4-(2-aminoethyl)phenol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

Biodegradation study was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 4-(2-aminoethyl) phenol
- Common name : Tyramine
- Molecular formula : C8H11NO
- Molecular weight : 137.1809 g/mol
- Smiles notation : NCCc1ccc(O)cc1
- InChl : 1S/C8H11NO/c9-6-5-7-1-3-8(10)4-2-7/h1-4,10H,5-6,9H2
- Substance type: Organic
- Physical state: Solid

Oxygen conditions:

not specified

Inoculum or test system:

other: Bacteria

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Test inoculums culture was isolated from winemaking process and from other habitats, etc.
- Laboratory culture: The test bacterial culture was obtained from ENOLAB collection, Spanish Type Culture Collection (CECT) and to the Reference Center for Lactobacilli (CERELA, Tucumán, Argentina).
- Method of cultivation: All strains were routinely grown overnight at 28 °C on modified MRS medium supplemented with L-cysteine 0.5 g/L and biogenic amines (Bas) (histamine, tyramine, and putrescine) at 10 mg/L each.

Duration of test (contact time):

48 h

Initial conc.:

150 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

(% degradation)

Details on study design:

TEST CONDITIONS
- Composition of medium: MRS medium was used as a test medium for the study.
- Additional substrate: The test medium was supplemented with L-cysteine and biogenic amines (BAs).
- Solubilising agent (type and concentration if used):
- Test temperature: 28⁰C
- pH: 5.5
- pH adjusted: yes

TEST SYSTEM
- Measuring equipment: After 48-h incubation at 28 °C, the reaction was stopped by adding 1 M HCl. Then, samples were centrifuged at 13,500 rpm for 5 min and filtered through 0.22-μm nylon membranes. Amine concentrations were measured by HPLC in an Agilent 1200SL HPLC system.

Parameter:

% degradation (test mat. analysis)

Value:

6.3

Sampling time:

48 h

Remarks on result:

other: %degradation by L. delbrueckii CECT 286

Parameter:

% degradation (test mat. analysis)

Value:

33.7

Sampling time:

48 h

Remarks on result:

other: %degradation by L. farciminis CRL 678

Parameter:

% degradation (test mat. analysis)

Value:

33

Sampling time:

48 h

Remarks on result:

other: %degradation by L. plantarum ENOLAB J16

Parameter:

% degradation (test mat. analysis)

Value:

41.7

Sampling time:

48 h

Remarks on result:

other: %degradation by L. plantarum ENOLAB Lb 98

Parameter:

% degradation (test mat. analysis)

Value:

42.9

Sampling time:

48 h

Remarks on result:

other: %degradation by L. plantarum ENOLAB Lb 132

Parameter:

% degradation (test mat. analysis)

Value:

39

Sampling time:

48 h

Remarks on result:

other: %degradation by L. plantarum ENOLAB Lb 291

Parameter:

% degradation (test mat. analysis)

Value:

8.6

Sampling time:

48 h

Remarks on result:

other: %degradation by L. plantarum ENOLAB Lb 140

Parameter:

% degradation (test mat. analysis)

Value:

40

Sampling time:

48 h

Remarks on result:

other: %degradation by P. acidilactici CECT 5930

Details on results:

Test substance undergoes 6.3, 33.7, 33, 41.7, 42.9, 39, 8.6 and 40% degradation by using inoculums L. delbrueckii CECT 286, L. farciminis CRL 678, L. plantarum ENOLAB J16, L. plantarum ENOLAB Lb 98, L. plantarum ENOLAB Lb 132, L. plantarum ENOLAB Lb 291, L. plantarum ENOLAB Lb 140 and P. acidilactici CECT 5930, respectively after a period of 48 hrs.

Table:Degradation percentages of three amines in modified Dapkevicius’medium supplemented with 150 mg/L of amines, and adjusted to 5.5 pH, after 48 h of incubation.

