Tomaz Langenbach

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The closing down of a lindane factory near Rio de Janeiro, over 45 years ago, left an area heavily contaminated with hexachlorocyclohexane (HCH). Remediation by soil liming was applied by government authorities in 1995. This study aims to evaluate the HCH distribution and impact on soil microbiota due to contamination and liming. Microcosm experiments with(More)
This study combined laboratory based microcosm systems as well as field experiments to evaluate the mobility of atrazine on a Ultisol under humid tropical conditions in Brazil. Results from sorption experiments fit to the Freundlich isotherm model [K(f) 0.99 mg kg(-1)/(mg l(-1))(1/n)], and indicate a low sorption capacity for atrazine in this soil and(More)
Microbial displacement in the soil is an important process for bioremediation and dispersal of wastewater pathogens. We evaluated cell movement in surface and subsurface red-yellow podzolic soil driven by advection and microbial motility and also survival of a microbial population at high pressure as is prevalent in deep soil layers. Pseudomonas fluorescens(More)
14C-terbuthylazine was applied to three Brazilian soils in closed aerated laboratory microcosms, both under standardized and under natural Brazilian climate conditions. Volatilization from soil to air, leaching from soil to percolate water, and transport from upper to deeper soil layers were higher in sandy soil than in clay soil and in organic soil.(More)
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(More)
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(More)
The fate of (14)C atrazine was investigated using microcosms and an undisturbed Red-Yellow Latossol (Oxisol) under simulated rainfall conditions of 200 mm water month(-1). Experiments were carried out using microcosm cores, the first with an uncovered surface soil; the second set with uncovered subsurface soil; the third with subsurface soil covered with 3(More)
Incorporation of 14C-labeled biopterin into Crithidia fasciculata was inhibited by 1 mM colchicine or lumicolchicine. These substance do not penetrate the cell membrane, hence they cannot interact with the subpellicular microtubules. In view of this, interference of colchicine with biopterin transport must occur on the outer surface of the cell membrane.(More)