Heterologous Expression of BetL, a Betaine Uptake System, Enhances the Stress Tolerance of<i>Lactobacillus salivarius</i>UCC118

Sheehan, V.; Sleator, Roy D.; Fitzgerald, Gerald F.; Hill, Colin

doi:10.1128/aem.72.3.2170-2177.2006

Cited by 119 publications

(88 citation statements)

References 60 publications

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“…Furthermore, strains expressing betL exhibited a significant increase in resistance to several stresses. For example, the percent survival of UCC118-betL + during freeze drying was 36 %, compared to 18 % for UCC118-betL − (Sheehan et al, 2006). Moreover, the tre locus plays critical role in freeze drying of L. acidophilus.…”

Section: Important Parameters Affecting Microencapsulationmentioning

confidence: 99%

Technology and potential applications of probiotic encapsulation in fermented milk products

2014

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Fermented milk products containing probiotics and prebiotics can be used in management, prevention and treatment of some important diseases (e.g., intestinal-and immune-associated diseases). Microencapsulation has been used as an efficient method for improving the viability of probiotics in fermented milks and gastrointestinal tract. Microencapsulation of probiotic bacterial cells provides shelter against adverse conditions during processing, storage and gastrointestinal passage. Important challenges in the field include survival of probiotics during microencapsulation, stability of microencapsulated probiotics in fermented milks, sensory quality of fermented milks with microencapsulated probiotics, and efficacy of microencapsulation to deliver probiotics and their controlled or targeted release in the gastrointestinal tract. This study reviews the current knowledge, and the future prospects and challenges of microencapsulation of probiotics used in fermented milk products. In addition, the influence of microencapsulation on probiotics viability and survival is reviewed.

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Section: Important Parameters Affecting Microencapsulationmentioning

confidence: 99%

Technology and potential applications of probiotic encapsulation in fermented milk products

2014

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“…The disadvantage of pre-exposure to sublethal stresses is that it may result in significant decreases in cellular activity, cell yield and process volumetric productivity (Doleyres & Lacroix, 2005). Other alternative methods for improving probiotic viability are genetic modification (Sheehan et al, 2006;Sheehan et al, 2007;Sleator & Hill, 2007), immobilization (Doleyres et al, 2004), two-step fermentations, www.intechopen.com use of oxygen-impermeable containers and microencapsulation (Özer et al, 2009). Of these techniques, microencapsulation is relatively new and has been investigated by various researchers.…”

Section: Methods For Improving Probiotic Viabilitymentioning

confidence: 99%

Probiotics - What They Are, Their Benefits and Challenges

Thantsha¹,

Mamvura²,

Booyens³

2012

New Advances in the Basic and Clinical Gastroenterology

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“…In addition to expanding our knowledge of salt tolerance mechanisms, this study may also facilitate the development of novel drug targets and related approaches to control resident gut microbiota (Sleator, 2010a, b). Ultimately some of the salt tolerance mechanisms identified might be used as part of a 'pathobiotechnology' or 'metabiotechnology' (Culligan et al, 2009) strategy for the design of improved probiotic cultures with greater resistance to process induced stresses (such as spray and freeze drying), as well as improved gut colonization (Sheehan et al, 2006;Sheehan et al, 2007;Watson et al, 2008 for such examples). This will hopefully result in a broader and more comprehensive representation of salt tolerance mechanisms in this unique environment.…”

Section: Discussionmentioning

confidence: 99%

Functional metagenomics reveals novel salt tolerance loci from the human gut microbiome

et al. 2012

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Metagenomics is a powerful tool that allows for the culture-independent analysis of complex microbial communities. One of the most complex and dense microbial ecosystems known is that of the human distal colon, with cell densities reaching up to 10 12 per gram of faeces. With the majority of species as yet uncultured, there are an enormous number of novel genes awaiting discovery. In the current study, we conducted a functional screen of a metagenomic library of the human gut microbiota for potential salt-tolerant clones. Using transposon mutagenesis, three genes were identified from a single clone exhibiting high levels of identity to a species from the genus Collinsella (closest relative being Collinsella aerofaciens) (COLAER_01955, COLAER_01957 and COLAER_01981), a high G þ C, Gram-positive member of the Actinobacteria commonly found in the human gut. The encoded proteins exhibit a strong similarity to GalE, MurB and MazG. Furthermore, pyrosequencing and bioinformatic analysis of two additional fosmid clones revealed the presence of an additional galE and mazG gene, with the highest level of genetic identity to Akkermansia muciniphila and Eggerthella sp. YY7918, respectively. Cloning and heterologous expression of the genes in the osmosensitive strain, Escherichia coli MKH13, resulted in increased salt tolerance of the transformed cells. It is hoped that the identification of atypical salt tolerance genes will help to further elucidate novel salt tolerance mechanisms, and will assist our increased understanding how resident bacteria cope with the osmolarity of the gastrointestinal tract.

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Heterologous Expression of BetL, a Betaine Uptake System, Enhances the Stress Tolerance ofLactobacillus salivariusUCC118

Cited by 119 publications

References 60 publications

Technology and potential applications of probiotic encapsulation in fermented milk products

Technology and potential applications of probiotic encapsulation in fermented milk products

Probiotics - What They Are, Their Benefits and Challenges

Functional metagenomics reveals novel salt tolerance loci from the human gut microbiome

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