Applications Of Exopolysaccharides Research Articles

OPTIMIZATION OF PHYSIOLOGICAL PARAMETERS FOR EXOPOLYSACCHARIDE PRODUCTION USING Pseudomonas aeruginosa MSSRFV42

Exopolysaccharides (EPS) are long-chain polysaccharides containing branched, repeating units of sugars or sugar derivatives such as glucose, fructose, mannose and galactose etc, which are secreted into their surrounding environment during the bacterial growth. Due to their unique properties and vast array of application, isolation and study of new EPS producing microbes is highly concerned issue. In the present study potent exopolysaccharide producing AB4 bacteria (Pseudomonas aeruginosa MSSRFV42) which was previously isolated and screened from marine sample was used. To increase the yield of exopolysaccharide significant physiological parameter were determined Submerged fermentation at pH 10 and temperature of 300C gave maximum yield of EPS after 72 hrs incubation using 1% inoculums in media containing 3.5% NaCl. Outcome of this study will definitely contribute in the elucidation components of AB4 EPS in various industries . Keywords: EPS, Pseudomonas aeruginosa, Optimization

Review on microbial production of exopolysaccharides and its applications

Exopolysaccharides (EPS) are bio-molecules produced by variety of microorganisms by both eukaryotes and prokaryotic. EPS are high molecular weight molecules available in both homopolysaccharide and heteropolysaccharide. Plants are the primary source of exopolysaccharides (EPS); however, microbiological EPS have a diverse range of structures and functions that enable them to endure harsh environmental conditions. Studying the structure and composition of exopolysaccharides is crucial for understanding their beneficial functions and potential applications in different fields such as food, dairy, medical, pharmaceutical, cosmetics and other industries. This review briefly describes how extremities trigger microbes to produce EPS with unique properties. In addition, it covers optimization and strain improvement methods to increase the productivity of microbes, extraction and purification methods. Similarities and differences of solid-state fermentation and submerged fermentation for EPS production from Bacteria and Fungi are sighted in this review. Applications of EPS in different fields owing to their various physicochemical properties are also discussed in this review. This review provides explanations with respect to microbial habitats, fermentation scales, purification methods and recent research on their potential applications.

Assessment of microbial exopolysaccharides for improving soil fertility and crop yield in semi-arid India

Soil degradation and poor fertility are major concerns in semi-arid regions of India. Microbial exopolysaccharides (EPS) have demonstrated potential in mitigating abiotic and biotic stresses in these areas. However, the studies on the impact of EPS on crop performance and soil fertility under natural field conditions remain limited. To address this knowledge gap, a field experiment was conducted during the rainy season of 2019-20 and 2020-21 at ICAR-NIASM, Baramati, Maharashtra, to examine the effects of microbial EPS on average crop yields of soybean and maize, microbial colonization status in soybean and maize, and soil fertility parameters in basaltic soils of India. Seeds inoculated with Rhizobium or nitrogen fixers and 10 kg ha-1 EPS resulted in a significant increase in soybean and maize yields by 57.7% and 44.8%, respectively, compared to the control. Additionally, the Rhizobium treated seeds with EPS 10 kg ha-1 showed improvements in soil organic carbon, dehydrogenase activity, and nitrogen content by 15.5%, 214.5%, and 70.0%, respectively, in soybean compared to the control. Conversely, the application of microbial EPS did not cause any significant change in soil pH, E.C., or available P, K, Fe, Mn, and Zn contents in both crops. While the presence of EPS within the rhizosphere of soybean actively promoted nodule formation, it also enhanced microbial colonization within the rhizosphere of both soybean and maize. Moreover, the best subset regression analysis revealed that EPS altered the soil parameters for the yield of both crops. The findings of this study suggest that EPS treatment, in combination with Rhizobium or nitrogen fixers, can significantly enhance crop yield, promote nodule formation in soybean, and improve microbial colonization within the rhizosphere of both soybean and maize. These results highlight the potential of microbial EPS as a viable and sustainable solution to address soil degradation and poor fertility in semi-arid regions of India.

