Bacterial degradation of synthetic and kraft lignin by axenic and mixed culture and their metabolic products (original) (raw)
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Applied Water Science, 2015
Continuous discharge of lignin containing colored wastewater from pulp paper mill into the environment has resulted in building up their high level in various aquatic systems. In this study, the chemical texture of kraft lignin in terms of pollution parameters (COD, TOC, BOD, etc.) was quite different and approximately twofold higher as compared to model lignin at same optical density (OD 3.7 at 465 nm) and lignin content (2000 mg/L). For comparative bacterial degradation and detoxification of model and kraft lignin two bacteria Citrobacter freundii and Serratia marcescens were isolated, screened and applied in axenic and mixed condition. Bacterial mixed culture was found to decolorize 87 and 70 % model and kraft lignin (2000 mg/L), respectively; whereas, axenic culture Citrobacter freundii and Serratia marcescens decolorized 64, 60 % model and 50, 55 % kraft lignin, respectively, at optimized condition (34°C, pH 8.2, 140 rpm). In addition, the mixed bacterial culture also showed the removal of 76, 61 % TOC; 80, 67 % COD and 87, 65 % lignin from model and kraft lignin, respectively. High pollution parameters (like TOC, COD, BOD, sulphate) and toxic chemicals slow down the degradation of kraft lignin as compared to model lignin. The comparative GC-MS analysis has suggested that the interspecies collaboration, i.e., each bacterial strain in culture medium has cumulative enhancing effect on growth, and degradation of lignin rather than inhibition. Furthermore, toxicity evaluation on human keratinocyte cell line after bacterial treatment has supported the degradation and detoxification of model and kraft lignin.
Bacterial Lignin Peroxidase Mediated Biobleaching and Biodegradation of Paper and Pulp Mill Effluent
IOSR Journal of Environmental Science, Toxicology and Food Technology, 2016
Large amount of lingo-cellulosic waste generated by forestry, agricultural practices, paper-pulp industries and textile dye-stuff industries poses a severe environmental pollution problem. Paper factory effluent is one of the major pollutants on the earth because it is highly coloured. The persistent dark brown colour is due to dissolved lignin based synthetic, aromatic and chlorinated compounds derived from the blow heat condensate, pulp decker washing, chlorine and alkali bleach waste, black liquor spillage and foul evaporator condensate. Selection of correct and ecofriendly treatment method for paper-pulp mill waste-water prior to discharge into the environment is still a matter of concern. In the present study, the application of the lignin peroxidase enzyme as crude extracts of the bacterial isolate cultures was reported as an effective tool in biobleaching and biodegradation of paper pulp mill effluent which was measured spectrophotometrically. The isolates Sphingomonas paucimobilis and Corynebactrium jeikeium were found to be an efficient biobleaching agent as compared to the other isolates studied. They showed 91.32%, 86.57%, 84.21% and 83.82%, 82.43% and 78.94% biobleaching respectively when applied as axenic cultures while the mixed consortia being the most effective showed the biobleaching in the range of 91.61%, 89.47% and 86.84% of the effluent 50%, 75% and 100% respectively.
Lignin Decolorization and Degradation of Pulp and Paper Mill Effluent by Ligninolytic Bacteria
The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize the Century pulp and paper mill effluent. Among four bacterial strains, three bacterial strains Bacillus subtilis, Bacillus endo-phyticus, Bacillus sp. were capable of ligninolytic activity. Consortium made by these bacterial strains enhances the degradation of lignin as well as decolorization. Various nitrogen source, carbon source, pH, temperature and low molecular weight organic acids were used in the optimization process of decolorization and degradation of lignin in paper mill effluent. Maximum decolorization 68.29% was found at pH 7.92, temperature 33°C, in the presence of glucose (as carbon source) 0.99% and yeast extract (as nitrogen source) 0.36% when it was optimized through response surface methodology.
