Extracellular Exopolysaccharides Research Articles

Exploring rose absolute and phenylethyl alcohol as novel quorum sensing inhibitors in Pseudomonas aeruginosa and Chromobacterium violaceum

Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5–33.5%), swarming motility (94.7–64.5%), and biofilm formation (98.53–55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.

Antibacterial activities of coumarin-3-carboxylic acid against Acidovorax citrulli.

Coumarin-3-carboxylic acid (3-CCA), previously screened from natural coumarins, was found to possess strong antibacterial activity against Acidovorax citrulli (Ac). In order to further evaluate the activity of this compound against plant bacterial pathogens and explore its potential value as a bactericidal lead compound, the activity of 3-CCA against 14 plant pathogenic bacteria in vitro and in vivo was tested. Results showed that 3-CCA exhibited strong in vitro activities against Ac, Ralstonia solanacearum, Xanthomonas axonopodis pv. manihotis, X. oryzae pv. oryzae, and Dickeya zeae with EC50 values ranging from 26.64 μg/mL to 40.73 μg/mL. Pot experiment results showed that 3-CCA had powerful protective and curative effects against Ac. In addition, the protective efficiency of 3-CCA was almost equivalent to that of thiodiazole copper at the same concentration. The results of SEM and TEM observation and conductivity tests showed that 3-CCA disrupted the integrity of the cell membrane and inhibited polar flagella growth. Furthermore, 3-CCA resulted in reductions in motility and extracellular exopolysaccharide (EPS) production of Ac while inhibiting the biofilm formation of Ac. These findings indicate that 3-CCA could be a promising natural lead compound against plant bacterial pathogens to explore novel antibacterial agents.

Microbial exopolysaccharides in the biomedical and pharmaceutical industries

The most significant and renewable class of polymeric materials are extracellular exopolysaccharides (EPSs) produced by microorganisms. Because of their diverse chemical and structural makeup, EPSs play a variety of functions in a variety of industries, including the agricultural industry, dairy industry, biofilms, cosmetics, and others, demonstrating their biotechnological significance. EPSs are typically utilized in high-value applications, and current research has focused heavily on them because of their biocompatibility, biodegradability, and compatibility with both people and the environment. Due to their high production costs, only a few microbial EPSs have been commercially successful. The emergence of financial barriers and the growing significance of microbial EPSs in industrial and medical biotechnology has increased interest in exopolysaccharides. Since exopolysaccharides can be altered in a variety of ways, their use is expected to increase across a wide range of industries in the coming years. This review introduces some significant EPSs and their composites while concentrating on their biomedical uses.

Characterization of IcaB protein Poly-N-acetylglucosamine (dPNAG) De-N-acetylase involved in Staphylococcus epidermidis biofilm formation

Quorum sensing (QS) is type of behaviour coordinating bacterial cell-cell interaction involved in EPS production, cell motility, toxin secretion, biofilm. Biofilms forming multidrug-resistant Staphylococcus epidermidis (MRSE) are major threats to public health undergoing slime formation and bacteremia. Biofilms causes nosocomial infection, chronic skin damage, vaginal wall inflammation, gut infection, endocardium infection and stomach infection. One of the serious concern is biofilm formation, which helps to prevent antibiotics diffusion leading to decrease in bacterial metabolic activity mechanism. Methicillin-resistant biofilm forming S. epidermidis, RP62A (ATCC 35984) isolate is slime-producing isolate. RP62A isolates has been well characterized from molecular and infection studies revealing that plasmid (pEpi62) carries antibiotics resistance genes to penicillin, kanamycin, erythromycin and streptomycin. De-N-acetylation of poly-N-acetylglucosamine (dPNAG) is an extracellular exopolysaccharide for biofilm development. We have characterized IcaB gene and protein sequence involved in Staphylococcus epidermidis biofilm formation.

Biosorption of Cd+2 and Pb+2 by Exopolysaccharide Extracted from Lactobacillus fermentum 6b; Adsorption Isotherm and Kinetic Studies.

