Isotope Fractionation (δ13C, δ15N) in the Microbial Degradation of Bromoxynil by Aerobic and Anaerobic Soil Enrichment Cultures

2020 ◽  
Vol 68 (6) ◽  
pp. 1546-1554
Author(s):  
Nadav Knossow ◽  
Hagar Siebner ◽  
Anat Bernstein
1984 ◽  
Vol 30 (12) ◽  
pp. 1458-1466 ◽  
Author(s):  
B. S. Rajagopal ◽  
V. R. Rao ◽  
G. Nagendrappa ◽  
N. Sethunathan

Metabolism of side chain and ring 14C-labelled carbaryl and carbofuran in a mineral salts medium by soil-enrichment cultures and a Bacillus sp. was studied. A change in the substrate of the medium from carbaryl to carbofuran led to a marked shift in the dominant bacterium from Bacillus sp. to Arthrobacter sp. although carbaryl-enrichment culture was the primary inoculum in both media. Hydrolysis was the major route of microbial degradation of both carbamate insecticides. During carbaryl degradation by enrichment cultures and Bacillus sp., 1-naphthol and 1,4-naphthoquinone accumulated in the medium. Of the three metabolites formed from carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran were further metabolized rapidly, while carbofuran phenol was resistant to further degradation. Evolution of 14CO2 and other gaseous 14C-labelled products from both side chain and ring labels was negligible. This and slow degradation of the hydrolysis products led to significant accumulation of 14C in the medium even after prolonged incubation.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Pankaj Kumar Arora ◽  
Ashutosh Sharma ◽  
Hanhong Bae

Indole and its derivatives, including 3-methylindole and 4-chloroindole, are environmental pollutants that are present worldwide. Microbial degradation of indole and its derivatives can occur in several aerobic and anaerobic pathways; these pathways involve different known and characterized genes. In this minireview, we summarize and explain the microbial degradation of indole, indole-3-acetic acid, 4-chloroindole, and methylindole.


1978 ◽  
Vol 24 (7) ◽  
pp. 798-803 ◽  
Author(s):  
M. Sielicki ◽  
D. D. Focht ◽  
J. P. Martin

Microbial degradation of [β-14C]polystyrene and 1,3-diphenylbutane, a compound structurally representing the smallest repeating unit of styrene (dimer), was investigated in soil and liquid enrichment cultures. Degradation rates in soil, as determined by 14CO2 evolution from applied [14C]polystyrene, varied from 1.5 to 3.0% for a 4-month period. Although relatively low, these percentages were 15 to 30 times greater than values previously reported. Enrichment cultures, containing 1,3-diphenylbutane as the only carbon source, were used to determine the mechanisms of microbial oxidation of the polymer chain ends. Metabolism of 1,3-diphenylbutane appeared to involve the attack by a monooxygenase to form 2-phenyl-4-hydroxyphenylbutane followed by a further oxidation and subsequent fission of the benzene ring to yield 4-phenylvaleric acid and an unidentified 5-carbon fragment via the classic meta-fission pathway. Phenylacetic acid was probably formed from 4-phenylvaleric acid by subsequent β-oxidation of the side chain, methyl-oxidation, and decarboxylation. An initial examination of the population of microorganisms in the diphenylbutane enrichment cultures indicated that these oxidative reactions are carried out by common soil microorganisms of the genera Bacillus, Pseudomonas, Micrococcus, and Nocardia.


2016 ◽  
Vol 50 (6) ◽  
pp. 3091-3100 ◽  
Author(s):  
Steffen Kümmel ◽  
Robert Starke ◽  
Gao Chen ◽  
Florin Musat ◽  
Hans H. Richnow ◽  
...  

1998 ◽  
Vol 32 (5) ◽  
pp. 598-603 ◽  
Author(s):  
William F. Cowen ◽  
Ann M. Gastinger ◽  
Christine E. Spanier ◽  
Jerod R. Buckel ◽  
Robert E. Bailey

1967 ◽  
Vol 13 (1) ◽  
pp. 21-25 ◽  
Author(s):  
H. R. Krouse ◽  
R. G. L. McCready ◽  
S. A. Husain ◽  
J. N. Campbell

A number of Salmonella species are capable of fractionating sulfur isotopes during sulfite reduction under aerobic and anaerobic conditions. The product H2S may be enriched in 32S by over 3% as compared to the initial sulfite 32S/34S composition. This is significantly higher than the isotope effect realized in the equivalent inorganic chemical reduction.


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