Understanding and controlling the release mechanism of Escherichia coli in double W₁/O/W₂emulsion globules in the presence of NaCl in the W₂phase

Abstract

The results suggest that release of bacteria from W1/O/W2 emulsion can be controlled by varying the formulation. Release occurs due to oil globule bursting independent to diffusion.

Incorporation of water-in-oil-in-water (W 1 /O/W 2 ) double emulsion in a set-type yogurt model

“…In the case of osmotic pressure-based destabilisation of W 1 /O/W 2 emulsions, polysaccharides or salts were dissolved and the size of the inner droplets was manipulated by altering the chemical potential of the external and internal water phases and resulting to water transport and swelling/shrinking (Mezzenga, Folmer, & Hughes, 2004). Recently, the authors investigated the release mechanism of GFP-tagged Escherichia coli in a W 1 /O/W 2 model by altering the osmotic balance, through increasing salt concentration, as it could take place in fermentation (El Kadri, Overton, Bakalis & Gkatzionis, 2015;El Kadri, Gun, Overton, Bakalis & Gkatzionis, 2016). Bacterial release was found to be affected by the concentration of emulsifiers, osmotic balance alteration…”

Modulating the release of Escherichia coli in double W1/O/W2 emulsion globules under hypo-osmotic pressure

“…Recently we have reported the mechanism by which Escherichia coli is released from W 1 /O/W 2 emulsion globules in the presence of NaCl in W 2 and we found that by changing the emulsion structure this mechanism can be controlled. 16 However, there is a lack of studies investigating the release of bacteria from the W 1 phase of W 1 /O/W 2 emulsions in hypo-osmotic conditions which as opposed to hyper-osmotically triggered release formulations provides a sustained release of salts as well as bacterial cells over a period of time in a controlled manner which is desirable in certain applications.…”

A polyhydroxyalkanoate‐based encapsulating strategy for ‘bioplasticizing’ microorganisms

“…Recently, 3D microenvironments based on ionotropic hydrogels such as alginate or chitosan have been employed to contain and grow bacterial biofilms. However, these formulations swell uncontrollably and are chemically labile (Rodríguez‐Huezo et al ., ; El Kadri et al ., ; van der Ark et al ., ). Considering its biocompatible and biodegradable properties, mclPHA constitutes an attractive material for encapsulation, but the use of organic solvents during the double emulsion W 1 /O/W 2 technology might impact cell viability in bacteria, as occurs in P. putida .…”