The use of polysaccharide-based materials presents an eco-friendly technological solution, by reducing dependence on fossil resources while reducing a product's carbon footprint, when compared to conventional plastic packaging materials. This review discusses the potential of polysaccharides as a raw material to produce multifunctional materials for food packaging applications. The covered areas include the recent innovations and properties of the polysaccharide-based materials. Emphasis is given to hemicelluloses, marine polysaccharides, and bacterial exopolysaccharides and their potential application in the latest trends of food packaging materials, including edible coatings, intelligent films, and thermo-insulated aerogel packaging.

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Water kefir is a beverage fermented by a microbial consortium captured in kefir grains. The kefir grains matrix is composed of polysaccharide, primarily dextran, which is produced by members of the microbial consortium. In this study, we have isolated lactic acid bacteria (LAB) from non-commercial water kefir grains (from Belgrade, Serbia) and screened for dextran production. Among twelve LAB isolates three produced slime colonies on modified MRS (mMRS) agar containing sucrose instead of glucose and were presumed to produce dextran. Three LAB were identified, based on morphological, physiological and biochemical characteristics and 16S rRNA sequencing, as Leuconostoc mesenteroides (strains T1 and T3) and Lactobacillus hilgardii (strain T5). The isolated strains were able to synthesize a substantial amount of dextran in mMRS broth containing 5% sucrose. Maximal yields (11.56, 18.00 and 18.46 g/l) were obtained after 16, 20 and 32 h for T1, T3 and T5, respectively. Optimal temperature for dextran production was 23 o C for two Leuconostoc mesenteroides strains and 30 °C for Lactobacillus hilgardii strain. The produced dextrans were identified based on paper chromatography, while the main structure characteristics of purified dextran were observed by FT-IR spectroscopy. Our study shows that water kefir grains are a natural source of potent dextran producing LAB.

The production of dextransucrase (DS) by Leuconostoc mesenteroides T3, novel isolate from water kefir grain, was studied and optimized. Bacterial supernatant reached activity of 3.1 U/ml when the culture was grown at 23 °C and under static culture condition using classical Tsuchiya medium for DS production. The increase of sucrose concentration to 7% led to an increase of DS activity by 52% compared to the control. Medium with 2% beef extract and 1% yeast extract resulted in 4.52 U/ml, which was 47% higher than in the control (with 2% yeast extract). Finally, the increase of K 2 HPO 4 concentration from 2 to 3% resulted in the increased enzyme activity by 28%. Enzyme purified by polyethylene glycol 400 fractionation displayed maximum activity at 30 °C and pH 5.4. Zymogram analysis confirmed the presence of DS of approximately 180 kDa. The addition of divalent cations Ca 2+ , Mg 2+ , Fe 2+ and Co 2+ led to a minor increase of DS activity, while the addition of Mn 2+was the most prominent with 73% increase. These findings classify dextransucrase from Leuconostoc mesenteroides T3 as promising candidate for production of dextran, which has numerous applications in various industries.Lactic acid bacteria (LAB) are one of the main classes of microorganisms that are known to produce several industrially important biomolecules among which exopolysaccharides (EPS) have the widest range of uses [1]. Fermentation processes for EPS production are quite expensive due to purification costs, giving an advantage to the use of enzymes. Current challenges in the LAB enzymes production include both strain improvement and enhancement of enzyme production.Dextransucrase (DS) is an extracellular enzyme that belongs to the class of glucosyltransferases [2] and it is mainly produced by microorganisms belonging to the families Lactobacillaceae and Streptococcaceae, especially by the genera Lactobacillus, Leuconostoc and Streptococcus [3]. Enzyme DS catalyzes the transfer reaction of glucosyl residues from sucrose to dextran polymer chain and releases fructose [4,5]. In the presence of appropriate acceptor (glucose, maltose, isomaltose, etc.) this enzyme can also produce oligosaccharides [6].

Cellulases are industrially important enzymes with a potential to convert cellulose into fermentable sugars. Novel bacterial isolate Paenibacillus sp. CKS1 was tested for cellulase activity and the optimal conditions for carboxymethyl cellulase (CMCase) production were determined. Maximum CMCase activity was obtained in the third passage of the bacterial culture after 3 days of incubation at 30 °C. Cellobiose and yeast extract was the optimal source of carbon and nitrogen for induction of CMCase activity. In addition, with initial pH 7 of the medium and 40 ml of working volume in 500 ml culture flasks with shaking at 150 rpm, the maximum CMCase activity in a crude culture supernatant reached value of 0.532±0.006 U/ml. For crude CMCase, optimal temperature was 50 °C and optimal pH 4.8, respectively. HPLC analysis confirmed the bacterium is capable to hydrolise CMC to glucose and other soluble sugars.