Biodegradation of DDT by stimulation of indigenous microbial populations in soil with cosubstrates

• Published in: Biodegradation (Dordrecht) Vol. 24; no. 2; pp. 215 - 225
• Main Authors: Ortíz, Irmene, Velasco, Antonio, Le Borgne, Sylvie, Revah, Sergio
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-04-2013; Springer; Springer Nature B.V
• Subjects: Acetic acid; Aquatic Pollution; Aromatic compounds; Bacteria; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Carbon dioxide; Carbon sources; DDD; DDE; DDT; DDT - metabolism; Dichlorodiphenyl Dichloroethylene - metabolism; Environment and pollution; Ethane; Fundamental and applied biological sciences. Psychology; Geochemistry; Hydrocarbons, Chlorinated - metabolism; Industrial applications and implications. Economical aspects; Life Sciences; Metabolites; Microbial activity; Microbiology; Microorganisms; Mineralization; Nitrous oxide; Organic acids; Original Paper; Pesticides; Phenol; Phenols; Soil (material); Soil contamination; Soil Microbiology; Soil microorganisms; Soil pollution; Soil Science & Conservation; Terrestrial Pollution; Toluene; Waste Management/Waste Technology; Waste Water Technology; Water Management; Water Pollution Control; Biodegradation; Biostimulation; Cosubstrates; DDT; Organochlorine pesticides; Soils; Pesticides; Stimulation; Microorganism
• ISSN: 0923-9820; 1572-9729
• DOI: 10.1007/s10532-012-9578-1

Stimulation of native microbial populations in soil by the addition of small amounts of secondary carbon sources (cosubstrates) and its effect on the degradation and theoretical mineralization of DDT [l,l,l-trichloro-2,2-bis(
p
-chlorophenyl)ethane] and its main metabolites, DDD and DDE, were evaluated. Microbial activity in soil polluted with DDT, DDE and DDD was increased by the presence of phenol, hexane and toluene as cosubstrates. The consumption of DDT was increased from 23 % in a control (without cosubstrate) to 67, 59 and 56 % in the presence of phenol, hexane and toluene, respectively. DDE was completely removed in all cases, and DDD removal was enhanced from 67 % in the control to ~86 % with all substrates tested, except for acetic acid and glucose substrates. In the latter cases, DDD removal was either inhibited or unchanged from the control. The optimal amount of added cosubstrate was observed to be between 0.64 and 2.6 mg C
. The CO
2
produced was higher than the theoretical amount for complete cosubstrate mineralization indicating possible mineralization of DDT and its metabolites. Bacterial communities were evaluated by denaturing gradient gel electrophoresis, which indicated that native soil and the untreated control presented a low bacterial diversity. The detected bacteria were related to soil microorganisms and microorganisms with known biodegradative potential. In the presence of toluene a bacterium related to
Azoarcus
, a genus that includes species capable of growing at the expense of aromatic compounds such as toluene and halobenzoates under denitrifying conditions, was detected.