ORIGINAL ARTICLE Degradation of 2,4,6-Trinitrophenol (TNP) by Arthrobacter sp. HPC1223 Isolated from Effluent Treatment Plant (original) (raw)
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Arthrobacter sp. HPC1223 (Genebank Accession No. AY948280) isolated from activated biomass of effluent treatment plant was capable of utilizing 2,4,6 trinitrophenol (TNP) under aerobic condition at 30°C and pH 7 as nitrogen source. It was observed that the isolated bacteria utilized TNP up to 70 % (1 mM) in R2A media with nitrite release. The culture growth media changed into orange-red color hydride-meisenheimer complex at 24 h as detected by HPLC. Oxygen uptake of Arthrobacter HPC1223 towards various nitro/amino substituted phenols such as dinitrophenol (1.2 nmol/min/mg cells), paranitrophenol (0.9 nmol/ min/mg cells), 2-aminophenol (0.75 nmol/min/mg cells), p-aminophenol (0.4 nmol/min/mg cells), phenol (0.56 nmol/min/mg cells) and TNP (2.42 nmol/min/mg cell) was analysed, which showed its additional characteristic of broad substrate catabolic capacity. The present study thus report a novel indigenous bacteria isolated from activated sludge utilized TNP and has broad catabolic potential towards substituted phenols.
Studies on Biodegradation of P-Nitrophenol by Arthrobacter chlorophenolicus and Its Metabolites
The biodegaradation of p-nitrophenol was studied experimentally at different initial p-nitrophenol concentrations under different environmental and operational conditions (like incubation temperature, pH, inoculum size etc.) by using microbial strain Arthrobacter chlorophenolicus A6. The rate of degradation of p-nitrophenol was observed maximum at incubation temperature 30˚C and pH 7 ± 0.2, inoculum size OD 600 = 0.2, incubation rotor speed 150 rpm, pH in the range 5-8 and temperature 25-3C. In experiments on kinetic studies the initial concentration of biomass is fixed OD 600 =0.2 and variation in biomass concentration has been experimentally observed with time at p-nitrophenol concentrations (10-200 mg/l). The value of maximum specific growth rate is found to be equal to 2.370 h -1 and it is achieved at initial p-nitrophenol concentration of about 70 mg/l. The p-nitrophenol is inhibitory type substrate and the inhibition effect of p-nitrophenol becomes predominant above 70 mg/l. T...
Biodegradation of p-nitrophenol in an aqueous waste stream by immobilized bacteria
Applied and environmental microbiology, 1990
Microbiological analyses of activated sludge reactors after repeated exposure to 100 mg of p-nitrophenol (PNP) per liter resulted in the isolation of three Pseudomonas species able to utilize PNP as a sole source of carbon and energy. Cell suspensions of the three Pseudomonas sp., designated PNP1, PNP2, and PNP3, mineralized 70, 60, and 45% of a 70-mg/liter dose of PNP in 24, 48, and 96 h, respectively. Mass-balance analyses of PNP residues for all three cultures showed that undegraded PNP was less than 1% (less than 50 micrograms); volatile metabolites, less than 1%; cell residues, 8.4 to 14.9%; and water-soluble metabolites, 1.2 to 6.7%. A mixed culture of all three PNP-degrading Pseudomonas sp. was immobilized by adsorption onto diatomaceous earth biocarrier in a 1.75-liter Plexiglas column. The column was aerated and exposed to a synthetic waste stream containing 629 to 2,513 mg of PNP per liter at flow rates of 2 to 15 ml/min. Chemical loading studies showed that the threshold ...
Batch Biodegradation of Para-Nitrophenol Using Arthrobacter chlorophenolicus A6
Applied Biochemistry and Biotechnology, 2011
The present study reports the kinetics of p-nitrophenol (PNP) biodegradation by Arthrobacter chlorophenolicus A6 in batch shake flasks for initial PNP concentrations in the range of 25-225 mg l −1 . Results of batch growth kinetics of A. chlorophenolicus A6 at various initial PNP concentrations revealed that the culture followed substrate inhibition kinetics with estimated decay coefficient value of 0.0132 h −1 . Biokinetic constants involved in the process were estimated by fitting the experimental data to several substrate inhibition kinetics models available from the literature. Among the models tested, Webb model fitted the experimental data best with the least root mean square error value, and the estimated model constants values were μ=0.161 h −1 , K i =128 mg l −1 , K s =60.15 mg l −1 , and K=100 mg l −1 . In addition, observed and theoretical yield coefficients, maintenance energy, and specific growth rate of the culture at various initial PNP concentrations were also investigated in the study.
