Effect of additional carbon source on biodegradation of linear alkylbenzene sulfonate by las-utilizing bacteria (original) (raw)
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Anionic surfactants, the earliest and the most common surfactants in detergent and cosmetic product formulations contribute significantly to the pollution profile of the ecosystem. Linear alkylbenzene sulfonates (LAS), a major chemical constituent of detergents, forms an imperative group of anionic surfactants. Bioremediation of LAS by conventional processes such as activated sludge is ineffective due to the low kinetics of degradation by unsuitable organisms and foam production. Hence this study was focused on isolating and characterizing indigenous LASdegrading bacteria from soil. Twenty different LASdegrading bacteria were isolated from detergentcontaminated soil by enrichment culture technique and degradation efficiency was assessed by Methylene Blue Active Substances (MBAS) assay and by reverse-phase high-performance liquid chromatography (HPLC) analysis. The most efficient LASdegrading isolates, L9 (81.33±0.7) and L12 (81.81± 0.8), were selected and identified as Pseudomonas nitroreducens (MTCC 10463) and Pseudomonas aeruginosa (MTCC 10462). The 16S rDNA sequences of the isolates were deposited in NCBI GenBank under the accession numbers HQ 271083 (L9) and HQ 271084 (L12). The isolates were capable of degrading 0.05 g/l LAS at 25 °C and pH 7.0–7.5. Presence of a solid support caused biofilm formation which in turn enhanced LAS degradation. The isolates tend to display diauxic growth with alternate carbon source such as dextrose. These isolates also have the capability to degrade other xenobiotics like hydrocarbons and pesticides. Since xenobiotic pollutants in nature occur as a mixture of compounds rather than single pollutants, the potential of these two indigenous LAS-degrading isolates to degrade multiple xenobiotics gains relevance. Keywords Biodegradation . Methylene Blue Active
Biodegradation of Coproducts of Commercial Linear Alkylbenzene Sulfonate
Environmental Science & Technology, 1997
Dialkyltetralin sulfonate (DATS) and single methyl-branched isomers of linear alkylbenzene sulfonate (iso-LAS) are coproducts that together can range from 1 to 10% of commercial LAS depending on the manufacturing process. Biodegradation studies using radiolabeled DATS and iso-LAS showed mineralization by indigenous microbial populations in laboratory simulations of aquatic and soil environments. Half-lives ranged from 2 to 20 days, which is rapid enough to suggest that accumulation would not occur in these environments. Upon exposure to laboratory activated sludge treatment, most model iso-LAS compounds showed greater than 98% parent compound removal, extensive mineralization (>50%), and 79-90% ultimate biodegradation (mineralization plus conversion to biomass). Activated sludge treatment of DATS and one of the iso-LAS isomers (methyl group attached to the benzylic carbon of the alkyl chain) resulted in >98% removal, 3-12% ultimate biodegradation and apparent formation of carboxylated biodegradation intermediates that accounted for 88-97% of the original material. These DATS and iso-LAS biodegradation intermediates continued to mineralize in simulated receiving water and soil environments at rates similar to that of sulfophenyl carboxylate (SPC) intermediates of a standard LAS.
Journal of Xenobiotics, 2012
Untreated detergent bearing wastes discharged into the environment are sources of linear alkylbenzene sulfonate (LAS). Detergent wastes usually do not contain nitrogen or contain very low amounts. Biostimulation by introducing limiting nutrient element can be useful in biotreatment of such waste. The effect of inorganic and organic nitrogen supplements on aerobic degradation of LAS by LAS-utilizing bacteria was examined. Phosphate-buffered LAS mineral media were prepared and supplemented with different nitrogen sources: NPK fertilizer (inorganic) and urea fertilizer (organic). Individual and various consortia of pure cultures of Alcaligenes odorans, Citrobacter diversus, Micrococcus luteus and Pseudomonas putida, previously isolated from a detergent effluent polluted stream, were used. Biodegradation of LAS was monitored in terms of half-life (t ½) of the surfactant. The rates of biodegradation by the consortia can be ranked as: 4-membered (t ½ =8-12 days) >3-membered (t ½ =8-13 days) >2-membered consortia (t ½ =10-15 days) >individuals (t ½ =9-16 days). The inorganic nitrogen source enhanced utilization of the surfactant, while organic nitrogen supplementation generally slowed degradation of the surfactant. In undertaking biotreatment of detergent bearing effluent, inorganic nitrogen should be used as biostimulant.
On the complete aerobic microbial mineralization of linear alkylbenzene sulfonate
Desalination, 2007
The xenobiotic organic compounds linear alkylbenzene sulfonates (LAS) are among the most thoroughly investigated with respect to biodegradability. Previous studies have shown that LAS are relatively rapidly degraded under aerobic conditions, but only very slowly or not at all degraded under anaerobic conditions. In the present work, the degree of primary and ultimate biodegradation of LAS by consortia of aerobic microorganisms was examined. The quantification of primary biodegradation was conducted via analysis of the LAS content in the mixed liquor, which was based on microwave-assisted-extraction (MAE) followed by solid phase extraction with liquid chromatography coupled with a fluorescence detector (HPLC-FD). The ultimate biodegradability of LAS was examined by measuring both the disappearance of the test compound and the formation of carbon dioxide using the OECD method 301B or the sulphate. It was found that the established enriched mixed microbial population was capable for complete mineralization of all LAS, as verified by the sulfate production as well as the application of the OECD method and the carbon mass balances carried out throughout the course of the conducted experiments. In particular, any intermediate compound formed during LAS biodegradation was rapidly decomposed, making any intermediate accumulation temporal.
