Dependence of Pseudomonas aeruginosa continous culture biosurfactant production on nutritional and environmental factors
Summary
Continuous culture studies with Pseudomonas aeruginosa were performed in order to establish nutritional and environmental conditions necessary for high production of biosurfactants. Empirical adjustments of the mineral medium formulation showed that better yields of the active compounds, rhamnolipids, are obtained by minimizing the concentration of the respective salts of magnesium, calcium, potassium, sodium and the trace elements. Improvements in performance were more evident when the intial substrate concentration, glucose, was increased up to 73 gl-1. Further, the ranges for pH (6.2 to 6.4) and temperature (32° to 34°C) that yield high biosurfactant biosynthesis were established. Concerning the physiological state of the microorganism, rhamnolipid formation was restricted to specific growth rates lower than D=0.14 h-1. By applying the conditions elaborated up to 300 mg rhamnose l-1 h-1 (equivalent to 685 mg rhamnolipid l-1 h-1) were obtained in a continuous production process.
Keywords
Pseudomonas Aeruginosa Substrate Concentration Specific Growth Specific Growth Rate Continuous CulturePreview
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