Pentachlorophenol and spent engine oil degradation by Mucor ramosissimus

Pentachlorophenol (PCP) has been widely used for many years and belongs to the most toxic pollutants. Spent engine oils enter environment every day in many ways. Both of them cause great environmental concern. In the present work we focused on identifying metabolites of PCP biodegradation formed in the cultures of Mucor ramosissimus IM 6203 and optimizing medium composition to enhance PCP removal in the presence of engine oil acting as a carbon source.Pentachlorophenol (PCP) to tetrachlorohydroquinone (TCHQ) transformation was the most interesting transformation conducted by the tested strain. TCHQ was further transformed to 2,3,5,6-TCP and 2,3,4,6-TCP. Strain IM 6203 is also capable of PCP transformation to corresponding anisoles – pentachloromethoxybenzene (PCMB) and pentachloroethoxybenzene (PCEB). Characterization of enzymatic background involved in PCP to TCHQ transformation showed that TCHQ formation is catalyzed by inductive and cytochrome P-450 dependent enzymatic system. Experiments conducted on mineral medium allowed defining the optimal quantitative and qualitative medium make-up for PCP to TCHQ transformation. Biodegradation of PCP on the optimized synthetic medium X was more efficient than on rich Sabouraud medium. The tested strain is capable of growing in the presence of spent engine oil therefore we checked the ability of PCP transformation on optimized synthetic medium containing oil as a carbon source. The obtained results showed that PCP removal and TCHQ formation occurred were found to be the most efficient on the oil containing medium (OX medium). PCP removal and TCHQ formation after 240 h of culturing reached 1.19 mg/l and 0.89 mg/l, respectively. Additionally, 55.5% of oil introduced to the medium was removed during 10 days of the experiment.PCP biodegradation mechanisms used by Mucor species have not been sufficiently explained. The presented results point to the tested strain as an interesting model for the research on fungal PCP biodegradation in the areas highly contaminated with engine oil and for its future application in PCP and oils removal.     

Enrichment, isolation and characterization of pentachlorophenol degrading bacterium Acinetobacter sp. ISTPCP-3 from effluent discharge site

Three pentachlorophenol (PCP) degrading bacterial strains were isolated from sediment core of pulp and paper mill effluent discharge site. The strains were continuously enriched in mineral salts medium supplemented with PCP as sole source of carbon and energy. One of the acclimated strains with relatively high PCP degradation capability was selected and characterized in this study. Based on morphology, biochemical tests, 16S rDNA sequence analysis and phylogenetic characteristics, the strains showed greatest similarity with Acinetobacter spp. The strain was identified as Acinetobacter sp. ISTPCP-3. The physiological characteristics and optimum growth conditions of the bacterial strain were investigated. The results of optimum growth temperature revealed that it was a mesophile. The optimum growth temperature for the strain was 30°C. The preferential initial pH for the strain was ranging at 6.5–7.5, the optimum pH was 7. The bacterium was able to tolerate and degrade PCP up to a concentration of 200 mg/l. Increase in PCP concentration had a negative effect on biodegradation rate and PCP concentration above 250 mg/l was inhibitory to its growth. Acinetobacter sp. ISTPCP-3 was able to utilize PCP through an oxidative route with ortho ring-cleavage with the formation of 2,3,5,6-tetrachlorohydroquinone and 2-chloro-1,4-benzenediol, identified using gas chromatograph–mass spectrometric (GC–MS) analysis. The degradation pathway followed by isolated bacterium is different from previously characterized pathway.     

Relationships between ligninolytic activities of Lentinula spp. and biotransformation of pentachlorophenol in sterile soil

Ligninolytic activities in strains of Lentinula edodes were related to pentachlorophenol biotransformation in sterile soil and activities in L. lepideus. Strains of L. edodes secreting laccase and manganese peroxidase activities also metabolized pentachlorophenol (PCP) significantly ( P < 0.05). Strains of L. lepideus showed neither enzymic activities nor xenobiotic breakdown. Lentinula edodes strains inhibited by PCP at 5 mg 1^-1 in agar, tolerated 200 mg kg^-1 in soil. Strain LE2 metabolized more PCP in nitrogen-sufficient than nitrogen-limited culture: the reverse was observed with Phanerochaete chrysosporium BKM 1767. Relationships between ligninolytic activities and pentachlorophenol breakdown in L. edodes indicated a suitability for soil bioremediation treatments.     

