Manganate(1-), glycinato-N,O)[sulfato(2-)-O]-, hydrogen

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: test meets generally accepted principles but with insufficient documentation, test performed prior to implementation of standard methods

Data source

Reference

Reference Type:

publication

Title:

OXIDATION OF CERTAIN AMINO ACIDS BY “RESTING” BACILLUS PROTEUS

Author:

FREDERICK BERNHEIM, MARY L. C. BERNHEIM, AND M. DOROTHY WEBSTER

Year:

1935

Bibliographic source:

Jour. Biol. Chem., 110, 165 (1935).

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Bacillus proteus Type X-2 was grown for 18 hours on beef extract agar slants at 37° and pH 7.4. Subsequently, 1 cc. of the suspension of bacteria was used in each Warburg vessel and the volume made up to 2 cc. with buffer and a solution of the amino acid to be tested.
- Short description of test conditions: The bacteria were then scraped off the slants, suspended in saline, and centrifuged. This washing was
repeated three times and then the bacteria were suspended in 0.05 M phosphate buffer of pH 7.8 so that there were approximately 7 billion per cc. The optimum pH for the oxidation of the amino acids is between 7.6 and 8.3.
- Parameters analysed / observed: The rate and amount of the oxygen uptake was then measured.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Glycine

EC Number:

200-272-2

EC Name:

Glycine

Cas Number:

56-40-6

Molecular formula:

C2H5NO2

IUPAC Name:

aminoacetic acid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

6 h

Initial test substance concentration

Initial conc.:

0.25 other: mg

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST SYSTEM
- Culturing apparatus: Warburg vessels

Reference substance

Reference substance:

not specified

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

104

Sampling time:

110 min

Remarks on result:

other: Observed O2 uptake

Remarks:

sampling time gives the oxidation rate based on the time necessary to reach one-half the final uptake

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Interpretation of results:

readily biodegradable

Conclusions:

In the present study of Bernheim et al. 'resting' Bacillus proteus were incubated with different amino acids, i.a. with 0.25 mg/cm³ glycine. The determined oxidation rate was 110 min and the oxygen uptake was 104 cm³. Furthermore, it was reported that glycine was completely metabolised in contrast to the other amino acids investigated. Thus, glycine is considered to be readily biodegradable under the conditions of the test.

Executive summary:

The biodegradation of glycine was determined in Bacillus proteus. The method of determination is considered sufficient, the study was conducted prior to implementation of standard guidelines. Bacillus proteus Type X-2 was grown for 18 hours on beef extract agar slants at 37° and pH 7.4. Subsequently,  a suspension of bacteria  was  used  in  each  Warburg  vessel  and  the  volume  made  up  to  2  cc.  with  buffer  and  a  solution  of  the  amino  acid  to  be  tested. The oxidation rate was measured after 6h. The authors were able to show that glycine in contrast to all other proteinogenic amino acids was fully metabolised by resting Bacillus proteus. Thus, glycine is considered readily biodegradable under the conditions of the test.