O,O-diethyl hydrogen phosphorodithioate

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water and sediment: simulation tests

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is a publication with detailed description of the method used.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

The degradation of sodium O,O-dietyl dithiophosphate by bacteria from metalworking fluids

Author:

Sherburn, R. E & Large, P. J.

Year:

1999

Bibliographic source:

Letters in Applied Microbiology, 28, 61-65

Materials and methods

Test guideline

Qualifier:

no guideline followed

Deviations:

not applicable

Principles of method if other than guideline:

Bacteria were isolated from contaminated metalworking fluids and identified using standard biochemical tests. Bacteria were cultured with the test substance NaDDP (sodium O,O-diethyl phosphorodithioate) and analysed for the formation of degradation products.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sodium O,O-diethyl dithiophosphate

EC Number:

222-079-2

EC Name:

Sodium O,O-diethyl dithiophosphate

Cas Number:

3338-24-7

IUPAC Name:

sodium O,O-diethyl dithiophosphate

Details on test material:

- Name of test material (as cited in study report): Sodium O,O-diethyl dithiophosphate (O,O-diethyl phosphorodithioate; NaDDP)

Radiolabelling:

no

Study design

Oxygen conditions:

not specified

Inoculum or test system:

other: bacterial growth medium

Duration of test (contact time):

120 min

Initial test substance concentration

Initial conc.:

50 mmol/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: Production of degradation products

Details on study design:

TEST CONDITIONS
- Composition of medium:
per 1 L of solution: 0.4 g MgSO4*7H2O, 7 g (NH4)SO4, 25 mg FeSO4*7H2O, 4.1 mg MnSO4*4H2O, 4.4 mg ZnSO4*7H2O, 0.79 mg CuSO4*5H2O, 73.4 mg CaCl2*2H2O, 80 mmol/L potassium sodium phosphate buffer (pH 7) and 50 mmol/L glycerol

TEST SYSTEM
ethanol was measured colorimemetrically with alcohol oxidase;
aldehydes were measured by the MBTH method;
phosphate was measured by the method of Lowry and Lopez;
hydrogen sulphide was measured by the method of Trüper and Schlegel;
acid phosphorodiesterase activity was measured by incubating extract in 2.2 mmol/L sodium citrate buffer (pH 6) with 0.1 mmol/L 2'-deoxythymidine-3'-(4-nitro-phenyl)phosphate for 5 min and stopping the reaction by adding 2.9 mL of 0.1 mol/L NaOH, absorbance was then measured at 405 nm;
alkaline phosphodiesterase activity was measured by incubating extract in 0.2 mol/L Tris-HCl (pH 8.9) containing 3.3 mg bis-4-nitrophenyl phosphate/mL, absorbance was determined at 405 nm;
protein concentrations were measured by the Bradford method with a bovine gamma-globulin standard.

SAMPLING
- Sampling frequency: every 5 minutes

Reference substance

Reference substance:

not specified

Results and discussion

Test performance:

Approximately 30 organisms were isolated from contaminated metalworking fluids. Most were gram-negative rod-shaped bacteria. Four organisms were selected for the study: AV1, CL1, FM2 and SP1.

Transformation products:

yes

Identity of transformation products

Identity of transformation products 1

Reference

Reference substance name:

Unnamed

IUPAC name:

alcohol

Identifier:

common name

Identity:

alcohol

Identity of transformation products 2

Reference

Reference substance name:

Unnamed

IUPAC name:

aldehyde

Identifier:

common name

Identity:

aldehyde

Identity of transformation products 3

Reference

Reference substance name:

Unnamed

IUPAC name:

phosphate

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 604-302-9]

Identifier:

common name

Identity:

phosphate

Details on results:

Bacteria isolated from contaminated metalworking fluids:
AV1 (Flavobacterium) reduced nitrate, had urease activity, assimilated glucose, arabinose, mannose, N-acetyl-glucosamine, maltose and malate.
CL1 (Bacillus) reduced nitrate, had beta-glucosidase, beta-galactosidase activities and assimilated glucose, arabinose, mannose, mannitol, maltose, gluconate, malate and citrate.
FM2 (Aeromonas) produced indole and acid, had beta-glucosidase activity and assimilated N-acetylglucosamine, maltose and citrate.
SP1 (Pseudomonas) assimilated glucose, arabinose, mannose, N-acetylglucosamine, maltose and malate.

Formation of products from sodium diethyl dithiophosphate (NaDDP):
Extracts of all the organisms studied produced alcohol, aldehyde and phosphate in excess. No products were found in control experiments where boiled extracts were used or where the extract was omitted. In all cases, ethanol was present in lower detectable quantities than aldehyde or phosphate. Of the four organisms studied, Flavobacterium (AV1) appeared to catabolize the test material most rapidly. However, only 10% of the total phosphate of the NaDDP molecle was realized during the 2 hour study period. No hydrogen sulphide production by any of the four organisms was detected under the assay conditions used. Neither was alkaline phosphodiesterase activity detected.

Results with reference substance:

Not applicable

Any other information on results incl. tables

No other information.

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

not applicable

Conclusions:

The breakdown of sodium O,O-diethyl dithiophosphate by four bacterial strains (Aeromonas, Pseudomonas, Flavobacterium and Bacillus) isolated from contaminated metalworking fluids was shown to involve the successive formation of ethanol, aldehyde and orthophosphate.

Executive summary:

Four bacterial strains were isolated from contaminated metalworking fluids and subsequently identified as Aeromonas, Pseudomonas, Flavobacterium and Bacillus.

These bacterial strains were cultured in the presence of the test substance sodium O,O-diethyl dithiophosphate and samples were taken every 5 minutes over a 2 hour period and examined for degradation products of the test substance.

Ethanol, aldehyde and orthophosphate were identified as breakdown products of the test substance.