Purification and properties of pentachlorophenol hydroxylase, a flavoprotein from Flavobacterium sp. strain ATCC 39723.

A pentachlorophenol (PCP) hydroxylase which catalyzed the conversion of PCP to 2,3,5,6-tetrachlorohydroquinone and released iodide from triiodophenol in the presence of NADPH and oxygen was identified. The enzyme was purified by protamine sulfate precipitation, ammonium sulfate precipitation, hydrophobic chromatography, anion-exchange chromatography, gel filtration chromatography, and crystallization. The enzyme was a monomer with a molecular weight of 63,000. Under certain conditions, dimer and multimer conformations were also observed. The pI of the enzyme was pH 4.3. The optimal conditions for activity were a pH of 7.5 to 8.5 and a temperature of 40 degrees C. Each enzyme molecule contained one flavin adenine dinucleotide molecule. The Km for PCP was 30 microM and the Vmax was 16 mumol/min/mg of protein. The enzymatic reaction required 2 mol of NADPH per mol of halogenated substrate. On the basis of the data we present, it is likely that PCP hydroxylase is a flavoprotein monooxygenase. The addition of flavins to the reaction mixture did not stimulate the enzymatic reaction; however, we identified the photodegradation of triiodophenol and tribromophenol, but not PCP, by flavin mononucleotide or riboflavin and light.     

Physiological properties and substrate specificity of a pentachlorophenol-degradingPseudomonas species

A bacterial strain capable of utilizing pentachlorophenol (PCP) as sole source of carbon and energy for growth was isolated from enrichment cultures containing 100 mg/l PCP in a mineral salts medium inoculated with contaminated soil from a lumber treatment waste site. The isolate, designated strain SR3, was identified as a species ofPseudomonas by virtue of its physiological and biochemical characteristics. Mineralization of PCP byPseudomonas sp. strain SR3 was demonstrated by loss of detectable PCP from growth medium, stoichiometry of chloride release (5 equivalents of chloride per mole of PCP), and formation of biomass consistent with the concentration of PCP mineralized. PCP-induced cells of strain SR3 showed elevated rates of oxygen consumption in the presence of PCP, and with different chlorinated phenols, with complete degradation of 2,3,5,6-, 2,3,6-, 2,4,6-, 2,4-, and 2,6-chloro-substituted phenols. Concentrations of PCP up to 175 mg/liter supported growth of this organism, but maximal rates of PCP removal were observed at a PCP concentration of 100 mg/liter. Based on its degradative properties,Pseudomonas sp. strain SR3 appears to have utility in bioremediation of soil and water contaminated with PCP.Abbreviations DCP dichlorophenol - TCP trichlorophenol - TeCP tetrachlorophenol Contribution No. 750 from the United States Environmental Protection Agency Environmental Research Laboratory, Gulf Breeze, FL32561, USA. A preliminary report of this work has appeared in abstract form (Resnick & Chapman 1990; Abstr. Annu Meet Amer Soc Microbiol Q-70, p. 300).     

Evaluation of pentachlorophenol-degrading potentiality of Pseudomonas sp. in a soil microcosm

Pseudomonas sp. strain IST103 obtained from a stable consortium was capable of degrading pentachlorophenol (PCP) as sole carbon and energy source. The PCP-degrading potentiality of the strain was determined by growth of bacteria in culture medium, utilization of PCP by high performance liquid chromatography (HPLC), chloride release and ring cleavage. The strain was applied in two set of soil microcosms containing 20 and 40% moisture, each having different concentrations, 0, 10, 100, 500, and 1000 mg/l, of PCP. The result showed significant utilization of PCP (77% in 45 days) and higher growth of bacterial strain when PCP was applied in 100 mg/l concentration at 40% moisture. Inhibitory effects on the growth of bacterial strain were seen in 500 and 1000 mg/l concentration.     

