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Soil salinity has become a global issue that is directly related to land degradation and results in many changes in climate, ecosystem services, and biodiversity. The present study focuses on the investigation of beneficial properties of a plant probiotic bacterial strain as an eco-friendly and sustainable approach to promote crop growth in saline soil. The endophytic halotolerant strain Pseudomonas flavescens D5 isolated from common chicory (Cichorium intybus L.) was able to grow on a medium containing 15% NaCl; produced indole-3-acetic acid (45.2 μg mL−1) and polyhydroxyalkanoate (1.72 g L−1); and had amylolytic, cellulolytic, and proteolytic activities. Polyhydroxyalkanoate had a pronounced antifungal activity against Fusarium graminearum, F. solani, F. oxysporum, and Alternaria alternata. Under salt stress conditions, inoculation with Ps. flavescens D5 increased the shoot biomass of barley plants by 8–30%, root biomass by 7–20%, chlorophyll a by 18–52%, and chlorophyll b by 7–15%. The content of proline decreased by 1.5–1.8 times. An increase in the activity of antioxidant enzymes (catalase, guaiacol peroxidase, and ascorbate peroxidase) was determined. In inoculated plants growing in saline soil, the content of Na+ ions was lower by up to 54.8% compared to control. This strain is promising for stimulating plant growth and protecting them from diseases and other adverse environmental factors, including salt stress.

Orally delivered probiotics must survive transit through harsh environments during gastrointestinal (GI) digestion and be delivered and released into the target site. The aim of this work was to evaluate the survivability and delivery of gel-encapsulated Lactobacillus rhamnosus GG (LGG) to the colon. New hybrid symbiotic beads alginate/prebiotic pullulan/probiotic LGG were obtained by the extrusion method. The average size of the developed beads was 3401 µm (wet), 921 µm (dry) and the bacterial titer was 109 CFU/g. The morphology of the beads was studied by a scanning electron microscope, demonstrating the structure of the bacterial cellulose shell and loading with probiotics. For the first time, we propose adding an enzymatic extract of feces to an artificial colon fluid, which mimics the total hydrolytic activity of the intestinal microbiota. The beads can be digested by fecalase with cellulase activity, indicating intestinal release. The encapsulation of LGG significantly enhanced their viability under simulated GI conditions. However, the beads, in combination with the prebiotic, provided greater protection of bacteria, enhancing their survival and even increasing cell numbers in the capsules. These data suggest the promising prospects of coencapsulation as an innovative delivery method based on the inclusion of probiotic bacteria in a symbiotic matrix.

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