2014
Phenol and its compounds are one of the most important pollutants in the environment. P-Nitrophenol (PNP) is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. In this context, the study was conducted on biodegradation of phenolic compound; PNP by P. putida MTCC 1194. The present study was also examined the efficiency of biodegradation of PNP on different pH. When the ph was increased up to 9, transformed organism possessed nullified effect towards the 72hrs of all the treated concentrations. Though, in wild type colonies had a remarkably significant (p<0.0029) biodegrading efficiency noted in each different concentrations with its stipulated period of time. Protein was isolated from P. putida and transformed E. coli they were run on SDSPAGE and molecular weight was determined that P. putida have lower molecular weighed protein band such as 45.5 KDa, and transformed E. coli contains higher molecular weighed protei...
Chemosphere, 2006
The molecular and kinetic characterization of a microorganism able to aerobically degrade 4-nitrophenol (4NP) is presented. The microorganism was isolated from a mixed culture operating in a laboratory-scale sequencing batch reactor with an aerobic anoxic cycle. It was identified as a member of Ralstonia genus within Betaproteobacteria. It is a gram negative coccobacillum (cell length of 2-3 lm) able to aerobically store lipid inclusions when grown aerobically on nitrophenol as the sole carbon source in the range of tested concentrations (80-320 mg l À1 ). Batch kinetic tests were performed with the pure culture, while the kinetics of the mixed biomass was directly investigated in the reactor. For pure cultures exponential growth was observed, with growth rate values in the range of 2-6 d À1 ; in experiments with the mixed cultures 4NP concentrations were correlated with growth using the Haldane equation (k max = 0.30 mg 4NP mg À1 VSS h À1 ; K s = 55 mg 4NP l À1 and K I = 15 mg 4NP l À1 ). Observed pure culture growth rates were higher than those of mixed cultures. This result can be explained by considering that in mixed culture the biomass is evaluated as volatile suspended solids, including both specialized biomass for 4NP removal and denitrifying bacteria.
Journal of Bioscience and Bioengineering, 1999
In order to examine the microbial degradation of p-nitrophenol (PNP) by a mixed culture system and simultaneous removal of nitrite released via the degradation, an activated sludge retained in porous carrier particles and a suspension culture as a control were acclimated to artificial sewage containing PNP as the sole carbon source. The adaptation of microbes retained in porous carrier particles to PNP was faster than that of suspended microbes by more than 20 d. After microbial adaptation to PNP, it was degraded completely without significant accumulation of intermediate metabolites. The PNP degradation activity of the retained microbes was more than 2 times higher than that of the suspended microbes. By increasing the retained microbial concentration, nitrite released from the degraded PNP was removed by denitrification. This research demonstrates that using microbes retained in porous carrier particles is not only effective for reduction of acclimation time but also enables simultaneous removal of the nitrogen compounds resulting from the degradation of nitroaromatics.
Ecotoxicology and environmental safety, 2015
Nitroaromatics are widely used for industrial purposes and constitute a group of compounds of environmental concern because of their persistence and toxic properties. Biological processes used for decontamination of nitroaromatic-polluted sources have then attracted worldwide attention. In the present investigation m-nitrophenol (MNP) biodegradation was studied in batch and continuous reactors. A bacterial community able to degrade the compound was first selected from a polluted freshwater stream and the isolates were identified by the analysis of the 16S rRNA gene sequence. The bacterial community was then used in biodegradation assays. Batch experiments were conducted in a 2L aerobic microfermentor at 28°C and with agitation (200rpm). The influence of abiotic factors in the biodegradation process in batch reactors, such as initial concentration of the compound and initial pH of the medium, was also studied. Continuous degradation of MNP was performed in an aerobic up-flow fixed-be...