p-hydroxyphenylacetic acid

Endpoint summary

Description of key information

Biodegradation in water:

The test chemical 2-(4-hydroxyphenyl)acetic  acid (CAS no. 156-38-7) undergoes 100 % degradation in batch fixed bed  biofilm reactor  using  coculture of Pseudomonas putida DSM1868

Ralstonia sp. LD35 immobilised on Manville silica beads and on polyurethane foam cubes as inoculums within 50 hrs. On the basis of percent degradability it is concluded that test chemical 2-(4-hydroxyphenyl)acetic  acid (CAS no. 156-38-7) is readily biodegradable.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound p-hydroxyphenylacetic acid (CAS No. 156 -38 -7). If released in to the environment, 23.2 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical p-hydroxyphenylacetic acid in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.0789 %), indicates that test chemical p-hydroxyphenylacetic acid is not persistent in sediment.

Biodegradation in Soil:

The half-life period of test chemical p-hydroxyphenylacetic acid (CAS No. 156 -38 -7) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 76.8 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical p-hydroxyphenylacetic acid in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical p-hydroxyphenylacetic acid, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .

Additional information

Biodegradation in water:

Various experimental studies from different sources for target chemical p-hydroxyphenylacetic acid (CAS no. 156-38-7) have been studied and their results are summarized below for biodegradation in water endpoint.

 

 The first experimental study was done from Journal of Biotechnology (2001) in this study An experiment was performed by Lorenzo Bertin et al to determined the biodegradation potential of test chemical 2-(4-hydroxyphenyl)acetic acid (CAS no. 156-38-7). In this experiment coculture of Pseudomonas putida DSM1868 and Ralstonia sp. LD35 was immobilised on Manville silica beads(SB) and on polyurethane foam cubes(PU) was filled in two different fixed bed biofilm reactors. Then synthetic mixture of monoaromatic acid was prepared containing test chemical 2-(4-hydroxyphenyl)acetic acid at concentration of 4.60 mM and other monoaromatic acid at different concentrations. The medium was recycled from the top to the bottom of the SB bioreactor and PU bioreactor at the rate of 25 and 36 ml min1, respectively, for 2–4 days. Two ml samples of the recycled broth were taken out from the sampling port of each bioreactor 4–6 times a day and analysed for the concentration of freely suspended cells of both strains and for the concentration of the test chemical (and related biodegradation aromatic metabolites) In both the reactors test chemical undergoes 100 % degradation within 50 hrs therefore it is concluded that test chemical 2-(4-hydroxyphenyl)acetic acid is readily biodegradable.

 

Second experimental study was done from Journal of Industrial Microbiology (1996) in this study an experiment was performed by N Zouari et al to determine percent degradability of test chemical (2-(4-hydroxyphenyl)acetic acid (CAS n0. 156-38-7) by using different consortia of microorganisms isolated from muds and wastewaters from a local tannery factory, muds from an aerobic domestic wastewater treatment plant and soil samples from a local eucalyptus field(Tunisia). To cultivate microorganisms pretreated olive oil mill effluent (OOME) was used as medium. Since p-OOME contained a low concentration of nitrogen (0.85 g L-Z), some growth factors and a nitrogen source necessary for bacterial growth were added to growth flask and incubated for 2 weeks at 32 oC and different microbial consortia were formed. These different consortia of microorganisms were used as inoculums to degrade phenolic compound containing target chemical p-Hydroxyphenyl acetic acid. The test system for biodegradation experiment was 250 mL culture flask containing minimal salt medium , yeast extract and peptone phenolic compounds mixture containing target chemical p-Hydroxyphenyl acetic acid then it was inoculated by different microbial consortia for 7 days at pH 7.2 and 32 oC temperature and cultures were shaken at 250 rpm. After 7 days of incubation test chemical was analysed by using GC in a gas chromatograph (Shimadzu GC-9A). The phenols were extracted using ethylacetate/acetone (2:1) at pH 2.0. Two milliliters of the solvent were added to 1 ml of culture medium, centrifuged and the organic phase was harvested. GC conditions were: column SE 30 (30 m length, 0.5 mm ID, methyl silicone in the solid phase, injection temperature of 280oC and detector temperature of 300oC.  Percentage of target chemical remained after 7 days of incubation were analysed and results of all microbial consortia are mentioned in table 1. Percentage of test chemical p-Hydroxyphenyl acetic acid remained was 0.0 in most of the flasks inoculated by different consortia of microorganisms. Therefore percent degradation of test chemical p-Hydroxyphenyl acetic acid was determinedto be 100 % in 7 days. Therefore it is concluded that test chemical p-Hydroxyphenyl acetic acid is readily biodegradable.

