1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol

Endpoint summary

Description of key information

Biodegradation in water

Biodegradation study of test chemical was performed. The test is carried at a temperature of 37ᵒCwith a duration period of 2 days (Haiyan Xu et. al., 2010).The anaerobic bacterial species used in the study were obtained from the American Type Culture Collection (ATCC).All strains were preserved at-80ᵒC in 10 to 15% glycerol stocks and revived as needed.The bacterial strains were grown anaerobically at 37ᵒC by using BHI broth or MRS supplemented with various test chemical conc.. A loopful for each strain was cultured in static conditions at 37ᵒC for 24 h in an Erlenmeyer flask containing 10 ml medium for use as a seed culture. The bacterial seed cultures of 1.5 ml were inoculated into flasks containing 100 ml BHI broth. Test chemical stock solutions were added to the medium at final concentrations of 1.5µg/ml, the cultures were incubated at 37ᵒC in an anaerobic chamber for 2 days without agitation. Metabolites of the reduction of the test chemical were isolated and identified by HPLC andLiquid chromatography/ electrospray ionization mass spectrometry(LC/ESI-MS). Reduction of the dyes was determined by measuring the disappearance of the absorbance at 500 nm immediately after extraction with ethyl acetate as well. The results are presented in percentage (%) obtained by the means from triplicate incubations. Among the tested bacterial strains,B. vulgatus,B.ovatus,B. uniformis, B. distasonis,B. fragilis ,B. thetaiotaomicron,B. caccae,B. infantis, C. perfringens, C. indolis, C. clostridioforme,E. aerofaciens, E. limosum , E. faecalis, E. faecium,F. russi, F. nucleatum,L. paracasei,L. reuteri, L. rhamnosus,R. obeum and R. gnavuswere able to completely degrade (100%) the test chemical.The bacteria which are unable to degrade the test chemical areBifidobacterium catenulatum,Clostridium ramosum, Eubacterium tenue, Escherichia coliandPeptostreptococcus magnus ,respectively. The metabolite produced from test chemical by E. faecalis was identified aso-toluidine, based on an identical retention time of 7.42 min and ions atm/z108 [MH+] and 149 [MH⁺+acetonitrile].2,5-diaminotoluene from test chemical could not be detected in the extracted samples. No metabolites of test chemical produced byE. coliwas detected by LC/ESI-MS, indicating that the test chemical were not degraded by the bacterium. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

Additional information

Biodegradation in water

Various experimental studies of the test chemical were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (Haiyan Xu et. al., 2010),biodegradation experiment of test chemical was performed. The test is carried at a temperature of 37ᵒCwith a duration period of 2 days.The anaerobic bacterial species used in the study were obtained from the American Type Culture Collection (ATCC).All strains were preserved at-80ᵒC in 10 to 15% glycerol stocks and revived as needed.The bacterial strains were grown anaerobically at 37ᵒC by using BHI broth or MRS supplemented with various test chemical conc.. A loopful for each strain was cultured in static conditions at 37ᵒC for 24 h in an Erlenmeyer flask containing 10 ml medium for use as a seed culture. The bacterial seed cultures of 1.5 ml were inoculated into flasks containing 100 ml BHI broth. Test chemical stock solutions were added to the medium at final concentrations of 1.5µg/ml, the cultures were incubated at 37ᵒC in an anaerobic chamber for 2 days without agitation. Metabolites of the reduction of the test chemical were isolated and identified by HPLC andLiquid chromatography/ electrospray ionization mass spectrometry(LC/ESI-MS). Reduction of the dyes was determined by measuring the disappearance of the absorbance at 500 nm immediately after extraction with ethyl acetate as well. The results are presented in percentage (%) obtained by the means from triplicate incubations. Among the tested bacterial strains, B. vulgatus, B.ovatus, B. uniformis, B. distasonis, B. fragilis , B. thetaiotaomicron, B. caccae, B. infantis, C. perfringens, C. indolis, C. clostridioforme, E. aerofaciens, E. limosum , E. faecalis, E. faecium, F. russi, F. nucleatum, L. paracasei, L. reuteri, L. rhamnosus, R. obeum and R. gnavus were able to completely degrade (100%) the test chemical.The bacteria which are unable to degrade the test chemical are Bifidobacterium catenulatum, Clostridium ramosum, Eubacterium tenue, Escherichia coli and Peptostreptococcus magnus , respectively. The metabolite produced from test chemical by E. faecalis was identified aso-toluidine, based on an identical retention time of 7.42 min and ions atm/z108 [MH+] and 149 [MH++acetonitrile].2,5-diaminotoluene from test chemical could not be detected in the extracted samples. No metabolites of test chemical produced by E. coli was detected by LC/ESI-MS, indicating that the test chemical were not degraded by the bacterium. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