Biodegradation of phenol and <Emphasis Type="Italic">m</Emphasis>-cresol by <Emphasis Type="Italic">Candida albicans</Emphasis> PDY-07 under anaerobic condition

Strain Candida albicans PDY-07 was used to study the anaerobic biodegradation of phenol and m-cresol as single and dual substrates in batch cultures. The strain had a higher potential to degrade phenol than m-cresol. The cell growth kinetics of batch cultures with various initial m-cresol concentrations was investigated, and the Haldane kinetic model adequately described the dynamic behavior of cell growth on m-cresol. When cells grew on the mixture of phenol and m-cresol, substrate interactions were observed. Phenol inhibited the utilization of m-cresol; on the other hand, m-cresol also inhibited the degradation of phenol. However, the presence of low-concentration phenol enhanced m-cresol biodegradation; 100 mg/l m-cresol could be completely degraded within a shorter period of time than m-cresol alone in the presence of 150–300 mg/l phenol. The maximum m-cresol biodegradation rate was obtained at the existence of 200 mg/l phenol. Phenol was preferably utilized by the strain as a carbon and energy source. In addition, a sum kinetics model was used to describe the cell growth behavior in binary mixture of phenol and m-cresol, and the interaction parameters were determined. The model adequately predicted the growth kinetics and the interaction between the substrates.     

Identification and Kinetic Characteristics of an Indigenous Diesel-degrading Gordonia alkanivorans Strain

Summary An indigenous strain Gordonia alkanivorans CC-JG39 was isolated from oil-contaminated sludge of a local gas station located in central Taiwan. The bacterial isolate was able to grow on diesel-containing Bushnell–Haas medium and also tolerate various chemical additives frequently used in petroleum products (e.g. BETX, methyl-tert-butyl ether, and naphthalene). Kinetics of diesel-limited cell growth and biodegradation of diesel followed a Monod-type model. The kinetic constants for cell growth (μ_max and K_S,G) were 0.158 h⁻¹ and 3196 mg/l, respectively, while those for biodegradation of diesel (v_{max, diesel} and K_S,D) were 3.59 mg/h/mg cell and 2874 mg/l, respectively. G. alkanivorans CC-JG39 produced extracellular surface-active material, leading to a low surface tension of nearly 33 mN/m. The CC-JG39 strain also possessed the ability to float towards the oil/water interface. These features might play some roles in enhancing the mass transfer efficiency between oil substrate and the bacterial cells. Therefore, G. alkanivorans CC-JG39 may have potential applications in bioremediation of oil pollution sites.     

Antifungal activities of origanum oil against Candida albicans

The antimicrobial properties of volatile aromatic oils from medicinal as well as other edible plants has been recognized since antiquity. Origanum oil, which is used as a food flavoring agent, possesses a broad spectrum of in vitro antimicrobial activities attributed to the high content of phenolic derivatives such as carvacrol and thymol. In the present study, antifungal properties of origanum oil were examined both in vitro and in vivo. Using Candida albicans in broth cultures and a micro dilution method, comparative efficacy of origanum oil, carvacrol, nystatin and amphotericin B were examined in vitro. Origanum oil at 0.25 mg/ml was found to completely inhibit the growth of C. albicans in culture. Growth inhibitions of 75% and >50% were observed at 0.125 mg/ml and 0.0625 mg/ml level, respectively. In addition, both the germination and the mycelial growth of C. albicans were found to be inhibited by origanum oil and carvacrol in a dose-dependent manner. Furthermore, the therapeutic efficacy of origanum oil was examined in an experimental murine systemic candidiasis model. Groups of mice (n = 6) infected with C. albicans (5 × LD₅₀) were fed varying amounts of origanum oil in a final vol. of 0.1 ml of olive oil (vehicle). The daily administration of 8.6 mg of origanum oil in 100 l of olive oil/kg body weight for 30 days resulted in 80% survivability, with no renal burden of C. albicans as opposed to the group of mice fed olive oil alone, who died within 10 days. Similar results were obtained with carvacrol. However, mice fed origanum oil exhibited cosmetically better clinical appearance compared to those cured with carvacrol. The results from our study encourage examination of the efficacy of origanum oil in other forms of systemic and superficial fungal infections and exploration of its broad spectrum effect against other pathogenic manifestations including malignancy.     