2007
Eight aerobic bacterial strains were isolated from pulp paper mill effluent sludge. Out of eight through nutrient enrichment technique three potential aerobic bacterial strains ITRC S 6 , ITRC S 7 and ITRC S 8 were found capable to effectively degrade the kraft lignin (KL), a major byproduct of the chemical pulping process and main contributor to the colour and toxicity of effluent. Further, these potential strains (ITRC S 6 , ITRC S 7 and ITRC S 8) were biochemically characterised as Gram variable small rod, Gram negative rod and Gram positive rod respectively. Subsequently, 16S rRNA sequencing showed 95% base sequence homology and it was identified as Paenibacillus sp. (AY952466), Aneurinibacillus aneurinilyticus (AY856831), Bacillus sp. (AY952465) for ITRC S 6 , IITRC S 7 and ITRC S 8 , respectively. In batch decolourization experiments Bacillus sp. ITRC S 8 reduced the colour of lignin amended mineral salt medium, pH 7.6 by 65% after 6th d, at 30°C, A. aneurinilyticus ITRC S 7 by 56% and Paenibacillus ITRC S 6 43%. Under these conditions the three strains degraded the KL by 37%, 33% and 30%, respectively while the mixed culture of these three bacteria reduced colour by 69%, lignin by 40% and total substrate by 50% under same conditions. Biodegradation of the KL was not affected by low (<0.2 mg l À1) dissolved oxygen content; thus oxygen inhibition is more likely to be a metabolism-dependent event. Initially with 48 h incubation the decolourization was slow with decreased pH. Further incubation there was rapid decolourization with slight increase in pH at 6 d compared with initial pH by increasing culture optical density. The lignin analysis from medium with HPLC indicated complete degradation rather than biotransformation with complete loss of absorbance peak at 280 nm.
Bacterial Lignin Peroxidase: A Tool for Biobleaching and Biodegradation of Industrial Effluents
Abstract: Lignin, the nature’s plastic is the major pollutant from paper-pulp mill effluent due to its intense unaesthetic brown color, hydrophobicity and poor mechanical properties, tends to be a recalcitrant compound. Textile dyebased industries release colored effluents due to presence of large amount of mixture of dyes which is also hazardous. Microbial extracellular lignin peroxidase enzymes have a potential to degrade lignin and a wide range of complex aromatic dyestuffs. From various environmental niches eleven isolates were screened for lignolytic activity, out of which two bacterial isolates Pseudomonas aeruginosa and Serratia marcescens were able to decolorize 44% to 49% of lignin. The studies on biobleaching of paper-pulp mill effluent gave 60% to 75% color reduction and in case of textile dye- based effluent 50% to 58% decolourization was observed. The heterogeneous combination of lignin peroxidases from mixed consortia gave 80% to 85% color reduction in treatment of paper-pulp mill effluent and 70% to 75% decolourization in treatment of textile dye-based effluent which is significantly high. This system of lignin peroxidase may be efficiently used in biobleaching and biodegradation of effluents from respective industries. Keywords: Lignin Peroxidase, Decolourization, Paper-pulp mill effluent, Textile dye-based effluent.
Decolourisation and treatment of pulp and paper mill effluent by lignin-degradingBacillus sp
Journal of Chemical Technology & Biotechnology, 2007
Three lignin-degrading bacterial strains, identified as Paenibacillus sp., Aneurinibacillus aneurinilyticus and Bacillus sp. have been examined for the treatment of pulp and paper mill effluent. The results of this study revealed that all three bacterial strains effectively reduced colour (39-61%), lignin (28-53%), biochemical oxygen demand (BOD) (65-82%), chemical oxygen demand (COD) (52-78%) and total phenol (64-77%) within six days of incubation. However, the highest reduction in colour (61%), lignin (53%), BOD (82%) and COD (78%) was recorded by Bacillus sp. while, maximum reduction in total phenol (77%) was recorded with Paenibacillus sp. treatment. Significant reduction in colour and lignin content by these bacterial strains was observed after two days of incubation, indicating that bacterium initially utilized growth supportive substrates and subsequently chromophoric compounds thereby reducing lignin content and colour in the effluent. The total ion chromatograph (TIC) of compounds present in the ethyl acetate extract of control and bacterial treated samples revealed the formation of several lignin-related aromatic compounds. The compounds identified in extracts of treated samples by Paenibacillus sp were t-cinnamic acid and ferulic acid, while 3-hydroxy-4-methoxyphenol, vanillic acid and vanillin acid by A. aneurinilyticus and gallic acid and ferulic acid by Bacillus sp. respectively indicating the degradation of lignin present in the effluent. The identified compounds obtained after different bacterial treatments were found to be strain-specific. Among these identified compounds, ferulic acid, vanillic acid and vanillin could have immense value for their use in preservatives and in the food flavour industry.
Microbial treatment of industrial lignin: Successes, problems and challenges
Renewable and Sustainable Energy Reviews, 2017
Lignin, one of the major components of plant/lignocellulosic biomass, is an irregular 3-D polymer comprised of potentially valuable phenolic monomers. Currently lignin and its colloidal solution in water, black liquor, obtained as by-products in many biomass treatment processes, e.g., pulping in paper industry, remain to be considered recalcitrant substrates of a limited commercial value. This study reviews the recent research on both fungal and bacterial lignin degradation, with a focus on the characterization of degradation products. The specific features and biological treatment of industrial lignin and black liquor are detailed along with the degradation conditions employed, complementing other review articles focusing on natural lignin degradation. An overview of ligninolytic enzymes frequently identified among microorganisms is presented, with the emphasis on factors responsible for their regulation and induction including the mediators involved and multienzyme systems employed by natural lignin degraders. Efficient regulation of ligninolytic enzymes can be achieved through the optimization of a cultivation medium composition with supplementation of strain specific stimulatory components such as salts, low molecular weight phenolic compounds and nutrition sources. Current research efforts in characterizing lignin degradation products are reviewed with the emphasis on both destructive and non-destructive gas chromatographic methods as they are essential for future detailed kinetic and mechanistic studies.
