Continuous production of biosurfactant with foam fractionation

Abstract

AbstractA glucose‐limited chemostat was used to determine the growth parameters of BBK006 for continuous production of the biosurfactant surfactin. The continuous cultivation exhibited low maintenance metabolism (m = 0.39 mmolglucose gbacteria−1 h−1) and high molar growth yield ($Y_{x/S}^{\max} = 30.8$ gbacteria molglucose−1). It was found that the surfactin production rate in continuous culture was not only a function of dilution rate but also varied with the initial concentration of glucose in the feed. A high steady state concentration of surfactin (18 mg L−1) was maintained in the culture at a dilution rate of 0.2 h−1 when glucose concentration in the feed was 0.25 g L−1. This is the first demonstration of continuous surfactin production and recovery using glucose as a carbon source. The production of surfactin is known to be related to the age of the microorganisms and a simple mathematical model has been constructed to show how the age‐related production can be quantified. Copyright © 2006 Society of Chemical Industry