Biodegradation of diesel oil and production of fatty acid esters by a newly isolated Pseudomonas citronellolis KHA

The ability of a newly isolated Pseudomonas citronellolis KHA to degrade diesel oil and to synthesize fatty acid esters has been screened in aerobic batch cultures. The microorganism was able to grow with diesel oil at initial concentrations up to 126 g/l, with optimal growth at 25 g/l. Strain KHA has produced compounds showing strong emulsifying properties (E₂₄ = 75% at the end of the exponential growth phase). The crude extract reduces the surface tension of water from 72 mN m⁻¹ down to 35 mN m⁻¹ with a corresponding minimal concentration value of 60 mg/l. GC and GC–MS analysis of crude product show that the major components are those of hexadecanoic acid propyl ester and octadecanoic acid propyl ester, which have potential for applications in cosmetics, pharmaceutical and foods industries. In addition, strain KHA represents a valuable source of compounds with surface-active properties and potential for the application in clean up of the sites contaminated with hydrocarbons.     

Use of Brassica callus culture to induce sporulation in Alternaria brassicae (Berk.) Sacc.

A non-sporulating isolate of Alternaria brassicae, inoculated on callus culture of Brassica juncea cv. Kranti, colonized the callus and produced spores. When captafol, a fungicide, was added (100 mg/l) to the callus culture medium, if effectively checked fungal contamination and saprophytic growth of A. brassicae on culture medium, without adversely affecting callus growth or establishment of dual culture.     

Phytase production byAspergillus ficuum on semisolid substrate

Summary Phytase production byAspergillus ficuum was studied using solid state cultivation on several cereal grains and legume seeds. The microbial phytase was used to hydrolyze the phytate in soybean meal and cotton seed meal. Wheat bran, soybean meal, cottonseed meal and corn meal supported good fungal growth and yielded a high level of phytase when an adequate amount of moisture was present. The level of phytase production on solid substrate was higher than that obtained by submerged liquid fermentation. Higher levels of phosphorus (more than 10 mg Pi/100 g substrate) in the growth medium (static culture) inhibited phytase synthesis, and the degree of phosphorus inhibition was less apparent in semisolid medium than in liquid medium. A static cultivation on semisolid substrate produced a higher level of phytase (2-20-fold) than that obtained by agitated cultivation. The minimal amount of water required for growth and enzyme production on those substrates was about 15%, while the optimum level for phytase production was between 25 and 35% and that for cell growth was above 50%. Optimum pH for phytase production was between 4 and 6.A ficuum grew well on raw (unheated) substrate containing a minimal amount of water and produced as much phytase as on heated substrate. About half of the phytic acid in soybean meal and cottonseed meal was hydrolyzed by treatment withA. ficuum phytase.     

高效降解石油外生菌根真菌的室内筛选

对7个外生菌根真菌菌株在不同石油浓度培养基中的生长及其对石油的降解作用进行了研究。结果表明:(1)不同菌株在同一石油浓度培养基中生长速度不同,同一菌株在不同石油浓度培养基中的生长速度亦不同。菌株010和菌株025在不同石油浓度培养基中生长速度均较其他菌株快。菌株010的菌丝干重随着石油浓度的增加而增加,当石油质量浓度为500 mg/L时,菌丝干重达到最大值,高于对照5.27%,石油对其生长产生了促进作用;当石油质量浓度为700 mg/L时,菌丝干重低于对照,随着石油质量浓度的升高,菌株生长呈下降趋势。石油质量浓度为100 mg/L时,菌株025生长最慢,菌丝干重低于对照9.1%。随着石油浓度的增加,菌株生长加快,当石油质量浓度为500 mg/L时,菌丝干重高于对照;当石油质量浓度为700 mg/L时,菌株025菌丝干重最高,高于对照25.65%。随着石油浓度的再度升高,菌株生长呈下降趋势。(2)不同菌株在同一石油浓度下对石油的降解能力不同,同一菌株在不同石油浓度下对石油的降解能力亦不同。菌株025对石油的降解能力最强,对石油的降解能力随着石油浓度的升高而提高。当培养基中石油质量浓度为900 mg/L时,菌株025对石油的降解率最高,达到73.65%。(3)菌株0100、09、035、LH004的菌丝生物量与对石油的降解能力呈正相关。     

Isolation and identification of dieldrin-degrading Pseudonocardia sp. strain KSF27 using a soil-charcoal perfusion method with aldrin trans-diol as a structural analog of dieldrin

