Because of its safety, biological activities, and unique properties, exopolysaccharide (EPS) from lactic acid bacteria (LAB) has been developed as a potential biopolymer. A few studies have investigated the EPS produced by marine LAB. This study reports the wound healing activity of an EPS produced by a marine isolate identified asLactiplantibacillus plantarumEI6, in addition to assessingL. plantarumEI6's probiotic properties. EI6 demonstrated promising antimicrobial activity against different pathogenic bacteria, as well as the ability to withstand stomach pH 3, tolerate 0.3% bile salt concentration, and exhibit no signs of hemolysis. Furthermore, EI6 was able to produce 270 mg/L of EPS upon growth for 48 h at 37°C in an MRS medium enriched with 1.0% of sucrose. The chemical features of the novel EI6-EPS were investigated: the UV-vis estimated a high carbohydrate content of ~91.5%, and the FTIR emphasized its polysaccharide nature by the characteristic hydroxyl, amide I, II, & III, and glycosidic linkage regions. The GC-MS and NMR analyses revealed the existence of five monosaccharides, namely, rhamnose, galactose, mannose, glucose, and arabinose, existing mainly in the pyranose form and linked together by α- and β-glycosidic linkages. EI6-EPS was found to be safe (IC50 > 100 μg/ml) and induced human skin fibroblasts (HSF) proliferation and migration. These findings imply that EI6 can be used as a safe source of bioactive polymer in wound care.

In the current study, a significant amount of ulvan was extracted from Ulva lactuca collected from Alexandria coastline, Egypt, using a simple extraction method. According to the chemical analysis, the obtained polysaccharide content is estimated to be 36.50 g/100 g with a high sulfate content of 19.72%. Physio-chemically, the FTIR analysis confirmed the presence of sulfated groups attached to the carbohydrate backbone. The GC–MS results revealed the presence of various monosaccharides with relative abundances in the order: fucopyranose (22.09%) > L-rhamnose (18.17%) > L-fucose (17.46%) > rhamnopyranose (14.29%) > mannopyranose (8.59%) > α-D-glactopyranose (7.64%) > galactopyranose (6.14%) > β-arabinopyranose (5.62%). In addition, the SEM–EDX depicted an amorphous architecture with a majority wt% for the elements of C, O, and S. The partially purified ulvan demonstrated potent antimicrobial activity against some fish and human pathogenic microbes. The inhibition zone diameter ranged from 11 to 18 mm. On the other hand, the prepared ulvan-chitosan hydrogel significantly improved the antimicrobial activity as the inhibition zone diameter ranged from 12 to 20. Moreover, when compared to the controls, the extracted ulvan demonstrated anti-fouling properties and successfully disrupted the biofilm formed on a glass slide submerged in seawater.

Psychobiotics are a novel class of probiotics with potential to confer mental wellness via production of neuroactive compounds such as gamma-aminobutyric acid (GABA). The demand for new biological sources of GABA has increased steadily. Therefore, the current study reports the isolation of 17 presumptive lactic acid bacteria (LAB) from marine samples and their screening for GABA synthesis from monosodium glutamate (MSG) using thin-layer chromatography (TLC). The isolate SH9 was selected as a high GABA producing strain. The GABA content of SH9 cell free supernatant (CFS) was quantitatively determined by high performance liquid chromatography (HPLC) to be 0.97 g/L. SH9 was identified biochemically and molecularly as Enterococcus faecium (identity 99%). Moreover, SH9 demonstrated promising probiotic potentials; it gave no signs of hemolysis and could survive at low pH values and high bile salt concentrations. It also exhibited antimicrobial activity against highly pathogenic strains and the ability to grow at 6.5% NaCl. In addition, SH9 CFS showed anti-inflammatory and antioxidant properties. The glutamate decarboxylase (GAD) gene was detected in SH9 by using specific primers. Product of 540 bp was obtained, sequenced, and analyzed (accession number: MW713382). The inferred amino acid sequence was 99.3% identical to Lactobacillus plantarum M-6 gadB gene. The findings of this study suggest that the marine isolate E. faecium SH9 could be used as a novel psychobiotics in the development of GABA rich healthy products.

This study aims to obtain a novel probiotic strain adapted to marine habitats and to assess its antisepsis properties using a cecal ligation and puncture (CLP) model in rodents. The marine Enterococcus faecium EA9 was isolated from marine shrimp samples and evaluated for probiotic potential after phenotypical and molecular identification. In septic animals, hepatic and renal tissues were histologically and biochemically evaluated for inflammation and oxidative stress following the probiotic treatment. Moreover, gene expressions of multiple signaling cascades were determined using RT-PCR. EA9 was identified and genotyped as Enterococcus faecium with a 99.88% identity. EA9 did not exhibit any signs of hemolysis and survived at low pH and elevated concentrations of bile salts. Moreover, EA9 isolate had antibacterial activity against different pathogenic bacteria and could thrive in 6.5% NaCl. Septic animals treated with EA9 had improved liver and kidney functions, lower inflammatory and lipid peroxidation biomarkers, and enhanced antioxidant enzymes. The CLP-induced necrotic histological changes and altered gene expressions of IL-10, IL-1β, INF-γ, COX-2, SOD-1, SOD-2, HO-1, AKT, mTOR, iNOS, and STAT-3 were abolished by the EA9 probiotic in septic animals. The isolate Enterococcus faecium EA9 represents a promising marine probiotic. The in vivo antisepsis testing of EA9 highlighted its potential and effective therapeutic approach.