Exopolysaccharides produced by Bacillus spp. inhibit biofilm formation by Staphylococcus aureus strains associated with bovine mastitis

Bovine mastitis is a costly disease in the dairy sector worldwide. Here the objective was to identify and characterize anti-biofilm compounds produced by Bacillus spp. against S. aureus associated with bovine mastitis. Results showed that cell-free supernatants of three Bacillus strains (out of 33 analysed) reduced S. aureus biofilm formation by approximately 40 % without affecting bacterial growth. The anti-biofilm activity was associated with exopolysaccharides (EPS) secreted by Bacillus spp. The EPS decreased S. aureus biofilm formation in a dose-dependent manner, inhibiting biofilm formation by 83 % at 1 mg/mL. The EPS also showed some biofilm disruption activity (up to 36.4 %), which may be partially mediated by increased expression of the aur gene. The characterization of EPS produced by Bacillus velezensis 87 and B. velezensis TR47II revealed macromolecules with molecular weights of 31.2 and 33.7 kDa, respectively. These macromolecules were composed mainly of glucose (mean = 218.5 μg/mg) and mannose (mean = 241.5 μg/mg) and had similar functional groups (pyranose ring, beta-type glycosidic linkage, and alkynes) as revealed by FT-IR. In conclusion, this study shows the potential applications of EPS produced by B. velezensis as an anti-biofilm compound that could contribute to the treatment of bovine mastitis caused by S. aureus.

Promotion of Growth of Alfalfa by Erwinia persicina Cp2 Exopolysaccharides under NaCl Stress

Soil salinity poses a significant challenge to plant growth and agricultural productivity. Research demonstrated the potential of exopolysaccharides (EPS) to enhance plant growth and improve resistance to abiotic stress. Nevertheless, the precise regulatory mechanism by which EPS mediates salt tolerance in alfalfa (Medicago sativa) remains largely unexplored. To investigate the protective effects of EPS from Erwinia persicina Cp2 in enhancing salt stress tolerance in alfalfa, a hydroponic experiment was conducted on the ‘Aohan’ cultivar of alfalfa, and changes in germination rate, biomass, chlorophyll content, electrolyte leakage (EL), hydrogen peroxide (H2O2), malondialdehyde (MDA), proline (Pro), soluble sugar (SS), soluble protein (SP), and activities of superoxide dismutase (SOD) and peroxidase (POD) were analyzed with and without Cp2 EPS under 75 mmol/L NaCl conditions. The results show that the exposure of alfalfa to salt conditions seriously inhibited its germination and growth. However, it is interesting that the application of Cp2 EPS greatly alleviated the damage of salt stress on alfalfa and promoted the germination of alfalfa as well as the root length, seedling length, fresh weight, and dry weight of the plants. In addition, the increases in MDA, H2O2 content, and EL rate caused by salt stress were inhibited after Cp2 EPS treatment, while chlorophyll, Pro, SP, and SS contents as well as SOD and CAT activities were increased. Therefore, Cp2 EPS can significantly alleviate the toxic effect of 75 mmol/L NaCl stress on alfalfa, and comprehensive analysis shows that 1.5 g/L Cp2 EPS had the best alleviating effect on alfalfa at this salt stress concentration. This study lays a practical and theoretical foundation for the development of biogenic agents used to alleviate the growth of alfalfa in saline alkali soil.

Structural, compositional characterization of novel exopolysaccharide from halotolerant strain of Pseudomonas entomophila PE3 and their role in growth promotion of sunflower under saline condition