We isolated a novel aerobic dieldrin-degrading bacterium from an enrichment culture in a soil–charcoal perfusion system. Enrichment culture using a soil–charcoal perfusion system was an effective way to obtain microorganisms that degrade recalcitrant compounds. The soil–charcoal perfusion was performed using aldrin trans-diol, which was a metabolite of dieldrin. Aldrin trans-diol had higher bioavailability (2.5 mg/l) than dieldrin (0.1–0.25 mg/l), therefore it is possible for microorganisms to utilize it as a substrate in soil. After 100 days of circulation and three exchanges of the medium, the enriched charcoal was harvested and a bacterium isolated. The isolate was designated as strain KSF27 and was found to be closely related to Pseudonocardia spp. as determined by 16S rRNA sequencing analysis. Strain KSF27 degraded aldrin trans-diol by 0.05 μmol/l from an initial concentration of 25.5 μmol/l. The metabolite of aldrin trans-diol was detected by HPLC/MS and determined to be aldrindicarboxylic acid based on retention time and the MS fragment. Moreover, strain KSF27 degraded dieldrin from 14.06 μmol/l to 2.01 μmol/l over a 10-day incubation at 30 °C. This strain degraded dieldrin and other persistent organochlorine pesticides, such as α-endosulfan, β-endosulfan, endosulfan sulfate, heptachlor, heptachlor epoxide and chlordecone.     

Isolation and characterization of a new carbendazim-degrading <Emphasis Type="Italic">Ralstonia</Emphasis> sp. strain

A bacterial strain 1-1 capable of utilizing carbendazim was isolated from carbendazim-treated Qiyang red soils Hunan Province, China. It is gram-negative, rod-shaped, motile with peritrichous flagella, which formed round, smooth, convex and transparent colonies of about 1.1 mm diameter after 3 days of incubation on the isolation and purification medium using carbendazim as the sole carbon and energy sources. The degradation ratios of carbendazim by strain 1-1 were 19.16 and 95.96 in the carbendazim (500 mg/l)-degrading medium and the carbendazim (500 mg/l)-degrading medium supplemented with yeast extract (150 mg/l) within 24 days, respectively. Strain 1-1 was identified as Ralstonia sp. (β-Proteobacteria) based on the results of phenotypic features, G+C mol and phylogenetic analysis of 16S rDNA. Strain 1-1 could become a new bacterial resource for biodegrading carbendazim and might play a bioremediation role for soils contaminated by carbendazim.     

Pentachlorophenol degradation by Pseudomonas aeruginosa

Five Pseudomonas species were tested for ability to degrade pentachlorophenol (PCP). Pseudomonas aeruginosa completely degraded PCP up to 800 mg/l in 6 days with glucose as co-substrate. With 1000 mg PCP/l, 53% was degraded. NH₄ ⁺ salts were better at enhancing degradation than organic nitrogen sources and shake-cultures promoted PCP degradation compared with surface cultures. Degradation was maximal at pH 7.6 to 8.0 and at 30 to 37°C. Only PCP induced enzymes that degraded PCP and chloramphenicol inhibited this process. The PCP was degraded to CO₂, with release of Cl^-.The authors are with the Bacteriology Laboratory, Central Leather Research Institute, Madras-600 020, India.     

The microbial degradation of chlorophenolic preservatives in spent,pressure-treated timber

The reduction of pentachlorophenol in treated timber, after inoculation with pentachlorophenol-degrading bacterial species,Rhodococcus chlorophenolicus andFlavobacterium sp., and the white-rot fungusPhanerochaete chrysosporium, was monitored in solid substrate systems and in liquid culture suspensions. In solid substrate systems there was no significant pentachlorophenol degradation by the bacterial species under a variety of conditions. Under similar conditions,Phanerochaete chrysosporium transformed over 80% of the starting concentration of 500 ppm to pentachloroanisole. In liquid culture suspensions however, mid-exponential phaseFlavobacterium sp. cells were able to degrade over 99% of the pentachlorophenol in sawdust and wood chips due to the extraction of PCP from the timber as a water soluble salt. There were however no significant changes in the chlorinated dioxin components during this treatment.Abbreviations ATTC American type culture collection - AWPA American Wood Preservers' Association - DSM Deutsche Sammlung für Mikroorganismen - GC/MS gas chromatograph/mass spectrometer - HpCDD heptachlorodibenzo-p-dioxin - HpCDF heptachlorodibenzofuran - HxCDD hexachlorodibenzo-p-dioxin - HxCDF hexachlorodibenzofuran - ¹³C-OCDD carbon 13-labelled octachlorodibenzo-p-dioxin - OCDD octachlorodibenzo-p-dioxin - OCDF octachlorodibenzofuran - PCDDs polychlorinated dibenzo-p-dioxins - PCDFs polychlorinated dibenzofurans - PCP pentachlorophenol - PnCDD pentachlorodibenzo-p-dioxin - PnCDF pentachlorodibenzofuran - TCDD tetrachlorodibenzo-p-dioxin - TCDF terachlorodibenzofuran - TeCP tetrachlorophenol - WHC water holding capacity - w/v weight for volume ratio     

