Isolation, identification and characterization of a new lipolytic Pseudomonas sp., strain AHD‐1, from Tunisian soil

Abstract

A novel, lipid‐degrading bacterium (strain AHD‐1) was isolated from soil regularly contaminated with washing‐machine wastewater in Sfax, Tunisia. When this strain was grown in a medium containing 2% triacylglycerol, the hydrolysis products were found to be diacylglycerols, monoacylglycerols and free fatty acids. This strain was an aerobic, mesophilic, Gram‐negative, motile, non‐sporulating bacterium, capable of growing optimally at pH 7 and 27 °C. The predominant fatty acids were found to be C_16:1ω7c (31%), C_16:0 (28.1%), C_18:1ω7c (16.3%) and C_17:0 (5.8%). Phylogenetic analysis of the 16S rRNA gene showed that this isolate is a new strain belonging to the genus Pseudomonas. Strain AHD‐1 was found to be closely related to Pseudomonas azotoformans IAM 1603^T, Pseudomonas gessardii CIP 105469^T and Pseudomonas libanensis CIP 105460^T with 99.7%, 99.56% and 99.54% of similarity, respectively.

Keywords:

• Pseudomonas sp.
• isolation
• ARNr 16S
• triacylgycerols
• lipase

Acknowledgements

The authors are grateful to Dr. Robert Verger from EIPL‐CNRS for fruitful discussions. We also thank Dr. Slim Cherif from Centre de Biotechnologie de Sfax (Tunisia) for his help. The authors would like to express their gratitude to Dr. Jessica Blanc for her help with the English language of the manuscript.