Bacterial polysaccharide levan as stabilizing, non-toxic and functional coating material for microelement-nanoparticles

Bondarenko, Olesja; Ivask, Angela; Kahru, Anne; Vija, Heiki; Titma, Tiina; Visnapuu, Meeri; Joost, Urmas; Pudova, Ksenia; Adamberg, Signe; Visnapuu, Triinu; Alamäe, Tiina

doi:10.1016/j.carbpol.2015.09.093

Cited by 60 publications

(24 citation statements)

References 44 publications

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“…Moreover, if mineral nanoparticles were coated with respective levan, their toxic effect on Caco-2 cells was reduced (in the case of Se) or totally eliminated (in the case of Co 3 O 4 ). Two different assays unequivocally demonstrated that levan enhanced the metabolic activity of the Caco-2 cells, but did not induce cellular proliferation [67]. Concordant to these results, levan from a halophilic bacterium Halomonas sp.…”

Section: Resultsmentioning

confidence: 73%

“…So, Bondarenko et al . [67] showed that when levan-coated Co-nanoparticles were incubated with B . thetaiotaomicron , the metal was solubilized as the medium was acidified by levan fermentation products.…”

Section: Resultsmentioning

confidence: 99%

“…A recent in vitro assay by Bondarenko et al . [67] showed that Lsc3-produced levan had no harmful effect on metabolic activity and integrity of the Caco-2 cells. Moreover, if mineral nanoparticles were coated with respective levan, their toxic effect on Caco-2 cells was reduced (in the case of Se) or totally eliminated (in the case of Co 3 O 4 ).…”

Section: Resultsmentioning

confidence: 99%

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A Highly Active Endo-Levanase BT1760 of a Dominant Mammalian Gut Commensal Bacteroides thetaiotaomicron Cleaves Not Only Various Bacterial Levans, but Also Levan of Timothy Grass

et al. 2017

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Bacteroides thetaiotaomicron, an abundant commensal of the human gut, degrades numerous complex carbohydrates. Recently, it was reported to grow on a β-2,6-linked polyfructan levan produced by Zymomonas mobilis degrading the polymer into fructooligosaccharides (FOS) with a cell surface bound endo-levanase BT1760. The FOS are consumed by B. thetaiotaomicron, but also by other gut bacteria, including health-promoting bifidobacteria and lactobacilli. Here we characterize biochemical properties of BT1760, including the activity of BT1760 on six bacterial levans synthesized by the levansucrase Lsc3 of Pseudomonas syringae pv. tomato, its mutant Asp300Asn, levansucrases of Zymomonas mobilis, Erwinia herbicola, Halomonas smyrnensis as well as on levan isolated from timothy grass. For the first time a plant levan is shown as a perfect substrate for an endo-fructanase of a human gut bacterium. BT1760 degraded levans to FOS with degree of polymerization from 2 to 13. At optimal reaction conditions up to 1 g of FOS were produced per 1 mg of BT1760 protein. Low molecular weight (<60 kDa) levans, including timothy grass levan and levan synthesized from sucrose by the Lsc3Asp300Asn, were degraded most rapidly whilst levan produced by Lsc3 from raffinose least rapidly. BT1760 catalyzed finely at human body temperature (37°C) and in moderately acidic environment (pH 5–6) that is typical for the gut lumen. According to differential scanning fluorimetry, the Tm of the endo-levanase was 51.5°C. All tested levans were sufficiently stable in acidic conditions (pH 2.0) simulating the gastric environment. Therefore, levans of both bacterial and plant origin may serve as a prebiotic fiber for B. thetaiotaomicron and contribute to short-chain fatty acids synthesis by gut microbiota. In the genome of Bacteroides xylanisolvens of human origin a putative levan degradation locus was disclosed.

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Section: Resultsmentioning

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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A Highly Active Endo-Levanase BT1760 of a Dominant Mammalian Gut Commensal Bacteroides thetaiotaomicron Cleaves Not Only Various Bacterial Levans, but Also Levan of Timothy Grass

et al. 2017

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“…Recently, Bondarenko et al (2016) showed that the addition of a surface coating of levan, a fructose-composed biopolymer of bacterial origin, significantly reduced the toxic effects of Se-NPs in an in vitro assay on the human cell line Caco-2 cell line (colorectal adenocarcinomatous tissue of the human colon). Interestingly, the presence of recalcitrant components of EPS such as humic-like acids can reduce the bioavailability of contaminants to organisms due to the increased electrostatic repulsion (Lundqvist et al, 2010;Tang et al, 2015).…”

Section: Effect Of Eps On Nano-se Toxicitymentioning

confidence: 99%

“…Several studies have shown that organic matter, i.e. EPS and humic substances, influence the fate (size, shape or surface charge) and toxicity of engineered nanoparticles like Ag, TiO 2 , ZnS by limiting their dissolution and bioavailability (uptake) (Bondarenko et al, 2016;Gao et al, 2012;Lin et al, 2012;Moreau et al, 2007). But it is unclear whether NOM or EPS of biofilms associate with elemental selenium and influence the nano-Se bioavailability and toxicity.…”

Section: Introductionmentioning

confidence: 99%