 

Lactic acid bacteria (LAB)	Strain	Degradation (%)a,b
		Tyramine
L. delbrueckii L. farciminis L. plantarum L. plantarum L. plantarum L. plantarum L. plantarum P. acidilactici	CECT 286 CRL 678 ENOLAB J16 ENOLAB Lb 98 ENOLAB Lb 132 ENOLAB Lb 291 ENOLAB Lb 140 CECT 5930	6.3±0.52 33.7±0.24 33±0.13 41.7±0.32 42.9±0.22 39±0.41 8.6±0.46 40±0.23

 

Where,

a = Activity is expressed as a percentage of amine concentration present in the inoculated sample in relation to the uninoculated sample

b = Mean values (n=3)

 

Tyramine was degraded by eight strains, of which six of them reduced the initial concentration by a third. Tyramine was better degraded by four strains ofL. plantarum: Lb 132, Lb 98, Lb 291, and J16 (in decreasing order),P. acidilacticiCECT 5930, andL.farciminisCRL 678 (positive control for tyramine degradation).

 

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The percentage degradation of test substance 4-(2-Aminoethyl)phenol was determined to be 6.3, 33.7, 33, 41.7, 42.9, 39, 8.6 and 40% degradation by using inoculums L. delbrueckii CECT 286, L. farciminis CRL 678, L. plantarum ENOLAB J16, L. plantarum ENOLAB Lb 98, L. plantarum ENOLAB Lb 132, L. plantarum ENOLAB Lb 291, L. plantarum ENOLAB Lb 140 and P. acidilactici CECT 5930, respectively after a period of 48 hrs. Thus, based on percentage degradation (42.9% in 48 hrs), 4-(2-Aminoethyl)phenol is considered to be readily biodegradable in water.

Executive summary:

Biodegradation study was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol (CAS no. 51-67-2). The study was performed at a temperature of28⁰C and pH 5.5, respectively. Test bacterial culture was isolated from winemaking process and from other habitats, etc. The test culture was obtained fromENOLAB collection, Spanish Type Culture Collection (CECT) and to the Reference Center for Lactobacilli (CERELA, Tucumán, Argentina).All strains were routinely grown overnight at 28 °C on modified MRS medium supplemented with L-cysteine 0.5 g/L and biogenic amines (Bas) (histamine, tyramine, and putrescine) at 10 mg/L each. Initial test substance concentration used for the study was150 mg/l, respectively.A volume of 100μL of culture grown overnight on MRS supplemented with L-cysteine and BAs was used to inoculate the medium described with some modifications: 0.15 g/L of histamine, tyramine, and putrescine were added separately to the medium and the pH was adjusted to 5.5. After 48-h incubation at 28 °C, the reaction was stopped by adding1 M HCl. Then, samples were centrifuged at 13,500 rpm for5min and filtered through 0.22-μmnylonmembranes (Fisher). Amine concentrations were measured by HPLC in an Agilent 1200SL HPLC system. The HPLC system was equipped with an in-line degasser, auto-sampler, column heater, and a fluorescence detector. Chromatographic separation was performed on HPLC Luna C18 silica Phenomenex column (250×4.6 mm) with a guard column (20×4.6 mm) of the same type. A solution of methanol was used as mobile phase A and a solution of 140 mM sodium acetate trihydrate and 17 mM TEA adjusted to pH 5.05 as mobile phase B. Gradient conditions used for separation were described by Hernández-Orte et al.(2006). A sample volume of 10μL was buffered with 25μL of a solution containing 0.2 M sodium borate buffer (pH8.8) and 5 mM disodium EDTA. The derivatization reaction was performed by adding 15μL of 6-aminoquinolyl-Nhydroxysuccinimidyl carbamate (AQC solution Waters). Excitation and emission wavelengths of the fluorescence detector were set at 250 and 395 mm, respectively. A volume of 5μL of the derivatized sample was injected into HPLC system. HPLC column temperature was kept at 65 °C. Flow rate was set at 2 mL/min. Total elution time was 70 min. Degradation ratio relative to the uninoculated medium was calculated after 48 h of incubation.The percentage degradation of test substance4-(2-Aminoethyl)phenolwas determined to be 6.3, 33.7, 33, 41.7, 42.9, 39, 8.6 and 40% degradation by using inoculumsL. delbrueckii CECT 286,L. farciminis CRL 678,L. plantarum ENOLAB J16,L. plantarum ENOLAB Lb 98,L. plantarum ENOLAB Lb 132,L. plantarum ENOLAB Lb 291,L. plantarum ENOLAB Lb 140 andP. acidilactici CECT 5930, respectively after a period of 48 hrs. Thus, based on percentage degradation (42.9% in 48 hrs),4-(2-Aminoethyl)phenolis considered to be readily biodegradable in water.