Degradation of lignin by Bacillus altitudinis SL7 isolated from pulp and paper mill effluent
Water Science and Technology, 2021
Lignin is a major by-product of pulp and paper industries, and is resistant to depolymerization due to its heterogeneous structure. Degradation of lignin can be achieved by the use of potential lignin-degrading bacteria. The current study was designed to evaluate the degradation efficiency of newly isolated Bacillus altitudinis SL7 from pulp and paper mill effluent. The degradation efficiency of B. altitudinis SL7 was determined by color reduction, lignin content, and ligninolytic activity from degradation medium supplemented with alkali lignin (3 g/L). B. altitudinis SL7 reduced color and lignin content by 26 and 44%, respectively, on the 5th day of incubation, as evident from the maximum laccase activity. Optimum degradation was observed at 40°C and pH 8.0. FT-IR spectroscopy and GC-MS analysis confirmed lignin degradation by emergence of the new peaks and identification of low-molecular-weight compounds in treated samples. The identified compounds such as vanillin, 2-methyoxyhenol, 3-methyl phenol, oxalic acid and ferulic acid suggested the degradation of coniferyl and sinapyl groups of lignin. Degradation efficiency of B. altitudinis SL7 towards high lignin concentration under alkaline pH indicated the potential application of this isolate in biological treatment of the lignin-containing effluents.
Process Biochemistry, 2005
Several ligninolytic microorganisms isolated from the environment of a small pulp and paper mill were evaluated for their ability to decolorize dark brown colored effluents of an agriresidue-based pulp and paper mill and their decolorization efficiency was compared with two known lignin degrading organisms, Phanerochaete chrysosporium and Trametes versicolor. Two isolates, identified as Aspergillus fumigatus and Aspergillus flavus produced higher degrees of color reduction. A. fumigatus showed highest efficiency for effluent decolorization and was capable of producing extracellular laccase, manganese peroxidase and xylanase. This culture was capable of decolorizing effluents over pH range 6.0-9.0, the optimum being pH 8.0 and hence no adjustment of effluent pH for decolorization was necessary. Cellulose, sucrose, glucose and xylose could be used as co-substrate and no additional nitrogen source was necessary for effluent decolorization. Studies on molecular size distribution of untreated effluent and effluent decolorized by A. fumigatus showed that the high-and medium-molecular weight colored compounds are biochemically degraded and depolymerized. #
Isolation and Screening of Lignin Degrading Bacteria from Different Natural and Organic Sources
International Journal of Current Microbiology and Applied Sciences
Increased consumption and high dependence on nonrenewable sources has substantially contributed to global warming and environmental pollution. Hence, alternative strategies for energy production have to be looked and one of the alternative is producing 2 nd generation Bio-ethanol from lingo-cellulosic material. Maize cob is one of the Lignocellulosic material is one the substrate, which can be used for Bio-ethanol production (It is rind after removing the seeds). The present study is focused on to look for novel strains of lignin degrading bacteria from various organic sources. The different sample sources used for the isolation of lignin degrading bacteria were from cow dung, compost, forest soil, garden soil in agriculture college, Hassan. Enrichment of sample source was also done by mixing the paper, corncob, compost, cowdung and soil in different proportions and kept for 15 days at room temperature. Enriched samples were also used as a source for isolation of lignin degraders. Totally 64 colonies were isolated by screening in 7 different sample sources, from those 64 isolates, only 25 isolates confirmed as lignin degraders through conformational test. Decolourization zone produced by 25 isolates was measured. Eight isolates that produced large decolurization zone (0.5 to 1 cm) were selected and further screened for their tolerance to lignin by culturing them on 2% lignin. The results pertaining to growth on 2% Alkaline lignin is, isolate CC-10 was grown within 24hr followed by CM-3, PC-2,PC-3, PC-5 and CC-8 they were grown within 48hr. The growth of FS-3 and CC-10 were seen within 72hr. Based on the results obtained the slow grower FS-3 and CC-10 was discarded. Six potential isolates which are showing large clear zone (decolourized) of methylene blue dye and also rapid growth on MSM with 2% alkaline lignin were selected. Based on this to reconfirm the isolates as a lignin degrading bacteria Protein profiling of the six isolates has been done by using SDS-PAGE technique.