Cellular antioxidant properties of nontoxic exopolysaccharide extracted from Lactobacillales (Weissella cibaria) isolated from Korean kimchi

The inhibitory effects of endophytic metabolites on glycated proteins under non-communicable disease conditions: A review

Protein glycation in human body is closely linked to the onset/progression of diabetes associated complications. These glycated proteins are commonly known as advanced glycation end products (AGEs). Recent literature has also highlighted the involvement of AGEs in other non-communicable diseases (NCDs) such as cardiovascular, cancer, and Alzheimer's diseases and explored the impact of plant metabolites on AGEs formation. However, the significance of endophytic metabolites against AGEs has recently garnered attention but has not been thoroughly summarized thus far. Therefore, the objective of this review is to provide a comprehensive overview of the importance of endophytic metabolites in combating AGEs under NCDs conditions. Additionally, this review aims to elucidate the processes of AGEs formation, absorption, metabolism, and their harmful effects. Collectively, endophytic metabolites play a crucial role in modulating signaling pathways and enhancing the digestibility properties of gut microbiota (GM) by targeting on AGEs/RAGE (receptor for AGEs) axis. Furthermore, these metabolites exhibit anti-AGEs activities similar to those derived from host plants, but at a lower cost and higher production rate. The use of endophytes as a source of such metabolites offers a risk-free and sustainable approach that holds substantial potential for the treatment and management of NCDs.

Fucoidan-coated cotton dressing functionalized with biomolecules capped silver nanoparticles (LB-Ag NPs-FN-OCG) for rapid healing therapy of infected wounds

The colonization of pathogenic microbes poses a significant clinical barrier that hinders the physiological wound-healing process. Addressing this challenge, we developed a novel wound dressing using a modified cotton gauze dressing coated with fucoidan and functionalized with silver nanoparticles (LB-Ag NPs-FN-OCG) for the rapid treatment of infected wounds. Firstly, phytochemical-capped LB-Ag NPs were synthesized and characterized using high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), and zeta potential analysis. Secondly, different concentrations of LB-Ag NPs (0.1%-1%) were functionalized into FN-OCG to identify appropriate concentrations that were non-toxic with superior antibacterial activities. Screening assays, including antibacterial, hemolysis, chick chorioallantoic membrane (CAM) assay, and cytotoxicity assay, revealed that LB-Ag NPs (0.5%)-FN-OCG were non-toxic and demonstrated greater efficiency in inhibiting bacterial pathogens (Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Listeria monocytogenes) and promoting fibroblast cell (NIH3T3) migration. In vivo assays revealed that LB-Ag NPs (0.5%)-FN-OCG treatment exhibited excellent wound healing activity (99.73 ± 0.01%) compared to other treatments by inhibiting bacterial colonization, maintaining the blood parameters, developing granulation tissue, new blood vessels, and collagen deposition. Overall, this study highlights that LB-Ag NPs (0.5%)-FN-OCG serve as a antibacterial wound dressing for infected wound healing applications.

Potential Health Benefits of Fermented Vegetables with Additions of Lacticaseibacillus rhamnosus GG and Polyphenol Vitexin Based on Their Antioxidant Properties and Prohealth Profiles

Fermented vegetables are increasingly being recognized as an important dietary component, particularly of plant-based diets, to achieve a sustainable healthy gut because of their microbial diversity and antioxidant properties. However, the functional relevance of fermented vegetables varies based on the raw ingredients used and nutrient supplementation. Therefore, in the present study, we investigated the microbial diversity and antioxidant activity of three formulas of fermented vegetables (standard, supplemented with Lacticaseibacillus rhamnosus GG, and supplemented with polyphenol vitexin) at days 0 and 15. The bacterial community profiles were determined through 16S rRNA sequencing analysis, and antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl and by measuring the oxygen radical absorbance capacity, the ferric reducing ability of plasma, and the total phenolic content. The results confirm microbial diversity in the taxonomic composition of the different formulas of fermented vegetables, with different bacteria predominating, particularly lactic acid bacteria including the genera Weissella, Pedicocccus, Leuconostoc, and Lactobacillus. Spearman's correlation analysis showed significant differences in the specific bacteria present in the different formulas of fermented vegetables that conferred antioxidant capacity. Our findings show that supplementation with L. rhamnosus GG and polyphenol vitexin may effectively enhance the functional relevance of foods by promoting cellular protection against oxidative stress.