In recent years, the biosorption of heavy metals by Lactobacillus strains has received attention from researchers. We aimed to remove of heavy metals lead and cadmium from L. fermentum 6b exopolysaccharide in 2021. Extracellular exopolysaccharide was first extracted from selected probiotic strain, and then the effect of variables such as pH, the extracted exopolysaccharide adsorbent dose, contact time, heavy metal concentration, and temperature on the adsorption rate was investigated. The adsorption isotherms of Langmuir and Freundlich were also examined. Pseudo-first and pseudo-second-order kinetics equations were also investigated for the desired surface adsorption. The adsorption process at pH=6.5, contact time=80 min, pollutant concentration=100 mg.L-1, adsorbent dose (extracted exopolysaccharide) =1500 mg.L-1, temperature=35°C for cadmium; pH= 6, contact time=60 min, contaminant concentration of 100 mg.L-1, adsorbent dose (extracted exopolysaccharide) =1500 mg.L-1 temperature=of 35 °C for lead had optimum condition. The adsorption process corresponded to Freundlich isotherm with R2=0.958 and R2=0.988, and pseudo-second-order kinetic with R2=0.99 and R2=0.85 for cadmium and lead, respectively. The exopolysaccharide extracted from L. fermentum 6b isolate can have an acceptable removal potential for lead and cadmium heavy metals.

Non-filamentous sludge bulking induced by exopolysaccharide variation in structure and properties during aerobic granulation

The forming mechanism of non-filamentous sludge bulking during aerobic granulation were investigated basing on three feeding strategies (R1 direct aeration after fast feeding, R2 anaerobic stirring after fast feeding and R3 anaerobic plug-flow slow feeding). Results showed that strong selection stress (shortening settling time) led to a sharp flocs washout and the subsequent increase of food to microorganisms (F/M) in R1 and R3 reactors, but not found in R2 due to the different strategies of feeding modes. With the increase of F/M, zeta potential and hydrophobicity of sludge surfaces significantly decreased and thus leading to an enhanced repulsive force and energy barriers for sludge aggregation. Particularly, when F/M exceeded 1.2 kgCOD/(kgMLSS·d), non-filamentous sludge bulking was ultimately triggered in R1 and R3. Further analysis showed that massive extracellular exopolysaccharide (PS) accumulated on the surfaces of non-filamentous bulking sludge due to the increased abundance of the microorganisms related to PS secretion during sludge bulking. In addition, significantly increased intracellular second messenger (c-di-GMP), a key substance regulating PS biosynthesis, was confirmed via its concentration determination as well as microbial function prediction analysis, which played a critical role in sludge bulking. Combing with the systematic detection from surface plasmon resonance system, rheometer and size-exclusion chromatography-multiangle laser light detection-refractive index system, higher molecular weight, compact conformation, higher viscosity and higher hydrophilicity was determined in sludge bulking PS relative to PS extracted from non-filamentous bulking sludge. Clearly, the changes of PS (content, structures and properties) driven by c-di-GMP are the dominant mechanism for the formation of non-filamentous sludge bulking during aerobic granulation. This work could provide theoretical support for successful start-up and application of aerobic granular sludge technology.

Cryoprotectant role of exopolysaccharide ID1 in the vitrification/in-straw warming of in vitro-produced bovine embryos.

The cold-adapted bacterium Pseudomonas sp. ID1 produces the extracellular exopolysaccharide ID1 (EPS ID1) with cryoprotective activity. This study was designed to optimize the vitrification/in-straw warming protocol of in vitro-produced (IVP) blastocysts by adding EPS ID1 to the vitrification media. Day 7-expanded blastocysts were vitrified/warmed using the VitTrans device after the addition of 0 or 100 μg/mL EPS ID1 to the vitrification media. Blastocysts vitrified by the Cryotop method and fresh non-vitrified blastocysts served as controls. Outcomes were assessed in the warmed embryos in terms of survival rates and mRNA relative abundances of BAX, BCL2, GPX1, and CDX2 genes. No differences in survival rates were observed at 3h post-warming between vitrification treatments. At 24 h post-warming, the addition of EPS prior to vitrification with the VitTrans device produced similar survival rates to Cryotop-vitrified embryos and similar hatching rates to fresh non-vitrified or Cryotop-vitrified embryos. No differences emerged in BCL2 gene expression. Lower BAX (p < .05) and higher GPX1 (p < .05) and CDX2 (p < .1) gene expression were observed in expanded and/or hatched blastocysts derived from VitTrans-EPS-vitrified embryos when compared to those from the non-supplemented group. In conclusion, addition of EPS not only promoted blastocyst survival and hatching after VitTrans vitrification/warming but also modified the expression of genes associated with better embryo quality.