Description of key information

Biodegradation study was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol (CAS no. 51-67-2) (S. Callejón, et. al; 2014). The study was performed at a temperature of28⁰C and pH 5.5, respectively. Test bacterial culture was isolated from winemaking process and from other habitats, etc. The test culture was obtained fromENOLAB collection, Spanish Type Culture Collection (CECT) and to the Reference Center for Lactobacilli (CERELA, Tucumán, Argentina).All strains were routinely grown overnight at 28 °C on modified MRS medium supplemented with L-cysteine 0.5 g/L and biogenic amines (Bas) (histamine, tyramine, and putrescine) at 10 mg/L each. Initial test substance concentration used for the study was150 mg/l, respectively.A volume of 100μL of culture grown overnight on MRS supplemented with L-cysteine and BAs was used to inoculate the medium described with some modifications: 0.15 g/L of histamine, tyramine, and putrescine were added separately to the medium and the pH was adjusted to 5.5. After 48-h incubation at 28 °C, the reaction was stopped by adding1 M HCl. Then, samples were centrifuged at 13,500 rpm for5min and filtered through 0.22-μmnylonmembranes (Fisher). Amine concentrations were measured by HPLC in an Agilent 1200SL HPLC system. The HPLC system was equipped with an in-line degasser, auto-sampler, column heater, and a fluorescence detector. Chromatographic separation was performed on HPLC Luna C18 silica Phenomenex column (250×4.6 mm) with a guard column (20×4.6 mm) of the same type. A solution of methanol was used as mobile phase A and a solution of 140 mM sodium acetate trihydrate and 17 mM TEA adjusted to pH 5.05 as mobile phase B. Gradient conditions used for separation were described by Hernández-Orte et al.(2006). A sample volume of 10μL was buffered with 25μL of a solution containing 0.2 M sodium borate buffer (pH8.8) and 5 mM disodium EDTA. The derivatization reaction was performed by adding 15μL of 6-aminoquinolyl-Nhydroxysuccinimidyl carbamate (AQC solution Waters). Excitation and emission wavelengths of the fluorescence detector were set at 250 and 395 mm, respectively. A volume of 5μL of the derivatized sample was injected into HPLC system. HPLC column temperature was kept at 65 °C. Flow rate was set at 2 mL/min. Total elution time was 70 min. Degradation ratio relative to the uninoculated medium was calculated after 48 h of incubation.The percentage degradation of test substance4-(2-Aminoethyl)phenolwas determined to be 6.3, 33.7, 33, 41.7, 42.9, 39, 8.6 and 40% degradation by using inoculumsL. delbrueckii CECT 286,L. farciminis CRL 678,L. plantarum ENOLAB J16,L. plantarum ENOLAB Lb 98,L. plantarum ENOLAB Lb 132,L. plantarum ENOLAB Lb 291,L. plantarum ENOLAB Lb 140 andP. acidilactici CECT 5930, respectively after a period of 48 hrs. Thus, based on percentage degradation (42.9% in 48 hrs),4-(2-Aminoethyl)phenolis considered to be readily biodegradable in water.

