Continuous rhamnolipid production with integrated product removal by foam fractionation and magnetic separation of immobilized Pseudomonas aeruginosa

Abstract

Increasing interest in biological surfactants has led to intensified research directed at more cost-efficient production of biosurfactants, relative to traditional surface-active components based on petrochemical feedstocks. This publication will focus on a new integrated process for continuous rhamnolipid (RL) production. RL was synthesized by Pseudomonas aeruginosa DSM 2874 and was continuously removed in situ by foam fractionation. To prevent loss of the biocatalyst through foaming, bacteria were entrapped in magnetic alginate beads. Immobilizates were retained from the foam by high-gradient magnetic separation and back-flushed in the bioreactor at constant intervals. It was demonstrated that continuous RL production in a 10-L bioreactor over several cycles with intermediate growth periods is feasible. Complete separation of RLs from the production medium with an average enrichment ratio of 15 in the collapsed foam was demonstrated, yielding a final RL amount of 70 g after four production cycles.

Influencing factors in the CO-precipitation process of superparamagnetic iron oxide nano particles: A model based study

“…The applications range from wastewater treatment [1,2], to electrode material in lithium ion batteries [3][4][5], magnetic fluids respectively ferrofluids [6][7][8], used e.g. as magnetic inks for jet printing [9,10], biosensing applications [11,12], medical applications, such as targeted drug delivery [13,14], contrast agents in magnetic resonance imaging [15][16][17][18][19][20], and also biotechnological processing [21][22][23][24] and carrier materials for biocatalysts [25], to sum up a few. All of these applications require high magnetization values and a narrow particle size distribution.…”

Biosurfactant Production by Pseudomonas aeruginosa BN10 Cells Entrapped in Cryogels

“…Furthermore, the capacity for rhamnolipid production by both free and alginate-entrapped cells of Pseudomonas fl uorescence was investigated in batch cultures, and it was confi rmed that immobilization increased the biosurfactant recovery (Abouseoud et al, 2008). Heydl et al (2011) reported a new integrated process for continuous rhamnolipid production by Pseudomonas aeruginosa DSM 2874 entrapped in magnetic alginate beads, reaching a fi nal amount of 70 g rhamnolipid after four production cycles in a 10-l bioreactor.…”

Process improvement for fermentation coupling with foam separation: a convenient strategy for cell recycle

“…Winterburn et al [12] developed an FCFS setup for continuously recovering extracellular biosurfactants from fermenters to foam separation column. Heyd et al [3] reported that bacteria could be entrapped in magnetic alginate beads to prevent loss of the cell through foaming. Cui et al [13] developed a technology of fermentation coupling with foam fractionation and membrane module.…”

“…[1] As well as other separation technologies, foam separation can be used as an in situ product removal technology. [2][3][4] Comparing with classic separation technologies, such as extraction, ion-exchange adsorption, evaporation, and membrane separation, foam separation has many advantages: first of all, foam is milder than organic solvent. Thus, it avoids the loss of biomass because of organic solvent toxicity.…”

“…[4,7] There were rarely studies on process improvement for this technology such as how to control the biomass overflowing. [3] However, the influence of biomass overflowing, which has adverse effects on specific productivity, [8] total titer, and downstream separation process, [9] cannot be ignored. [10,11] References on process improvement of FCFS have included equipment design and improvement.…”