Screening Three Strains of Pseudomonas aeruginosa: Prediction of Biosurfactant-Producer Strain

Saeed Torkzadeh,Masoud Ahmadi Afz,Gholamreza Dehghan-No,Effat C Behravan,Mohammad Hasan Mosh

doi:10.3844/ajassp.2009.1453.1457

Abstract

Problem statement: The chemical surfactants have some disadvantages; especially, toxicity and no biodegradability. Approach: Biosurfactants were the structurally diverse group of surface-active molecules synthesize by micro-organisms. The microbial surfactants were interesting, because of the biodegradable and have many applications in industry, agriculture, medicine. Results: In the present study, the production of biosurfactant by three strains of Pseudomonas aeruginosa (PTCC 1074, 1310 and 1430) was investigated. The hemolytic and foam forming activity of different strains were studied and consequently, P. aeruginosa PTCC 1074 was selected as the suitable strain. P. aeruginosa PTCC 1074 was grown in the nutrient broth medium and biosurfactant production was evaluated every 24 h by emulsification index and surface tension for the best of production time. After that, in order to get maximum production of biosurfactant, the selected strain was grown with different additives in nutrient broth and the best culture medium was found. The biosurfactant was isolated from the supernatant and its amphipathic structure was confirmed by chemical methods. Conclusion: Biosurfactant produced by Pseudomonas aeruginosa PTCC 1074 would be considered as a suitable surfactant in industries due to its low toxicity.

Highlights

Microbial-derived surfactants are amphipatic molecules produced by a wide variety of bacteria, yeasts and filamentous fungi
The results of foam forming activity test for three different strains indicate that P. aeruginosa Persian Culture Type Collection (PTCC) 1074 produces more foam than the other strains (Table 2)
Time (h) Paraffin oil Castor oil Olive oil Screening for biosurfactant producer strain: The screening of biosurfactant-producing microorganisms is generally carried out using monitoring parameters that estimate surface activity, such as surface tension, the ability to emulsify oils’ hemolytic capacity and foam activity

Summary

Introduction

Microbial-derived surfactants are amphipatic molecules produced by a wide variety of bacteria, yeasts and filamentous fungi. The most important advantage of biosurfactants when compared to synthetic surfactants is their ecological acceptance, owing to their low toxicity and biodegradable nature[1]. Another advantage of biosurfactants is that they can be modified by biotransformation to generate new products for specific requirements[2]. The antimicrobial activity showed by rhamnolipids is another promising field of application for these molecules Bacteria of the genus Pseudomonas are known to produce a glycolipid surfactant containing rhamnose and 3-hydroxy fatty acids[6]. The production of biosurfactant by three strains of P. aeruginosa is reported and investigated some physicochemical properties such as foam activity and emulsification index of produced biosurfactant

Methods

Results

Conclusion