Pseudomonas entomophila PE3, a plant growth promoting bacterium, was characterized for exopolysaccharides (EPS) production under different saline conditions. EPS production was optimized using Box-Behnken Design and response surface methodology (RSM). Carbohydrate, protein and phenolic contents of EPS were maximum at 2 % and minimum at 8 % NaCl concentration. Gas chromatography-mass spectrometry (GC-MS) analysis showed that EPS was composed of unusual trisaccharide melezitose and non-carbohydrate moieties included proteins, esters, carboxylic acid and composition changed on exposure to salinity. X-ray diffraction (XRD) analysis showed amorphous nature of EPS interrupted with salt crystals. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were conducted to report changes in morphology and elemental composition of EPS under saline and non-saline conditions. 1H NMR spectroscopy showed peaks of melezitose (α-D glucose and β-D fructose) in EPS at all salt concentrations. Additional sugars (α-D glucose and α-D galactose) were reported in EPS extracted at 2 % NaCl. The exhibition of salt-tolerance traits by EPS further confirmed the polymer as ‘stress molecule’. The study also reported that upon application of EPS and PE3, salt-stressed sunflower plants showed significant improvement in growth and productivity under pot conditions. The novel bioformulation also instigated salt-tolerance traits in treated plants and improved their survival under unhospitable conditions, thereby promoting the concept of sustainable agriculture.

Optimization, Probiotic Characteristics, and Rheological Properties of Exopolysaccharides from Lactiplantibacillus plantarum MC5.

This study optimized the exopolysaccharides (EPS) production for Lactiplantibacillus plantarum MC5 (Lp. plantarum MC5) and evaluated the resistance to human simulated digestive juices, antioxidant activity in vitro, and rheological properties of EPS-MC5. The results showed that maximum EPS production of 345.98 mg/L (about 1.5-old greater than the initial production) was obtained at optimal conditions of inoculum size (4.0%), incubation time (30 h), incubation temperature (34.0 °C), and initial pH value (6.40). Furthermore, the resisting-digestion capacity of EPS-MC5 after 180 min in α-amylase, simulated gastric juice (pH 2.0, 3.0, 4.0), and simulated intestinal juice (pH 6.8) was 98.59%, 98.62%, 98.78%, 98.86%, and 98.74%, respectively. In addition, the radical scavenging rates of DPPH•, ABTS•, •OH, and ferric-iron reducing power (OD700) of EPS-MC5 were 73.33%, 87.74%, 46.07%, and 1.20, respectively. Furthermore, rheological results showed that the EPS-MC5 had a higher apparent viscosity (3.01 Pa) and shear stress (41.78 Pa), and the viscoelastic modulus (84.02 and 161.02 Pa at the shear frequency of 100 Hz). These results provide a new insight into the application of EPS in human health and functional foods, which could also improve theoretical guidance for the industrial application of EPS.

Optimization of medium compositions and functional characteristics of exopolysaccharide from Paenibacillus polymyxa ATCC 824

Paenibacillus polymyxa ATCC 824 can produce exopolysaccharides (EPS) as non-toxic biomaterials that is safe for plant and soil health. The cells of P. polymxya ATCC 842 known as a good plant growth promoting bacteria. Unfortunately EPS as biopolymers that contributed to soil health. Nowadays, it's showing interest in the production, characterization, and application of EPS derived from various microorganisms. Because of their unique structures, plant growth-promoting bacteria polysaccharides have unique properties and applications in agriculture. This work aims to develop production medium for high cell mass cultivation of P. polymxya ATCC 842 co-currently fort production of EPS. The main medium component such as sucrose, yeast extract and K2HPO4 were selected as variables and statistically optimized based on Box-Behnken design in shake flask levels. The optimal medium composition by RSM composed of (g/L): sucrose, 30; yeast extract, 30; K2HPO4, 5.72; NH2NO4, 5; KH2PO4, 1.9 and MgSO4, 0.5. The growth in the optimized medium showing the cell mass was increased 20.36 g L −1 about 7.51-fold higher co-currently increased EPS production about 6.71-fold higher (16.46 gL −1)than the unoptimized medium after 36 h of cultivation. The model was significant and subsequently validated through the growth kinetics studies showing that the optimized medium have better growth of P. polymyxa ATCC 842 with a specific growth rate of 1.397 h −1 and EPS productivity about 0.68gL −1 h −1. Furthermore, HPLC analysis showing that EPS is composed monomer of fructose and glucose. Meanwhile, FTIR analysis showed the presence of hydroxyl, carboxyl groups, and glycosidic linkages which showed the composition of the polysaccharide bound by α-(1 → 6). The SEM analysis showed EPS appears as a homogenous spherical with irregular porosity for high water holding capacity of the soil. Based on these findings, EPS produced by Paenibacillus polymyxa has a variety of useful properties that make it suitable for use in agriculture.