For the test chemical, biodegradation study was performed. The test is carried at a temperature of 37ᵒC with a duration period of 2 days (peer reviewed journal, 2010). The anaerobic bacterial species used in the study were obtained from the American Type Culture Collection (ATCC).All strains were preserved at-80ᵒC in 10 to 15% glycerol stocks and revived as needed.The bacterial strains were grown anaerobically at 37ᵒC by using BHI broth or MRS supplemented with various Sudan dye. A loopful for each strain was cultured in static conditions at 37ᵒC for 24 h in an Erlenmeyer flask containing 10 ml medium for use as a seed culture. The bacterial seed cultures of 1.5 ml were inoculated into flasks containing 100 ml BHI broth. Dye stock solutions were added to the medium at final concentrations of 10 mg/ml, the cultures were incubated at 37ᵒC in an anaerobic chamber for 2 days without agitation. Metabolites of the reduction of the test chemical were isolated and identified by HPLC and Liquid chromatography/ electrospray ionization mass spectrometric(LC/ESI-MS).Reduction of the dyes was determined by measuring the disappearance of the absorbance at 500 nm immediately after extraction with ethyl acetate as well. The results are presented in percentage (%) obtained by the means from triplicate incubations. Among the tested bacterial strains, B. infantis, C. indolis, E. faecalis, L. rhamnosus and R. obeum were able to completely degrade (100%) the test chemical whereas partial degradation of the test chemical occurred by the bacterial strains such as B. ovatus, B. distasonis, B. thetaiotaomicron, B.caccae, C. clostridioforme, E. faecium, F. russi and L. paracasei. Thus, the test chemical is readily biodegradable in water. The bacteria which are unable to degrade the test chemical areB. vulgatus, B. uniformis, B. fragilis, B. longum, B. adolesecentis, B. catenulatum, B. angulatum, C. perfringens, C. butyricum, C. ramosum, C. difficle, C. leptum, E. aerofaciens, E. limosum, E. tenue, E. coli, F. nucleatum, L. bifidus, L. reuteri, L. ruminis, P. magnus and R. gnavus. The metabolite produced from test chemical by E. faecalis was identified as 2,4-dimethylaniline, based on an identical retention time of 16.55 min and ions at m/z 122 [MH+] and 163 [MH+ + acetonitrile]. 1-Amino-2-naphthol from test chemical could not be detected in the extracted samples. No metabolites of test chemical produced by E. coli was detected by LC/ESI-MS, indicating that the test chemical were not degraded by the bacterium. Thus, based on percentage degradation, the test chemical is considered to be readily biodegradable in water.

 

In a supporting study from peer reviewed journal (D. Brown et. al., 1987),biodegradation experiment was carried out for determining the biodegradability rate of the test chemical. Activated sludge was used as an inoculum and the study was performed under anaerobic conditions at a temperature of 35°C for a period of 56 days. Samples of the aqueous phase were analyzed either qualitatively or quantitatively by an appropriate chromatographic method for the presence of certain of the expected aromatic amine metabolites. The percentage degradation of test chemical was determined to be 100% degradation by appropriate chromatography method in 7 days. The metabolites identified by the appropriate chromatographic method were 4,4 '-diamino-3,3'-dimethyl biphenyl and 4-methyl benzenesulphonic acid- (4'-aminophenyl) ester, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

On the basis of above results for test chemical, it can be concluded that the test chemical can be considered to be readily biodegradable in nature.