Paper Mill Effluent Decolorization by Fifty Streptomyces Strains (original) (raw)
Related papers
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. #
Applied Microbiology and Biotechnology, 1997
Two Streptomyces strains, UAH 30 and UAH 51, have been shown to decolourise a paper-mill effluent obtained after semichemical alkaline pulping of wheat straw. Fractionation of the effluent decolourised by strains UAH 30 and UAH 51 showed that 60% and 80% respectively of the alkali-lignin fraction have been removed from the effluent after 7 days of growth. 13C NMR cross polarization and magic angle spinning (CPMAS) spectra of the alkali-lignin remaining in the effluent after decolourisation revealed a decrease in the relative amount of aromatic lignin units compared to that obtained from the untreated effluent along with a reduction in the ratio of syringyl:guaiacyl units. Gas chromatography/mass spectrometry analysis of the low-molecular-mass compounds extracted from the decolourised effluent revealed the presence of new aromatic lignin-related compounds that were not present in the untreated control effluent. This was linked to a general depolymerization of larger lignin molecules occurring during decolourisation by the two Streptomyces strains. Identification of low-molecular-mass aromatic compounds extracted from the decolourised effluent revealed only the presence of p-hydroxyphenyl units in effluents decolourised by the strain UAH 30 while p-hydroxyphenyl, guaiacyl and syringyl units were detected in effluents decolourised by Streptomyces strain UAH 51. The study indicates that, while decolourisation is a common feature of the two Streptomyces strains, the mechanisms involved in the degradation of the lignin fractions may be different and strain-specific.
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.
2016
Pulp and paper mill effluent is rich in lignocellulosic compounds, and lignin is the major colour-imparting constituent present in it. The present study deals with isolation of a potential bacterium for decolourization of pulp and paper mill effluent. A promising lignin-degrading bacterium RJH-3 was isolated from sludge of pulp and paper mill and identified as bacillus subtilis subsp. inaquosorum strain by 16s rRNA gene sequencing. During wastewater degradation study by batch mode, the isolate reduced 59.6% lignin content, 61.3% colour, and 64.1% COD after 144 h of incubation. The bacterium was able to degrade lignin and decolorize pulp and paper mill effluent to the permissible discharge limit within 48 h retention time (RT) during the reactor study. The isolate efficiently reduced lignin (45.1%), colour (48.8%), and COD content (59.1%) at 48 h RT from the pulp and paper mill effluent at alkaline pH (8.3±0.3).
Bioresource Technology, 2006
In the present study sequential anaerobic and aerobic treatment in two steps bioreactor was performed for removal of colour in the pulp and paper mill effluent. In anaerobic treatment, colour (70%), lignin (25%), COD (42%), AOX (15%) and phenol (39%) were reduced in 15 days. The anaerobically treated effluent was separately applied in bioreactor in presence of fungal strain, Paecilomyces sp., and bacterial strain, Microbrevis luteum. Data of study indicated reduction in colour (95%), AOX (67%), lignin (86%), COD (88%) and phenol (63%) by Paecilomyces sp. where as M. luteum showed removal in colour (76%), lignin (69%), COD (75%) AOX (82%) and phenol (93%) by day third when 7 days anaerobically treated effluent was further treated by aerobic microorganisms. Change in pH of the effluent, and increase in biomass of microorganisms substantiated results of the study, which was concomitant to the treatment method.
Effect ofStreptomyces viridosporus T7A on kraft lignin
Journal of Industrial Microbiology, 1990
The ability of the lignino-cellulolytic actinomycete Streptomyces viridosporus T7A to attack purified fractions of kraft lignin was examined. In the presence of 0.3% yeast extract, high-molecular weight kraft lignin (MW > 3000, ether-insoluble fraction) does not affect growth of this microorganism significantly, whereas low-molecular weight kraft lignin (MW < 3000, ether-soluble fraction) inhibits its development. Accordingly, average molecular weight of the ether-insoluble fraction after bacterial growth remained unaltered, as measured by Sephadex G-50 gel permeation chromatography. Slight modifications were detected by high performance liquid chromatography in the ether-soluble fraction after incubation with the microorganism. S. viridosporus T7A partially decolorized Remazol Brilliant Blue R during growth on wheat lignocellulose. However, decolorization of either fraction of kraft lignin was not observed. These results suggest that the filamentous bacterium S. viridosporus T7A is not suitable for pulp mill effluent treatment.