The application of exopolysaccharides (EPS) can prevent viral disease of fish

In the frame of investigations on the use of exopolysaccharides (EPS) from Arthrospira platensis in carp and koi cultures, two animal experiments were carried out to assess their efficiency as prophylactic and metaphylactic (therapeutic) measures against koi herpesvirus disease (KHVD). In experiment 1, carp were treated with algae biomass (BM) and EPS before and after infection with European lineage koi herpesvirus (KHV-E). In experiment 2, carp were treated with EPS prior and after the infection with Taiwan isolate of KHV (KHV-T), only prior to infection with higher concentration of EPS or only after the infection with KHV-T. No conclusive protection against KHV was observed in experiment 1 in carp treated with BM. In groups where EPS was applied, carp were protected to a certain extent. In experiment 2, carp were protected significantly against a severe KHVD outbreak. In the prophylactic group, which received a double EPS concentration for six weeks, and in the metaphylactic group, KHVD was stopped. Fish developed antibodies against EPS as well as against KHV at day 30 post infection.

Prospects and functionality of bacterial exopolysaccharides in dairy foods: A Review

Lactic acid bacteria (LAB) produces exopolysaccharides (EPS), which are used to make fermented dairy products like dahi, yoghurt, cheese, fermented cream, and milk-based desserts.EPS synthesis by LAB varies greatly in terms of quantity, chemical compositions, molecular size, charge, presence of side chains, and molecule rigidity. Firmness and creaminess are two main sensory qualities that influence customer preference for dairy products.EPSs can perform as texturizers and stabilisers, raising the viscosity of a final product and boosting the rigidity of the casein network by binding hydration water and interacting with other milk constituents such proteins and micelles.As a result, EPS can help to reduce syneresis and improve product stability. The application of EPS in a dairy food matrix remains a challenge in order to better meet customer demand for appealing, flavorful, and even healthier products.

Recent Advances of Microalgae Exopolysaccharides for Application as Bioflocculants

Microalgae are used in flocculation processes because biopolymers are released into the culture medium. Microalgal cell growth under specific conditions (temperature, pH, luminosity, nutrients, and salinity) provides the production and release of exopolysaccharides (EPS). These biopolymers can be recovered from the medium for application as bioflocculants or used directly in cultivation as microalgae autoflocculants. The optimization of nutritional parameters, the control of process conditions, and the possibility of scaling up allow the production and industrial application of microalgal EPS. Therefore, this review addresses the potential use of EPS produced by microalgae in bioflocculation. The recovery, determination, and quantification techniques for these biopolymers are also addressed. Moreover, other technological applications of EPS are highlighted.

Microbial exopolysaccharides: role in functional food engineering and gut‐health management

SummaryThe objective of this review was to evaluate the structural and functional role of Microbial exopolysaccharides (EPS) in food products. EPS are biologically produced natural macromolecules that provides distinctive rheological and physicochemical properties to food matrix. Understanding the interactions of EPS with food components at the molecular level enables the application in bakery products, dairy/non‐dairy‐based functional products, processed meat, as probiotics delivery vehicles, etc. Further information at the biological level throws light on the potential use for immunomodulation, microbiota modulation, and gut‐health management. At present, though the commercial applications of these polysaccharides are limited due to lower yield, the bio‐thickening properties at lower concentrations increases its scope for structural and functional food production through ex‐vivo/in‐vivo applications. The information relating to the successful application of EPS for functional foods is scattered and the exploited structural‐functional relationships are crucial for laying further investigations to develop futuristic products. This article discusses the application of EPS in functional food products and the prospective benefits.