Multifunctional chitosan-bimetallic nanocarrier deliver 5-fluorouracil for enhanced treatment of pancreatic and triple-negative breast cancer

This work aimed to prepare multifunctional aptamer-conjugated, photothermally responsive 5-fluorouracil (5fu)-loaded chitosan-bimetallic (Au/Pd) nanoparticles (APT-CS-5fu-Au/Pd NPs) for improved cytotoxicity in two cancer cell lines (PANC-1 and MDA-MD 231). The CS-5fu-Au/Pd NPs were polydispersed with a size of 34.43 ± 1.59 nm. FTIR analysis indicated the presence of CS, 5fu in CS-5fu-Au/Pd NPs. The 2 theta degrees in CS-5fu-Au/Pd NPs accounted for CS and Au/Pd. Additionally, AGE revealed the conjugation of APT in CS-5fu-Au/Pd NPs. The APT-CS-5fu-Au/Pd NPs (180 μg/mL) with NIR treatment increased the temperature to >50 °C. The optimized 5fu input was 0.075 % in CS-5fu-Au/Pd NPs, exhibiting a hydrodynamic size of 112.96 ± 17.23 nm, DEE of 64.2 ± 3.77 %, and DLE of 11.1 ± 0.65 %. A higher level of 5fu release (69.8 ± 2.78 %) was observed under pH 5.4 at 74 h. In conclusion, NIR-APT-CS-5fu-Au/Pd NPs did not cause toxicity to RBC and Egg CAM, but increased cytotoxicity in MDA-MB 231 and PANC-1 cells by triggering oxidative stress-mediated cell death.

Exopolysaccharides of lactic acid bacteria: Structure, biological activity, structure-activity relationship, and application in the food industry: A review

Over the past few decades, researchers have discovered that probiotics play an important role in our daily lives. With the further deepening of research, more and more evidence show that bacterial metabolites have an important role in food and human health, which opens up a new direction for the research of lactic acid bacteria (LAB) in the food and pharmaceutical industry. Many LAB have been widely studied because of the ability of exopolysaccharides (EPS). Lactic acid bacteria exopolysaccharides (LAB EPS) not only have great potential in the treatment of human diseases but also can become natural ingredients in the food industry to provide special qualitative structure and flavor. This paper has organized and summarized the biosynthesis, strain selection, production process parameters, structure, and biological activity of LAB EPS, filling in the monotony and incompleteness of previous articles' descriptions of LAB EPS. Therefore, this paper focuses on the general biosynthetic pathway, structural characterization, structure-activity relationship, biological activity of LAB EPS, and their application in the food industry, which will help to deepen people's understanding of LAB EPS and develop new active drugs from LAB EPS. Although the research results are relatively affluent, the low yield, complex structure, and few clinical trials of EPS are still the reasons that hinder its development. Therefore, future knowledge expansion should focus on the regulation of structure, physicochemical properties, function, higher production of EPS, and clinical trial applications, which can further increase the commercial significance and value of EPS. Furthermore, better understanding the structure-function relationship of EPS in food remains a challenge to date.

Effects of different stress conditions on the production, bioactivities, physicochemical and structural characteristics of exopolysaccharides synthetized by Schleiferilactobacillus harbinensis Z171

This study systematically investigated the effects of stress conditions including temperature, pH, H2O2, NaCl, antibiotics on the production and in vitro cholesterol-lowering activity of the exopolysaccharide (EPS) synthetized by Schleiferilactobacillus harbinensis Z171. Additionally, the influences of the optimal stress condition combined with different carbon sources on EPS production were examined, shedding light on the structural characteristics, physicochemical properties and bioactivities of EPSs. The results demonstrated that the EPS produced under H2O2 stress was optimal and presented excellent resistance to simulated gastric juice and α-amylase. Three main fractions, denoted as G-EPS1, F-EPS1 and S-EPS1, were isolated by cellulose DEAE-52 chromatography from crude EPSs synthetized using glucose, fructose and sucrose as carbon sources, respectively. Among them, F-EPS1 possessed the highest cholesterol-lowering, antioxidant and hypoglycemic activities, with the highest molecular weight 91.03 kDa, largest particle size 40.14 nm and apparent viscosity 288.2 mPa·s. Three EPSs exhibited irregular sheet-like and granular structures with good thermal stability. Structural characterization of F-EPS1a (a purified fraction from F-EPS1) revealed that it was a mannan mainly composed of →2)-α-D-Manp-(1→, →3)-α-Manp-(1→ and →2,6)-α-D-Manp-(1→ with branch chains containing α-D-Manp-(1→. F-EPS1a has more potential to be a natural cholesterol-lowering, hypoglycemic and antioxidant supplements in the food industry.