Diaryl Urea Derivative Molecule Inhibits Cariogenic Streptococcus mutans by Affecting Exopolysaccharide Synthesis, Stress Response, and Nitrogen Metabolism

Different small molecules have been developed to target cariogenic bacteria Streptococcus mutans. Based on target-based designing and in silico screening, a novel diaryl urea derivative, 1,3-bis[3,5-bis(trifluoromethyl)phenyl]urea (BPU), has previously been found effective in inhibiting the growth of S. mutans. However, the exact mechanism remains unclear. This current study aimed to explore the antimicrobial and antibiofilm effects of BPU on S. mutans and locate key enzymes and biological processes affected by the molecule via in silico molecular docking analysis and transcriptomic profile. Our in vitro results confirmed that BPU was capable of inhibiting planktonic growth as well as biofilm formation of S. mutans. The virtual binding analysis predicted that the molecule had strong binding potentials with vital enzymes (3AIC and 2ZID) involved in extracellular exopolysaccharide (EPS) synthesis. The predicted inhibitive binding was further confirmed by in vitro quantification of EPS, which found a decreased amount of EPS in the biofilms. The transcriptomic profile also found differential expression of genes involved in EPS synthesis. Moreover, the transcriptomic profile implied alterations in stress response and nitrogen metabolism in S. mutans treated with BPU. Examination of differentially expressed genes involved in these biological processes revealed that altered gene expression could contribute to impaired growth, biofilm formation, and competitiveness of S. mutans. In conclusion, the novel diaryl urea derivative BPU can inhibit the virulence of S. mutans by affecting different biological processes and serves as a potent anti-caries agent.

The Cell Membrane of a Novel Rhizobium phaseoli Strain Is the Crucial Target for Aluminium Toxicity and Tolerance.

Soils with low pH and high aluminium (Al) contamination restrict common bean production, mainly due to adverse effects on rhizobia. We isolated a novel rhizobium strain, B3, from Kenyan soil which is more tolerant to Al stress than the widely used commercial strain CIAT899. B3 was resistant to 50 µM Al and recovered from 100 µM Al stress, while CIAT899 did not. Calcein labeling showed that less Al binds to the B3 membranes and less ATP and mScarlet-1 protein, a cytoplasmic marker, leaked out of B3 than CIAT899 cells in Al-containing media. Expression profiles showed that the primary targets of Al are genes involved in membrane biogenesis, metal ions binding and transport, carbohydrate, and amino acid metabolism and transport. The identified differentially expressed genes suggested that the intracellular γ-aminobutyric acid (GABA), glutathione (GSH), and amino acid levels, as well as the amount of the extracellular exopolysaccharide (EPS), might change during Al stress. Altered EPS levels could also influence biofilm formation. Therefore, these parameters were investigated in more detail. The GABA levels, extracellular EPS production, and biofilm formation increased, while GSH and amino acid level decreased. In conclusion, our comparative analysis identified genes that respond to Al stress in R. phaseoli. It appears that a large portion of the identified genes code for proteins stabilizing the plasma membrane. These genes might be helpful for future studies investigating the molecular basis of Al tolerance and the characterization of candidate rhizobial isolates that perform better in Al-contaminated soils than commercial strains.

La importancia de las fuentes de carbono y nitrógeno en la síntesis de exopolisacáridos y su importancia industrial

Exopolysaccharides (EPSs) are classified in two groups, homopolysaccharides (HoPs) and heteropolysaccharides (HePs), are produced by lactic acid bacteria (LAB) and used in a range of industrial applications including the medical and food industries. HoPs are extracellular EPSs and their production depends on extracellular enzymes, while HePs are intracellular EPSs. Their nature (extra or intracellular) directly impacts production rates, HoPs having higher yields. The development of processes for producing EPSs has attracted great interest, since novel application trends have emerged due to the great diversity of recent information generated on EPSs properties. HoPs have been synthesized by fermentation using bacterial cells and a cell-free enzymatic process, while HePs have been produced only by fermentation. The analysis of the EPSs production processes indicates that macronutrients such as the carbon and nitrogen source used in the culture media are very important for the synthesis of EPSs and the enzymes involved, understanding their importance can assist to design processes for production of EPSs with desirable characteristics and yields according to the needs of the processes and products to which they are applicable. This review emphasized in the analyses of carbon and nitrogen sources used for EPSs production and their functional applications and productive aspects.