Genome Mining Associated with Analysis of Structure, Antioxidant Activity Reveals the Potential Production of Levan-Rich Exopolysaccharides by Food-Derived Bacillus velezensis VTX20

Exopolysaccharides (EPSs) produced by Bacillus species have recently emerged as promising commercial antioxidants in various industries, such as pharmaceutics and biomedicine. However, little is known about EPS production and function from Bacillus velezensis so far. In the present study, the effect of sugar sources on EPS production by B. velezensis VTX20 and the genetic biosynthesis, characteristics, and antioxidant activity of the resulting EPS were evaluated. The strain VTX20 produced the maximum EPS yield of 75.5 ± 4.8 g/L from an initial 200 g/L of sucrose after a 48-h cultivation. Through genomic analysis, ls-levB operon was found, for the first time, to be responsible for the levan-type EPS production in B. velezensis. Biochemical and structural characterization further confirmed the majority of levan, followed by an extremely low level of dextran biopolymer. The water solubility index and water holding capacity of the EPSs were 81.9 ± 3.4% and 100.2 ± 3.4%, respectively. In vitro antioxidant activity analyses showed strong scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical values of 40.1–64.0% and 16.0–40%, respectively. These findings shed light on the EPS biosynthesis of B. velezensis at both structural and genetic levels and the potential application of EPS as a natural antioxidant for pharmaceutical and biomedical industries.

Efficacy of rhizobacterial exopolysaccharides in improving plant growth, physiology, and soil properties.

The current study investigated the influence of exopolysaccharides (EPSs) producing plant growth-promoting rhizobacteria (PGPR) on the growth, physiology, and soil properties. The pre-isolated and compatible EPS producing PGPR strains were first screened based on improvement in soil aggregates in an incubation study. The screened strains (Rhizobium phaseoli strain Mn-6, Pseudomonas bathysetes strain LB5, and unidentified strain R2) were then employed in pot study for assessing improvements in maize growth, physiology, and soil properties. Eight treatments including T1 = control, T2 = Mn-6, T3 = R2, T4 = LB5, T5 = Mn-6 + R2, T6 = Mn-6 + LB5, T7 = R2 + LB5, and T8 = Mn-6 + R2 + LB5 were applied in completely randomized design (CRD) hexa replicated (half for root and half for soil, and yield attributes). The results depicted that among various treatments, the application of PGPR strain Mn-6 increased plant height, root length, root fresh and dry weight, root length density, SPAD value, leaf areas index, photosynthesis rate, transpiration, and stomatal conductance by 24, 79, 72, 90, 49, 35, 23, 21, 75, and 77%, respectively, compared with non-inoculated treatment. Similarly, significant improvement in maize yield and soil physical properties was also observed in response to the application of EPS-producing PGPR. Therefore, it is concluded that the application of EPS producing PGPR is an effective strategy to improve plant growth, physiology, yield, and soil physical properties. Moreover, EPS-producing PGPR should be exploited in field studies for their potential in improving plant growth and soil properties.

Production, characterization and bio-emulsifying application of exopolysaccharides from Rhodotorula mucilaginosa YMM19.

Microbial exopolysaccharides (EPS) are high molecular weight polymers having different sugar residues. EPS have potential applications in different fields, such as medicine, food and environment. Therefore, there is a growing interest in production, characterization and application of EPS from different microorganisms. The present study designed to investigate the production and characterization of EPS from Rhodotorula mucilaginosa YMM19 isolated from Morus nigra L. fruits as well as to examine their potential emulsifying properties. Effect of NaCl concentration, incubation period and pH on the production of EPS was studied. The maximum EPS production by yeast was achieved at 10% NaCl (9741.84mg/l). The best incubation time for production of EPS was 5days. Production of EPS decreased under neutral condition and increased at acidic and alkaline condition. The structural feature of EPS was examined by FT-IR and NMR spectral analysis and confirmed the presence of glucose, glucopyranose and galactose. The isolated EPS showed higher emulsification capacity with emulsification activity of 71% and emulsifying index of 60%. The EPS gave strong emulsification for farnesol and was more effective than sodium dodecyl sulphate, a reference emulsifier, in enhancing the herbicidal activity of farnesol against Melilotus indicus under greenhouse condition. The results suggest that the EPS produced by YMM19 strain has a potential to be used as emulsifying agent in pesticide formulations.