The Weissella and Periweissella genera: up-to-date taxonomy, ecology, safety, biotechnological, and probiotic potential

Bacteria belonging to the genera Weissella and Periweissella are lactic acid bacteria, which emerged in the last decades for their probiotic and biotechnological potential. In 2015, an article reviewing the scientific literature till that date on the taxonomy, ecology, and biotechnological potential of the Weissella genus was published. Since then, the number of studies on this genus has increased enormously, several novel species have been discovered, the taxonomy of the genus underwent changes and new insights into the safety, and biotechnological and probiotic potential of weissellas and periweissellas could be gained. Here, we provide an updated overview (from 2015 until today) of the taxonomy, ecology, safety, biotechnological, and probiotic potential of these lactic acid bacteria.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 10⁶ Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.

Exopolysaccharide from Lactococcus hircilactis CH4 and Lactobacillus delbrueckii GRIPUMSK as new therapeutics to treat biofilm pathogens, oxidative stress and human colon adenocarcinoma

Naturally occurring biopolymers like exopolysaccharides (EPS) secreted by lactic acid bacteria (LAB) has gained significant attention as they are cost effective, renewable and safe. In order to prevent the rapid increase in antibiotic resistant bacteria, the EPS of LAB offers novel approach of targeting the antibiotic resistant pathogens by limiting their effects on environment. Accordingly, in this study, the production, purification, characterization and biological properties of exopolysaccharides from Lactococcus hircilactis strain CH4 and Lactobacillus delbrueckii strain GRIPUMSK were performed. The optimization of lactic acid bacterial strains for exopolysaccharide production was done by response surface methodology and changing the carbon sources in the growth media. The carbohydrate and protein of exopolysaccharide 1 were 79.7 % and 8.7 % respectively and exopolysaccharide 2 were 75.2 % and 9.3 % respectively. When compared with the commercial emulsifier sodium dodecyl sulfate, both the exopolysaccharides have shown good emulsifying activity. Both the exopolysaccharides were linear homo-polysaccharide as determined by Fourier transform infrared spectroscopy and Nuclear magnetic resonance spectra. Scanning electron microscopy showed that the exopolysaccharides were porous and capable of holding water. The exopolysaccharides were partially crystalline as confirmed by X-ray diffraction spectra. Exopolysaccharides from L. hircilactis and L. delbrueckii exhibited significant antimicrobial activity against H. pylori, S. flexneri, S. pyogenes, E. faecalis and C. albicans. Both the exopolysaccharides revealed significant 2,2-diphenyl-1-picrylhydrazyl and hydrogen peroxide scavenging ability with the IC50 value of 100 μg/ml and 80 μg/ml respectively. Exopolysaccharides from L. hircilactis and L. delbrueckii at 100 μg/ml showed significant anticancer activity on HT-29 cells with 58.4 % and 58.7 % respectively. These findings proved that exopolysaccharides from the two selected lactic acid bacterial strains could be explored as natural bioactive carbohydrate polymer for biomedical applications.

Unveiling the Structural Characteristics and Bioactivities of the Polysaccharides Extracted from Endophytic Penicillium sp

Polysaccharides are abundantly present in fungi and are gaining recognition for their exceptional bioactivities. Hence, the present study aimed to extract intracellular polysaccharides (IPS-1 and IPS-2) from the endophytic Penicillium radiatolobatum and compare their physicochemical and bioactive attributes. The monosaccharide composition analysis revealed the existence of galactose, glucose, and mannose in both the IPS, while a trace amount of xylose was found in IPS-1. Further, FT-IR, 1H NMR, and 13C NMR analysis suggested that the IPS-2 was mainly composed of the β-(1→4)-D-Galactose and β-(1→4)-D-Glucose as the main chain, with the β-(1→6)-D-mannose as branched chains. Compared to IPS-1, the IPS-2 showed higher antioxidant activities with an IC50 value of 108 ± 2.5 μg/mL, 272 ± 4.0 μg/mL, and 760 ± 5.0 μg/mL for ABTS+ scavenging, DPPH radical scavenging, and ferric reducing power, respectively. In addition, the IPS-2 inhibited the viability of prostate cancer (PC-3) cells (IC50; 435 ± 3.0 μg/mL) via apoptosis associated with mitochondrial membrane potential collapse and altered morphological features, which was revealed by cellular staining and flow cytometric analysis. Moreover, no apparent cytotoxic effects were seen in IPS-2-treated (1000 μg/mL) non-cancerous cells (HEK-293 and NIH3T3). Overall, the findings of this study suggest that P. radiatolobatum could be a potent source of polysaccharides with promising antioxidant and anticancer activity.