Additional information

Various experimental key and supporting studies for the target compound 4 -(2 -Aminoethyl)phenol (CAS No. 51-67-2) and supporting study for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (S. Callejón, et. al; 2014),biodegradation study was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol (CAS no. 51-67-2). The study was performed at a temperature of28⁰C and pH 5.5, respectively. Test bacterial culture was isolated from winemaking process and from other habitats, etc. The test culture was obtained from ENOLAB collection, Spanish Type Culture Collection (CECT) and to the Reference Center for Lactobacilli (CERELA, Tucumán, Argentina).All strains were routinely grown overnight at 28 °C on modified MRS medium supplemented with L-cysteine 0.5 g/L and biogenic amines (Bas) (histamine, tyramine, and putrescine) at 10 mg/L each. Initial test substance concentration used for the study was150 mg/l, respectively. A volume of 100μL of culture grown overnight on MRS supplemented with L-cysteine and BAs was used to inoculate the medium described with some modifications: 0.15 g/L of histamine, tyramine, and putrescine were added separately to the medium and the pH was adjusted to 5.5. After 48-h incubation at 28 °C, the reaction was stopped by adding1 M HCl. Then, samples were centrifuged at 13,500 rpm for5min and filtered through 0.22-μmnylonmembranes (Fisher). Amine concentrations were measured by HPLC in an Agilent 1200SL HPLC system. The HPLC system was equipped with an in-line degasser, auto-sampler, column heater, and a fluorescence detector. Chromatographic separation was performed on HPLC Luna C18 silica Phenomenex column (250×4.6 mm) with a guard column (20×4.6 mm) of the same type. A solution of methanol was used as mobile phase A and a solution of 140 mM sodium acetate trihydrate and 17 mM TEA adjusted to pH 5.05 as mobile phase B. Gradient conditions used for separation were described by Hernández-Orte et al.(2006). A sample volume of 10μL was buffered with 25μL of a solution containing 0.2 M sodium borate buffer (pH8.8) and 5 mM disodium EDTA. The derivatization reaction was performed by adding 15μL of 6-aminoquinolyl-Nhydroxysuccinimidyl carbamate (AQC solution Waters). Excitation and emission wavelengths of the fluorescence detector were set at 250 and 395 mm, respectively. A volume of 5μL of the derivatized sample was injected into HPLC system. HPLC column temperature was kept at 65 °C. Flow rate was set at 2 mL/min. Total elution time was 70 min. Degradation ratio relative to the uninoculated medium was calculated after 48 h of incubation. The percentage degradation of test substance4-(2-Aminoethyl)phenol was determined to be 6.3, 33.7, 33, 41.7, 42.9, 39, 8.6 and 40% degradation by using inoculums L. delbrueckii CECT 286,L. farciminis CRL 678,L. plantarum ENOLAB J16,L. plantarum ENOLAB Lb 98,L. plantarum ENOLAB Lb 132,L. plantarum ENOLAB Lb 291,L. plantarum ENOLAB Lb 140 and P. acidilactici CECT 5930, respectively after a period of 48 hrs. Thus, based on percentage degradation (42.9% in 48 hrs),4-(2-Aminoethyl)phenolis considered to be readily biodegradable in water.

 

Another biodegradation study was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol (CAS no. 51-67-2) by using various lactic acid bacterial strains as the test inoculum(Almudena García-Ruiz, et. al; 2011). The study was performed at a temperature of30⁰C and pH 5.5, respectively.A total of 85 LAB, includingOenococcus oeni(42 strains),Pediococcus parvulus(7 strains),P. pentosaceus(4 strains),Lactobacillusplantarum(6 strains),L. hilgardii(9 strains),L. zeae(3 strains),L. casei(7 strains),L. paracasei(5 strains) and Leuconostoc mesenteroides (2 strains) were used in this study. Test cultures can also be isolated in our laboratory from musts and wines (young, wood-aged and biologically aged sherry wines) and from winemaking products (fermentation lees) over an 8-year period and properly identified by 16S rRNA partial gene sequencing.The LAB strains belong to the bacterial culture collection of the Institute of Industrial Fermentations (IFI), CSIC, Spain.Test inoculum was cultivated for 24–48 h.The media MLO (pH 4.8) was used as a culture medium for the study. These bacteria werecultivated for 3–4 days. All bacteria were incubated at 30 °C.The strains were kept frozen at−70 °C in a sterilized mixture of culture medium and glycerol (50:50, v/v).Initial test substance concentration used for the study was150 mg/l, respectively.The ability of wine LAB strains to degrade the biogenic amine tyramine was tested in a model system. The broth consisted of MRS or MLO added separately of 0.15 g/L of tyramineand adjusted to pH 5.5.LAB strains were incubated at 30 °C in this model system in duplicateand on at least two different days. Samples were taken at time 0 andafter 48 (LAB nonO. oeni)–72 (O. oeni) hours of incubation.Biogenic amines were analyzed by reversed-phase (RP)-HPLC. Briefly, a liquid chromatograph consisting of a Waters 600 controller programmable solvent module, a WISP 710B autosampler (Waters, Milford, MA, USA) and an HP 1046-Afluorescence detector (Hewlett Packard) were used. Chromatographic data were collected and analyzed with a Millenium 32 system. The separations were performed on a Waters Nova-Pak C18 (150×3.9 mm i.d., 60 Å, 4μm) column, with a matching guard cartridge of the same type. Samples were submitted to an automatic precolumn derivatization reaction witho-phthaldialdehyde (OPA) prior to injection. Derivatized amines were detected using the fluorescence detector (excitation wavelength of 340 nm, and emission wavelength of 425 nm). Samples were previously filtered through Milliporefilters (0.45μm) and then directly injected in duplicate into the HPLC system. All reagents used were HPLC grade.Cell cultures of 85 strains representing 9 species of wine LAB were investigated for their potential to degrade/eliminate tyramine the major biogenic amines present in wines.. Out of 9 strains, 6 of them were able to degrade tyramine. The strain L. caseiI FI-CA 52, exhibited the greatest potential tyramine degradation (55%), respectively. The percentage degradation of test substance4-(2-Aminoethyl)phenolwas determined to be 55, 17, 15, 12, 22 and 54% degradation by using inoculum L. casei IFI-CA 52,L. plantarum IFI-CA 54,P. parvulus IFI-CA 31, P. pentosaceus IFI-CA 30,P. pentosaceus IFI-CA 83 and P. pentosaceus IFI-CA 86, respectively after a period of 48 hrs. Thus, based on percentage degradation (55% in 48 hrs),4-(2-Aminoethyl)phenolis considered to be readily biodegradable in nature.