 

 

Third experimental study was done from Applied and Environmental Microbiology (1998) in this study an experiment was performed by Paula M et al to determined the biodegradation potential of test chemical p-hydroxyphenylacetic acid (CAS no. 156-38-7) for this different cultures were isolated from anaerobic sediments from various geographic locations. A defined mineral salts medium was used for isolation and cultivation of the phenolic compound-degrading strains such as strain PH002 and strain FL05 . Enrichment cultures were prepared from argon-sparged sediment slurry prepared in the defined mineral salts medium (2:1, wt/vol). Ten milliliter portions of this slurry were added to 90-ml portions of argon-sparged medium in 160-ml serum bottles. The bottles were closed with neoprene rubber stoppers. Phenol was added at a starting concentration of 0.5 mM. Cultures were incubated without shaking at 30°C. Then the culture suspensions were transferred to glass screw-cap tubes, and substrates was added from sterile, anaerobic stock solutions to a final concentration of approximately 1 mM. Sterile control and substrate free medium was taken as control. The first sample (time zero) was taken immediately after substrate addition. The tubes were placed in a 30°C water bath, and samples (0.2 ml) were taken periodically with argon-flushed syringes. The samples were quickly pelleted in a microcentrifuge, after which the supernatant was diluted with 0.05 N HCl (1:4) and stored at 4°C before analysis. After analysis it is observed that test chemical is utilized by both the strains in anaerobic condition. Therefore it is concluded that test chemical p-hydroxyphenylacetic acid (CAS no. 156-38-7) is degradable can be utilized by two different strains of bacteria strain PH002 and strain FL0 when it is present in medium as sole carbon source in anaerobic condition .

 

 

The fourth experimental study was done from J. Agric. Food Chem (1997) in this study to determine the biodegradability of test chemical hydroxyphenylacetic acid ( CAS no. 156-38-7) an experiment was performed using BOD bottles . The test chemical was introduced into the BOD bottles as sole carbon sources at a concentration of 2 mg of carbon per bottle. The compounds were added in acetone solutions, and the acetone was evaporated prior to the addition of 02-saturated water. Each bottle received 5 mg of Hudson Collamer silt loam as a source of the microbial inoculum. The bottles were filled with the air-saturated salts solution and closed with glass stoppers. Then bottles were incubated in dark at 25 oC. Sampling was done at regular interval and O2 consumption was measured by using oxygen analyzer, Model 53. Biodegradability of test chemical p-hydroxyphenylacetic acid (156-38-7) was determined by using O2 consumption as parameter, total duration of experiment was 20 days. Test chemical showed more than 5 µg/mL O2 consumption in 2 days.  On the basis of this O2 consumption value it can be concluded that test chemical is biodegradable.

 

 

Fifth study was done from Journal of General Microbiology (1958 ) by R. B. CAIN in this study an experiment was performed to determine the biodegradation potential of test chemical p-Hydroxyphenylacetic acid (CAS no.156-38-7). In this experiment bacteria was isolated from garden soils, manure heaps, or heavily polluted streams by using enrichement culture method. The isolated bacterial species was identified as p-Hydroxyphenylacetic acid. After 7 days of incubation growth was estimated turbidimetrically in a 'Unicam' model S.P. 350 D.G. colorimeter at 530 mp using 10 mm. square glass cells, the optical density measurements. On the basis of growth of bacteria it is concluded that test chemical p-Hydroxyphenylacetic acid (CAS no.156-38-7) is biodegradable.

 

Last experimental study was done from Arch Microbiology (1986) in this study an experiment was performed to determine the degradation potential of test chemical p-Hydroxyphenylacetic acid (CAS no. 156-38-7) in this experiment the anerobic bacteria was isolated from by using enrichment culture in anaerobic condition. The isolated bacteria was initially named as ph01 strain then by using this strain biodegradation of test chemical was performed and latter it was characterized as Desulfobacterium phenolicum which produced H2S gas duration degradation experiment in 10 days and test chemical was also utilized completely by this bacteria. The test chemical p-Hydroxyphenylacetic acid showed 100 % degradation by Desulfobacterium phenolicum sp. (ph01) in anerobic condition 10 days. On the basis of percent degradability it is concluded that test chemical is readily biodegradable.

 

 On the basis of all the experimental studies mentioned above it is observed that test chemical p-Hydroxyphenylacetic acid (CAS no. 156-38-7) is degradable by many different bacteria from different sources in various different conditions both aerobically as well as anarobically by using many different parameters. Therefore it is concluded that test chemical is readily biodegradable.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound p-hydroxyphenylacetic acid (CAS No. 156 -38 -7). If released in to the environment, 23.2 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical p-hydroxyphenylacetic acid in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.0789 %), indicates that test chemical p-hydroxyphenylacetic acid is not persistent in sediment.

Biodegradation in Soil:

The half-life period of test chemical p-hydroxyphenylacetic acid (CAS No. 156 -38 -7) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 76.8 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical p-hydroxyphenylacetic acid in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical p-hydroxyphenylacetic acid, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .