Alginate/PVA Beads for Levan Production by Zymomonas mobilis

Abstract

The levan is a biopolymer of great importance to the food industry since it is capable of defining and modifying the structure of one food, acting as stabilizer, thickener, gelling agent and being largely responsible for the texture of processed foods. The levan production by bacterial cell immobilization may potentialize the results of these studies, having advantages such as: high cell concentrations inside the reactor, increase the substrate absorption rate, improve the performance and reduce the risk of microbial contamination. Thus, this study aims to evaluate the levan production by immobilized Zymomonas mobilis in hybrid system of alginate/polyvinyl alcohol (PVA) when submitted to different sucrose concentrations (5, 10, 25 and 30%), pH (5.7 and 7.0) and incubation temperature of 30C for 12, 18 and 24 h. The results showed that the best levan production rate was 18.66 g/L at 30% sucrose concentration, with productivity 1.55 g/L/h at pH 7.0. Practical Applications The biopolymer called levan is a nontoxic, nonmutagenic, odorless, tasteless and soluble dietary fiber; it has physiological effects that depend on its size and linkage type, and its fermentability. It can be produced by bacterial fermentation like Zymomonas mobilis. The administration of levan in human diet (5.5–6 g, twice a day) for 2–3 months reduced body weight and body fat mass. The input of levan showed in some studies an increase of divalent cation (Zn, Mg and Fe) and calcium absorption in rats. In the food industry, levan improves the rheological properties and functional characteristics of dairy products, such as yogurt. Its application includes use as a stabilizer, emulsifier, surface agent, encapsulating agent and flavor and fragrances carrier.

An investigation of operational parameters of jet cutting method on the size of Ca‐alginate beads

“…The dripping process has been proved to be the most versatile technique to enable application of sodium alginate. Since this technique uses mild operational conditions, it is suitable for preserving thermolabile compounds, such as drugs, organisms, proteins or fragrances (Gaonkar et al, ; Gul & Dervisoglu, ; Lorenzetti, Moro, & García‐Cruz, ; Rakmai, Cheirsilp, & Prasertsan, ). Besides this technique has potential to be scaled up, due to its simplicity, the yield of beads production is high due to the low losses of material during the formation of bead (Oxley, ).…”

Assessment of the microbial diversity of Chinese Tianshan tibicos by single molecule, real-time sequencing technology

“…The Zymomonas mobilis species is likely related to ethanol production; it showed a high performance in response to external stresses such as high ethanol concentration, high temperature, and harsh acidic fermentation conditions (Wang et al, 2016;Zhang et al, 2016). In addition, Zymomonas mobilis has anti-leukemic activity, antitumor effects, and prebiotic activity (Einsfeldt et al, 2016;Lorenzetti et al, 2015;Yoon et al, 2004). No Acetobacter was detected in this study, despite representatives of this genus have previously been isolated from other tibicos (Gulitz et al, 2011;Marsh et al, 2013).…”

Production and сharacterization of the exopolysaccharide from strain Paenibacillus polymyxa 2020

“…It was reported that during continuous cultivation of Z . mobilis CCT4494, when immobilized in Ca- alginate gel the amounts of levan can range from 18.84 up to 112.53 g/L dependent on the incubation time [ 26 ]. Komagataeibacter xylinus , the producer of bacterial cellulose can also produce levan [ 27 , 28 ].…”