Impact of biosurfactant produced by Bacillus spp. on biodegradation efficiency of crude oil and anthracene.

Biosurfactants are surface active molecules generated by various microorganisms, including bacteria, actinobacteria, algae, and fungi. In this study, bacterial strains are isolated from soil contaminated with used motor oil and examined for potential biosurfactant production. A minimum salt medium (MSM), with crude oil as the only carbon source, is used to isolate potential biosurfactant-producing bacterial strains. About 23 strains are isolated, and all are subjected to the primary screening methods for biosurfactant production. Based on the emulsification index, oil displacement, and drop collapse screening methods, two isolates with potential biosurfactant-producing ability are selected for further studies. The synthesis of biosurfactants, crude oil and anthracene biodegradation is carried out with strains DTS1 and DTS2. Both strains show significant outcomes in crude oil degradation. In addition, both strains can utilize anthracene as the sole carbon source. During the degradation course, changes in the growth conditions are continuously monitored by measuring turbidity and pH. In this degradation study, the biosurfactant production aptitude of the isolated strains plays an essential role in increasing the bioavailability of hydrophobic hydrocarbons. These strains are identified down to the molecular level by employing 16S rRNA gene sequencing, and the acquired sequences are submitted to get the accession numbers. These prospective strains can be utilized to remediate hydrocarbon-contaminated environments.

Correlation of soil microbiome with crude oil contamination drives detection of hydrocarbon degrading genes which are independent to quantity and type of contaminants.

The impacts of crude oil contamination on soil microbial populations were explored in seven different polluted areas near oil and gas drilling sites and refineries of Assam, India. Using high-throughput sequencing techniques, the functional genes and metabolic pathways involved in the bioconversion of crude oil contaminants by the indigenous microbial community were explored. Total petroleum hydrocarbon (TPH) concentrations in soil samples ranged from 1109.47 to 75,725.33 mg/kg, while total polyaromatic hydrocarbon (PAH) concentrations ranged from 0.780 to 560.05 mg/kg. Pyrene, benzo[a]anthracene, naphthalene, phenanthrene, and anthracene had greater quantities than the maximum permitted limits, suggesting a greater ecological risk, in comparison to other polyaromatic hydrocarbons. According to the metagenomic data analysis, the bacterial phyla Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroides were the most prevalent among all polluted areas. The most prominent hydrocarbon degraders in the contaminated sites included Burkholderia, Mycobacterium, Polaromonas, and Pseudomonas. However, the kinds of pollutants and their concentrations did not correlate with the abundances of respective degrading genes for all polluted locations, as some of the sites with little to low PAH contamination had significant abundances of corresponding functional genes for degradation. Thus, the findings of this study imply that the microbiome of hydrocarbon-contaminated areas, which are biologically involved in the degradation process, has various genes, operons and catabolic pathways that are independent of the presence of a specific kind of contaminant.

Regeneration of Phytochemicals by Structure-Driven Organization of Microbial Biosynthetic Steps.

Medicinal phytochemicals, such as artemisinin and taxol, have impacted the world, and hypericin might do so if its availability issue could be addressed. Hypericin is the hallmark component of Saint John's wort (Hypericum perforatum L.), an approved depression alleviator documented in the US, European, and British pharmacopoeias with its additional effectiveness against diverse cancers and viruses. However, the academia-to-industry transition of hypericin remain hampered by its low in planta abundance, unfeasible bulk chemical synthesis, and unclear biosynthetic mechanism. Here, we present a strategy consisting of the hypericin-structure-centered modification and reorganization of microbial biosynthetic steps in the repurposed cells that have been tamed to enable the designed consecutive reactions to afford hypericin (43.1 mg L-1 ), without acquiring its biosynthetic knowledge in native plants. The study provides a synthetic biology route to hypericin and establishes a platform for biosustainable access to medicinal phytochemicals.

Investigation of biosurfactants produced by three indigenous bacterial strains, their growth kinetics and their anthracene and fluorene tolerance.