Study of anti-fatigue activity of polysaccharide from fruiting bodies of Armillaria gallica

Fatigue is a common physiological response that is closely related to energy metabolism. Polysaccharides, as excellent dietary supplements, have been proven to have a variety of pharmacological activities. In this study, A 23.007 kDa polysaccharide from Armillaria gallica (AGP) was purified and performed structural characterization, including analysis of homogeneity, molecular weight and monosaccharide composition. Methylation analysis is used to analyze the glycosidic bond composition of AGP. The mouse model of acute fatigue was used to evaluate the anti-fatigue effect of AGP. AGP-treatment improved exercise endurance in mice and reduced fatigue symptoms caused by acute exercise. AGP regulated the levels of adenosine triphosphate, lactic acid, blood urea nitrogen and lactate dehydrogenase, muscle glycogen and liver glycogen of acute fatigue mice. AGP affected the composition of intestinal microbiota, the changes of some intestinal microorganisms are correlated with fatigue and oxidative stress indicators. Meanwhile, AGP reduced oxidative stress levels, increased antioxidant enzyme activity and regulated the AMP-dependent protein kinase/nuclear factor erythroid 2-related factor 2 signaling pathway. AGP exerted an anti-fatigue effect through modulation of oxidative stress, which is related to intestinal microbiota.

Rhizoctonia solani AG1 IA extracellular polysaccharides: Structural characterization and induced resistance to rice sheath blight

Sheath blight, caused by Rhizoctonia solani (R. solani), is one of the most serious diseases of rice. Extracellular polysaccharides (EPS) are complex polysaccharides secreted by microbes that have a pivotal role in the plant-microbe interaction. At present, many studies have been carried out on R. solani, but it is not very clear whether the EPS is secreted by R. solani exists. Therefore, we isolated and extracted the EPS from R. solani, two kinds of EPS (EW-I and ES-I) were obtained by DEAE-cellulose 52 and Sephacryl S-300HR column further purification, and their structures were characterized by FT-IR, UV, GC, and NMR analysis. The results showed that EW-I and ES-I had similar monosaccharide composition but different molar ratio, they were composed of fucose, arabinose, galactose, glucose, and mannose with a ratio of 7.49: 27.72: 2.98: 6.66: 55.15 and 3.81: 12.98: 6.15: 10.83: 66.23, and their backbone may be composed of →2)-α-Manp-(1→ residues, beside ES-I was highly branched compared to EW-I. The exogenous application of EW-I and ES-I had no effect on the growth of R. solani AG1 IA itself, but their pretreatment of rice induced plant defense through activation of the salicylic acid pathway, resulting in enhanced resistance to sheath blight.

Capsular polysaccharide-amikacin nanoparticles for improved antibacterial and antibiofilm performance

Natural nanoscale polysaccharide and its application have attracted much attention in recent years. In this study, we report for the first time that a novel naturally occurring capsular polysaccharide (CPS-605) from Lactobacillus plantarum LCC-605, which can self-assemble into spherical nanoparticles with an average diameter of 65.7 nm. To endow CPS-605 with more functionalities, we develop amikacin-functionalized capsular polysaccharide (CPS) nanoparticles (termed CPS-AM NPs) with improved antibacterial and antibiofilm activities against both Escherichia coli and Pseudomonas aeruginosa. They also exhibit faster bactericidal activity than AM alone. The high local positive charge density of CPS-AM NPs facilitates the interaction between the NPs and bacteria, leading to extraordinary bactericidal efficiencies (99.9 % and 100 % for E. coli and P. aeruginosa, respectively, within 30 min) by damaging the cell wall. Very interestingly, CPS-AM NPs exhibit an unconventional antibacterial mechanism against P. aeruginosa, that is, they can induce plasmolysis, along with bacterial cell surface disruption, cell inclusion release and cell death. In addition, CPS-AM NPs exhibit low cytotoxicity and negligible hemolytic activity, showing excellent biocompatibility. The CPS-AM NPs provide a new strategy for the design of next-generation antimicrobial agents that can reduce the working concentration of antibiotics to fight against bacterial resistance.

Probiotic Weissella cibaria displays antibacterial and anti-biofilm effect against cavity-causing Streptococcus mutans

Streptococcus mutans is a significant contributor to dental caries and causes functional and aesthetic discomfort. Weissella cibaria strains were isolated from kimchi, and their functional properties were determined. In this study, the antibacterial and antibiofilm effects of four W. cibaria strains (D29, D30, D31, and B22) were evaluated against three S. mutans strains using culture fluid and cell-free supernatants. The results showed that W. cibaria reduced the exopolysaccharides production and auto-aggregation, increased co-aggregation, and downregulated virulence factors, leading to the inhibition of bacterial growth and biofilm formation. These findings were confirmed using scanning electron microscopy and confocal laser scanning microscopy. These results indicate that oral health can be potentially improved by W. cibaria.

