This study describes the development of a new combined polysaccharide-matrix-based technology for the immobilization of Lactobacillus rhamnosus GG (LGG) bacteria in biofilm form. The new composition allows for delivering the bacteria to the digestive tract in a manner that improves their robustness compared with planktonic cells and released biofilm cells. Granules consisting of a polysaccharide matrix with probiotic biofilms (PMPB) with high cell density (>9 log CFU/g) were obtained by immobilization in the optimized nutrient medium. Successful probiotic loading was confirmed by fluorescence microscopy and scanning electron microscopy. The developed prebiotic polysaccharide matrix significantly enhanced LGG viability under acidic (pH 2.0) and bile salt (0.3%) stress conditions. Enzymatic extract of feces, mimicking colon fluid in terms of cellulase activity, was used to evaluate the intestinal release of probiotics. PMPB granules showed the ability to gradually release a large number of viable LGG cells in the model colon fluid. In vivo, the oral administration of PMPB granules in rats resulted in the successful release of probiotics in the colon environment. The biofilm-forming incubation method of immobilization on a complex polysaccharide matrix tested in this study has shown high efficacy and promising potential for the development of innovative biotechnologies.

Microbial polysaccharides are promising components for wound-care products. This study reports the development of wound-healing antimicrobial hydrogels, based on pullulan from Aureobasidium pullulans, combined with mesenchymal cell-derived conditioned medium. Structural characterization of pullulan was confirmed by FTIR and NMR. Twenty-three formulations containing pullulan, chitosan, gelatin, citric acid, and antimicrobial agents were prepared. Physicochemical screening identified optimal hydrogels: No. 22 (1.2% pullulan, 1.2% chitosan, 0.2% citric acid, 2.4% gelatin, 0.1% conditioned medium, 0.4% glutaraldehyde) and No. 23 (2.4% pullulan, no chitosan, the remaining components identical to those in No. 22). Both exhibited pH values of 5.34 and 5.49, moisture content of 92%, swelling capacities of 175% and 213%, and dynamic viscosity between 58–120 mPa·s. Cytotoxicity testing with human mesenchymal stem cells showed no significant toxicity, with both hydrogels supporting cell adhesion and proliferation. Antimicrobial assays demonstrated inhibitory activity against Staphylococcus aureus and Escherichia coli for both formulations; only hydrogel No. 23 inhibited Pseudomonas aeruginosa. In vitro scratch assays revealed that hydrogel No. 23 significantly promoted fibroblast migration, achieving 30.25% scratch closure after 24 h. The developed formulations combine favorable physicochemical properties with antimicrobial efficacy and regenerative potential, supporting further evaluation as advanced wound-healing and anti-burn dressings.

The aim of this study is to develop and comprehensively evaluate the efficacy of an innovative formulation of a biological preparation consisting of a bacterial consortium (Serratia proteamaculans B5, Pseudomonas putida D7 and Lysinibacillus sp. S1), embedded in a pullulan polysaccharide matrix, as an agent for inducing systemic resistance in barley (Hordeum vulgare L.) to phytopathogenic stress caused by Fusarium graminearum. To optimize the product’s protective efficacy and minimize the pesticide load on the agroecosystem, a reduced dose of Fundazol (50% of the standard rate) was incorporated into the formulation. The constituent strains exhibited high indole-3-acetic acid production (53.29–69.2 μg·mL⁻¹) and strong antagonistic activity against phytopathogenic fungi, with inhibition zones reaching up to 32.5 mm. Pot and field trials were conducted to comprehensively assess the effect of the biological product on the stress tolerance of barley plants. Pre-sowing seed treatment reduced proline accumulation (by up to 2.3-fold), maintained photosynthetic pigment levels, and increased field germination to 79%. Under infectious field conditions, treatment with the biopreparation contributed to the stabilization of yield structure parameters (treated plants exhibited increases in height and biomass of 9–21%) and the improvement of grain quality indicators. Overall, the results obtained demonstrate the potential of the developed biopreparation as a component of comprehensive protection strategies and as an inducer of plant priming mechanisms.