 

In a supporting study, biodegradation experiment was conducted for evaluating the percentage biodegradability of test substance 4-(2-Aminoethyl)phenol (CAS no. 51-7-2) by using Brevibacterium linens LTH 456 and LTH 3686as the test inoculums. B. linens was grown on a medium composed of (all wtlvol) tryptone (0.1%), yeast extract (0.05%) , NaCI (0.05%), and glucose (0.01%). The pH was adjusted to 7.2. Cultures were aerobically grown at 30°C. The growth was followed with a spectrophotometer (DU-64, Beckman Instruments, Munich, Germany) at 578 nm and viable counts were determined on the medium described above solidified with 1.5% agar. Initial test substance conc. used for the study was79.56 mg/l (0.58 mM).Cells of B. linens LTH 456 and LTH 3686 were harvested in the middle and at the end of the exponential growth phase, washed once with 0.05 M phosphate buffer (pH 7 adjusted before autoclaving), resuspended in a buffer at pH 7 supplemented with histamine (0.54 mM) and tyramine (0.58 mM) and incubated at 30°C for 28 to 38 h. The cell concentration was adjusted to OD578=10 spectrophotometrically (Spectrophotometer DU-64).In an amine-buffer system, the amine degradation by cells in the exponential growth phase was higher than that by the stationary-phase cells. The percentage degradation of test substance 4-(2-Aminoethyl)phenol was determined to be approx. 60 and 100% by using inoculum B. linens LTH 456 and 3686in 30 & 35 hrs, respectively. Thus, based on percentage degradation, 4-(2-Aminoethyl)phenol is considered to be readily biodegradable in nature.

 

For the read across chemical 2-phenylethylamine (CAS no. 64-04-0) from authoritative database (J-CHECK & HSDB, 2017 and EnviChem, 2014), biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of read across substance 2 -phenylethylamine (CAS no. 64 -04 -0). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I) under aerobic conditions. Activated sludge was used as a test inoculums for the study. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance 2 -phenylethylamine was determined to be 58, 81, 99 and 95% by BOD(NO2), BOD(NH3), TOC removal and UV-Vis parameter in 14 days. Thus, based on percentage degradation, 2 -phenylethylamine is considered to be readily biodegradable in nature.

 

On the basis of above results for target chemical 4-(2-Aminoethyl)phenol (from peer reviewed journals), and for its read across substance (from authoritative database J-CHECK, HSDB and EnviChem), it can be concluded that the test substance 4-(2-Aminoethyl)phenol can be expected to be readily biodegradable in nature.