Optimization and cholesterol-lowering activity of exopolysaccharide from Lactiplantibacillus paraplantarum NCCP 962

Exopolysaccharides (EPSs) are biological polymers with unique structural features have gained particular interest in the fields of food, chemistry and medicine, and food industry. EPS from the food-grade lactic acid bacteria (LAB) can be used as a natural food additives to commercial ones in the processing and development of functional foods and nutraceuticals. The current study was aimed to explore the EPS-producing LAB from the dahi; to optimize the fermentation conditions through Plackett-Burman (PB) and response surface methodology (RSM); and to study its physicochemical, rheological, functional attributes, and cholesterol-lowering activity. Lactiplantibacillus paraplantarum NCCP 962 was isolated among the 08 strains screened at the initial stage. The PB design screened out four independent factors that had a significant positive effect, i.e., lactose, yeast extract, CaCl₂, and tryptone, while the remaining seven had a non-significant effect. The RSM exhibited lactose, yeast extract, and CaCl_2, significantly contributing to EPS yield. The maximum EPS yield (0.910 g/L) was obtained at 6.57% lactose, 0.047% yeast extract, 0.59% CaCl_2, and 1.37% tryptone. The R² value above 97% explains the higher variability and depicts the model's validity. The resulted EPS was a heteropolysaccharide in nature with mannose, glucose, and galactose monosaccharides. FTIR spectrum reflected the presence of functional groups, i.e., O-H, C-H, C = O, C-O-H, and CH₂. SEM revealed a porous and rough morphology of EPS, also found to be thermally stable and negligible weight loss, i.e., 14.0% at 257 °C and 35.4% at 292.9 °C was observed in the 1st and 2nd phases, respectively. Rheological attributes revealed that strain NCCP 962 had high viscosity by increasing the EPS concentration, low pH, and temperature with respectable water holding, oil capacities, foaming abilities, and stability. NCCP 962 EPS possessed up to 46.4% reduction in cholesterol concentration in the supernatant. Conclusively, these results suggested that strain NCCP 962 can be used in food processing applications and other medical fields. KEY POINTS: • The fermentation conditions affect EPS yield from L. paraplantarum and significantly increased yield to 0.910 g/L. • The EPS was heteropolysaccharide in nature and thermally stable with amorphous morphology. • Good cholesterol-lowering potential with the best rheological, emulsifying, and foaming capacities.

Exopolysaccharides produced by Enterococcus genus - An overview

Exopolysaccharide (EPS) biomolecules produced by lactic acid bacteria (LAB) are of prodigious interest due to their unique structural, physico-chemical, and functional characteristics. Several genera of LAB including Enterococcus spp. have been studied for EPS production by various research groups worldwide. EPS produced by various strains from Enterococcus spp. have shown a wide range of functional and technological properties with potential commercial applications. Numerous techniques are used in the characterization of Enterococcus EPS to reveal their structure, linkage, monosaccharide units, functional groups, morphology, and thermal properties. Bioactive potentials of Enterococcus EPS include antioxidant, antibacterial, antibiofilm, anticancer, immunological, prebiotic, and antidiabetic potentials which have been widely reported. These functional and biological properties make Enterococcus EPS a candidate of great importance for multiple applications in the area of food, pharmaceuticals, biomedical and environmental. This review is focused on EPS produced by various strains of the Enterococcus genus isolated from different sources. Several procedures and parameters involved in the production and purification of Enterococcus EPS are also deliberated along with the functional aspects and potential applications.

In Vitro Probiotic Characterization and Safety Assessment of Lactic Acid Bacteria Isolated from Raw Milk of Japanese-Saanen Goat (Capra hircus)

