Research Article Open Access

An in vitro Assessment on the Efficacy of Clay-Based Formulated Cells of Pseudomonas Isolate UTAR EPA2 for Petrol Degradation

A. S.Y. Ting1, M. T. Fang1 and C. S. Tee1
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American Journal of Applied Sciences
Volume 7 No. 2, 2010, 178-184


Submitted On: 27 January 2010 Published On: 28 August 2010

How to Cite: Ting, A. S., Fang, M. T. & Tee, C. S. (2010). An in vitro Assessment on the Efficacy of Clay-Based Formulated Cells of Pseudomonas Isolate UTAR EPA2 for Petrol Degradation. American Journal of Applied Sciences, 7(2), 178-184.


Problem statement: Application of free-cell forms is usually impractical to achieve satisfactory bioremediative effect because the microbes are encumbered by the biotic and abiotic stresses from the environment. Approach: In this study, a hydrocarbon-degrading bacterium (Pseudomonas isolate UTAR EPA2) was formulated with various combinations of formulative materials, comprising of clay-based carrier materials such as Bentonite (B) and Kaolin (K), enrichment materials such as Non-fat skimmed milk (N) and Sucrose (S) and a UV-protectant agent Para-aminobenzoic acid (P). Formulated cells were treated to sunlight exposure for 6 h to mimic the conditions in the environment prior to testing for their efficacy in degrading petrol, a mixed hydrocarbon substrate. Results: Cells in all formulations including free-cell suspension were able to degrade petrol with a relatively high degradation efficacy of more than 66% even after exposure to sunlight. Degradation efficacy was slightly higher for kaolin-based formulated cells compared to bentonite-based formulations, especially after exposure to sunlight, although their percentages of degradation were not statistically different. Nevertheless, kaolin-based formulations have very low viable cell count especially in formulations with P (KP, KNP, KSP, KNSP). This suggested that aside from viable cells, the physical properties of the clays could have also contributed to the degradation of petrol. Conclusion: For storage purposes and applications in the field, we suggest that the bacterium is formulated with bentonite-based formulations especially using Bentonite (B) clay singly, as relatively high percentage of petrol degradation and viable cell count was achieved with this formulation.

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  • Cell viability
  • formulation
  • hydrocarbon-degrading bacterium
  • petrol degradation
  • UV irradiation