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Environmental fate & pathways

Biodegradation in soil

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Administrative data

Endpoint:
biodegradation in soil
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Study period:
1957
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Non GLP, no substance id, research article. although these limitations are present, the study clearly shows that the test was performed correctly and the conslusion is valid. therefore it can be used in a weight of ecidence approach

Data source

Reference
Reference Type:
publication
Title:
Decomposition of chloro-substituted aliphatec acids by soil bacteria
Author:
Jensen HL
Year:
1957
Bibliographic source:
Ca. J. Microbiol. 3:151-164

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: scientific valid
Principles of method if other than guideline:
Chloride and Bromide were determined by the Mohr method
GLP compliance:
no
Test type:
laboratory

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
not available
Radiolabelling:
no

Study design

Oxygen conditions:
not specified
Soil classification:
other: loamy garden soil
Details on soil characteristics:
The medium was lIsually dispensed in 5 ml. portions in test tubes as 4 ml.
of basal or soil extract medium and 1 ml. solution of the chioro-organic acids
as sodium salts plus various enrichments of the basal medium (amino acius,
vitamins, yeast extract, etc.). The basal and soil extract media were sterilized
by autoclaving, and the salts of the chloro organicacids were added aseptically
from stock solutions sterilized by filtration, to give a final concentration of
0.02 to 0.05 M. Ann excess of sterile calcium carbonate was added to media
with di- and tri-chloroacetate and dichloropropionate in order to offset the
acidification due to the production of hydrochloric acid on dissimilation of
the acid radical. Inoculum was provided as one drop per tube of a thin
suspension of cells from agar slope cultures. The temperature of incubation
was 25 C. unless otherwise stated.
Initial test substance concentration
Soil No.:
#1
Initial conc.:
ca. 0.1 other: %
Based on:
other: air dry soil
Experimental conditions
Soil No.:
#1
Temp.:
30
Details on experimental conditions:
Basal medium with 0.04 MCA waws inoculated with fresh
soil and incubated; .a visible turbidity developed after 1 to 2 weeks, and,
after a transfer to fresh medium, platings were made on a corresponding solid
medium with 2% agar. Five strains of bacteria wcre isolated, three (A, K,
and T) from' field soils, one (H) from Garden soil, and one (R) from reclaimed
salt marsh soil. None of these soils had previously been treated with
MCA.

Results and discussion

% Degradationopen allclose all
Soil No.:
#1
% Degr.:
90
Parameter:
CO2 evolution
Sampling time:
4 d
Soil No.:
#1
% Degr.:
90
Parameter:
other: Cl evolution
Sampling time:
4 d
Transformation products:
yes
Identity of transformation productsopen allclose all
No.:
#1
Reference
Reference substance name:
Unnamed
Inventory number:
InventoryMultipleMappingImpl [inventoryEntryValue=EC 231-595-7]
IUPAC name:
chloride
CAS number:
7647-01-0
No.:
#1
Reference
Reference substance name:
Unnamed
IUPAC name:
CO2
Identifier:
common name
Identity:
CO2
Evaporation of parent compound:
not measured
Volatile metabolites:
yes
Residues:
no
Details on results:
The organism is active in the decomposition of monochloroacctate in the
soil as well as in vitro, as shown by the experiment A loamy
garden soil of pH 7.2 was given an addition of 0.1% monochloroacetic acid
(as sodium salt, and calculated on the basis of air-dry soil), and adjusted to
approximately two-thirds water-holding capacity. A portion of this treated
soil was inoculated with a thin cell suspension of strain R grown on mono·
chloroacetate agar (other tests showed that the inoculation alone did not
significantly influence the soil metabolism). Production of carbon dioxide and
of ionized chloride was then determined during an 8-day period at 25 C.
The addition of chloroacetate alone results in a slight depression of carbon
dioxide compared with the control soil for the first 2 days; a rapid increase
then sets in and subsides after 6 days, when the excess in carbon dioxide
production over control soil corresponds to a release of approximately 90% of
the chloroacetate-carbon. Coincident with the rise in carbon dioxide evolution,
the ionization of the chlorine begins, and it reaches almost 100% after 6 days.
When bacterial suspension is also added, the lag in carbon dioxide production
is eliminated, and the chlorine is completely ionized after 2 days. Under the
conditions of this experiment monochloroacetate thus appears to be very
readily dissimilated in soil.
Results with reference substance:
NA

Applicant's summary and conclusion

Conclusions:
Study shows that MCA can be regarded as readily biodegradable to soil in a weight of evidence approach based on this article.
Executive summary:

Three groups of bacteria capable of bacteria capable of decomposing chloro-substituted aliphatic acids were isolated from soil by means of selected media. A group of Pseudomonas~like bacteria (A) decomposed monochloroacetate (MCA), bromoacetate) readily in media with yeast extract, or amino acids.