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Chau, T. Lú; Guillán, A.; Roca, Enrique; Núñez, Marı́a José; Lema, Juan M.

doi:10.1023/a:1005669618337

Cited by 12 publications

(3 citation statements)

References 10 publications

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“…Even earlier Sayadi, Nasri, Berry, demonstrated that after 120 generations (counted in planktonic cultures) 88% of encapsulated E. coli cells retained plasmids compared to only 40% of planktonic cells (Sayadi, Nasri, Berry, Barbotin, & Thomas, 1987). Our data (Figure 6b,c) are consistent with these observations, as well as with more recent reports demonstrating that encapsulation enhances the stability of a wide variety of plasmids in both bacteria and yeast (Lú Chau, Guillán, Roca, Núñez, & Lema, 2000;Park & Chang, 2000).…”

Section: Encapsulation Enhances Fusant Genome Stabilitysupporting

confidence: 92%

Encapsulation enhances protoplast fusant stability

Gulli

Kroll

Rosenzweig

2020

Biotech & Bioengineering

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A barrier to cost-efficient biomanufacturing is the instability of engineered genetic elements, such as plasmids. Instability can also manifest at the whole-genome level, when fungal dikaryons revert to parental species due to nuclear segregation during cell division. Here, we show that by encapsulating Saccharomyces cerevisiae-Pichia stipitis dikaryons in an alginate matrix, we can limit cell division and preserve their expanded metabolic capabilities. As a proxy to cellulosic ethanol production, we tested the capacity of such cells to carry out ethanologenic fermentation of glucose and xylose, examining substrate use, ploidy, and cell viability in relation to planktonic fusants, as well as in relation to planktonic and encapsulated cell cultures consisting of mixtures of these species. Glucose and xylose consumption and ethanol production by encapsulated dikaryons were greater than planktonic controls.Simultaneous co-fermentation did not occur; rather the order and kinetics of glucose and xylose catabolism by encapsulated dikaryons were similar to cultures where the two species were encapsulated together. Over repeated cycles of fed-batch culture, encapsulated S. cerevisiae-P. stipitis fusants exhibited a dramatic increase in genomic stability, relative to planktonic fusants. Encapsulation also increased the stability of antibiotic-resistance plasmids used to mark each species and preserved a fixed ratio of S. cerevisiae to P. stipitis cells in mixed cultures. Our data demonstrate how encapsulating cells in an extracellular matrix restricts cell division and, thereby, preserves the stability and biological activity of entities ranging from genomes to plasmids to mixed populations, each of which can be essential to cost-efficient biomanufacturing.

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Section: Encapsulation Enhances Fusant Genome Stabilitysupporting

confidence: 92%

Encapsulation enhances protoplast fusant stability

Gulli

Kroll

Rosenzweig

2020

Biotech & Bioengineering

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“…Calcium gels are often used in bead form as an immobilization matrix for animal cells or plant protoplast 329. It was claimed that encapsulation enhanced the stability of plasmids and enzymatic expression 330. Microparticles were also obtained by emulsion; this method allows one to obtain beads with smaller pores 331, 332.…”

Section: Seaweed Polysaccharidesmentioning

confidence: 99%

Main properties and current applications of some polysaccharides as biomaterials

Rinaudo

2007

Polymer International

877

537

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This review concerns the applications of some polysaccharides in the domain of biomaterials and bioactive polymers. Natural polysaccharides from different sources have been studied for a long time, and their main properties are summarized in this paper; some of their derivatives obtained by chemical modification are also described. The main polysaccharides currently used in the biomedical and pharmaceutical domains are chitin and its derivative chitosan, hyaluronan and alginates. Alginates are well known for their property of forming a physical gel in the presence of divalent counterions (Ca, Ba, Sr) whereas carrageenans form a thermoreversible gel; these seaweed polysaccharides are mainly used to encapsulate different materials (cells, bacteria, fungi). Other promising systems are the electrostatic complexes formed when an anionic polysaccharide is mixed with a cationic polysaccharide (e.g. alginate/chitosan or hyaluronan/chitosan). An important development of the applications of polysaccharides can be predicted for the next few years in relation to their intrinsic properties such as biocompatibility and biodegradability in the human body for some of them; they are also renewable and have interesting physical properties (film‐forming, gelling and thickening properties). In addition, they are easily processed in different forms such as beads, films, capsules and fibres. Copyright © 2007 Society of Chemical Industry

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“…54 The immobilization carriers are thought to protect the cells by providing stabilization of cell membranes and increased cell permeability Beg et al 55 preventing the cells from entering the liquid medium while still allowing penetration of substrates. It is also possible that immobilized cells may not grow or grow slowly and become stable having minimized cellular activities, 56 and then regenerate with more vigorous growth at the beginning of each cycle upon exposure to fresh medium.…”

Section: Repeated Batch Fermentations and Immobilized Cell Storagementioning

confidence: 99%

Repeated batch fermentation of immobilizedE. coliexpressingVitreoscillahemoglobin for long-term use

et al. 2017

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This study describes an efficient and reusable process for ethanol production from medium containing whey powder, using alginate immobilized ethanologenic E. coli strains either expressing (TS3) or not expressing (FBR5) Vitreoscilla hemoglobin. Reuseabilities of the FBR5 and TS3 strains were investigated regarding their ethanol production capacities over the course of 15 successive 96-h batch fermentations. The ethanol production was fairly stable over the entire duration of the experiment, with strain TS3 maintaining a substantial advantage over strain FBR5. Storage of both strains in 2 different solutions for up to 60 d resulted in only a modest loss of ethanol production, with strain TS3 consistently outperforming strain FBR5 by a substantial amount. Strains stored for 15 or 30 d maintained their abilities to produce ethanol without dimunition over the course of 8 successive batch fermentations; again strain TS3 maintained a substantial advantage over strain FBR5 throughout the entire experiment. Thus, immobilization is a useful strategy to maintain the advantage in ethanol productivity afforded by expression of Vitreoscilla hemoglobin over long periods of time and large numbers of repeated batch fermentations, including, as in this case, using media with food processing wastes as the carbon source.

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Cited by 12 publications

References 10 publications

Encapsulation enhances protoplast fusant stability

Encapsulation enhances protoplast fusant stability

Main properties and current applications of some polysaccharides as biomaterials

Repeated batch fermentation of immobilizedE. coliexpressingVitreoscillahemoglobin for long-term use

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