Two novel probiotic strains of lactic acid bacteria were successfully isolated from the raw milk of dairy Japanese-Saanen goats. Selection criteria for positive candidates were grown on de Man-Rogosa-Sharpe or M17 selective medium at 30, 35, or 42 °C anaerobically, and characterized based on Gram reaction, catalase test, and tolerance to low pH and bile salts. Among the 101 isolated positive candidates, two strains, YM2-1 and YM2-3, were selected and identified as Lacticaseibacillus rhamnosus using 16S rDNA sequence similarity. Culture supernatants of the two strains exhibited antipathogenic activity against Salmonella enterica subsp. enterica serovar. Typhimurium, Shigella sonnei, methicillin-resistant Staphylococcus aureus, methicillin-sensitive Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157. The antipathogenic activities were retained to some extent after neutralization, indicating the presence of antipathogenic substances other than organic acids in the culture supernatants. The two strains were sensitive with coincidental minimum inhibition concentrations (indicated in the parentheses hereafter) to ampicillin (0.25 μg/mL), chloramphenicol (4 μg/mL), gentamycin (4 μg/mL), kanamycin (64 μg/mL), streptomycin (16 μg/mL), and tetracycline (4 μg/mL). Furthermore, the two strains were resistant to clindamycin (16 μg/mL) and erythromycin (4 μg/mL). In addition, both YM2-1 and YM2-3 strains showed less unfavorable activities, including bile acid bioconversion, carcinogenic-related enzymes, mucin degradation, plasminogen activation, and hemolysis, than the detection limits of in vitro evaluation methods used in this study. In summary, L. rhamnosus YM2-1 and YM2-3 are highly safe and promising probiotic strains applicable in the dairy industry, and were first isolated from the raw milk of Japanese-Saanen goats.

Photothermally responsive chitosan-coated iron oxide nanoparticles for enhanced eradication of bacterial biofilms

This work developed a pH/NIR responsive antibacterial agent (CS-FeNPs) composed of chitosan (CS) and Fe₃O₄ nanoparticles (FeNPs). CS triggers bacterial attraction through surface charge, while Fe acts as a photothermal agent (PTA). The CS-Fe NPs exhibited antibacterial and antibiofilm activity against both bacteria (G+/G-). However, higher activity was observed against bacteria (G-) due to electrostatic interactions. The CS-FeNPs bind with the bacterial membrane through electrostatic interactions and disturb bacterial cells. Later, in an acidic environment, CS-FeNPs bind with bacterial membrane, and NIR irradiation leads the antibacterial activity. CS-FeNPs exhibited a potential photothermal conversion efficiency (η) of 21.53 %. Thus, it converts NIR irradiation into heat to kill the bacterial pathogen. The CS-FeNPs were found to be less cytotoxic with great antibacterial efficiency on planktonic bacteria and their biofilm, which indicates that they deserve to develop potential and safe treatment strategies for the treatment of bacterial infections.

Potential Applications of an Exopolysaccharide Produced by Bacillus xiamenensis RT6 Isolated from an Acidic Environment

The Bacillus xiamenensis RT6 strain was isolated and identified by morphological, biochemical and molecular tests from an extreme acidic environment, Rio Tinto (Huelva). Optimisation tests for exopolysaccharide (EPS) production in different culture media determined that the best medium was a minimal medium with glucose as the only carbon source. The exopolymer (EPS_t) produced by the strain was isolated and characterised using different techniques (GC-MS, HPLC/MSMS, ATR-FTIR, TGA, DSC). The molecular weight of EPS_t was estimated. The results showed that the average molecular weight of EPS_t was approximately 2.71 × 10⁴ Da and was made up of a heteropolysaccharide composed of glucose (60%), mannose (20%) and galactose (20%). The EPS_t showed antioxidant capabilities that significantly improved cell viability. Metal chelation determined that EPS_t could reduce the concentration of transition metals such as iron at the highest concentrations tested. Finally, the emulsification study showed that EPS_t was able to emulsify different natural polysaccharide oils, reaching up to an 80% efficiency (olive and sesame oil), and was a good candidate for the substitution of the most polluting emulsifiers. The EPS_t was found to be suitable for pharmaceutical and industrial applications.

Antioxidant and Antibacterial Effects of Potential Probiotics Isolated from Korean Fermented Foods