The study explored the polycyclic aromatic hydrocarbon tolerance of indigenous biosurfactant producing microorganisms. Three bacterial species were isolated from crude oil contaminated sites of Haldia, West Bengal. The three species were screened for biosurfactant production and identified by 16S rRNA sequencing as Brevundimonas sp. IITISM 11, Pseudomonas sp. IITISM 19 and Pseudomonas sp. IITISM 24. The strains showed emulsification activities of 51%, 57% and 63%, respectively. The purified biosurfactants were characterised using FT-IR, GC-MS and NMR spectroscopy and found to have structural similarities to glycolipopeptides, cyclic lipopeptides and glycolipids. The biosurfactants produced were found to be stable under a wide range of temperature (0-100 °C), pH (4-12) and salinity (up to 20% NaCl). Moreover, the strains displayed tolerance to high concentrations (275 mg/L) of anthracene and fluorene and showed a good amount of cell surface hydrophobicity with different hydrocarbons. The study reports the production and characterisation of biosurfactant by Brevundimonas sp. for the first time. Additionally, the kinetic parameters of the bacterial strains grown on up to 300 mg/L concentration of anthracene and fluorene, ranged between 0.0131 and 0.0156 µmax (h-1), while the Ks(mg/L) ranged between 59.28 and 102.66 for Monod's Model. For Haldane-Andrew's model, µmax (h-1) varied between 0.0168 and 0.0198. The inhibition constant was highest for Pseudomonas sp. IITISM 19 on anthracene and Brevundimonas sp. IITISM 11 on fluorene. The findings of the study suggest that indigenous biosurfactant producing strains have tolerance to high PAH concentrations and can be exploited for bioremediation purposes.

Non-Polymeric Nanogels as Versatile Nanocarriers: Intracellular Transport of the Photosensitizers Rose Bengal and Hypericin for Photodynamic Therapy.

The use of nanocarriers for intracellular transport of actives has been extensively studied in recent years and represents a central area of nanomedicine. The main novelty of this paper lies on the use of nanogels formed by a low-molecular-weight gelator (1). Here, non-polymeric, molecular nanogels are successfully used for intracellular transport of two photodynamic therapy (PDT) agents, Rose Bengal (RB) and hypericin (HYP). The two photosensitizers (PSs) exhibit different drawbacks for their use in clinical applications. HYP is poorly water-soluble, while the cellular uptake of RB is hindered due to its dianionic character at physiological pH values. Additionally, both PSs tend to aggregate precluding an effective PDT. Despite the different nature of these PSs, nanogels from gelator 1 provide, in both cases, an efficient intracellular transport into human colon adenocarcinoma cells (HT-29) and a notably improved PDT efficiency, as assessed by confocal laser scanning microscopy and flow cytometry. Furthermore, no significant dark toxicity of the nanogels is observed, supporting the biocompatibility of the delivery system. The developed nanogels are highly reproducible due to their non-polymeric nature, and their synthesis is easily scaled up. The results presented here thus confirm the potential of molecular nanogels as valuable nanocarriers, capable of entrapping both hydrophobic and hydrophilic actives, for PDT of cancer.

Comparative metabolome-based classification of Senna drugs: a prospect for phyto-equivalency of its different commercial products.

INTRODUCTION: The demand to develop efficient and reliable analytical methods for the quality control of nutraceuticals is on the rise, together with an increase in the legal requirements for safe and consistent levels of its active principles. OBJECTIVE: To establish a reliable model for the quality control of widely used Senna preparations used as laxatives and assess its phyto-equivalency. METHODS: A comparative metabolomics approach via NMR and MS analyses was employed for the comprehensive measurement of metabolites and analyzed using chemometrics. RESULTS: Under optimized conditions, 30 metabolites were simultaneously identified and quantified including anthraquinones, bianthrones, acetophenones, flavonoid conjugates, naphthalenes, phenolics, and fatty acids. Principal component analysis (PCA) was used to define relative metabolite differences among Senna preparations. Furthermore, quantitative 1H NMR (qHNMR) was employed to assess absolute metabolites levels in preparations. Results revealed that 6-hydroxy musizin or tinnevellin were correlated with active metabolites levels, suggesting the use of either of these naphthalene glycosides as markers for official Senna drugs authentication. CONCLUSION: This study provides the first comparative metabolomics approach utilizing NMR and UPLC-MS to reveal for secondary metabolite compositional differences in Senna preparations that could readily be applied as a reliable quality control model for its analysis.

Polyaromatic hydrocarbons impair phosphorus transport by the arbuscular mycorrhizal fungus Rhizophagus irregularis.