World Journal of Microbiology and Biotechnology, 2005
Paecilomyces sp. and Pseudomonas syringae pv myricae (CSA105) were isolated from sediment core of drainage of the pulp and paper mill industry. Fungi and bacteria were applied for treatment of pulp and paper mill effluent in a two-step and three-step fixed film sequential bioreactor containing sand and gravel at the bottom of the reactor for immobilization of microbial cells. Degradation of chlorinated phenols and formation of their metabolites were determined by high performance liquid chromatography. The microbes exhibited significant reduction in colour (88.5%), lignin (79.5%), chemical oxygen demand (87.2%) and phenol (87.7%) in two-step aerobic sequential bioreactor, and colour (87.7%), lignin (76.5%), chemical oxygen demand (83.9%) and phenol (87.2%) in three-step anaerobic-aerobic sequential bioreactor.
Decolourization And Detoxification Of Pulp And Paper Mill Effluent By Microorganisms
Three fungal strains were isolated from sediments of pulp and paper mill in which PF7 reduced colour (27%) and lignin content (24%) of the effluent on 5th day. PF7 was identified as Cryptococcus sp. isolate FIST3 on the basis of ITS1 and ITS2 region sequences. The process of decolourization optimized, in shake flask experiments, by Taguchi approach indicated optimum conditions: temperature (30-35 • C); shaking condition (125 rpm); dextrose (1.0% w/v); tryptone (0.1% w/v); inoculum size (7.5% w/v); pH (5) and duration (24 h). Overall evaluation criterion (OEC) value before optimization was 32.3. There was 38% improvement in the process with final OEC value, 44.6 ± 2.02, at optimum conditions. The colour content of the effluent reduced by 50-53% and lignin content 35-40% after treatment at optimum conditions. Variation in pH from 5 to 6 had most significant effect on decolourization (72%) while variation in temperature from 30 • C to 35 • C had no effect on the process. Treated effluent was further evaluated for toxicity by alkaline single cell (comet) gel electrophoresis (SCGE) assay using Saccharomyces cerevisiae MTCC 36 as model organism, indicated 45% reduction. The results showed significant reduction in colour, lignin and toxicity of the effluent and this process can be scale up to industrial level.
Advances in Microbiology
Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzymes and constitute considerable proportion of the soil or aquatic micro-flora responsible for degradation of biomass in natural environment. Presently, most of the commercially exploited lignocellulases and commercial biodegradation processes rely mostly on fungal or bacterial microorganisms. Actinomycetes are relatively less explored for biodegradation processes that utilize lignocellulases for solid agro-waste management and waste water treatment. There is also a need to search and explore novel actinomycete strains for various biodegradation applications. This study involved examining the possibility of using only potent actinomycetes strains for the composting process by creating the consortium of such strains that could produce thermo-tolerant and alkali-tolerant key enzymes necessary for the degradation of cellulose, hemi-cellulose and lignin. The newly developed actinomycete consortium was tested for the composting activity and the composting process was optimized. The analysis of the composted material generated under ideal condition, demonstrated desirable physical and chemical characteristics. Paper pulp effluent poses a hazard to waterways due to toxicity. The toxicity of this mill effluent can be attributed to a compound called lignin and its chlorinated derivatives that are let out during the treatment of lignocellulosic constituents. Current study also involves the use of a strain of actinomycete having ability to produce enzyme laccase, which is active under alkaline condition for the treatment of paper pulp effluent. Enzyme laccase is known for its ability to attack phenolic components of lignin and common hazardous component of effluent, polycyclic aromatic hydrocarbons (PAH). Aerobic treatment of effluent by actinomycete strain indicated 21% reduction in COD at pH 7.5 after 14 days under optimum condition.