Exopolysaccharide Produced from Rhizobium spp. - An Interesting Product for Industry and Environment

: Most legume species, such as soybeans, beans, and clover, have the ability to establish a symbiotic relationship with nitrogen-fixing bacteria in the soil, which promotes plant growth and productivity. Exopolysaccharide macromolecules are particularly necessary for binding the bacteria to root hairs and initiating the deformation of root hairs, thus trapping the bacteria to initiate root invasion through a tube-like infection thread. Very few studies have focused on the isolation and characterization of new rhizobial exopolysaccharides, despite their unique and specific biological and physicochemical properties. However, rhizobial exopolysaccharides may be studied in detail in the near future, for the development of suitable substitutes for xanthan gum. This review discusses some analytical strategies for characterization of rhizobial exopolysaccharide, the relation between their structure and properties, and a novel application of rhizobial exopolysaccharides. The potential application of exopolysaccharides and living cells as biosorbents has also been reviewed.

Therapeutic Effect of Calcipotriol Pickering Nanoemulsions Prepared by Exopolysaccharides Produced by Bacillus halotolerans FYS Strain on Psoriasis.

PurposeMany exopolysaccharides (EPS) have significant emulsifying activity. Some EPS produced by the marine bacterial strain FYS have stronger emulsifying activity in the form of nanoparticles, suggesting that they could potentially form Pickering emulsions. We prepared novel EPS/CT Pickering nanoemulsions (ECPN) with EPS as emulsifiers and assessed their ability to ameliorate the poor permeability of calcipotriol (CT) in skin affected by psoriasis vulgaris.MethodsA strain of marine bacterium FYS was identified. Molecular weight, monosaccharide composition and microstructure of EPS were determined by gel permeation chromatography, high-performance liquid chromatography and scanning electron microscopy. EPS nanoparticles were prepared by adjusting the pH, and the emulsifying activity was studied at different pH. ECPN were prepared by ultrasound and optimized by the response surface method. The size distribution, microstructure, stability and in vitro drug release of ECPN were studied. The therapeutic effect of ECPN on psoriasis vulgaris was explored by animal experiments and characterizing histomorphology in vivo.ResultsA phylogenetic tree revealed that FYS was a Bacillus halodurans strain. EPS produced by the strain were heteropolysaccharides with a three-dimensional network composed of glucose, galactose, glucuronic acid, rhamnose, galacturonic acid and mannose (32.0:34.3:9.7:7.4:10.3:6.3). The EPS can form nanoparticles at pH = 4–6 with enhanced emulsifying ability. Transmission electron microscopy revealed that EPS nanoparticles adhered to the surface of oil droplets to stabilize the emulsions via a Pickering emulsification mechanism. The prepared ECPN have high stability with a sustained-release effect. Finally, animal experiments showed that ECPN effectively shortened the treatment course of psoriasis vulgaris.ConclusionEPS is highly possible to have the potential Pickering emulsification mechanism. The stability of the nanoemulsion was high. ECPN also showed potential for use in the treatment of psoriasis vulgaris. This study provides new insight into the medical applications of EPS and the treatment of psoriasis.

Application of Extractive Fermentation on the Recuperation of Exopolysaccharide from Rhodotorula mucilaginosa UANL-001L