A total of sixteen bacterial strains were isolated and identified from the fourteen types of Korean fermented foods that were evaluated for their in vitro probiotic potentials. The results showed the highest survivability for Bacillus sp. compared to Lactobacillus sp. in simulated gastric pH, and it was found to be maximum for B. inaquosorum KNUAS016 (8.25 ± 0.08 log10 CFU/mL) and minimum for L. sakei KNUAS019 (0.8 ± 0.02 log10 CFU/mL) at 3 h of incubation. Furthermore, B. inaquosorum KNUAS016 and L. brevis KNUAS017 also had the highest survival rates of 6.86 ± 0.02 and 5.37 ± 0.01 log10 CFU/mL, respectively, in a simulated intestinal fluid condition at 4 h of incubation. The percentage of autoaggregation at 6 h for L. sakei KNUAS019 (66.55 ± 0.33%), B. tequilensis KNUAS015 (64.56 ± 0.14%), and B. inaquosorum KNUAS016 (61.63 ± 0.19%) was >60%, whereas it was lower for L. brevis KNUAS017 (29.98 ± 0.09%). Additionally, B. subtilis KNUAS003 showed higher coaggregation at 63.84 ± 0.19% while B. proteolyticus KNUAS001 found at 30.02 ± 0.33%. Among them, Lactobacillus sp. showed the best non-hemolytic activity. The highest DPPH and ABTS radical scavenging activity was observed in L. sakei KNUAS019 (58.25% and 71.88%). The cell-free supernatant of Lactobacillus sp. considerably inhibited pathogenic growth, while the cell-free supernatant of Bacillus sp. was moderately inhibited when incubated for 24 h. However, the overall results found that B. subtilis KNUAS003, B. proteolyticus KNUAS012, L. brevis KNUAS017, L. graminis KNUAS018, and L. sakei KNUAS019 were recognized as potential probiotics through different functional and toxicity assessments.

Polysaccharides of Weissella cibaria Act as a Prebiotic to Enhance the Probiotic Potential of Lactobacillus rhamnosus

This work aimed to investigate the effect of EPS (extracellular polysaccharide) of Weissella cibaria as a prebiotic to promote the growth and antibacterial properties of Lactobacillus rhamnosus. The morphological, growth behavior, and antibacterial properties of L. rhamnosus were determined in MRSB (de Man Rogosa Sharpe broth) supplemented with different concentrations of EPS (0.1-2%). The results revealed that the incorporation of the EPS (2%) in MRSA improved the bacterial growth in terms of colony-forming unit (CFU, 0.7 × 10⁵ CFU/mL) compared to L. rhamnosus grown in bare MRSA. The SEM observation revealed that EPS incorporation in the MRSB culture media does not affect the morphological properties of L. rhamnosus. Moreover, it was confirmed that the extract of probiotics cultured in MRSA supplemented with EPS (2%) was exhibited strong antibacterial and antibiofilm activity against targeted pathogens. This L. rhamnosus extract was found to be biocompatible evidanced by erythrocyte hemolysis assay. These results confirmed that EPS regulates the growth of probiotics, resists pathogen infection, and biocompatibility.

Extraction, Structural Analysis, and Biofunctional Properties of Exopolysaccharide from Lactiplantibacillus pentosus B8 Isolated from Sichuan Pickle

Two novel exopolysaccharides, named LPB8-0 and LPB8-1, were isolated and purified from Lactiplantibacillus pentosus B8. Moreover, their structure and bioactivities were evaluated through chemical and spectral means. The study results demonstrated that LPB8-0 was primarily composed of mannose and glucose and had an average molecular weight of 1.12 × 10⁴ Da, while LPB8-1 was composed of mannose, glucose, and galactose and had an average molecular weight of 1.78 × 10⁵ Da. Their carbohydrate contents were 96.2% ± 1.0% and 99.1% ± 0.5%, respectively. The backbone of LPB8-1 was composed of (1→2)-linked α-D-Manp and (1→6)-linked α-D-Manp. LPB8-0 and LPB8-1 had semicrystalline structures with good thermal stability (308.3 and 311.7 °C, respectively). SEM results displayed that both LPB8-0 and LPB8-1 had irregular thin-slice shapes and spherical body structures. Additionally, an emulsifying ability assay confirmed that LPB8-0 and LPB8-1 had good emulsifying activity against several edible oils, and this activity was retained under acidic, neutral, and high temperature conditions. Furthermore, an antioxidant assay confirmed that LPB8-1 had stronger scavenging activity than LPB8-0. Overall, these results provide a theoretical basis for the potential application of these two novel exopolysaccharides as natural antioxidants and emulsifiers in the food and pharmaceutical industries.

Purinoceptor Targeted Cytotoxicity of Adenosine Triphosphate-Conjugated Biogenic Selenium Nanoparticles in Human Colon Cancer Cells

