating the degradation process of kraft lignin by β-proteobacterium, Pandoraea sp. ISTKB.
abstract: The present study investigates the kraft lignin (KL) degrading potential of novel alkalotolerant Pandoraea sp. ISTKB utilizing KL as sole carbon source. The results displayed 50.2 % reduction in chemical oxygen demand (COD) and 41.1 % decolorization after bacterial treatment. The maximum lignin peroxidase (LiP) and manganese peroxidase (MnP) activity detected was 2.73 and 4.33 U ml(-1), respectively, on day 3. The maximum extracellular and intracellular laccase activities observed were 1.32 U ml(-1) on day 5 and 4.53 U ml(-1) on day 4, respectively. The decolorization and degradation was maximum on day 2. Further, it registered an increase with the production of extracellular laccase. This unusual trend of decolorization and degradation was studied using various aromatic compounds and dyes. SEM and FTIR results indicated significant change in surface morphology and functional group composition during the course of degradation. Gas chromatography and mass spectroscopy (GC-MS) analysis confirmed KL degradation by emergence of new peaks and the identification of low molecular weight aromatic intermediates in treated sample. The degradation of KL progressed through the generation of phenolic intermediates. The identified intermediates implied the degradation of hydroxyphenyl, ferulic acid, guaiacyl, syringyl, phenylcoumarane, and pinoresinol components commonly found in lignin. The degradation, decolorization, and GC-MS analysis indicated potential application of the isolate Pandoraea sp. ISTKB in treatment of lignin-containing pollutants and KL valorization.
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
authors.forename: Madan
authors.initials: M
authors.lastname: Kumar
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Singh
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Singh
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
authors.forename: Anjali
authors.initials: A
authors.lastname: Singhal
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India. isthakur@hotmail.com.
authors.forename: Indu Shekhar
authors.initials: IS
authors.lastname: Thakur
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D020562:Betaproteobacteria / Q000201:enzymology / Q000378:metabolism*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D008401:Gas Chromatography-Mass Spectrometry; D042845:Laccase / Q000378:metabolism; D008031:Lignin / Q000032:analysis / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism; D010636:Phenols / Q000032:analysis / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010636:Phenols; C076151:Kraft lignin; D008031:Lignin; D042845:Laccase; D010544:Peroxidases; C042858:lignin peroxidase
keywords: Biodegradation; Dyes; FTIR; GC-MS; Kraft lignin; Pandoraea sp. ISTKB