Phosphate uptake by plant roots is mainly mediated by arbuscular mycorrhizal fungi (AMF). However, the impact on phosphorus (P) transport of polycyclic aromatic hydrocarbons (PAH), persistent organic pollutants widely found in altered soils, is not known up today. Here, we monitored the Rhizophagus irregularis fungal growth and the fungal P transport ability from the extraradical mycelium to the host transformed chicory roots in the presence of anthracene and benzo[a]pyrene (B[a]P) and the combination of both PAH, under in vitro conditions. Firstly, our findings showed that PAH have detrimental effect on the fungal growth. The combination of both PAH was more toxic than each of the PAH individually due to synergistic effects. Secondly, PAH affected the P transport by the fungus from the medium to the roots. This was evidenced by either the decrease in (33)P quantity transported in the roots as well as the decrease in acid phosphatase activity in the mycorrhizal roots. Moreover, the fungal alkaline phosphatase activities remained constant in the extraradical mycelium as well as in the roots in the absence and in the presence of PAH. The GintPT and GiALP (encoding a P transporter and an alkaline phosphatase respectively) gene expressions were also found to be similar in the extraradical mycelium treated with PAH or not (control). These findings suggested that the P uptake by R. irregularis was not affected by PAH but probably the transport from the extraradical mycelium to the intraradical mycelium.

Biodegradation of petroleum hydrocarbons in the presence of nickel and cobalt.

Bioremediation of environments co-contaminated with hydrocarbons and heavy metals often pose a challenge as heavy metals exert toxicity to existing communities of hydrocarbon degraders. Multi-resistant bacterial strains were studied for ability to degrade hydrocarbons in chemically defined media amended with 5.0 mM Ni(2+), and Co(2+). The bacteria, Pseudomonas aeruginosa CA207Ni, Burkholderia cepacia AL96Co, and Corynebacterium kutscheri FL108Hg, utilized crude oil and anthracene without lag phase at specific growth rate spanning 0.3848-0.8259 per day. The bacterial populations grew in hydrocarbon media amended with nickel (Ni) and cobalt (Co) at 0.8393-1.801 days generation time (period of exponential growth, t = 15 days). The bacteria degraded 96.24-98.97, and 92.94-96.24% of crude oil, and anthracene, respectively, within 30 days without any impedance due to metal toxicity (at 5.0 mM). Rather, there was reduction of Ni and Co concentrations in the axenic culture 30 days post-inoculation to 0.08-0.12 and 0.11-0.15 mM, respectively. The metabolic functions of the bacteria are active in the presence of toxic metals (Ni and Co) while utilizing petroleum hydrocarbons for increase in biomass. These findings are useful to other baseline studies on decommissioning of sites co-contaminated with hydrocarbons and toxic metals.

The influence of rhein 8-O-ß-D-glucopyranoside on the purgative action of sennoside A from rhubarb in mice.

Rhubarb is one of the most well-known herbal medicines that constitute daiokanzoto (DKT), which is clinically effective for constipation. Sennoside A is transformed into an active metabolite, rheinanthrone, by intestinal bacteria. Sennoside A in rhubarb showed significantly accelerated metabolic activity in intestinal bacteria in comparison with sennoside A alone. In this study, we investigated the influence of rhubarb constituents on the metabolism and purgative activity of sennoside A. The 20% MeOH-eluted fraction separated by MCI-gel CHP-20P column chromatography from the water extract of rhubarb showed sennoside A metabolic activity similar to that of rhubarb extract. The 20% MeOH elute was further purified and rhein 8-O-ß-D-glucopyranoside (RG) was isolated. The metabolic activity of sennoside A was significantly accelerated by increasing the level of RG. Moreover, rhein, emodin and aloe-emodin also accelerated sennoside A metabolism. The purgative activity of sennoside A was significantly accelerated when RG or rhein was concomitantly given with sennoside A in a dose-dependent manner. These results suggest that anthraquinones contribute to the purgative action of sennoside A in rhubarb. Therefore, it is assumed that the influence of anthraquinones on the fate of rheinanthrone transformed from sennoside A may promote the purgative action of sennoside A.

Alteromonas as a key agent of polycyclic aromatic hydrocarbon biodegradation in crude oil-contaminated coastal sediment.

Following the 2007 oil spill in South Korean tidal flats, we sought to identify microbial players influencing the environmental fate of released polycyclic aromatic hydrocarbons (PAHs). Two years of monitoring showed that PAH concentrations in sediments declined substantially. Enrichment cultures were established using seawater and modified minimal media containing naphthalene as sole carbon source. The enriched microbial community was characterized by 16S rRNA-based DGGE profiling; sequencing selected bands indicated Alteromonas (among others) were active. Alteromonas sp. SN2 was isolated and was able to degrade naphthalene, phenanthrene, anthracene, and pyrene in laboratory-incubated microcosm assays. PCR-based analysis of DNA extracted from the sediments revealed naphthalene dioxygenase (NDO) genes of only two bacterial groups: Alteromonas and Cycloclasticus, having gentisate and catechol metabolic pathways, respectively. However, reverse transcriptase PCR-based analysis of field-fixed mRNA revealed in situ expression of only the Alteromonas-associated NDO genes; in laboratory microcosms these NDO genes were markedly induced by naphthalene addition. Analysis by GC/MS showed that naphthalene in tidal-flat samples was metabolized predominantly via the gentisate pathway; this signature metabolite was detected (0.04 µM) in contaminated field sediment. A quantitative PCR-based two-year data set monitoring Alteromonas-specific 16S rRNA genes and NDO transcripts in sea-tidal flat field samples showed that the abundance of bacteria related to strain SN2 during the winter season was 20-fold higher than in the summer season. Based on the above data, we conclude that strain SN2 and its relatives are site natives--key players in PAH degradation and adapted to winter conditions in these contaminated sea-tidal-flat sediments.

Biodegradation of anthracene by Aspergillus fumigatus.

An anthracene-degrading strain, identified as Aspergillus fumigatus, showed a favorable ability in degradation of anthracene. The degradation efficiency could be maintained at about 60% after 5d with initial pH of the medium kept between 5 and 7.5, and the optimal temperature of 30 °C. The activity of this strain was not affected significantly by high salinity. Exploration on co-metabolism showed that the highest degradation efficiency was reached at equal concentration of lactose and anthracene. Excessive carbon source would actually hamper the degradation efficiency. Meanwhile, the strain could utilize some aromatic hydrocarbons such as benzene, toluene, phenol etc. as sole source of carbon and energy, indicating its degradation diversity. Experiments on enzymatic degradation indicated that extracellular enzymes secreted by A. fumigatus could metabolize anthracene effectively, in which the lignin peroxidase may be the most important constituent. Analysis of ion chromatography showed that the release of anions of A. fumigatus was not affected by addition of anthracene. GC-MS analysis revealed that the molecular structure of anthracene changed with the action of the microbe, generating a series of intermediate compounds such as phthalic anhydride, anthrone and anthraquinone by ring-cleavage reactions.

Improved bioavailability and biodegradation of a model polyaromatic hydrocarbon by a biosurfactant producing bacterium of marine origin.

Polyaromatic hydrocarbons (PAHs) are organic pollutants mostly derived from the processing and combustion of fossil fuels and cause human health hazards. In the present study a marine biosurfactant producing strain of Bacillus circulans was used to increase the bioavailability and consequent degradation of a model polyaromatic hydrocarbon, anthracene. Although the organism could not utilize anthracene as the sole carbon source, it showed better growth and biosurfactant production in an anthracene supplemented glycerol mineral salts medium (AGlyMSM) compared to a normal glycerol mineral salts medium (GlyMSM). The biosurfactant product showed high degree of emulsification of various hydrocarbons. Analysis by gas chromatography (GC), high performance thin layer chromatography (HPTLC) and Fourier transform infrared spectroscopy (FTIR) showed that the biosurfactant could effectively entrap and solubilize PAH. Thin layer chromatographic analysis showed that anthracene was utilized as a carbon substrate for the production of biosurfactant. Thus organic pollutant anthracene was metabolized and converted to biosurfactants facilitating its own bioremediation.

The content of secondary phenol metabolites in pruned leaves of Aloe arborescens, a comparison between two methods: leaf exudates and leaf water extract.

Aloe arborescens plants, originating from the deserts of South Africa, are grown in the Introduction Garden at Sede Boker in the Negev Desert of Israel. In previous studies, we developed agro-technical methods to raise the content of secondary phenol metabolites (SPhMs) in the Aloe leaves. Plants that are subjected to repeated leaf pruning respond by increasing the content of their SPhMs. The SPhMs found in Aloe arborescens include barbaloin, aloenin and derivatives of aloeresin. Such compounds are used for many purposes, including human skin protection from sun and fire burns and high radiation, as products of the pharmaceutics and cosmetics industries, and as food supplements for treating stomach ulcers and diabetes. In the current study, the SPhMs were separated from pruned leaves of the same A. arborescens plants at the same time by two methods: (1) exudation by squeezing the tissues of the leaves, (2) immersion of the leaves' pruned cut bottom in water and collection of the extract. The exudates and extract were frozen, freeze-dried to a powder and the SPhMs were then separated by chromatography. The yield of powder from water extraction from pruned leaves was much lower than the yield from the exudates. However, higher percentages of the powder from the water extraction contained SPhMs (between 80 and 92.7%). The content of powder in leaf exudates from pruned leaves was much higher because the SPhMs were squeezed out from the cells and tissues. However, the percentages of SPhMs in this powder were much lower (between 39 and 62%).

Effect of rhamnolipids on degradation of anthracene by two newly isolated strains, Sphingomonas sp. 12A and Pseudomonas sp. 12B.

Anthracene is a PAH that is not readily degraded, plus its degradation mechanism is still not clear. Thus, two strains of bacteria-degrading bacteria were isolated from longterm petroleum-polluted soil and identified as Sphingomonas sp. 12A and Pseudomonas sp. 12B by a 16S rRNA sequence analysis. To further enhance the anthracene-degrading ability of the two strains, the biosurfactants produced by Pseudomonas aeruginosa W3 were used, which were characterized as rhamnolipids. It was found that these rhamnolipids dramatically increased the solubility of anthracene, and a reverse-phase HPLC assay showed that the anthracene degradation percentage after 18 days with Pseudomonas sp. 12B was significantly enhanced from 34% to 52%. Interestingly, their effect on the degradation by Sphingomonas sp. 12A was much less, from 35% to 39%. Further study revealed that Sphingomonas sp. 12A also degraded the rhamnolipids, which may have hampered the effect of the rhamnolipids on the anthracene degradation.

Production and properties of a biosurfactant applied to polycyclic aromatic hydrocarbon solubilization.

Microorganisms isolated from a soil sample collected from a gasoline filling station (located in Guwahati) were tested for their pyrene- and anthracene-degrading potential. Preliminary studies showed the ability of the organism to grow on carbon-free mineral medium (CFMM) supplemented with pyrene as the sole source of carbon. The organisms were found to produce a bioemulsifier when grown on CFMM with glucose or glycerol and/or pyrene as the carbon source. The organisms could also utilize anthracene when grown on mineral salt medium along with 2% glycerol. Within 2 d, anthracene concentration dropped less than 30% of the original concentration. Approximately 100 mg of the emulsifier was isolated from 25 mL of the 5-d-grown culture. The emulsifier was tested to produce emulsion with both an aliphatic and an aromatic group of hydrocarbons and resulting emulsions were found to be stable for a long period of time when kept at 10-15 degrees C. The emulsifier was also quite stable in a pH range of 3.0-11.0. In a concentration range of 0.5-10 mg/mL, it resulted in a linear increment of apparent pyrene and anthracene solubility in water.

Antioxidative and antigenotoxic effects of Japanese horse chestnut (Aesculus turbinata) seeds.

Japanese horse chestnut seed extract (HCSE) dose-dependently inhibited the autooxidation of linoleic acid (IC(50): 0.2 mg/ml), and the inhibition was almost complete at a concentration of 1 mg/ml. The HCSE scavenged DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals and superoxide anions with EC(50)s of 0.65 and 0.21 mg/ml, respectively. However, it had no effect on hydrogen peroxide. The HCSE inhibited the genotoxicities of furylfuramide, N-methyl-N-nitrosourea, methyl methanesulfonate, mitomycin C, 2-aminoanthracene and aflatoxin B1 at a concentration of 1 mg/ml or more. Total polyphenol content of the HCSE was 21 mg/g (13 mg/g-seeds). These results indicate that the Japanese horse chestnut seed is an antioxidative and antimutagenic botanical resource.

Solid phase synthesis of anthraquinone peptides and their evaluation as topoisomerase I inhibitors.

Anthraquinone peptide derivatives have previously been shown to inhibit the enzyme topoisomerase I (topo I), a pharmaceutical target for the prevention of malignant carcinomas. A highly efficient procedure for the attachment of the anthraquinone moiety to the N-terminus of a peptide on a solid support is reported. This methodology provides a convenient method for the synthesis of labelled peptides, with potential applications for chemotherapy, DNA detection and protein purification. As the synthetic strategy utilizes the solid phase, it should also be amenable to the generation of combinatorial libraries. The utility of the method by synthesizing a pool of peptides and assaying for topo I inhibition is demonstrated.

[Abiotic elicitation of the explant culture of Rheum palmatum L. by heavy metals]. / Abiotická elicitace explantátové kultury Rheum palmatum L. tezkými kovy.

Elicitation-produced stress activates the defensive reactions of the plant or plant explant, which result, among others, in a change in the transcription of the genes coding the enzymes influencing biosynthesis of secondary metabolites. The present paper investigated the effect of ions of heavy metals in concentrations od 1; 10, and 100 microM on the production of anthracene derivatives by the explant culture of Rheum palmatum L. cultivated on Murashige-Skoog medium with an addition of 10 mg.l(-1) of alpha-naphthylacetic acid. The periods of application of elicitation were 6; 24; 48, and 168 hours. It follows from the results that the applied abiotic elicitation positively influenced the production mainly in suspension culture. The maximal increase in the content of anthracene derivatives versus the control by 66% was observed after 48-hour action of 10 microM concentration of cadmium chloride. Aluminium chloride produced the largest increase in the production after 6-hour application of a 100 microM concentration, when in comparison with the control culture the production was stimulated by 60%.

Membrane-related effects underlying the biological activity of the anthraquinones emodin and barbaloin.

Commercial plant extracts containing anthraquinones are being increasingly used for cosmetics, food and pharmaceuticals due to their wide therapeutic and pharmacological properties. In this work, the interaction with model membranes of two representative 1,8-dihydroxyanthraquinones, barbaloin (Aloe) and emodin (Rheum, Polygonum), has been studied in order to explain their effects in biological membranes. Emodin showed a higher affinity for phospholipid membranes than barbaloin did, and was more effective in weakening hydrophobic interactions between hydrocarbon chains in phospholipid bilayers. Whereas emodin induced the formation of hexagonal-H(II) phase, barbaloin stabilized lamellar structures. Barbaloin promoted the formation of gel-fluid intermediate structures in phosphatidylglycerol membranes at physiological pH and ionic strength values. It is proposed that emodin's chromophore group is located at the upper half of the membrane, whereas barbaloin's one is in a deeper position but having its glucopyranosyl moiety near the phospholipid/water interface. Moreover, membrane disruption by emodin or barbaloin showed specificity for the two major phospholipids present in bacterial membranes, phosphatidylethanolamine and phosphatidylglycerol. In order to relate their strong effects on membranes to their biological activity, the capacity of these compounds to inhibit the infectivity of the viral haemorrhagic septicaemia rhabdovirus (VHSV), a negative RNA enveloped virus, or the growth of Escherichia coli was tested. Anthraquinone-loaded liposomes showed a strong antimicrobial activity whereas these compounds in their free form did not. Both anthraquinones showed antiviral activity but only emodin was a virucidal agent. In conclusion, a molecular mechanism based on the effect of these compounds on the structure of biological membranes is proposed to account for their multiple biological activities. Anthraquinone-loaded liposomes may suppose an alternative for antimicrobial, pharmaceutical or cosmetic applications.

Influence of peanut oil on microbial degradation of polycyclic aromatic hydrocarbons.

Peanut oil amendment (0.1%-0.2% (v/v)) increased the biodegradation of various polycyclic aromatic hydrocarbons (PAHs) by 15%-80% with a mixed bacterial culture and a pure culture of Comamonas testosteroni in aqueous media and in PAH-contaminated weathered soil slurry systems. The stimulatory effect on biodegradation was more pronounced with the high molecular weight PAHs (e.g., >3 rings). The presence of peanut oil also accelerated the biodegradation of PAHs sorbed onto activated carbon, indicating its potential application in the bioregeneration of activated carbon.