Biopolymer production by bacteria isolated from native stingless bee honey, Scaptotrigona jujuyensis

The products of stingless bees have been used in traditional medicine. These products have gained economic potential not only for their historical valuation but also to produce added value related to the knowledge of the qualities of their indigenous microbiota. The isolates from honey and pollen of Scaptotrigona jujuyensis, a stingless bee from Northern Argentina were studied. These were able to produce hydrolytic enzymes: protease, amylase, xylanase, cellulose, and lipase, and growing in bile salts.The isolate 4A was identified as a Bacillus sp. and was able to produce extracellular exopolysaccharides (EPS). The carbohydrate composition of EPS consisted predominantly of fructose (44.6%). Structural characterization of EPS using Fourier-transform infrared spectroscopy (FTIR) showed high similarity with levan.The EPS showed antimicrobial activity and the capacity to form emulsion hydrogels with omega-3 polyunsaturated fatty acids (PUFA) from ray liver oil and chia oil. The prebiotic property of Lactobacillus casei was evaluated with EPS and its mix with omega-3 PUFA. L. casei, showed better growth. Thus, an EPS with emulsifying hydrogel capacity and prebiotic activity was produced from the native microbial flora present in the honey of a stingless bee, which could be an added-value product of the S. jujuyensis colony used as a new nutraceutical.

Production of welan gum from cane molasses by Sphingomonas sp. FM01

As an extracellular exopolysaccharide, welan gum could serve as a suspending agent, stabilizer, emulsifier and thickener with characteristics that include bio-adhesion, non-toxicity, biocompatibility and biodegradability. In this study, Sphingomonas sp. FM01 was applied to effectively produce welan gum using cane molasses as the carbon source. After pretreatment with phosphoric acid and polyacrylamide, 60 g/L cane molasses combined with 6.0 g/L beef extract, 3 g/L KH2PO4, 0.5 g/L MgSO4, 15 mmol/L H2O2 and 4 mg/L niacin significantly improved the fermentation performance of Sphingomonas sp. FM01, increasing the production of welan gum to 37.65 g/L. Investigation of the rheological behavior of the welan gum obtained from the molasses-welan gum mixture showed it had an acceptable molecular weight and similar rheological properties and better viscosity stability compared to that obtained from sucrose, indicating that cane molasses could be explored as a suitable and inexpensive substrate for cost-effective welan gum production.

Purification and characterization of Inonotus hispidus exopolysaccharide and its protective effect on acute alcoholic liver injury in mice.

This study characterized the Inonotus hispidus extracellular exopolysaccharide (IHEPS) from fermentation broth and investigated its liver protective effect on acute alcoholic liver injury in mice. The characterization of IHEPS was analyzed by HPLC, UV-vis and FT-IR. To determine the liver protective effect of IHEPS, mice were administered with IHEPS once daily for 3 weeks, before ethanol induced acute alcoholic liver injury. Biochemical parameters of liver function, histopathological sections, mRNA and protein expression of related antioxidant enzymes were compared between with or without IHEPS administrated mice. As a result, IHEPS could extend the duration of righting reflex, shorten the durations of the recovery, and decrease the liver index in acute alcoholic liver mice. At the same time, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) levels were decreased in IHEPS mice. Moreover, increased alcohol dehydrogenase (ADH), catalase (CAT) and superoxide dismutase (SOD) levels were also found in IHEPS mice. Furthermore, IHEPS activated Nrf2 signaling pathway and increased the expression of downstream related antioxidant enzymes, such as NQO1, CAT and Cu-Zn SOD.

Microbial diversity and health-promoting properties of the traditional Bulgarian yogurt

ABSTRACTBulgarian yogurt is usually associated with good health and longevity. This study aimed to analyse the current microbial content of homemade Bulgarian yogurt. Identification by 16S rDNA sequencing revealed that out of 76 isolated strains, 53% belonged to Lactobacillus delbrueckii subsp. bulgaricus, 14% to other lactobacilli, and 32% to lactic acid cocci (Streptococcus thermophilus, Pediococcus acidilactici, Enterococcus faecium and Leuconostoc). All isolates inhibited the growth of pathogenic bacteria (10% of them by the putative action of bacteriocins); 18 isolates were able to produce extracellular exopolysaccharides (EPS), whereas 24% of them demonstrated extremely high proteolytic activity. Remarkably, 10 Lb. bulgaricus strains produced prebiotic galactooligosaccharides (GOS). High-resolution accurate mass spectrometry (HRAMS) analysis revealed production of tri- and tetrasaccharides containing atypical β(1→4) glycosidic bonds, reported for the first time for Lb. bulgaricus. Based on the beneficial features, along with good technological behaviour, we recommend several isolates as highly promising for Bulgarian yogurt starters.

Antifungal Effects of Saponin Extract from Rhizomes of Dioscorea panthaica Prain et Burk against Candida albicans.

Candida albicans is the most common fungal pathogen causing serious diseases, while there are only a paucity of antifungal drugs. Therefore, the present study was performed to investigate the antifungal effects of saponin extract from rhizomes of Dioscorea panthaica Prain et Burk (Huangshanyao Saponin extract, HSE) against C. albicans. HSE inhibits the planktonic growth and biofilm formation and development of C. albicans. 16–64 μg/mL of HSE could inhibit adhesion to polystyrene surfaces, transition from yeast to filamentous growth, and production of secreted phospholipase and could also induce endogenous reactive oxygen species (ROS) production and disrupt cell membrane in planktonic cells. Inhibitory activities against extracellular exopolysaccharide (EPS) production and ROS production in preformed biofilms could be inhibited by 64–256 μg/mL of HSE. Cytotoxicity against human Chang's liver cells is low, with a half maximal inhibitory concentration (IC50) of about 256 μg/mL. In sum, our study suggested that HSE might be used as a potential antifungal therapeutic against C. albicans.

Biocatalytic production of extracellular exopolysaccharide dextran synthesized by cells of Leuconostoc mesenteroides

Results are presented from studies and a comparative analysis of the production of the commercially important product dextran from sucrose using fed-batch cultivated cells of the Leuconostoc mesenteroides subsp. dextranicum B-5481 bacterium either immobilized in a polyvinyl alcohol (PVA) cryogel or in the form of a suspension. It is shown that under identical process conditions, the concentration of dextran is 1.2 times higher when using immobilized cells instead of free cells. The high productivity of dextran formation (4.2 g/(L h)) under the conditions of fed-batch cultivation of the immobilized cells and the ability of these cells to function without losing their metabolic activity for at least five operating cycles are demonstrated. The productivity of the developed biocatalyst is 5 times higher than that of Weissella confusa cells immobilized in a calcium alginate gel and 34 times higher than that of Leuconostoc mesenteroides KIBGE HA1 cells immobilized in a polyacrylamide gel. The molecular weight of the dextran samples produced by the immobilized L. mesenteroides B-5481 cells is half that of the polymer produced by the free cells, expanding the range of possible applications of the polysaccharide with no additional hydrolysis.

Bacteriophages targeting Enterococcus faecalis strains - a potential new root canal therapy

ABSTRACTThe most common isolated species from recalcitrant endodontic infections is Enterococcus faecalis, a gram positive multiply drug-resistant and environmentally stable bacterium. As a potential route to a biological solution to E. faecalis root-canal infection we aimed to isolate, characterise and test in vitro a range of lytic bacteriophages targeted against E. faecalis isolates from oral endodontic infections obtained from labs across Europe.Five bacteriophages were isolated from concentrated waste water named (SHEF2,4,5,6,7) that belong to the Siphoviridae family. They are specific to E. faecalis with genome sizes ranging from 39-43kb. Full chromosome sequences of SHEF2,4 and 5 alongside biological evidence revealed that they are lytic bacteriophages which place them as suitable candidate for therapy. We tested the ability of these phages to eradicate biofilm from abiotic surfaces and a novel cross-sectional tooth model while also showing that they are able to rescue Zebrafish embryos from E. faecalis systemic clinical strain infection. Finally, we established that the extracellular exopolysaccharide of E. faecalis was the bacterial docking target of these phages during the initial stages of phage infection. We suggest that these or other bacteriophages might be novel adjuncts to current endodontic therapy to eradicate recalcitrant biofilm and antibiotic resistant E. faecalis.

An extracellular polymeric substance quickly chelates mercury(II) with N-heterocyclic groups

A strain of Klebsiella oxytoca DSM 29614 is grown on sodium citrate in the presence of 50 mg l−1 of Hg as Hg(NO3)2. During growth, the strain produces an extracellular polymeric substance (EPS), constituted by a mixture of proteins and a specific exopolysaccharide. The protein components, derived from the outer membrane of cells, are co-extracted with the extracellular exopolysaccharide using ethanol. The extracted EPS contains 7.5% of Hg (total amount). This indicates that EPS is an excellent material for the biosorption of Hg2+, through chemical complexation with the EPS components. The binding capacity of these species towards Hg2+ is studied by cyclic voltammetry, and Hg L3-edge XANES and EXAFS spectroscopy. The results found indicate that Hg2+ is mainly bound to the nitrogen of the imidazole ring or other N-heterocycle compounds. The hydroxyl moities of sugars and/or the carboxyl groups of two glucuronic acids in the polysaccharide can also play an important role in sequestring Hg2+ ions. However, N-heterocyclic groups of proteins bind Hg2+ faster than hydroxyl and carboxyl groups of the polysaccharide.

Mechanisms of intrinsic resistance and acquired susceptibility of Pseudomonas aeruginosa isolated from cystic fibrosis patients to temocillin, a revived antibiotic

The β-lactam antibiotic temocillin (6-α-methoxy-ticarcillin) shows stability to most extended spectrum β-lactamases, but is considered inactive against Pseudomonas aeruginosa. Mutations in the MexAB-OprM efflux system, naturally occurring in cystic fibrosis (CF) isolates, have been previously shown to reverse this intrinsic resistance. In the present study, we measured temocillin activity in a large collection (n = 333) of P. aeruginosa CF isolates. 29% of the isolates had MICs ≤ 16 mg/L (proposed clinical breakpoint for temocillin). Mutations were observed in mexA or mexB in isolates for which temocillin MIC was ≤512 mg/L (nucleotide insertions or deletions, premature termination, tandem repeat, nonstop, and missense mutations). A correlation was observed between temocillin MICs and efflux rate of N-phenyl-1-naphthylamine (MexAB-OprM fluorescent substrate) and extracellular exopolysaccharide abundance (contributing to a mucoid phenotype). OpdK or OpdF anion-specific porins expression decreased temocillin MIC by ~1 two-fold dilution only. Contrarily to the common assumption that temocillin is inactive on P. aeruginosa, we show here clinically-exploitable MICs on a non-negligible proportion of CF isolates, explained by a wide diversity of mutations in mexA and/or mexB. In a broader context, this work contributes to increase our understanding of MexAB-OprM functionality and help delineating how antibiotics interact with MexA and MexB.

Biocatalytic Production of Extracellular Exopolysaccharide – Dextran Synthesizing by Leuconostoc mesenteroides Cells

The article presents results of investigation and comparative analysis of process characteristics of commercially important dextran production from sucrose by using immobilized cells of bacteria Leuconostoc mesenteroides subsp. dextranicum B–5481 in forms of free and immobilized into poly(vinyl alcohol) cryogel. It was shown that dextran concentration was 1.2 times higher up to 1.2 times when immobilized cells were used in comparison with suspended cells under identical process conditions. The high process productivity was revealed (4.2 g/l/h) under batch fermentation conditions for immobilized cells in addition to their prolonged operation activity without any loss of metabolic activity for at least 5 working cycles. In comparison with analogues the productivity of developed biocatalyst was 5 times higher than that of Weissella confusa cells immobilized in calcium alginate gel, and 34-times higher as compared to Leuconostoc mesenteroides KIBGE HA1 cells entrapped into polyacrylamide gel. Samples of dextran produced by immobilized cells L. mesenteroides B -5481 had twice lower molecular weight as compared to the polymer synthesized by free cells. This characteristic expands the range of possible applications of the obtained polysaccharide without need in its additional hydrolysis.