Biodegradation of linear alkylbenzene sulfonates in sulfate-leached soil mesocosms
Chemosphere, 2003
Surface active agents (surfactants) are chemical compounds which are massively used as raw material in detergent production. Synthetic type surfactants are often used because they perform better and more economical compared to natural detergents. Linear Alkyl Benzene Sulfonate (LAS) is one of synthetic surfactants that is widely used. Although LAS is biodegradable, its introduction to the environment in big amount harms the water bodies. Research on biodegradation of LAS with 100 ppm, 400 ppm, 700 ppm, 1000 ppm and 1500 ppm concentrations was conducted by using consortium of bacteria comprises of Pseudomonas aeroginosa, Bacillus subtilis, Bacillus aglomerans, Bacillus cereus, Bacillus alvae. Experiments were carried out in twelve days, in 29 o C temperature with initial total inoculum bacteria 1,59 x 10 8 CFU/mL. Results showed that this type of bacterial consortium could live until 1500 ppm in LAS environment. However, significant growth rate did not occurr, 0.039 -0.042 hour -1 and not too efficiently reduce Chemical Oxygen Demand (COD) for those systems. Surface tension in several variated concentration of LAS: 0 ppm >100 ppm >400 ppm >700 ppm, LAS 700 ppm = 1000 ppm = 1500 ppm.
Biodegradation of Linear Alkylbenzene Sulfonates and Their Degradation Intermediates in Seawater
Environmental Science & Technology, 2004
A bacterial consortium capable of degrading the linear alkylbenzene sulfonate (LAS) was isolated from the wastewater treatment plant. The bacterial consortium consisted of two members, Pantoea agglomerans and Serratia odorifera 2. Cells were grown evenly together in a minimal medium (M9) and nutrient broth (NB). The bacterial consortium was able to grow in the minimal medium containing LAS as the only carbon source. The percentage degradation of 200 ppm LAS by this bacterial consortium was better when cells were grown in NB (∼70%) than in the M9 medium (36%). Also, the degradation ability by the bacterial consortium was very much higher than by its individual cells. This work shows that the two bacteria complement each other in the degrading ability of LAS, indicating catabolic cooperation between the two consortium members. An incubation temperature of 32 • C, an agitation rate of 250 rev min −1 , and the addition of different carbon and nitrogen sources all independently caused complete mineralization of 200 mg L −1 LAS within 48-72 h.
1 Biodegradation of Linear Alkyl Benzene Sulfonate by Bacterial Consortium
2015
Surface active agents (surfactants) are chemical compounds which are massively used as raw material in detergent production. Synthetic type surfactants are often used because they perform better and more economical compared to natural detergents. Linear Alkyl Benzene Sulfonate (LAS) is one of synthetic surfactants that is widely used. Although LAS is biodegradable, its introduction to the environment in big amount harms the water bodies. Research on biodegradation of LAS with 100 ppm, 400 ppm, 700 ppm, 1000 ppm and 1500 ppm concentrations was conducted by using consortium of bacteria comprises of Pseudomonas aeroginosa, Bacillus subtilis, Bacillus aglomerans, Bacillus cereus, Bacillus alvae. Experiments were carried out in twelve days, in 29oC temperature with initial total inoculum bacteria 1,59 x 108 CFU/mL. Results showed that this type of bacterial consortium could live until 1500 ppm in LAS environment. However, significant growth rate did not occurr, 0.039 – 0.042 hour-1 and n...
Biodegradation Of Linear Alkyl Benzene Sulfonate By Bacterial Consortium
2006
Surface active agents (surfactants) are chemical compounds which are massively used as raw material in detergent production. Synthetic type surfactants are often used because they perform better and are more economical compared to natural detergents. Linear Alkyl Benzene Sulfonate (LAS) is one of the synthetic surfactants that is widely used. Although LAS is biodegradable, its introduction to the environment in big amounts harms water bodies. Research on biodegradation of LAS with 100 ppm, 400 ppm, 700 ppm, 1000 ppm and 1500 ppm concentrations was conducted by using consortium of bacteria comprising of Pseudomonas aeroginosa, Bacillus subtilis, Bacillus aglomerans, Bacillus cereus, Bacillus alvae. Experiments were carried out for twelve days, at 29oC with initial total inoculum of bacteria at 1,59 x 108 CFU/mL. Results showed that this type of bacterial consortium could tolerate 1500 ppm in LAS environment. However, significant growth rate did not occurr, 0.039 – 0.042 hour -1 and...
Biodegradability of linear alkylbenzene sulfonates subjected to wet air oxidation
Journal of Chemical Technology and Biotechnology, 2002
Shake flask experiments were conducted to determine the biodegradability of aqueous linear alkylbenzene sulfonate (LAS) and LAS (1600 mg dm−3) subjected to wet air oxidation (WAO), to assess the suitability of WAO as a pre-treatment for biological degradation. The effects of WAO temperature (180–240 °C) and the concentration of the orthophosphoric acid catalyst (0–1.0 mol dm−3) were investigated. Results showed that a higher WAO temperature increased the biodegradability of the WAO effluent. This was due to a greater removal of both recalcitrant sulfonated organics and organic concentration (TOC and COD). Conversely, greater orthophosphoric acid concentrations decreased the biodegradability of the WAO effluents. This was because the higher acid concentration increased the ionic strength and changed the WAO intermediate and product distribution, inhibiting microbial action. Nevertheless, the effluents from both variations of WAO were still more biodegradable than LAS at equivalent concentrations. However, since higher WAO temperatures can substantially increase capital costs, future work should focus on developing a WAO catalyst that both desulfonates and mildly oxidises LAS at moderate temperatures (200 °C).© 2002 Society of Chemical Industry