ABSTRACT
The genetic modified Pseudomonas fluorescens Br 12, resistant to kanamycin and rifampycin, was used to follow the cotransport of the organochlorine acaricide dicofol through a nonsterilized soil column. P. fluorescens was found to bioaccumulate dicofol with the highest bioconcentration factor of 279 within 30 min. Separate soil column experiments where applied P. fluorescens or [14C]dicofol were submitted to heavy rain simulation did not reveal any correlation between the distribution patterns of P. fluorescens and [14C]dicofol in the leachate fractions (r = 0.3). Similar experiments with P. fluorescens that previously had bioaccumulated [14C]dicofol demonstrated a high correlation of these bacteria and radioactivity in the leachate fractions (r = 0.8). The total recovery of radioactivity in the leachate, when [14C]dicofol was previously bioaccumulated in bacteria, was more than two times higher (4.5%) than the total recovery of radioactivity in the leachate when [14C] dicofol was directly applied in the soil (2%). This indicates cotransport by Pseudomonas. Fractionation and analysis of soil columns indicated that most of the bioaccumulated dicofol was rapidly released and adsorbed in soil, while bacteria moved down by leaching.
Subject(s)
Dicofol/pharmacokinetics , Insecticides/pharmacokinetics , Pseudomonas fluorescens/physiology , Soil Pollutants/pharmacokinetics , Carbon Radioisotopes/pharmacokineticsABSTRACT
The organochlorine Thiodan CE inhibited growth and nitrogenase activity of Azospirillum lipoferum. The active ingredient, Endosulfan, was nonspecifically bound to proteins and mainly adsorbed to the cell envelope with small amounts transported into cytosol. The involvement of the external membrane and cyst formation in protection against hazardous substances is discussed.