Degradation of polychlorinated phenols by Streptomyces rochei 303

The strain Streptomyces rochei 303 (VKM Ac-1284D) is capable of utilizing 2-chloro-,2,4-,2,6-dichloro- and 2,4,6-trichlorophenols as the sole source of carbon. Its resting cells completely dechlorinated and degraded 2-, 3-chloro-; 2,4-, 2,6-, 2,3-, 2,5-, 3,4-, 3,5-dichloro-; 2,4-, 2,6-dibromo-; 2,4,6-, 2,4,5-, 2,3,4-, 2,3,5-, 2,3,6-trichlorophenols; 2,3,5,6-tetrachloro- and pentachlorophenol. During chlorophenol degradation, a stoichiometric amount of chloride ions was released and chlorohydroquinols were formed as intermediates. In cell-free extracts of S. rochei, the activity of hydroxyquinol 1,2-dioxygenase was found. The enzyme was induced with chlorophenols. Of all so far described strains degrading polychlorophenols, S. rochei 303 utilized a wider range of chlorinated phenols as the sole sourse of carbon and energy.Abbreviations CP chlorophenol - DCP dichlorophenol - TCP trichlorophenol - TeCP tetrachlorophenol - PCP pentachlorophenol - DBrP dibromophenol - CHQ chlorohydroquinol - DCHQ dichlorohydroquinol - HHQ hydroxyhydroquinol - CHHQ chlorohydroxyhydroquinol - CC chlorocatechol - TLC thin layer chromatography - GC/MC chromato-mass-spectrometry - HPLC high-performance liquid chromatography     

Morphological characterization of in-vitro human hair keratinolysis,produced by identified wild strains of Chrysosporium species

Chrysosporium species were isolated from soil and keratinized material. Primary isolation was performed following the general method of hair baiting on modified Czapek-agar media with washed, defated and sterilized human hair fragments added. Strains were maintained in test tubes of potato dextrose agar at 29 °C and cultivated on phytone yeast extract agar at 28 °C for 14 days for identification. Isolates were characterized using Van Oorschot's key. Keratinolytic activity was expressed following a subjective scale representing degree/severity of attack upon hair surface and presence of fungal structures observed in substrate. Culture results and characterization methods were effective for soil Chrysosporium strain isolation. A new hair attack mode is described. Of 71 keratinolytic fungal isolates, eight (12%) Chrysosporium species were identified. One keratinolytic Chrysosporium sp. isolate is yet to be identified.This revised version was published online in October 2005 with corrections to the Cover Date.     

Multisubstrate monod kinetic model for simultaneous degradation of chlorophenol mixtures

Chlorophenols (CPs) are persistent and highly toxic compounds rated as priority pollutants by the Environmental Protection Agency (EPA). Frequently, these compounds are present as mixtures of CPs in industrial wastewaters. Therefore the study of biodegradation on mixed pollutants is an important aspect of biodegradation and wastewater treatment. In this work, we studied the multisubstrate degradation of CPs by a mixed culture of Pseudomonas aeruginosa and a novel Acromobacter sp. capable of using pentachlorophenol (PCP), 2,4,6 trichlorophenol (2,4,6 TCP) and 2,3,5,6 tetrachlorophenol (2,3,5,6 TeCP) as the sole sources of carbon and energy. The main objective of this work was to evaluate the effect of substrate mixtures on the degradation kinetics of PCP. Batch experiments were conducted with each CP separately and in mixtures of PCP + 2,4,6 TCP, PCP + 2,3,5,6 TeCP, and PCP + 2,4,6 TCP + 2,3,5,6 TeCP. Based upon our results we have concluded that the simultaneous degradation of CPs is a key factor contributing to the improvement of PCP degradation. The kinetic parameters for PCP and 2,4,6 TCP were obtained by fitting the data to a Monod kinetics model. Using such parameters, the model was able to predict simultaneous multisubstrate degradation of PCP with others CPs.