Mass production of bacterial communities adapted to the degradation of volatile organic compounds (TEX)

Abstract

This study focuses on the mass cultivation of bacteria adapted to the degradation of a mixture composed of toluene, ethylbenzene, o-, m- and p-xylenes (TEX). For the cultivation process Substrate Pulse Batch (SPB) technique was adapted under well-automated conditions. The key parameters to be monitored were handled by LabVIEW software including, temperature, pH, dissolved oxygen and turbidity. Other parameters, such as biomass, ammonium or residual substrate concentrations needed offline measurements. SPB technique has been successfully tested experimentally on TEX. The overall behavior of the mixed bacterial population was observed and discussed along the cultivation process. Carbon and nitrogen limitations were shown to affect the integrity of the bacterial cells as well as their production of exopolymeric substances (EPS). Average productivity and yield values successfully reached the industrial specifications, which were 0.45 kg(DW)m(-3) d(-1) and 0.59 g(DW)g (C) (-1) , respectively. Accuracy and reproducibility of the obtained results present the controlled SPB process as a feasible technique.

Isolation and characterization of ethylbenzene degrading Pseudomonas putida E41

“…These results showed that P. putida E41 is more effective for ethylbenzene degradation than other bacteria reported in other studies (Bielefeldt and Stensel, 1999;Deeb and Cohen, 1999;Attaway and Schmidt, 2002;Lee et al, 2002;Li et al, 2006;Lapertot et al, 2007;Plaza et al, 2007).…”

“…Their high water solubility, compared to other fuel components, contribute to their mobility, enabling them to migrate in the subsurface and eventually contaminate drinking water supplies (Blume, 1990;Leiwandowski et al, 1997;Chang et al, 2001;Margesin et al, 2003). In spite of governmental intervention in many countries, their emission into the environment is still increasing (Lapertot et al, 2007). The bioremediation of these substances has become an alternative to the traditional physical and chemical methods, which can be costly and produce hazardous products (Singleton, 1994;Abuhamed et al, 2004;Bordel et al, 2007).…”

Enhancing Production of Adapted Bacteria To Degrade Chlorinated Aromatics

“…which were able to degrade a mixture of toluene, ethylbenzene, and xylenes. 14 These metabolites could protect the bacterial cells against the omnipresence of CB and DCB. Indeed, the two molecules as well as their metabolites of degradation are lipophilic and toxic; they are known to be responsible for cellular and wall damages.…”

“…The same behavior has already been reported. 14,18,19 In the case of chlorinated solvents, the substrate removal can be directly correlated with the chloride released in the cultivation medium during the reaction phase. Note that this should be distinguished from the full mineralization of the substrate.…”

Toluene biodegradation in a two phase partitioning system—Use of a biodegradable solvent

“…Among all these procedures, bioremediation appears to be an economical, energy-efficient and environmentally sound approach [3], it is also the cleanest one in the case of BTEX because they can be completely mineralized and do not generate secondary effluent problems [4]. In spite of this, the use of biological elimination methods for VOC is limited by the difficulty of achieving substrate absorption in water at the appropriate concentration.…”