Exopolysaccharides (EPS) are high molecular weight biomaterials of industrial interest due to their variety of applications in the pharmaceutical, cosmetic, environmental, and food industries. EPS produced by Rhodotorula mucilaginosa UANL-001 L has sparked interest due to its bio-adsorbent and wide spectrum antimicrobial properties. However, full exploitation and commercial application of EPS has been restrained due to low yields and high production costs. In the present work, the production and separation of EPS from Rhodotorula mucilaginosa UANL-001L was attempted through extractive fermentation in order to increase EPS production while simplifying the recovery process. Extractive fermentation was implemented with a thermoseparating polymer for phase formation (EOPO 970 and EOPO 12,000); culture viability, biomass generation, EPS production, rheological system properties, and phase formation time and temperature were monitored throughout the process. Extractive fermentation of Rhodotorula mucilaginosa UANL-001L with EOPO 970 resulted in a 42% EPS and 7% biomass recovery on the top phase after 5 to 13-min phase formation time and temperatures between 30 and 40 °C. This is the first report of extractive fermentation application for EPS production by yeast of the genera Rhodotorula, resulting in an interesting strategy for EPS production and recovery, although further optimization is needed.

Microencapsulation of Probiotics by Exopolysaccharides-sodium Alginate and Evaluation of their Survival in Simulated GI Conditions

Background: The viability of the probiotics reduces because of the high acid and bile salt concentrations present in the stomach. Probiotic cultures can be protected during processing, storage and passage of the probiotic product through the gastrointestinal tract by the technique of microencapsulation. Objective: In the present study, Exopolysaccharides (EPS) and sodium alginate are incorporated in a different ratio to form the encapsulation matrix. They have also been checked for improving the viability of lactic acid bacteria in simulated GI conditions. Methods: EPS were isolated from a reference strain of L. acidophillus and the two strains P8 and Cu3 isolated from pumpkin and cucumber. Microencapsulated beads were formed using a different combination of EPS and sodium alginate and were analysed in terms of viability, bile tolerance, acid tolerance, survival in gastrointestinal conditions, and antibiotic susceptibility conditions. Results: The results indicated that the increasing concentration of EPS has significantly increased the survival of microencapsulated probiotic in simulated gastrointestinal conditions. The treatment T4 was found to be the best for all the tested conditions. Conclusion: This study has shown the potential application of EPS in microencapsulation to protect probiotics against the adverse condition of the gastrointestinal tract.

Ultrasound-Assisted Preparation of Exopolysaccharide/Nystatin Nanoemulsion for Treatment of Vulvovaginal Candidiasis.

PurposeAs one of the classic anti-Canidia albicans (CA) and vulvovaginal candidiasis (VVC) drugs, nystatin (NYS) is limited by poor water solubility and easy aggregation. Traditional NYS vaginal delivery formulations do not fully adapt to the specific environment of the vaginal cavity. The use of exopolysaccharides (EPS) has great application potential in emulsifiers, but its use has not been reported in nanoemulsions. In this work, an EPS/NYS nanoemulsion (ENNE) was developed to improve the activities of NYS against CA and VVCMethodsThe ENNE was prepared by ultrasonic method using EPS as an emulsifier, liquid paraffin oil as an oil phase, PEG400 as a co-emulsifier, and NYS as the loaded drug. ENNE preparation was optimized by response surface method. After optimization, in vitro and in vivo analysis of the anti-CA activity; animal experiments; staining with propidium iodide (PI), periodic acid-schiff (PAS), and hematoxylin-eosin (H&E); and cytokine experiments were performed to investigate the therapeutic ability against VVC.ResultsThe optimal formulation and preparation parameters of ENNE were determined as follows: EPS content of 1.5%, PEG400 content of 3.2%, NYS content of 700 μg/mL, paraffin oil content of 5.0%, ultrasonic time of 15 min, and ultrasonic amplitude of 35%. The ENNE showed an encapsulated structure with an average particle size of 131.1 ± 4.32 nm. ENNE exhibited high storage and pH stability, as well as slow release. The minimum inhibitory concentration (MIC) of ENNE against CA was only 0.125 μg/mL and the inhibition zone was 19.0 ± 0.5 mm, for greatly improved anti-CA effect. The prepared ENNE destroyed the membrane of CA cells, and exhibited good anti-CA effect in vivo and therapeutic ability against VVC.ConclusionThe results of this study will promote the application of EPS in nanotechnology, which should lead to new and effective local drug formulations for treating VVC.