Growth Kinetics and Toxicity of Enterobacter cloacae Grown on Linear Alkylbenzene Sulfonate as Sole Carbon Source

Abstract

A successful attempt was made to isolate linear alkylbenzene sulfonate (LAS)-degrading bacteria from soil irrigated with wastewater. The isolated bacteria were able to use LAS as sole carbon and energy source. Maximum growth rates on LAS reached only 0.27 h(-1). 16S-rRNA sequencing and fatty-acid analysis placed the bacteria in the genus Enterobacter cloacae. The growth curves of E. cloacae both in the presence of and the absence of LAS were monitored using measurements of optical density at 600 nm in two different media, nutrient broth and M9 minimal medium, and were modeled mathematically. Growth in NB fit the Riccati and Voltera models, indicating that LAS is not toxic to E. cloacae cells. However, growth of E. cloacae in LAS-containing MM fit the Riccati and Voltera models, whereas growth in LAS-free MM fit the Riccati model only. Furthermore, the kinetic data shown were modeled by Monod's, Andrew's, and Tessier's specific growth rate equations, coupled with the rate of consumption of different concentrations of LAS as sole carbon and energy source, and we determined that Andrew's model best fit these data adequately as a result of the cell-inhibitory effect.

Biodegradation of 2-Chlorobenzoic Acid byEnterobacter cloacae: Growth Kinetics and Effect of Growth Conditions

“…It was identified as previously described (Khleifat et al 2008) by 16S rDNA and fatty acid analysis. To guarantee the use of 2-CBA, 3-CBA, 4-CBA, and 3,4-CBA as carbon and energy sources by this bacterium, in preliminary experiment we implied a minimal medium that had these organic compounds as the only carbon sources.…”

“…The bacterium used in these experiments, Enterobacter cloacae, was originally isolated from soil irrigated with wastewater on the basis of its ability to grow with linear alkylbenzene sulfonate (LAS) as the sole source for carbon and energy (Khleifat et al 2008). It was identified by 16S rDNA and fatty acid analysis.…”

“…We report here on the bacterial strain E. cloacae that was isolated and characterized using standard methods, 16S rRNA, and fatty acid analysis (Khleifat et al 2008). This strain was capable of growing on 2-CBA as the sole carbon and energy source.…”

“…The use of microorganisms to biodegrade organic compounds from a polluted environment represents a potential solution to such environmental problems (Deweerd and Bedard 2007;Khleifat et al 2008). The discharge of chlorinated organic compounds into the environment is a widespread concern because of their toxicity to humans and wildlife as well as it Monochlorinated and polychlorinated benzoic acids (CBAs) have been intentionally released to the environment as a result of the production of many kinds of herbicides, pesticides, alkyl benzenes, and polychlorinated biphenyls (PCBs) (Krooneman et al 1996;Khleifat 2007b).…”

Effect of Copper Chemical Form on The Growth of Pseudomonas aeruginosa Isolated from Burned Patients and on Its Cu Uptake

“…However, cells that was adapted to copper had no such a response (Yoneyama and Nakae, 1996;Teitzel et al, 2006). It was reported that, microorganisms are able to adjust to the existence of toxic substances by using a succession of adaptation strategies such as alteration in lipid composition of cell membranes to recompense for these substances induced surge in membrane fluidity (Khleifat, 2007;Khleifat et al, 2008). Bacterial resistance to copper metal has demonstrated an important contribution to the competitive endurance of some pseudomonads in such environment (Yang et al, 1993).…”