Sapindus saponins' impact on hydrocarbon biodegradation by bacteria strains after short- and long-term contact with pollutant.

The introduction of high toxicity petroleum contaminants to the natural environment causes damage to ecosystems and the aesthetics of the surroundings. Therefore it is critical to enhance microbial community performance to manage the degradation process. This paper analyses the effect of natural surfactants from the tree Sapindus mukorossi on biodegradation of hydrocarbons. Analysis of cell surface hydrophobicity and zeta potential confirmed effective modifications of the cell surface parameters essential for the bioavailability of contaminants to microorganisms. Interestingly, favorable differences were observed only for microorganisms from non-contaminated soil. There was also recorded an increase in diesel oil biodegradation to 41% for Sphingomonas sp. and 56% for Pseudomonas alcaligenes on addition of 100mgL(-1) of Sapindus saponins. The addition of natural surfactants has no significant impact on bacterial strains isolated from long-term contaminated soil. This research demonstrates that the addition of Sapindus extract could be a useful tool to improve the effectiveness of microbial degradation of hydrocarbon pollutants by environmental strains in recently contaminated.