The adenosine triphosphate (ATP)-conjugated biogenic selenium nanoparticles (SeNPs) for P2 (purinoceptors) receptor-targeted anti-colon cancer activity were developed in this study. First, the SeNPs were synthesized using Trichoderma extracts (TE) and then conjugated with ATP to enhance their anticancer activity. The developed SeNPs had an oval crystalline structure with an average diameter size of 26.45 ± 1.71 d. nm, while the ATP-SeNPs were 78.6 ± 2.91 d. nm. The SeNPs contain Se, and less persistence of P while the ATP-SeNPs have high level of P, and Se in the energy-dispersive spectroscopy (EDS). Further, both nanoparticles exhibited larger sizes in the dynamic light scattering (DLS) analysis than in the transmission electron microscopy (TEM) analysis. The DLS and Fourier transform infrared spectroscopy (FTIR) results provide evidence that the amine group (-NH2) of ATP might bind with the negatively charged SeNPs through covalent bonding. The IC50 concentration was 17.25 ± 1.16 µg/mL for ATP-SeNPs and 61.24 ± 2.08 µg/mL against the caco-2 cell line. The IC50 results evidenced the higher cytotoxicity of ATP-SeNPs in the caco-2 cell line than in HEK293 cells. ATP-SeNPs trigger the anticancer activity in the caco-2 cell line through the induction of mitochondrial membrane potential (MMP) loss and nucleus damage. The biocompatibility test of hemolysis and the egg CAM assay confirmed the non-toxicity of these nanoparticles. Overall, the results proved that the newly developed ATP-SeNPs exhibited higher cytotoxicity in the caco-2 cell line than SeNPs. However, further molecular and in vivo experiments are required to develop the ATP-SeNPs as a candidate drug for cancer-targeted therapeutics.

Exopolysaccharide Produced by Probiotic Bacillus albus DM-15 Isolated From Ayurvedic Fermented Dasamoolarishta: Characterization, Antioxidant, and Anticancer Activities

An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus albus DM-15, isolated from the Indian Ayurvedic traditional medicine Dasamoolarishta. Gas chromatography-mass spectrophotometry and nuclear magnetic resonance (NMR) analyses revealed the heteropolymeric nature of the purified EPS with monosaccharide units of glucose, galactose, xylose, and rhamnose. Size-exclusion chromatography had shown the molecular weight of the purified EPS as around 240 kDa. X-ray powder diffraction analysis confirmed the non-crystalline amorphous nature of the EPS. Furthermore, the purified EPS showed the maximum flocculation activity (72.80%) with kaolin clay and emulsification activity (67.04%) with xylene. In addition, the EPS exhibits significant antioxidant activities on DPPH (58.17 ± 0.054%), ABTS (70.47 ± 0.854%) and nitric oxide (58.92 ± 0.744%) radicals in a concentration-dependent way. Moreover, the EPS showed promising cytotoxic activity (20 ± 0.97 μg mL^–1) against the lung carcinoma cells (A549), and subsequent cellular staining revealed apoptotic necrotic characters in damaged A549 cells. The EPS purified from the probiotic strain B. albus DM-15 can be further studied and exploited as a potential carbohydrate polymer in food, cosmetic, pharmaceutical, and biomedical applications.

High-Efficiency Production of Auricularia polytricha Polysaccharides Through Yellow Slurry Water Fermentation and Its Structure and Antioxidant Properties

Yellow slurry water is a kind of nutrient-rich wastewater of tofu. Firstly, the medium of yellow slurry was optimized. Then, APP40, APP60, and APP80 were obtained by sedimentation with different concentration of ethanol (40, 60, and 80%). The physicochemical properties and primary structures of the three polysaccharides were studied by high performance anion exchange chromatography (HPAEC), high performance gel filtration chromatography (HPGFC), scanning electron microscope (SEM), atomic force microscope (AFM), and Fourier transform infrared (FT-IR) spectrometer. Finally, the effects of three polysaccharides on antioxidation activity were studied. According to the experimental optimization the results, the biomass and the production of Auricularia polytricha Polysaccharides (APPS) reached the peak, and they were 13.5 ± .655 and 9.42 ± .253 g/L (p < .05). The SEM and the AFM showed that the height of APP80 gradually increased from 31.1 to 46.7 nm and from APP40 to APP80. The particle size of APP80 increased, the pores decrease or even disappear, and the molecules begin to aggregate. The FT-IR spectrum analysis showed that the three polysaccharides possessed key functional groups. The carbohydrate content of APP40, APP60, and APP80 was 20.2, 34.25, and 31.73%. The molecular weights of APP40, APP60, and APP80 are 9.462 × 10⁴, 8.742 × 10⁴, and 8.091 × 10⁴ Da, respectively. The three polysaccharides were composed of rhamnose, galactose, glucose, mannose, and xylose but with different molar ratio. APP80 showed strong reducing ability and scavenging activity of 2,2–diphenyl–1–picrylhydrazyl (DPPH) and hydroxyl radicals through antioxidant activities evaluated in vitro. This study introduces a way for the effective use of yellow slurry water.